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This paper proposes an improved method for the preliminary evaluation of minimum-propellant trajectories to Near-Earth Asteroids (NEAs). The method applies to missions from Earth to asteroids with small eccentricity and inclination. A planar and a plane-change problem can be distinguished. In the planar problem, the solution assumes that multiple burn arcs are performed in correspondence of the apsides of the target asteroid in order to change the initial spacecraft orbit (i.e., Earth’s orbit) into the target one. The number of arcs is established once the time of flight is given (1 burn at each apsis per revolution, 1 revolution per year can be assumed). The length and propellant consumption of each arc to attain the required changes of semi-major axis and eccentricity are computed by a procedure based on Edelbaum’s approximation, which is well-suited to the problem at hand, as eccentricity changes are expected to be small for feasible missions. No numerical integration is required, but only the numerical solution of a three-unknown algebraic system is needed, making the procedure extremely fast. Plane change is taken into account assuming a constant out-of-plane thrust angle during each burn. A previous simple formulation used an averaged thrust effect over one revolution and neglected the fact that plane changes are more effective at the nodes. Several improvements are here introduced, which greatly increase the method accuracy. The influences of the eccentricity change, the angle between the asteroid line of nodes and line of apsides, and the expected length of the arc are considered: In fact, when the eccentricity is small, the thrust arc can be performed at the nodes where the inclination is efficiently changed, with little penalty in the planar maneuver. An efficient plane change is also performed when the angle between the asteroid line of nodes and line of apsides is small and/or the length of the arc is large, because, in this case, the node is comprised in the apsidal burn. A simple corrective formula accounts for this effect. The new method shows remarkable accuracy. The results comparison with solutions obtained with an indirect optimization method for a set of more than 60 NEAs shows a 0.95 correlation coefficient in the propellant masses. The estimation error is below 10% for 75% of the targets, below 15% for 95% of the targets, and always below 20%.

The Miniaturised Asteroid Remote Geophysical Observer (M-ARGO) mission is designed to be ESA’s first stand-alone CubeSat to independently travel in deep space with its own electric propulsion and direct-to-Earth communication systems in order to rendezvous with a near-Earth asteroid. Deep-space Cubesats are appealing owing to the scaled mission costs. However, the operational costs are comparable to those of traditional missions if ground-based orbit determination is employed. Thus, autonomous navigation methods are required to favour an overall scaling of the mission cost for deep-space CubeSats. M-ARGO is assumed to perform an autonomous navigation experiment during the deep-space cruise phase. This paper elaborates on the deep-space navigation experiment exploiting the line-of-sight directions to visible beacons in the Solar System. The aim is to assess the experiment feasibility and to quantify the performances of the method. Results indicate feasibility of the autonomous navigation for M-ARGO with a 3σ accuracy in the order of 1000 km for the position components and 1 m/s for the velocity components in good observation conditions, utilising miniaturized optical sensors.

The near-Earth objects with low-Jovian Tisserand invariant (TJ) represent about 9 per cent of the known objects orbiting in the near-Earth space, being subject of numerous planetary encounters and large temperature variations. We aim to make a spectral characterization for a large sample of NEOs with TJ ≤ 3.1. Consequently, we can estimate the fraction of bodies with a cometary origin. We report new spectral observations for 26 low-TJ NEOs. The additional spectra, retrieved from different public data bases, allowed us to perform the analysis over a catalogue of 150 objects. We classified them with respect to Bus-DeMeo taxonomic system. The results are discussed regarding their orbital parameters. The taxonomic distribution of low-TJ NEOs differs from the entire NEOs population. Consequently, TJ ∼ 3 can act as a composition border too. We found that 56.2 per cent of low-TJ NEOs have comet-like spectra and they become abundant (79.7 per cent) for TJ ≤ 2.8. 16 D-type objects have been identified in this population, distributed on orbits with an average TJ = 2.65 ± 0.6. Using two dynamical criteria, together with the comet-like spectral classification as an identification method and by applying an observational bias correction, we estimate that the fraction of NEOs with a cometary nature and H ∈ (14, 21) mag has the lower and upper bounds (1.5 ± 0.15) and (10.4 ± 2.2) per cent. Additionally, our observations show that all extreme cases of low-perihelion asteroids (q ≤ 0.3 au) belong to S-complex.

