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1. Heatshields for Aerogravity Assist Vehicles Whose Deceleration at Titan Saves Mass for Future Flagship Class Exploration of Enceladus

Author

James O. Arnold, T. R. Spilker, D. M. Cornelius, G. A. Allen Jr, A. M. Brandis, D. A. Saunders, M. Qu, R.W. Powell, M. L. Cable, and R. A. S. Beck

Subjects
Chemistry And Materials (General)
Abstract

This paper reports the feasibility of using mature heatshield materials for an aerogravity assist (AGA) vehicle whose deceleration in Titan’s atmosphere is a mass-saving enabler for nine different Enceladus missions (T. Spilker et al. 2009). A geometry for the Titan AGA vehicle is recommended as are high-fidelity flow computations on that shape.

Published
2020

2. Multiprobe Mission Architecture Options for a Uranus Flagship Mission

Author

Stephen J. Horan, David H. Atkinson, Angela L. Bowes, Archit Arora, Sarag J. Saikia, Thomas R. Spilker, Robert A. Dillman, and Kunio M. Sayanagi

Subjects
Atmospheric measurements, Space and Planetary Science, Atmospheric entry, Uranus, Aerospace Engineering, Environmental science, Architecture, Current (fluid), Ice giant, Astrobiology
Abstract

In situ atmospheric measurements are a high priority for any future Flagship mission to the Ice Giants; however, most current mission concepts only include a single atmospheric entry probe in their...

Published
2021
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3. Aerocapture Assessment for NASA Ice Giants Pre-Decadal Survey Mission Study

Author

Jon Sims, John Elliott, Archit Arora, Kyle M. Hughes, James Millane, James A. Cutts, James M. Longuski, Sarag J. Saikia, Nitin Arora, Thomas R. Spilker, Anastassios E. Petropoulos, Alec Mudek, Kim Reh, Paul Witsberge, and Ye Lu

Subjects
020301 aerospace & aeronautics, Meteorology, Uranus, Aerocapture, Aerospace Engineering, 02 engineering and technology, 01 natural sciences, Aerobraking, 010305 fluids & plasmas, Heat capacity rate, 0203 mechanical engineering, Space and Planetary Science, Neptune, Space Shuttle thermal protection system, 0103 physical sciences, Environmental science, Terrestrial planet, Ice giant
Abstract

A performance analysis for aerocapture at Uranus and Neptune is presented and considers entry corridor width, peak deceleration, peak heat rate, total heat load, and the effect of postcapture orbit...

Published
2021
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4. Qualitative Assessment of Aerocapture and Applications to Future Missions

Author

Nitin Arora, James A. Cutts, Patricia Beauchamp, Michelle M. Munk, Paul Wercinski, Richard W. Powell, Thomas R. Spilker, Mark Adler, and Robert D. Braun

Subjects
Aerodynamic force, Control algorithm, Space and Planetary Science, Computer science, business.industry, Space Shuttle thermal protection system, Aerocapture, Aerospace Engineering, Aerospace engineering, Current (fluid), business, Planetary Science Decadal Survey
Abstract

We examine the current state of readiness of aerocapture at several destinations of interest, to identify what technologies are needed and to determine if a technology demonstration mission is requ...

Published
2019
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5. In Situ exploration of the giant planets

Author

Don Banfield, Olivier Mousis, Mark Hofstadter, Leigh N. Fletcher, Sushil K. Atreya, Jean-Pierre Lebreton, Athena Coustenis, Francesca Ferri, Magali Deleuil, Peter Wurz, Kathleen Mandt, Thibault Cavalié, J. Hunter Waite, Thomas R. Spilker, Paul Hartogh, Heike Rauer, Kunio M. Sayanagi, Ethiraj Venkatapathy, Thierry Fouchet, Stas Barabash, Amy Simon, Tristan Guillot, R. Hueso, Jean-Baptiste Renard, Agustín Sánchez-Lavega, Michel Blanc, Richard M. Ambrosi, David H. Atkinson, Pascal Rannou, Georges Durry, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ASP 2021, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Radio and Space Plasma Physics Group [Leicester] (RSPP), University of Leicester, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Cornell University [New York], Swedish Institute of Space Physics [Uppsala] (IRF), PSA Peugeot - Citroën (PSA), PSA Peugeot Citroën (PSA), ASP 2019, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Departamento de Fisica Aplicada [Bilbao], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Groupe de Recherche sur les Institutions, le Droit de l'Aménagement, de l'Urbanisme et de l'Habitat (GRIDAUH), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Space Science Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Physikalisches Institut [Bern], Universität Bern [Bern], Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Università degli Studi di Padova = University of Padua (Unipd), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), and Universität Bern [Bern] (UNIBE)

Subjects
Exploration of Saturn, Atmospheres, Solar System, 010504 meteorology & atmospheric sciences, Galileo Probe, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Formation, FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Astrobiology, Jupiter, Entry probes, Neptune, Planet, Saturn, 0103 physical sciences, Giant planets, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Uranus, Entry probes · Giant planets · Formation · Composition · Atmospheres, Astronomy and Astrophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Composition, Astrophysics - Earth and Planetary Astrophysics
Abstract

Remote sensing observations suffer significant limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. This impacts our knowledge of the formation of these planets and the physics of their atmospheres. A remarkable example of the superiority of in situ probe measurements was illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases' abundances and the precise measurement of the helium mixing ratio were only made available through in situ measurements by the Galileo probe. Here we describe the main scientific goals to be addressed by the future in situ exploration of Saturn, Uranus, and Neptune, placing the Galileo probe exploration of Jupiter in a broader context. An atmospheric entry probe targeting the 10-bar level would yield insight into two broad themes: i) the formation history of the giant planets and that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. An atmospheric probe could represent a significant ESA contribution to a future NASA New Frontiers or flagship mission to be launched toward Saturn, Uranus, and/or Neptune., 27 pages, 9 figures, White Paper submitted in response to ESA's Call for Voyage 2050 Science Themes. arXiv admin note: substantial text overlap with arXiv:1708.00235

Published
2021
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6. Atmospheric Entry Probes in the Outer Solar System: Developing a Software Tool to Assess Trajectory Options

Author

Alena Probst, Linda J. Spilker, Thomas R. Spilker, David H. Atkinson, Olivier J. Mousis, Mark Hofstadter, and Amy Simon

Abstract

The composition of outer planet atmospheres holds fundamental clues to understanding the formation and evolution of the solar system. Measurements of noble gas abundances and key isotope ratios help constrain formation models, and along with measurements of atmospheric structure and dynamics they reveal formation and evolutionary processes [1], [2]. These enable conclusions about giant planet formation and possible migration during the epoch of solar system formation. With the Galileo Probe laying the foundation of in situ atmospheric measurements of the outer planets by exploring Jupiter, entry probe missions to Saturn, Uranus and Neptune are essential to complete the picture of how our solar system evolved to its present state. During the development of entry probe missions, the interplanetary and probe approach trajectory, as well as the selection of the entry interface zone, are critical elements to mission success. Both elements are driven by considerations such as spacecraft safety (e.g. avoiding rings), while balancing science and engineering requirements at the same time (e.g. highly interesting science and entry zone vs. optimal communication geometry between probe and relay spacecraft). Due to the complexity of the problem, there is no analytical solution for finding the ‘best’ trajectory. Instead, one relies on the experience and intuition of mission designers to select a few possible interplanetary trajectories, which are then explored in detail to see how they meet science and engineering requirements. This approach leaves a huge trade space unexplored and may find a local, rather than a global optimum trajectory for the mission. We are addressing this gap by developing a software tool called VAPRE (Visualization of Atmospheric PRobe Entry Conditions for different bodies and trajectories) [3], [4] that allows us to explore those previously unexplored trade spaces. VAPRE can process thousands of trajectories, significantly more than in the currently common mission design processes. Due to its flexible architecture, VAPRE can be adapted and extended to accommodate new science and engineering constraints for different or similar mission scenarios. In our talk, we will present an example of how the tool can be used to design a flyby mission to a giant planet that delivers an atmospheric probe considering opportunities between 2028 and 2042.

Published
2021
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7. Technologies for Ocean Worlds

Author

Amanda R. Hendrix, Terry Hurford, Linda Spilker, Britney E. Schmidt, Jeff S. Bowman, Alfred S. McEwen, Scott G. Edgington, Kunio M. Sayanagi, Jeffrey M. Moore, Morgan L. Cable, Patricia Beauchamp, Abigail Rymer, and Thomas R. Spilker

Published
2021
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9. Prospects to study the Ice Giants with the ngVLA

Author

S. Luszcz-Cook, Chris Moeckel, Edward Molter, Katherine de Kleer, Mark Gurwell, Thomas R. Spilker, Joshua Tollefson, Arielle Moullet, Imke de Pater, Robert J. Sault, Leigh N. Fletcher, Stefanie N. Milam, and Bryan J. Butler

Subjects
Ice giant, Astrobiology
Published
2021
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13. Mitigating barriers in communication with migrants, results from a survey among health personnel

Author

R Spilker and C Nordström

Subjects
Economic growth, media_common.quotation_subject, Immigration, Public Health, Environmental and Occupational Health, Equity (finance), Norwegian, computer.software_genre, language.human_language, Health services, Health personnel, language, Multilingualism, Business, computer, Interpreter, media_common, Patient education
Abstract

Background Ensuring equity in health for migrant is a challenge for society and the health services. This survey map the challenges health personnel face in communication with immigrant patients, and how they wish to mitigate these challenges. Results can be used to inform implementation of measures for health personnel to better meet the needs of their patients. Methods In 2017, we conducted a short online survey to map the experiences and needs of health personnel in providing information to patients and relatives with immigrant backgrounds. The questionnaire consisted of six questions with answer options and opportunities to elaborate free-text answers. The survey was distributed through two migrant health networks coordinated by the National Competence Centre for Migration and Health (NAKMI), and by the Norwegian Nurses Organization to different section members. 549 people responded. Most of them nurses (41.5%) and doctors (12.4%) but also other health personnel as midwives, administrative staff, physiotherapists and psychologists. Results Nearly 50% of the respondents stated that they experienced weekly or more often communication difficulties with immigrant patients. To overcome communication barriers more than 90% say they would use interpreters when possible, use relatives as interpreters (55%) and/or a multilingual colleague (50%). To mitigate communication challenges, respondents said translated written materials (66%), simple language (43%) or use of pictures, films etc (37%) would be of help. More than 80% believe an electronic resource that gathers advice on how to customize and facilitate information and patient education, overview of translated material and good actions and project experiences will be a good help. Conclusions There is a need for increased access to knowledge and resources that can mitigate communication barriers between health personnel and migrant patients. Key messages There is a need for a comprehensive system approach to communication barriers in the Norwegian health care system. Health personnel need better access to tools that can help them provide equitable health care to migrants.

Published
2020
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14. Small Next-Generation Atmospheric Probe (SNAP) Concept to Enable Future Multi-Probe Missions: A Case Study for Uranus

Author

T. R. Spilker, S. J. Horan, R. E. Fairbairn, Kunio M. Sayanagi, L. W. Taylor, S. J. Primeaux, Trevor Grondin, J. Li, D. G. Goggin, Sarag J. Saikia, Ryan M. McCabe, D. Hope, C. Thames, Archit Arora, T. O. Clark, Michael H. Wong, S. C. Bowen, A. D. Scammell, James M. Longuski, L. D. Tran, Ankit Parikh, Amy Simon, D. J. Peterson, K. M. Somervill, H. P. Tosoc, Angela L. Bowes, J. S. Brady, W. C. Edwards, T. E. Marvel, David H. Atkinson, S. I. Infeld, J. P. Leckey, and Robert A. Dillman

Subjects
010504 meteorology & atmospheric sciences, Cost estimate, business.industry, Uranus, Astronomy and Astrophysics, 01 natural sciences, Wind speed, law.invention, Orbiter, Space and Planetary Science, Neptune, law, Atmospheric entry, Space Shuttle thermal protection system, 0103 physical sciences, Environmental science, Aerospace engineering, business, 010303 astronomy & astrophysics, Ice giant, 0105 earth and related environmental sciences
Abstract

We present the outcome of a mission concept study that designed a small atmospheric entry probe and examined the feasibility and benefit of a future multi-probe mission to Uranus. We call our design the Small Next-generation Atmospheric Probe (SNAP). The primary scientific objective of a multi-probe mission is to reveal spatial variability of atmospheric conditions. This article first highlights that not all measurements must be repeated by multiple probes; some quantities, notably the noble gas abundances and elemental isotopic ratios, are not expected to be variable, and thus need to be performed only by a single large Primary Probe. Our study demonstrates that, by focusing its measurements on spatially variable quantities including atmospheric vapor concentrations, thermal stratification and wind speed, a viable atmospheric probe design is realized with an entry system with 50-cm heatshield diameter and 30-kg atmospheric entry mass. As a case study, we present a detailed analysis of adding SNAP to a notional Uranus Orbiter with Probe mission, which launches in 2031 and arrives at Uranus in 2043, designed by the NASA-funded Science Definition Team study in 2017. We demonstrate that, with minimal changes to the notional carrier mission, a large Primary Probe and SNAP can be delivered to the winter and summer hemispheres to examine seasonal atmospheric variabilities, and transmit data to the Orbiter, which in turn relays the data to Earth. The additional maneuvers needed to deliver SNAP totals a Delta-V of 84 m/s, and consumes 43 kg of propellant. The addition of SNAP is expected to cost $79.5 million in FY2018 dollars; thus, our study demonstrates that a multi-probe mission can be implemented with a 4% cost increase relative to the $2.0 billion cost estimate of the notional mission designed by NASA’s Ice Giant Flagship Science Definition Team study reported in 2017. The SNAP design incorporates several technologies that are currently under development at various Technology Readiness Levels (TRL) between TRL = 4 and TRL = 6. In particular, our study recommends targeted technology development in Thermal Protection System materials, advanced batteries, and miniaturized instruments to enable and enhance future small atmospheric probes like SNAP.

Published
2020
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15. Science Payload for Ice Giant Entry Probes

Author

David H. Atkinson, Olivier Mousis, and Thomas R. Spilker

Subjects
Payload, Ice giant, Geology, Astrobiology
Abstract

To discern the origin and evolution of the solar system including the formation of the terrestrial planets, an understanding of giant planet formation and evolution is needed. Among the most important measurements are the atmospheric composition, structure, and processes of the ice giant. Noble gas abundances in particular are diagnostic of the conditions under which the giant planets formed, and the abundances of cloud-forming (condensable) species are indicators of both the characteristics of the protosolar nebula at the time and location of planetary formation as well as the mechanisms by which additional heavy elements might have been delivered to the planets. Although many key properties of ice giant systems can be accessed by remote observations from flyby and orbiting spacecraft, measurements of the abundances of the noble gas and key isotopes as well as deeper thermal structure, dynamics, clouds, and other atmospheric processes require direct in situ exploration by an atmospheric entry probe.Entry probe measurements can be classified as either Tier 1 or Tier 2. Tier 1 represents the minimum, threshold science required to justify the probe mission. Tier 2 is high value science that would complement and enhance the Tier 1 measurements, but alone are not enough to justify the entry probe mission.Tier 1 measurements include atmospheric abundances of noble gases (including helium), key noble gas isotope ratios 22Ne/20Ne, 36Ar/38Ar, 129Xe/total Xe, 131Xe/total Xe, and 132Xe/total Xe, additional key isotopic ratios D/H, 3He/4He, and 15N/14N, and the atmospheric thermal structure along the probe descent trajectory. To achieve the Tier 1 measurements, the probe payload must include a mass spectrometer, a helium abundance detector, and an atmospheric structure instrument including pressure and temperature sensors and an atmospheric acoustic properties sensor for speed of sound measurements from which the ratio of ortho- to para- molecular hydrogen can be determined. Depending on mission architecture and probe-carrier telecom design, Tier 1 science can be achieved with a relatively shallow probe descending to several bars.Tier 2 science includes additional key isotopic ratios such as 13C/12C and 18O/17O/16O, abundance of condensables, and additional atmospheric structure and processes including the dynamics of the atmosphere (winds and waves), the net balance of upwelling thermal infrared and downwelling solar visible radiative fluxes, and the location, structure, composition and properties of the clouds. The presence of the disequilibrium species such as PH3, CO, AsH3, GeH4, and SiH4 is primarily due to atmospheric convective upwelling, and abundance measurements would help constrain both the composition of the very deep atmosphere and deep atmosphere chemistries. Additional instrumentation necessary to fully achieve the Tier 2 objectives includes a net flux radiometer, a Nephelometer, and an ultrastable oscillator (USO) as part of the telecommunications system to enable probe Doppler tracking for measurements of atmospheric dynamics.To address all the Tier 1 and Tier 2 science objectives, a deep probe to 10 bars and beyond would provide measurements of atmospheric thermal structure, dynamics, and processes at levels beyond the direct influence of sunlight that are out of reach of remote sensing.