Statler et al., NASA’s Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to ∼10% and characterization of the Didymos binary system. But DART is a single experiment; how could these results be used in a future planetary defense necessity involving a different asteroid? We examine what aspects of Dimorphos’s response to kinetic impact will be constrained by DART results; how these constraints will help refine knowledge of the physical properties of asteroidal materials and predictive power of impact simulations; what information about a potential Earth impactor could be acquired before a deflection effort; and how design of a deflection mission should be informed by this understanding. We generalize the momentum enhancement factor β, showing that a particular direction-specific β will be directly determined by the DART results, and that a related direction-specific β is a figure of merit for a kinetic impact mission. The DART β determination constrains the ejecta momentum vector, which, with hydrodynamic simulations, constrains the physical properties of Dimorphos’s near-surface. In a hypothetical planetary defense exigency, extrapolating these constraints to a newly discovered asteroid will require Earth-based observations and benefit from in situ reconnaissance. We show representative predictions for momentum transfer based on different levels of reconnaissance and discuss strategic targeting to optimize the deflection and reduce the risk of a counterproductive deflection in the wrong direction., This work was supported in part by the DART mission, NASA contract No. 80MSFC20D0004 to JHU/APL. Some of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). S.C. acknowledges funding through the Crosby Fellowship of the Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology. E.D., S.I., A.L., M.P., A.R., and P.T. are grateful to the Italian Space Agency (ASI) for financial support through agreement No. 2019-31-HH.0 in the context of ASI’s LICIACube mission, and agreement No. 2022-8-HH.0 for ESA’s Hera mission. R.L. appreciates the funding from the European Union’s Horizon 2020 research and innovation program, grant agreement No. 870377 (project NEO-MAPP). P.M. acknowledges funding support from the French space agency CNES, ESA and the European Union’s Horizon 2020 research and innovation program under grant agreement No. 870377 (project NEO-MAPP). R.M. acknowledges support from a NASA Space Technology Graduate Research Opportunities (NSTGRO) Award (80NSSC22K1173). R.N. acknowledges support from NASA/FINESST (NNH20ZDA001N). J.O. and I.H. were supported by the Spanish State Research Agency (AEI) project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”—Centro de Astrobiología (CSIC-INTA). They are also grateful for all logistical support provided by Instituto Nacional de Técnica Aeroespacial (INTA). S.R.S. acknowledges support from the DART Participating Scientist Program, grant No. 80NSSC22K0318. J.M.T.R. was funded by FEDER/Ministerio de Ciencia e Innovación—Agencia Estatal de Investigación of Spain (grant No. PGC2018-097374-B-I00).

Photometric observations of the nearly equal-mass binary near-Earth asteroid 2017 YE5 were carried out at the Observatório Astronômico do Sertão de Itaparica (OASI, Brazil) and at the Blue Mountains Observatory (BMO, Australia) between 2018 July and August, shortly after it made a close approach to Earth in 2018 June. These observations allowed to determine an orbital period of the system in good agreement with the result of the radar observations. Our results also indicate that the 2017 YE5 system is not fully locked in a synchronous spin–orbit resonance, as there is a possible asynchronous component or tumbling rotator in the system. Additional data obtained at the Observatorio Astronómico Nacional de San Pedro Mártir (OAN-SPM, Mexico) in 2018 August allowed to derive the colour indices and the low-resolution spectrum, which indicate that the object has a very reddish surface similar to the outer Solar system objetcs. This is consistent with a dark albedo of about 3 per cent, derived from an effective diameter of the combined components and an absolute magnitude of 19.2. Infrared data obtained at the NASA’s Infrared Telescope Facility exhibit a thermal emission in the 2.5 $\mu$m range for which a low albedo of 2–4 per cent was adjusted by applying a thermal model. Regarding to the taxonomic classification, we found that the 2017 YE5 is a D-type in the Bus-DeMeo taxonomy. Therefore, according to our results and considering that the 2017 YE5 system has a typical comet orbit (TJ = 2.87), we suggest that it is a dormant Jupiter-family binary comet.