Published
2020
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16. Neptune Odyssey: A Flagship Concept for the Exploration of the Neptune–Triton System

Author

S. Alan Stern, Krista M. Soderlund, Tracy M. Becker, Ian J. Cohen, Linda Spilker, Joseph Williams, Adam Masters, Ralph L. McNutt, Seth Kijewski, Kelvin Murray, Imke de Pater, Jonathan J. Fortney, D. Alex Patthoff, Mike Norkus, Amy Simon, Gary Allen, Paul M. Schenk, Dinesh K. Prabhu, Weilun Cheng, Christopher J. Krupiarz, Frank Crary, Elizabeth Abel, Christopher J. Scott, Abigail Rymer, Jorge I. Nunez, Cindy Young, Brenda Clyde, Dana M. Hurley, Noam R. Izenberg, Kunio M. Sayanagi, Kevin B. Stevenson, A. M. Annex, Christian Campo, Soumya Dutta, Thomas R. Spilker, Tom Stallard, Hannah R. Wakeford, Carol Paty, Dan Rodriguez, Clint Apland, Ronald J. Vervack, Corey J. Cochrane, Janet Vertesi, Matthew M. Hedman, Susan L. Ensor, Jack Hunt, Marzia Parisi, Elena Provornikova, Jacob Wilkes, C. J. Hansen, James H. Roberts, George Hospodarsky, Martin T. Ozimek, Juan Arrieta, R. Nikoukar, Dan Gallagher, H. Todd Smith, Sarah E. Moran, Jeremy Rehm, Jay Feldman, Doug Crowley, Mark Hofstadter, Jonathan R. Bruzzi, Kirby Runyon, Emily S. Martin, Larry Wolfarth, George Clark, Leigh N. Fletcher, Kathleen Mandt, Robert Stough, Elizabeth P. Turtle, Curt Gantz, and Lynnae C. Quick

Subjects
Dwarf planet, 0211 other engineering and technologies, 02 engineering and technology, 7. Clean energy, 01 natural sciences, law.invention, Astrobiology, Jupiter, Orbiter, Neptune, law, Planet, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), 010303 astronomy & astrophysics, 021101 geological & geomatics engineering, Uranus, Astronomy and Astrophysics, Pluto, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Geology, Ice giant
Abstract

The Neptune Odyssey mission concept is a Flagship-class orbiter and atmospheric probe to the Neptune–Triton system. This bold mission of exploration would orbit an ice-giant planet to study the planet, its rings, small satellites, space environment, and the planet-sized moon Triton. Triton is a captured dwarf planet from the Kuiper Belt, twin of Pluto, and likely ocean world. Odyssey addresses Neptune system-level science, with equal priorities placed on Neptune, its rings, moons, space environment, and Triton. Between Uranus and Neptune, the latter is unique in providing simultaneous access to both an ice giant and a Kuiper Belt dwarf planet. The spacecraft—in a class equivalent to the NASA/ESA/ASI Cassini spacecraft—would launch by 2031 on a Space Launch System or equivalent launch vehicle and utilize a Jupiter gravity assist for a 12 yr cruise to Neptune and a 4 yr prime orbital mission; alternatively a launch after 2031 would have a 16 yr direct-to-Neptune cruise phase. Our solution provides annual launch opportunities and allows for an easy upgrade to the shorter (12 yr) cruise. Odyssey would orbit Neptune retrograde (prograde with respect to Triton), using the moon's gravity to shape the orbital tour and allow coverage of Triton, Neptune, and the space environment. The atmospheric entry probe would descend in ∼37 minutes to the 10 bar pressure level in Neptune's atmosphere just before Odyssey's orbit-insertion engine burn. Odyssey's mission would end by conducting a Cassini-like “Grand Finale,” passing inside the rings and ultimately taking a final great plunge into Neptune's atmosphere.

Published
2021
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17. Reference Model Payload for Ice Giant Entry Probe Missions

Author

T. R. Spilker, David H. Atkinson, Francesca Ferri, O. Mousis, Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Planetary probe instrumentation, 010504 meteorology & atmospheric sciences, Uranus, chemistry.chemical_element, 01 natural sciences, Atmosphere, Radiative flux, 0103 physical sciences, Thermal, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Helium, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Remote sensing, Radiometer, Nephelometer, In situ measurements, Noble gas, Astronomy and Astrophysics, Planetary science, chemistry, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Environmental science, Neptune, Atmospheric probes
Abstract

International audience; Descent probes afford the opportunity to make essential atmospheric measurements that are beyond the reach of remote sensing, including the atmospheric abundances of noble gases and key isotopes, and the structure of the atmosphere beneath the cloud tops. Measurements are defined as Tier 1, representing threshold science required to justify the probe mission, and Tier 2 representing valuable science that significantly complement and enhance the threshold measurements, but of themselves are not sufficient to justify the mission. Tier 1 measurements comprise atmospheric noble gas abundances including helium, key noble gas isotope ratios, and the thermal structure of the atmosphere. Instrumentation required to achieve the Tier 1 measurements include a mass spectrometer, a helium abundance detector, and an atmospheric structure instrument comprising both sensors for pressure, temperature, and atmospheric acoustic properties (speed of sound). Tier 1 science can be achieved with a probe making measurements near one to several bars. Tier 2 science includes measurements of key isotopic ratios, the abundances of atmospheric condensables and disequilibrium species, atmospheric dynamics, the net radiative flux transfer profile of the atmosphere, and the location, composition, properties, and structure of the clouds. To achieve all the Tier 2 science objectives requires a probe descending through at least ten bars carrying the full Tier 1 suite of instruments as well as a nephelometer, net flux radiometer, and an ultrastable oscillator to enable Doppler wind tracking of the probe throughout descent.

Published
2020
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18. Enabling technologies for ice giant exploration

Author

Thomas R Spilker

Subjects
020301 aerospace & aeronautics, Schedule, Computer science, General Mathematics, General Engineering, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Task (project management), 0203 mechanical engineering, Work (electrical), 0103 physical sciences, Systems engineering, 010303 astronomy & astrophysics, Ice giant
Abstract

Future missions to an ice giant planet, especially orbital missions, are technologically challenging. But with one exception, radioisotope power sources (RPSs), the technologies that would enable such missions are currently available. RPSs are not a new technology, but devices used in the past that are appropriate to an ice giant mission are no longer available without engineering development work (currently unfunded), and it is uncertain whether the new NASA unit under development will be available for flight in time to take advantage of the best transfer trajectories of the next 15 years. This paper describes technologies already in hand that enable an ice giant mission, but for them to be useful they must be maintained. If an enabling technology is lost a replacement must be developed, potentially impacting the cost and schedule of a mission. In addition to the enabling technologies, there are a number of technologies that, while not enabling, could greatly enhance the science return and science value of a mission, making the programmatic aspects of approval an easier task and the funding of those development tasks a high priority.This article is part of a discussion meeting issue ‘Future exploration of ice giant systems'.