The Miniaturised Asteroid Remote Geophysical Observer (M-ARGO) is planned to be the first standalone deep-space CubeSat mission to rendezvous with and characterise a near-Earth asteroid. To this aim, it is essential to assess the attainable set of target asteroids. This work presents the initial results of the mission analysis and design of M-ARGO. In particular, the original procedure developed to extract the reachable near-Earth asteroids and the subsequent down-selection process are shown. Hundreds of both time- and fuel-optimal low-thrust trajectory optimisation problems have been solved with an indirect approach, targeting asteroids pre-filtered from the Minor Planet Center Database. The method implements a realistic thruster model, featuring variable input power, thrust, and specific impulse, together with an accurate switching detection technique and analytic derivatives. The analysis shows that approximately 150 minor bodies are found potentially reachable by M-ARGO when departing from the Sun–Earth Lagrange point L 2 within a 3-year transfer duration. A manual inspection of the transfer features led to a subset of 41 targets seeming more promising according to mission technological requirements and constraints. Initial results indicate mission feasibility for M-ARGO, which has the potential to enable a completely new class of low-cost deep-space exploration missions.

We consider some aspects of the dynamic evolution of the population of near-Earth asteroids (NEAs): the change of the rate of NEA depletion with time, including the dependence of the rate on the initial parameters of the NEA orbits, the efficiency of various channels of NEA depletion, and diffusion of NEA orbits. We studied both real asteroids and a simulated population. For the study, 3024 real asteroids larger than 1 km with a perihelion distance $$q < 1.6$$ A.U. were selected, of which 833 NEAs had $$q < 1.3$$ , i.e., we explored almost all large NEAs. For some tasks, the population of NEAs was also modeled using NEOPOP (ESA) code. The orbits were integrated for 10 Myr using the REBOUND numerical complex. The solar gravitational field and field of planets, as well as the possibility of collisions, were considered. It is shown that the total population of NEAs has the median time of depletion $${{t}_{{{\text{NEA}}}}} \simeq 3.5$$ Myr; this rectifies the estimates of other authors. The main advantage of the present study is that, for the first time, the dependence on the initial values ​​of the orbital parameters—semi-major axis of the orbit and eccentricity was investigated. It is shown that this dependence is very strong: for the subset of asteroids with large $$a$$ and $$e$$ , $${{t}_{{{\text{NEA}}}}}$$ it is dozens of times lower than for the subset with small $$a$$ and $$e$$ . Obtained qualitative estimates of the dependence $${{t}_{{{\text{NEA}}}}}(a,\;e)$$ are important for the quantitative analysis regarding the various model adequacy of mechanisms of replenishing the population of NEAs. The details of the diffusion (mixing of parameters) of the asteroid orbits in the plane “a–e” in the process of evolution have been studied. During the integration time, 10% of the NEAs were ejected from the Solar System, 1.5% fell onto the planets (including 0.2% onto the Earth), 17% fell onto the Sun, and 12.5% ​​left the NEAs zone.