Published
2020
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19. The Future Exploration of Saturn

Author

Henrik Melin, Scott G. Edgington, Thomas R. Spilker, A. Wesley, Glenn S. Orton, F. J. Crary, Olivier Mousis, Thomas K. Greathouse, Sushil K. Atreya, and Kevin H. Baines

Subjects
Exploration of Saturn, Geology, Astrobiology
Published
2018
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24. Radioisotope power system-based enceladus smallsat mission concept: Enceladus express

Author

Steven L. McCarty, Young H. Lee, T. R. Spilker, Joseph E. Riedel, Brian Bairstow, and Steven R. Oleson

Subjects
Solar System, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, Gas giant, Solar energy, 01 natural sciences, Astrobiology, Planetary science, Deep space exploration, Saturn, Physics::Space Physics, 0103 physical sciences, Environmental science, Astrophysics::Earth and Planetary Astrophysics, business, Enceladus, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

The coming decades of planetary science and deep space exploration will likely have a combination of more ambitious missions and ever more constrained budgets. The outer solar system, in particular, poses a challenge for lower mission cost as the principal need for a robotic craft — a source of energy — is difficult to supply through conventional means (solar energy). Even as far from the Sun as Saturn, the solar energy density is only 1% of that at Earth. Not viewed typically as a power source for low-cost missions, radioisotope power systems (RPS) may well fill that role by providing power to small spacecraft in the outer solar system. And the outer solar system beckons with extremely compelling science. The rich dynamics of the atmospheres of the gas giants are continuously operating laboratories of extreme weather processes, examples of which in miniaturized scale may become more familiar here on Earth. Enceladus, a small moon of Saturn, has been seen by the Cassini mission to be a site of continuous high geologic activity, with plumes of water vapor and particles pumped hundreds of kilometers above the surface, indeed into Saturn orbit. The internal heating mechanisms of this activity beg for explanation, and more importantly, initial measurements by the Cassini spacecraft give tantalizing clues that the geo-thermal source of the heating is, in fact, maintaining a global sub-surface ocean, which in combination could provide a habitat for life. This paper will explore how existing and currently available RPS elements may make mission concepts to explore the intriguing science of Enceladus economically tractable, and at the same time provide a generic platform for other small but highly capable spacecraft to explore the outer solar system.

Published
2017
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25. Scientific rationale for Saturn's in situ exploration

Author

J. Poncy, C. Briois, D. Gautier, Jean-Pierre Lebreton, Andrew Morse, T. R. Spilker, Alexis Bouquet, K. Reh, T. Kostiuk, W. D Geppertt, Pgj Irwin, Ricardo Hueso, J. M. Petit, Carl D. Murray, David H. Atkinson, Matthew S. Tiscareno, Scott Bolton, Ravit Helled, Agustín Sánchez-Lavega, Matthew M. Hedman, S. Guerlet, A. Coustenis, Peter Wurz, James O'Donoghue, Kathrin Altwegg, D Lebleu, François-Xavier Schmider, Mohamad Ali-Dib, Georg Fischer, Nadine Nettelmann, Thibault Cavalié, Amy Simon, Aymeric Spiga, Michel Blanc, Olivia Venot, G. S. Orton, Tristan Guillot, Sushil K. Atreya, Miriam Rengel, O. Mousis, N. André, R. Moreno, J. H. Waite, Philippe Rousselot, Emmanuel Lellouch, Leigh N. Fletcher, Ioannis A. Daglis, Bernard Marty, Jonathan I. Lunine, Régis Courtin, Thierry Fouchet, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules ( UTINAM ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), University of Leicester, Physikalisches Institut [Bern], Universität Bern [Bern], ASP 2016, Laboratoire d'Astrophysique de Bordeaux [Pessac] ( LAB ), Université de Bordeaux ( UB ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Bordeaux ( UB ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Service de parasitologie - mycologie [CHU Pitié-Salpétrière], Assistance publique - Hôpitaux de Paris (AP-HP)-CHU Pitié-Salpêtrière [APHP], Tel Aviv University [Tel Aviv], Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], Centre de Recherches Pétrographiques et Géochimiques ( CRPG ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Le Collège d'études mondiales/FMSH, Fondation Maison des sciences de l'homme, K.U.Leuven, Centre for Medical Imaging, University College London, London, United Kingdom, Space Science Division [San Antonio], Southwest Research Institute [San Antonio] ( SwRI ), Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon, Institut Lumière Matière [Villeurbanne] ( ILM ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Géomatériaux et Modèles Géotechniques ( IFSTTAR/GERS/GMG ), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux ( IFSTTAR ) -PRES Université Nantes Angers Le Mans ( UNAM ), National Observatory of Athens ( NOA ), Department of Physics [Stockholm], Stockholm University, Stockholm University Astrobiology Centre, Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), University of Idaho [Moscow, USA], Departamento de Fisica Aplicada [Bilbao], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea ( UPV/EHU ), Department of Astronomy [Ithaca], Cornell University, Max-Planck-Institut für Sonnensystemforschung ( MPS ), Université Pierre et Marie Curie - Paris 6 ( UPMC ), Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -École polytechnique ( X ) -École des Ponts ParisTech ( ENPC ) -Centre National de la Recherche Scientifique ( CNRS ) -Département des Géosciences - ENS Paris, École normale supérieure - Paris ( ENS Paris ) -École normale supérieure - Paris ( ENS Paris ), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] ( LSCE ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Amélioration génétique et adaptation des plantes méditerranéennes et tropicales ( UMR AGAP ), Institut national de la recherche agronomique [Montpellier] ( INRA Montpellier ) -Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Centre de Coopération Internationale en Recherche Agronomique pour le Développement ( CIRAD ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), NASA Goddard Space Flight Center ( GSFC ), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, The Open University [Milton Keynes] (OU), Institut für Physik [Rostock], Universität Rostock, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Southwest Research Institute [San Antonio] (SwRI), NASA Goddard Space Flight Center (GSFC), University of Michigan [Ann Arbor], University of Michigan System, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), National Observatory of Athens (NOA), Austrian Academy of Sciences (OeAW), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Queen Mary University of London (QMUL), Department of Physics and Astronomy [Leicester], Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Center for Radiophysics and Space Research [Ithaca] (CRSR), Thales Alenia Space [Cannes], Thales Alenia Space, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH)-NASA, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Cornell University [New York], École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), University of Oxford, Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Tel Aviv University (TAU), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Thales Alenia Space [Toulouse] (TAS), THALES [France], Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Pitié-Salpêtrière [APHP], Fondation Maison des sciences de l'homme (FMSH), Université Claude Bernard Lyon 1 (UCBL), Institut Lumière Matière [Villeurbanne] (ILM), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Géomatériaux et Modèles Géotechniques (IFSTTAR/GERS/GMG), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM), Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Exploration of Saturn, Solar System, 010504 meteorology & atmospheric sciences, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Galileo Probe, Entry probe, FOS: Physical sciences, 7. Clean energy, 01 natural sciences, Astrobiology, Solar system formation, Jupiter, Giant planet formation, Planet, Saturn, 0103 physical sciences, Elemental and isotopic composition, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Giant planet, In situ measurements, Astronomy, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Saturn atmosphere, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Ice giant, Astrophysics - Earth and Planetary Astrophysics
Abstract

Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk elemental and isotopic composition would place important constraints on the volatile reservoirs in the protosolar nebula. We also show that the in situ measurement of CO (or any other disequilibrium species that is depleted by reaction with water) in Saturn's upper troposphere would constrain its bulk O/H ratio. We highlight the key measurements required to distinguish competing theories to shed light on giant planet formation as a common process in planetary systems with potential applications to most extrasolar systems. In situ measurements of Saturn's stratospheric and tropospheric dynamics, chemistry and cloud-forming processes will provide access to phenomena unreachable to remote sensing studies. Different mission architectures are envisaged, which would benefit from strong international collaborations., Comment: Submitted to Planetary and Space Science

Published
2016
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26. Atmospheric Planetary Probes and Balloons in the Solar System

Author

Christian Erd, Tibor S. Balint, Jeffery L. Hall, T. R. Spilker, K. Reh, Dennis L. Matson, Patricia Beauchamp, Jean-Pierre Lebreton, John Elliott, Nathan Strange, A. Coustenis, Sushil K. Atreya, David H. Atkinson, and Jonathan I. Lunine

Subjects
Aerobot, Physics, Solar System, biology, Mechanical Engineering, Aerospace Engineering, Astronomy, Venus, Planetary system, biology.organism_classification, Astrobiology, symbols.namesake, Primary (astronomy), Planet, Physics::Space Physics, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Titan (rocket family)
Abstract

A primary motivation for in situ probe and balloon missions in the solar system is to progressively constrain models of its origin and evolution. Specifically, understanding the origin and evolution of multiple planetary atmospheres within our solar system would provide a basis for comparative studies that lead to a better understanding of the origin and evolution of our own solar system as well as extra-solar planetary systems. Hereafter, the authors discuss in situ exploration science drivers, mission architectures, and technologies associated with probes at Venus, the giant planets and Titan.

Published
2011
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27. Millimeter and submillimeter measurements of asteroid (2867) Steins during the Rosetta fly-by

Author

Emmanuel Lellouch, P. J. Encrenaz, Peter Schloerb, Dominique Bockelée-Morvan, Nicolas Biver, Wing-Huen Ip, Ingrid Mann, C. Backus, M. A. Janssen, Gerard Beaudin, Paul Hartogh, Margaret A. Frerking, Stephen Keihm, L. W. Kamp, Seungwon Lee, T. Encrenaz, Mark Hofstadter, Björn Davidsson, Thomas R. Spilker, Jacques Crovisier, Samuel Gulkis, Jet Propulsion Laboratory, California Institute of Technology (JPL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Department of Earth and Planetary Science, Faculty of Science, Kobe University, and Five College Radio Astronomy Observatory, University of Massachusetts

Subjects
Physics, Radiometer, Spectrometer, Parabolic reflector, Astronomy, Astronomy and Astrophysics, law.invention, Telescope, Orbiter, Space and Planetary Science, law, Asteroid, Radiative transfer, Emissivity, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; The European Space Agency Rosetta Spacecraft passed within 803 km of the main belt asteroid (2867) Steins on 5 September 2008. The Rosetta Spacecraft carries a number of scientific instruments including a millimeter and submillimeter radiometer and spectrometer. The instrument, named MIRO (Microwave Instrument for the Rosetta Orbiter), consists of a 30-cm diameter, offset parabolic reflector telescope followed by two heterodyne receivers. Center-band operating frequencies of the receivers are near 190 GHz (1.6 mm) and 562 GHz (0.53 mm). Broadband continuum channels are implemented in both frequency bands for the measurement of near surface temperatures and temperature gradients. A 4096 channel CTS (chirp transform spectrometer) having 180 MHz total bandwidth and ˜44 kHz resolution is also connected to the submillimeter receiver. We present the continuum observations of asteroid (2867) Steins obtained during the fly-by with the MIRO instrument. Spectroscopic data were also collected during the fly-by using the MIRO spectrometer fixed-tuned to rotational lines of several molecules. Results of the spectroscopic investigation will be the topic of a separate publication. Comparative thermal models and radiative transfer calculations for Steins are presented. Emissivities of Steins were determined to be 0.6-0.7 and 0.85-0.9 at wavelengths of 0.53 and 1.6 mm, respectively. The thermal inertia of Steins was estimated to be in the range 450-850 J/(m 2 s 0.5 K). Assuming that the emissivity of Steins is determined by the Fresnel reflection coefficients of the surface material, the area-averaged dielectric constant of the surface material is in the range 4-20. These values are rock-like, and are unlike the powdered-regolith surface of the Moon.

Published
2010
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28. Static and dynamic mechanics of the temporomandibular joint: plowing forces, joint load and tissue stress

Author

R. Spilker, D. Marx, Yoly Gonzalez, Richard Ohrbach, Jeffrey C. Nickel, Mark W. Beatty, W.D. McCall, and Laura R. Iwasaki

Subjects
Extramural, Joint load, Orthodontics, Mechanics, Temporomandibular joint, Stress (mechanics), Bite force quotient, medicine.anatomical_structure, Disc displacement, Otorhinolaryngology, medicine, Surgery, Oral Surgery, Joint (geology), Mathematics
Abstract

OBJECTIVES - To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. SETTING AND SAMPLE POPULATION - Fifty-two subjects (30 female; 22 male) participated in the TMJ load experiments. MATERIAL AND METHODS - In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using anova. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD/+pain, n = 18; +DD/-pain, n = 17; -DD/-pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. RESULTS - The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R(2) = 0.85). +DD/-pain subjects produced 60% higher joint loads (ANOVA, p < 0.05), which increased bFEM-calculated compressive strain and peak total normal stress. CONCLUSIONS - Static and dynamic variables of the stress-field and subject-dependent joint load significantly affect disc mechanics.

Published
2009
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29. The Hera Saturn entry probe mission

Author

S. B. Calcutt, J. Poncy, David H. Atkinson, Agustín Sánchez-Lavega, J. H. Waite, Don Banfield, E. Kessler, Anthony Colaprete, T. R. Spilker, K. Reh, Daphne Stam, Andrew D. Holland, Georg Fischer, Jonathan I. Lunine, Olga Muñoz, Leigh N. Fletcher, Frans Snik, Michael Amato, Shahid Aslam, François-Xavier Schmider, P. Levacher, Michael K. Bird, Athena Coustenis, Simon Sheridan, Ricardo Hueso, Christoph U. Keller, Robert V. Frampton, Thibault Cavalié, Bernard Marty, D. Gautier, Andrew Morse, J. J. Fortney, Jean-Baptiste Renard, Peter Wurz, J. P. Lebreton, Tristan Guillot, Ethiraj Venkatapathy, Mark Leese, G. S. Orton, Sushil K. Atreya, Conor A. Nixon, Francesca Ferri, Magali Deleuil, O. Mousis, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), University of Idaho [Moscow, USA], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Ames Research Center (ARC), Thales Alenia Space [Toulouse] (TAS), THALES [France], The Boeing Company, Huntington Beach, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Leicester, Departamento de Fisica Aplicada [Bilbao], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), NASA Goddard Space Flight Center (GSFC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Faculty of Aerospace Engineering [Delft], Delft University of Technology (TU Delft), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), University of Michigan [Ann Arbor], University of Michigan System, Cornell University [New York], University of Oxford, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), The Open University [Milton Keynes] (OU), Leiden Observatory [Leiden], Universiteit Leiden, Leibniz-Institute of Photonic Technology, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Space Science Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Rheinische Friedrich-Wilhelms-Universität Bonn, ASP 2016, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), Department of Astronomy [Ithaca], ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Thales Alenia Space [Cannes], Thales Alenia Space, Universität Bern [Bern], University of Oxford [Oxford], Universiteit Leiden [Leiden], Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Cruz] (UCSC), and University of California

Subjects
Exploration of Saturn, Solar System, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, 7. Clean energy, 01 natural sciences, Astrobiology, Planet, Saturn, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Atmosphere, Giant planet, In situ measurements, Astronomy, Astronomy and Astrophysics, Probe, Exoplanet, ESA's Cosmic Vision Medium class size call, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, Formation and evolution of the Solar System, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The Hera Saturn entry probe mission is proposed as an M--class mission led by ESA with a contribution from NASA. It consists of one atmospheric probe to be sent into the atmosphere of Saturn, and a Carrier-Relay spacecraft. In this concept, the Hera probe is composed of ESA and NASA elements, and the Carrier-Relay Spacecraft is delivered by ESA. The probe is powered by batteries, and the Carrier-Relay Spacecraft is powered by solar panels and batteries. We anticipate two major subsystems to be supplied by the United States, either by direct procurement by ESA or by contribution from NASA: the solar electric power system (including solar arrays and the power management and distribution system), and the probe entry system (including the thermal protection shield and aeroshell). Hera is designed to perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere using a single probe, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets. Hera's aim is to probe well into the cloud-forming region of the troposphere, below the region accessible to remote sensing, to the locations where certain cosmogenically abundant species are expected to be well mixed. By leading to an improved understanding of the processes by which giant planets formed, including the composition and properties of the local solar nebula at the time and location of giant planet formation, Hera will extend the legacy of the Galileo and Cassini missions by further addressing the creation, formation, and chemical, dynamical, and thermal evolution of the giant planets, the entire solar system including Earth and the other terrestrial planets, and formation of other planetary systems., Comment: Accepted for publication in Planetary and Space Science