Funding Information: To achieve these objectives, Milani is carrying two scientific payloads, the ASPECT visual and near-infrared (Vis-NIR) imaging spectrometer and the VISTA thermogravimeter aimed at collecting and characterizing volatiles and dust particles below 10 μm. Additionally, navigation payloads include a visible navigation camera and lidar. The Milani consortium is composed of entities and institutions from Italy, the Czech Republic, and Finland. The consortium Prime is Tyvak International, responsible for the whole program management and platform design, development, integration, testing, and final delivery to the customer. Politecnico di Torino is tasked with defining requirements and performing thermal, radiation, and debris analysis. Politecnico di Milano is responsible for mission analysis and GNC. Altec will support the Ground Segment architecture and interface definition. Centro Italiano per la Ricerca Aerospaziale (CIRA) is responsible for the execution of the vehicle environmental campaign. HULD contributes to developing the mission-specific software. VTT is the main payload (ASPECT hyperspectral imager) provider and is supported by the following entities dealing with ASPECT-related development: University of Helsinki (ASPECT calibration); Reaktor Space Lab (ASPECT Data Processing Unit development), Institute of Geology of the Czech Academy of Sciences (ASPECT scientific algorithms requirements and testing); and Brno University of Technology (ASPECT scientific algorithms development). INAF-IAPS is the secondary Payload (VISTA, dust detector) provider. Funding Information: The Mission PI is appointed by ESA and is the primary interface to ESA. The Hera SMB consists of the ESA Hera Project Scientist (ESA PS), the Mission PI, and the Hera Advisory Board, consisting of four mission advisors. The Mission PI chairs the HIT and is supported by the Hera Advisory Board. The tasks of the Hera SMB are 1. advising the Hera mission project team on all aspects related to the Hera mission objectives; 2. ensuring that the WGs’ activities cover the needs of the Hera mission; 3. providing recommendations to ESA concerning the membership in the HIT; and 4. implementing the Publication Policy. Funding Information: Hera is the ESA contribution to the AIDA collaboration. Hera, Juventas, Milani, and their instruments are developed under ESA contract supported by national agencies. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 870377 (project NEO-MAPP), the CNRS through the MITI interdisciplinary programs, ASI, CNES, JAXA, the Academy of Finland project no. 335595, and was conducted with institutional support RVO 67985831 of the Institute of Geology of the Czech Academy of Sciences. M.L., E.P., P.T .and E.D. are grateful to the Italian Space Agency (ASI) for financial support through Agreement No. 2022-8-HH.0 in the context of ESA’s Hera mission. We are grateful to the whole Hera team, including Working Group core members and other contributors for their continuous efforts and support. Their names can be found on the following website: https:// www.heramission.space/team. Publisher Copyright: © 2022. The Author(s). Published by the American Astronomical Society. Hera is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October. It will rendezvous in late 2026 December with the binary asteroid (65803) Didymos and in particular its moon, Dimorphos, which will be impacted by NASA’s DART spacecraft on 2022 September 26 as the first asteroid deflection test. The main goals of Hera are the detailed characterization of the physical properties of Didymos and Dimorphos and of the crater made by the DART mission, as well as measurement of the momentum transfer efficiency resulting from DART’s impact. The data from the Hera spacecraft and its two CubeSats will also provide significant insights into asteroid science and the evolutionary history of our solar system. Hera will perform the first rendezvous with a binary asteroid and provide new measurements, such as radar sounding of an asteroid interior, which will allow models in planetary science to be tested. Hera will thus provide a crucial element in the global effort to avert future asteroid impacts at the same time as providing world-leading science.

The presented study examines contingency target selection and trajectory design for NASA’s Near-Earth Asteroid Scout mission under the assumption of a missed lunar gravity assist. Two previously considered asteroids are selected as potential targets for the given scenario based on favorable orbital characteristics for launch dates ranging from June 27, 2020 through July 26, 2020. Initially, a simplified circular restricted 3-body problem + ideal solar sail model is utilized to survey trajectory options for a month-long launch window. Selected solutions from this data set are then converged in an N-body ephemeris + non-ideal sail model. Results suggest that NEA Scout can still perform asteroid rendezvous mission under the missed lunar gravity assist scenario with new targets, 2019 GF1, 2018 PK21, and 2007 UN12, based on the target launch dates. Further target assessment is carried out for 165 days beyond the current June 27, 2020 launch date.

Asteroid mining has the potential to greatly reduce the cost of in-space manufacturing, production of propellant for space transportation and consumables for crewed spacecraft, compared to launching the required resources from the Earth’s deep gravity well. This paper discusses the top-level mission architecture and trajectory design for these resource-return missions, comparing high-thrust trajectories with continuous low-thrust solar-sail trajectories. The paper focuses on maximizing the economic Net Present Value, which takes the time-cost of finance into account and therefore balances the returned resource mass and mission duration. The different propulsion methods are compared in terms of maximum economic return and sets of attainable target asteroids. Results for transporting resources to geostationary orbit show that the orbital parameter hyperspace of suitable target asteroids is considerably larger for solar sails, allowing for more flexibility in selecting potential target asteroids. Also, results show that the Net Present Value that can be realized is larger when employing solar sailing instead of chemical propulsion. In addition, it is demonstrated that a higher Net Present Value can be realized when transporting volatiles to the Lunar Gateway instead of geostationary orbit. The paper provides one more step towards making commercial asteroid mining an economically viable reality by integrating trajectory design, propulsion technology and economic modelling.