Published
2016
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30. Determination of Alcohol Ethoxylate Components in Sewage Sludge

Author

R. Spilker, H.-P. Wingen, H. Klotz, E. Matthijs, P. Haas, Charles V. Eadsforth, H. Waldhoff, M. H. I. Comber, M. D. Burford, and G. Cassani

Subjects
Detection limit, Chromatography, General Chemical Engineering, Extraction (chemistry), General Chemistry, Condensed Matter Physics, Chloride, High-performance liquid chromatography, chemistry.chemical_compound, Anaerobic digestion, chemistry, medicine, Sewage treatment, Methanol, Sludge, medicine.drug
Abstract

An analytical method has been developed for the determination of alcohol ethoxylate (AE) components in sewage sludge. The method has been extensively ring tested in several industrial laboratories and concentrations in sludge samples from a number of EU countries have been obtained. The method is based on a methanol soxhlet extraction of centrifuged sludge, which is then cleaned up using an alumina column, followed by derivatisation with naphthoyl chloride and a further alumina column clean-up. The extract is analysed using high performance liquid chromatography (HPLC) with fluorescence detection. The method is capable of determining alcohol ethoxylate components in the range of C12–C18 alkyl chain lengths with an ethoxylate chain of EO4 up to approximately EO20 in sludge samples. The detection limit is approximately 20–30 mg kg−1 of total AEs in dry weight of sludge. Using the method, sludges from several European Sewage Treatment Plants (STP) were analysed. The concentration of the AEs, which are primarily linear, in digestor inlet averaged 1164 mg kg−1 (550–2947 mg kg−1) and in outlet sludges the mean value obtained was 167 mg kg−1 (−1). At those plants in which concentrations were monitored in both inlet and outlet sludges, removal of the AEs by anaerobic digestion at the STP averaged 82% (range 61–93%). The interlaboratory relative standard deviation of the procedure was around 40% for the digester sludges analysed. The method developed provides a more accurate estimate of the environmental level of AE components compared to existing colorimetric approaches, but the method will over-estimate the concentration of alcohol ethoxylates in sludges due to the non-specific nature of the detection. However, it is sufficiently robust and accurate to estimate alcohol ethoxylates in sludges and hence concentrations that could be applied to soil.

Published
2004
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31. Determination of low boiling solvents in liquid formulations by gas chromatography [H‐VIII 2a (Status: 01.10.2003)]

Author

R. Spilker and M. Hirschen

Subjects
Chromatography, Chemistry, Boiling, General Chemistry, Gas chromatography, Standard methods, Industrial and Manufacturing Engineering, Food Science, Biotechnology
Abstract

The following method was tested by the “Gemeinschaftsausschuss fur die Analytik von Tensiden (GAT)” in an interlaboratory test. GAT puts the method up for discussion and invites readers to make comments to the referees above. Afterwards it is intended to include this method in Section H – Surfactants, Chapter VIII of the DGF Standard Methods

Published
2004
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32. Saturn Ring Observer

Author

Thomas R. Spilker

Subjects
Ring (mathematics), Engineering, Observer (quantum physics), Saturn (rocket family), Cost estimate, business.industry, Rings of Saturn, Aerocapture, Aerospace Engineering, Propulsion, Aerospace engineering, business, Space exploration
Abstract

Scientists studying planetary ring systems and planetary system formation have long wanted close-up (a few km) observations of Saturn's rings to answer fundamental questions about ring particle characteristics and behavior. But missions to implement these observations involve post-approach Δ V requirements greater than 10 km / s , so past designs have called upon Nuclear Electric Propulsion—an untenable position in the current programmatic climate. A unique new mission design uses carefully designed aerocapture to decrease the Δ V requirement to as little as 3.5 km / s , a difficult but not impossible feat for high-performance chemical propulsion systems. Propulsion costs dominate cost estimates for the Saturn Ring Observer mission. Driving down propulsion costs is an important facet of the strategic technology program, one that would provide cost benefits to many other missions.

Published
2003
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33. Subsurface properties and early activity of comet 67P/Churyumov-Gerasimenko

Author

Christopher Jarchow, Seungwon Lee, Stephen Keihm, F. Peter Schloerb, Dominique Bockelée-Morvan, C. Leyrat, Michael Janssen, Samuel Gulkis, Pierre Encrenaz, Jacques Crovisier, Björn Davidsson, Emmanuel Lellouch, Mark Allen, Thérèse Encrenaz, Ladislav Rezac, Nicolas Biver, Thomas R. Spilker, Mathieu Choukroun, Paul Hartogh, Gerard Beaudin, Margaret A. Frerking, Paul von Allmen, Mark Hofstadter, Wing-Huen Ip, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS Paris)

Subjects
[PHYS]Physics [physics], Multidisciplinary, Chemistry, Comet, Atmospheric sciences, Spectral line, law.invention, Wavelength, Outgassing, Orbiter, 13. Climate action, law, Thermal, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Microwave, Water vapor, ComputingMilieux_MISCELLANEOUS
Abstract

Heat transport and ice sublimation in comets are interrelated processes reflecting properties acquired at the time of formation and during subsequent evolution. The Microwave Instrument on the Rosetta Orbiter (MIRO) acquired maps of the subsurface temperature of comet 67P/Churyumov-Gerasimenko, at 1.6 mm and 0.5 mm wavelengths, and spectra of water vapor. The total H 2 O production rate varied from 0.3 kg s –1 in early June 2014 to 1.2 kg s –1 in late August and showed periodic variations related to nucleus rotation and shape. Water outgassing was localized to the “neck” region of the comet. Subsurface temperatures showed seasonal and diurnal variations, which indicated that the submillimeter radiation originated at depths comparable to the diurnal thermal skin depth. A low thermal inertia (~10 to 50 J K –1 m –2 s –0.5 ), consistent with a thermally insulating powdered surface, is inferred.

Published
2015
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34. Potentiometrische Zweiphasentitration von anionaktiven Tensiden mit einer lösemittelbeständigen Elektrode — Deutsche Einheitsmethoden zur Untersuchung von Fetten, Fettprodukten, Tensiden und verwandten Stoffen: Analyse von grenzflächenaktiven Stoffen XXXVII

Author

H. Waldhoff, R. Spilker, J. Scherler, and R. Gerhards

Subjects
General Computer Science, Chemistry, Analytical chemistry, Electroanalytical method, General Earth and Planetary Sciences, Standard test, Analysis method, General Environmental Science
Published
1999
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37. Alkylbenzolsulfonat (LAS)- Konzentrationen im Lippe-Sediment eines Rhein-Altarmes

Author

P. Schöberl and R. Spilker

Subjects
Chemistry, General Chemical Engineering, Environmental chemistry, Sediment, Federal republic of germany, Sewage treatment, General Chemistry, Condensed Matter Physics, Soil contamination, West germany
Abstract

Dated sediment-Layers (1939-1991) of the Lippe-River (near Wesel) were studied for their LAS-concentrations. These concentrations ranged from 0 to 3,3 μg of linear alkylbenzenesulphonates per gram of dried sediment (< 60 μm). The LAS concentrations reflect relatively well the political (currency reform), economic and technical (sewage treatment) developments in the Federal Republic of Germany.