Small Celestial Bodies (SCBs) like Near Earth Asteroids (NEAs) as potential destinations for in-situ resource utilization form an integral part of establishing a sustainable human presence beyond the cis-lunar space. Autonomous navigation and distributed spacecraft architecture have been widely recognized as the most crucial technologies essential for executing sophisticated mission tasks in the proximity of these bodies. Current semi-autonomous methods used for proximity navigation require an initial mapping phase and ground intervention that are impediments for large scale missions envisioned for the future. This paper presents a method based on Simultaneous Localization and Mapping (SLAM) for a fully autonomous navigation of distributed spacecraft in SCB orbits. The spacecraft initially navigate independently using SLAM in separate local frames. Once sufficient landmarks have been encountered by the spacecraft, a map merging process that utilizes the common landmarks observed by all the spacecraft as pivots is invoked to consolidate the navigation models and state estimates from all the spacecraft in a common frame. The navigation process then proceeds in this common frame. The utility of the algorithm is assessed with a simulation experiment considering two spacecraft in orbit around a NEA. The results from the simulation indicate the suitability of the proposed method for proximity navigation and its prospects for further development.

Asteroid exploration missions must deal with large uncertainties in a target body’s gravity and shape as well as ephemeris errors upon rendezvous. Navigation and guidance are typically performed us...

There are currently over 20,000 known Near-Earth asteroids (NEAs) and more are being discovered on a daily basis. Near earth asteroids are the small bodies whose orbits bring them to within 1.3 AU of the Sun, which makes each one a useful opportunity for science and commercial missions. Here we design and generate a trajectory database for mining mission planning by using a high-performance computing system. The database contains 6373 accessible NEA missions with maximum mission durations of 6 years in the 2030–2065 timeframe. The accessible asteroids’ statistical results show that about 55% of accessible NEAs can provide stay-time of over 4 years in a 6-year mission. A general mining mission architecture is then proposed, and missions are constructed by using the architecture and the database. The taxonomy results for accessible asteroids from major taxonomy systems are summarized, and the available resources on these asteroids are analysed based on the taxonomy information. For the first time, the entire NEA population is assessed realistically from the perspective of asteroid mining and retrievable mass from each asteroid is quantified. Suitable targets for mining water, PGMs and other resources (e.g. silicates) in the 2030–2065 timeframe are identified. For the asteroids without taxonomy information, we did two analyses: assuming i) they are all C-type and ii) all non-C-type. Based on these assumptions, most suitable targets for water and non-water resource mining are identified. These results can be used as guidance for future asteroid mission target selection.

Sun–Earth/Moon L 4 and L 5 axial orbits provide ideal locations to monitor and search for near Earth asteroids. In this paper, an unstable L 5 axial orbit is selected as the target orbit, and then we first investigate transfers from the Earth to the target axial orbit in the ephemeris model. Based on the dynamical structure, we employ stable manifolds associated with the target axial orbit and lunar flyby technique in the preliminary design process. Then, we implement the multiple-shooting differential correction to refine the lunar flyby transfer orbit in the ephemeris model based on the preliminary design. Through a refinement strategy we proposed, a four-impulse lunar flyby transfer orbit from the initial low Earth orbit to the target axial orbit is obtained in the ephemeris model. Finally, we apply the optimal control method to design a low-thrust transfer for a small satellite to the target axial orbit based on the four-impulse transfer orbit. We obtain a low-thrust end-to-end transfer orbit with three thrust arcs via the optimization piece by piece. Numerical results indicate that the lunar flyby plays an important role in the low-thrust transfer orbit, and helps us efficiently decrease the fuel consumption.

Asteroid research is of global security interest, we are more afraid about any impact of these asteroids on Earth. We seek through this work to provide a study on the effect of the asteroid’s shape on the gravity aspect. Knowledge of the potential is crucial to bodies approaching the asteroid. There is a range of asteroid shapes to consider. Some well-known asteroids such Ceres, Vesta, Iris and Oumuamua are considered in this study. After determining the moment of inertia of the asteroids depending on their materials, the gravity fields and the potential gravity of the asteroids are established when varying their shapes. A representation of the gravity field is given in three dimensional coordinate systems. Also, the behavior of the potential gravity is drawing in the function of the object’s location. The second part is dealing with the interpretation of all the obtained results in order to deduce some rules and features which would be useful for the identification of the asteroids. Thus, by the best knowledge of the effect of the asteroid’s shape, we would be more informed in the survey of the hazardous near earth objects.

Compared with planets and their moons, small bodies retain the characteristics of their early formation. Therefore small bodies, especially Near Earth Asteroids (NEA), have become one of the most valuable targets in space exploration. This paper presents a review of the current status of small body exploration, including the science objectives, main optical imaging instruments and the main scientific results obtained from the relevant exploration missions in the past two decades. Then, it outlines and discusses future missions to small bodies by different space agencies, including those already planned and under development. Finally, it discusses the trend of optical imaging instrument development for exploring small bodies.