Published
1996
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38. Alkylbenzolsulfonat (LAS)-Monitoring

Author

P. Schöberl, H. Klotz, and R. Spilker

Subjects
chemistry.chemical_classification, Suspended solids, Water body, Chemistry, General Chemical Engineering, Environmental chemistry, Organic matter, General Chemistry, Condensed Matter Physics
Abstract

Several 4 to 7-months monitoring studies for LAS adsorbed to suspended solids were carried out at the rivers Isar Wupper and Chemnitz. The monitoring period started on march 1994 and ended on march 1995. The mean concentrations of LAS adsorbed to suspended solids (

Published
1996
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39. Fettsäureamidopropylbetaine — Gehalt an Monochloressigsäure und Dichloressigsäure Gemeinschaftsarbeiten der DGF, 151. Mitteilung: Deutsche Einheitsmethoden zur Untersuchung von Fetten, Fettprodukten, Tensiden und Verwandten Stoffen, 117. Mitt.: Analyse von grenzflächenaktiven Stoffen XXVI

Author

M. Arens and R. Spilker

Subjects
chemistry.chemical_compound, Measurement method, Betaine, Chromatography, Chemistry, Gas chromatography, Aliphatic compound
Published
1996
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40. The Thermal Profile and Water Abundance in the Venus Mesosphere from H2O and HDO Millimeter Observations

Author

José Cernicharo, Thomas R. Spilker, T. Encrenaz, Samuel Gulkis, Gabriel Paubert, and E. Lellouch

Subjects
Physics, biology, Astronomy and Astrophysics, Venus, Astrophysics, biology.organism_classification, Atmospheric sciences, Mesosphere, Atmosphere of Venus, Caltech Submillimeter Observatory, Deuterium, Space and Planetary Science, Mixing ratio, Spectral resolution, Water vapor
Abstract

The 183.310-GHz water vapor transition has been observed in the Venus atmosphere for the first time. The detection was made in January 1991, using the 30-m IRAM radiotelescope. A spectrum of Saturn, recorded during the same night, was used to remove the contribution due to terrestrial mesospheric water. Using the depth and the FWHM of the observed absorption line, we derive a water mixing ratio of 1.0 (+ 1.0, -0.5) ppm above the clouds, and a temperature of 140 (±10) K at the level z = 95 km ( P = 0.06 mb). In July 1993, we reobserved the HDO transition at 225.987 GHz, which we first detected in August 1990 (T. Encrenaz et al. 1991, Astron. Astrophys. 246, L63-L66). The new set of data was obtained at the Caltech Submillimeter Observatory (CSO), with improved signal-to-noise and spectral resolution with respect to previous measurements. From the 1993 data we derive a water mixing ratio of 7.0 (+5.0, -4.0) ppm above the clouds, and a temperature higher than 145 K at the z = 95-km level. The water abundance is derived assuming a deuterium enrichment factor of 120 with respect to the terrestrial value (C. de Bergh et al . 1991, Science 251, 547-549). If the deuterium enrichment factor is close to 160, as measured by G. L. Bjoraker et al . (1992, Bull. Am. Astron. Soc. 24, 995-995), the difference between the H 2 O measurements is reduced, but the data might still suggest some possible fluctuation in the water vapor content above the clouds between 1991 and 1993.

Published
1995
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41. OSS (Outer Solar System): a fundamental and planetary physics mission to Neptune, Triton and the Kuiper Belt

Author

S. V. Progrebenko, Bernard Foulon, Etienne Samain, Jean-Michel Courty, William M. Grundy, Orfeu Bertolami, Claus Lämmerzahl, John D. Anderson, Ravit Helled, Frank Postberg, Joachim Saur, Katrin Stephan, Antonella Barucci, J. Poncy, Nicole Schmitz, Patrick Brown, Benjamin Lenoir, Kim Reh, S. W. Asmar, Bruno Christophe, Brahim Lamine, Hanns Selig, Serge Reynaud, Rolland Lehoucq, Clélia Robert, Baptiste Cecconi, Frederico Francisco, Pierre Touboul, Laurent Lamy, Hansjörg Dittus, Jonathan Aurnou, Glenn S. Orton, Don Banfield, Leigh N. Fletcher, Linda Spilker, Frank Sohl, Jorge Páramos, Hauke Hussmann, Peter Wolf, Paulo Gil, Karl-Heinz Glassmeier, Nicolas André, A. Levy, Rory J. Bingham, Jörn Helbert, Kunio M. Sayanagi, Thomas R. Spilker, Ralf Srama, Candice Hansen, ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Departamento de Física e Astronomia [Porto] (DFA/FCUP), Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto-Universidade do Porto, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Imperial College London, Laboratoire Kastler Brossel (LKB (Jussieu)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), German Aerospace Center (DLR), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), DLR Institute of Planetary Research, Center of Applied Space Technology and Microgravity (ZARM), Universität Bremen, Géoazur (GEOAZUR 6526), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire national de métrologie et d'essais - Systèmes de Référence Temps-Espace (LNE - SYRTE), Systèmes de Référence Temps Espace (SYRTE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidade do Porto = University of Porto-Universidade do Porto = University of Porto, Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Kuiper Belt object, Solar System, Physics - Instrumentation and Detectors, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], gr-qc, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), NASA Deep Space Network, Great Dark Spot, Astronomy & Astrophysics, 01 natural sciences, 7. Clean energy, General Relativity and Quantum Cosmology, Astrobiology, Neptune, Planet, 0103 physical sciences, Triton, 14. Life underwater, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], physics.ins-det, 010303 astronomy & astrophysics, Fundamental physics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Spacecraft, business.industry, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), Deep space gravity, Planetary science, Space and Planetary Science, astro-ph.EP, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Formation and evolution of the Solar System, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astronomical and Space Sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

The present OSS mission continues a long and bright tradition by associating the communities of fundamental physics and planetary sciences in a single mission with ambitious goals in both domains. OSS is an M-class mission to explore the Neptune system almost half a century after flyby of the Voyager 2 spacecraft. Several discoveries were made by Voyager 2, including the Great Dark Spot (which has now disappeared) and Triton's geysers. Voyager 2 revealed the dynamics of Neptune's atmosphere and found four rings and evidence of ring arcs above Neptune. Benefiting from a greatly improved instrumentation, it will result in a striking advance in the study of the farthest planet of the Solar System. Furthermore, OSS will provide a unique opportunity to visit a selected Kuiper Belt object subsequent to the passage of the Neptunian system. It will consolidate the hypothesis of the origin of Triton as a KBO captured by Neptune, and improve our knowledge on the formation of the Solar system. The probe will embark instruments allowing precise tracking of the probe during cruise. It allows to perform the best controlled experiment for testing, in deep space, the General Relativity, on which is based all the models of Solar system formation. OSS is proposed as an international cooperation between ESA and NASA, giving the capability for ESA to launch an M-class mission towards the farthest planet of the Solar system, and to a Kuiper Belt object. The proposed mission profile would allow to deliver a 500 kg class spacecraft. The design of the probe is mainly constrained by the deep space gravity test in order to minimise the perturbation of the accelerometer measurement., 43 pages, 10 figures, Accepted to Experimental Astronomy, Special Issue Cosmic Vision. Revision according to reviewers comments

Published
2012
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42. Continuum and spectroscopic observations of asteroid (21) Lutetia at millimeter and submillimeter wavelengths with the MIRO instrument on the Rosetta spacecraft

Author

Thomas R. Spilker, L. W. Kamp, Stephen Keihm, Wing-Huen Ip, M. A. Janssen, Jacques Crovisier, Gerard Beaudin, N. Biver, Peter Schloerb, Emmanuel Lellouch, P. Encrenaz, Mark Hofstadter, Ingrid Mann, P. von Allmen, Samuel Gulkis, T. Encrenaz, C. Backus, Paul Hartogh, Paul R. Weissman, Sukhan Lee, Dominique Bockelée-Morvan, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS Paris)

Subjects
Physics, [PHYS]Physics [physics], Radiometer, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, Northern Hemisphere, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Regolith, 13. Climate action, Space and Planetary Science, Asteroid, 0103 physical sciences, Millimeter, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Southern Hemisphere, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Exosphere
Abstract

The European Space Agency's Rosetta spacecraft made a close flyby of asteroid (21) Lutetia on July 10, 2010. The spacecraft carries a dual-band radiometer/spectrometer instrument, named MIRO, which operates at 190 GHz (1.6 mm) and 560 GHz (0.5 mm). During the flyby, the MIRO instrument measured the temperature of Lutetia in both the northern and southern hemispheres. At the time of the flyby, the northern hemisphere was seasonally sun-lit and warmer than the southern hemisphere. Subsurface (depths from ∼2 mm to ∼2 cm) temperatures ranged from ∼200 K on the northern hemisphere to ∼60 K on the southern hemisphere. A lunar-like regolith – very low thermal inertia

Published
2012
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45. Rapid Mission Architecture trade study of Enceladus mission concepts

Author

Peter Tsou, Robert C. Moeller, Chester Borden, Joan Ervin, Debarati Chattopadhyay, Mark Adler, Nathan Strange, Elizabeth Deems, Robert Shotwell, Thomas R. Spilker, William D. Smythe, John R. Spencer, Bjorn Cole, and Anastassios E. Petropoulos

Subjects
Aerospace instrumentation, Engineering, Aeronautics, Saturn (rocket family), Research council, business.industry, Architecture, Enceladus, business, Planetary Science Decadal Survey, Astrobiology
Abstract

At the request of the Satellites Panel of the National Research Council (NRC) Planetary Science Decadal Survey, a Rapid Mission Architecture (RMA) study of possible missions to Saturn's moon Enceladus was conducted at the Jet Propulsion Laboratory in January and February of 2010. This was one of many studies commissioned by this NRC Decadal Survey. In this study, 15 Enceladus mission architectures were examined that spanned a broad range of potential science return and total estimated mission cost.

Published
2011
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46. Space missions trade space generation and assessment using the JPL Rapid Mission Architecture (RMA) team approach

Author

Thomas R. Spilker, Chester Borden, Robert E. Lock, William D. Smythe, and Robert C. Moeller

Subjects
Design studies, Engineering, Brainstorming, business.industry, Process (engineering), Systems engineering, Space (commercial competition), Architecture, Space research, business, Space exploration, Rapid assessment
Abstract

The JPL Rapid Mission Architecture (RMA) capability is a novel collaborative team-based approach to generate new mission architectures, explore broad trade space options, and conduct architecture-level analyses. RMA studies address feasibility and identify best candidates to proceed to further detailed design studies. Development of RMA first began at JPL in 2007 and has evolved to address the need for rapid, effective early mission architectural development and trade space exploration as a precursor to traditional point design evaluations. The RMA approach integrates a small team of architecture-level experts (typically 6–10 people) to generate and explore a wide-ranging trade space of mission architectures driven by the mission science (or technology) objectives. Group brainstorming and trade space analyses are conducted at a higher level of assessment across multiple mission architectures and systems to enable rapid assessment of a set of diverse, innovative concepts. This paper describes the overall JPL RMA team, process, and high-level approach. Some illustrative results from previous JPL RMA studies are discussed. 1 2

Published
2011
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48. New laboratory measurements on ammonia's inversion spectrum, with implications for planetary atmospheres

Author

Thomas R. Spilker

Subjects
Atmospheric Science, Materials science, Hydrogen, Absorption spectroscopy, Gas giant, Soil Science, chemistry.chemical_element, Aquatic Science, Oceanography, Spectral line, Optics, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Radio occultation, Helium, Earth-Surface Processes, Water Science and Technology, Ecology, business.industry, Giant planet, Paleontology, Forestry, Computational physics, Geophysics, chemistry, Space and Planetary Science, business, Microwave
Abstract

Microwave spectral measurements have been performed on pure room-temperature gaseous ammonia at frequencies from 1.75 to 18 GHz (1.7-17 cm), at 50-, 100-, and 300-torr pressures. These measurements are part of a laboratory program to measure the microwave absorption spectrum of ammonia, under conditions applicable to giant planet atmospheres, now in progress at the Jet Propulsion Laboratory. The pure ammonia data reported here agree well with previous data by Bleaney and Loubser (1950) at 100 and 300 torrs, and with predictions of the absorptivity formalism published by Berge and Gulkis. Success with pure ammonia but failure with mixtures of ammonia in hydrogen and helium (Spilker, 1990) indicates that the Berge and Gulkis formalism does not correctly handle foreign-gas effects on ammonia inversion lines. This may require modifying conclusions of radio astronomical and radio occultation studies that used this formalism. Notably, a suggested depletion of ammonia and superabundance of hydrogen sulfide may have been exaggerated as a result of inaccuracies in the Berge and Gulkis formalism.

Published
1993
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49. Interlaboratory trial on the analysis of alkylphenols, alkylphenol ethoxylates, and bisphenol A in water samples according to ISO/CD 18857-2

Author

I. Heinz, O. P. Heemken, H. Allmendinger, Enrico Veschetti, S. Frey, G. Donnevert, H. Woldmann, P. Hendel, A. Koch, R. Spilker, B. Jandel, G. Sawal, M. Ottaviani, V. Tobinski, W. Hartl, S. Geiss, C. Benthe, Cariton Kubwabo, R. Donau, and E. Stottmeister

Subjects
Detection limit, Chromatography, Alkylphenol, Chemistry, Elution, Gas Chromatography-Mass Spectrometry, Analytical Chemistry, Nonylphenol, chemistry.chemical_compound, Phenols, Limit of Detection, Water Pollutants, Solid phase extraction, Round robin test, Gas chromatography, Benzhydryl Compounds, Derivatization
Abstract

ISO/CD 18857-2 (International Organization for Standardization, Geneva) describes a new international standard method for the determination of octylphenol, nonylphenol, their mono- and diethyoxylates, and bisphenol A in nonfiltered samples of drinking, ground, surface, and wastewater. The method is based on the extraction of the analytes from an acidified water sample by solid phase extraction, solvent elution, derivatization, and determination by gas chromatography with mass spectrometric detection. For validation of this method, 14 laboratories from 4 different countries in Europe and Canada participated in an interlaboratory trial to determine the performance characteristics of the method, which are intended for publication in the corresponding standard. The interlaboratory trial was evaluated according to ISO 5725-2 and included two duplicate nonfiltered water samples: surface water containing the target compounds in an analyte concentration range from 0.05 to 0.4 microg/L and wastewater containing the target compounds in a concentration ranged from 0.1 to 5 microg/L. The repeatability variation coefficients (within-laboratory precision) varied for all samples and compounds between 1.9 and 7.8%, showing a sufficiently high repeatability of the method. The reproducibility variation coefficients (between-laboratory precision) were found to vary within a satisfactory range of 10.0-29.5% for surface water and 10.8-22.5% for wastewater. The recoveries as a measure of accuracy varied from 98.0 to 144.1% for surface water and from 95.4 to 108.6% for wastewater. The determined concentrations of the samples compared well to the "true" values, thus showing very satisfactory accuracy of the method. In the chromatogram of the surface water sample, a high unresolved background made up of coextractable matrix compounds was apparent. It is conceivable that compounds from this background may be responsible for enhanced recoveries of 144.1% for 4-nonylphenol (mixture of isomers) and of 123.4% for 4-nonylphenol monoethoxylate (mixture of isomers) in the surface water samples. The isotope-marked standard compounds developed in this context proved to be reliable internal standards that allow a precise and accurate quantitation of all compounds specified in ISO/CD 18857-2. The results of the interlaboratory trial confirmed that the analytical method is robust and reliable and can be used as a standard method to analyze the target compounds in water samples.

Published
2009

50. Analysis of architectures for the scientific exploration of Enceladus

Author

Robert C. Moeller, William D. Smythe, Nathan Strange, John Elliott, J.A. Wertz, Robert E. Lock, T. R. Spilker, and Chester Borden

Subjects
Class (computer programming), business.industry, Saturn, Suite, Timeline, Aerospace engineering, Architecture, business, Space research, Enceladus, Space exploration
Abstract

In 2007 a JPL Rapid Mission Architecture (RMA) analysis team identified and evaluated a broad set of mission architecture options for a suite of scientific exploration objectives targeting the Saturnian moon Enceladus. Primary science objectives were largely focused on examination of the driving mechanisms and extent of interactions by the plumes of Enceladus recently discovered by Cassini mission science teams. Investigation of the architectural trade space spanned a wide range of options, from high-energy flybys of Enceladus as a re-instrumented expansion on the Cassini mission, to more complex, multi-element combinations of Enceladus orbiters carrying multiple variants of in-situ deployable systems. Trajectory design emerged as a critical element of the mission concepts, enabling challenging missions on Atlas V and Delta IV-Heavy class launch vehicles. Various Enceladus Flagship-class mission concepts identified were analyzed and compared against several first-order figures of merit, including mass, cost, risk, mission timeline, and associated science value with respect to accomplishment of the full set of science objectives. Results are presented for these comparative analyses and the characterization of the explored trade space.

Published
2009
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