A novel concept for asteroid orbit control by restructuring asteroid surfaces to manipulate albedo and respective radiation pressure effects is introduced. The method itself is propellant-less allowing for prolonged operation and permitting the adaption and even reversing reflection changes. Microscopic restructuring of asteroid surface material allows further for asymmetric manipulation of reflective properties, which can be exploited for influencing orbit and attitude parameters. Asymmetric radiation pressures are well known for their ability to change the orbit of an asteroid through the Yarkovsky effect or rotational parameters by the YORP effect. It is shown that in the simplest form albedo manipulation of a solid surface asteroid can be achieved with a single spacecraft mission. A spacecraft will locally focus energy from a very low (pseudo-)orbit onto the asteroids surface. One technology candidate are CO2 laser systems, while other options exist. First, CO2 laser are used as conventional laser engravers to brighten mineralic and metallic surfaces. Second, CO2 laser cleaning systems are often used to remove silicate residue of industrial processes. It is calculated that an asteroid with a high albedo will experience significantly less Yarkovsky forces, resulting in reduced orbit drift and improved future predictability. Laser technology can further be exploited to create surface structures that represent an asymmetric saw tooth pattern (i.e. repeating sharp right triangles) by using femto second laser pulses or by an angled focal point. This asymmetric surface pattern leads to an angular dependent reflectivity, which can be exploited to create radiation pressure differences. When properly applied, countering spin-rate changes and rotation axis drift of the YORP effect is possible. A preliminary analysis indicates feasibility for a medium size probe equipped for laser treatment of Near Earth Object surfaces.

In cooperation with Russia, the Brazilian deep space mission ASTER plans to send a small spacecraft to investigate the triple asteroid 2001-SN263. The nearest launch opportunities for this project include June 2022 and June 2025. One main exploration campaign is being planned with focus on the largest asteroid (Alpha). Among the instruments under development, a laser altimeter (named ALR) was preliminarily designed and presented in 2010–2011. Many studies to define mission and instruments requirements were performed aiming at the characterization of important issues for the successful realization of the mission. Among them, the identification of a suitable trajectory that could be followed by the ASTER spacecraft in the encounter phase, when the main campaign will take place. This paper describes the effort undertaken with focus on the laser altimeter operation. Possible encounter trajectories were modelled and simulated to identify suitable approach parameters and conditions allowing the accomplishment of the intended investigation. The simulation also involves the instrument operation, considering approach geometry, attitude, relative motion, time/date, and the dynamics of the main asteroid. From the laser altimeter point of view, keeping in mind the desired coverage results (50% minimum surface coverage of asteroid Alpha, complying with horizontal and vertical resolution requirements), results point out crucial features for the encounter trajectory, like the need for a small inclination (10-6 degrees; with respect to the asteroid's orbit), the most favourable spacecraft positioning (between the Sun and the asteroid) and pointing condition (back to the Sun), the minimum amount of achievable surface coverage (58%, focused on central areas), and the most proper time to conduct the main campaign (January 2025). Concerning the instrument, results offer refined values for divergence angle (500 to 650 μrad, half-cone), pulse repetition frequencies (from 1/20 to 1 Hz), and consequent data generation rates. A simulation tool that can use any 3D generated trajectories as input data was created for the analyses presented here. Although created for the ALR in this mission, this simple analysis tool can be adapted to other instruments in this or other missions.

This study is focused on the relationships between the κ-Cygnid meteor shower and different groups of asteroids crossing the Earth’s orbit (the so-called near-Earth objects (NEOs)). The analysis is based on the visible structure of the meteor shower and a comprehensive strategy for estimating the proximity of orbits of two bodies. The κ-Cygnid meteor shower (abbreviated as KCG) is observed from August 3 to August 25 every year; it is classified as a minor shower, and the size of its mean orbit is around 3.2 AU, while the geocentric velocity is 20.9 km/s. No parent body (PB) of the shower has been found among comets so far. Relationships between the shower and asteroids, as potential PBs of the shower, are under active examination; some hypotheses on this subject can be found on the website of the Meteor Data Center (MDC) of the International Astronomical Union (IAU).

The orbital siphon is a novel concept for propellantless payload transfer from the surface of a rotating body to orbit. In the context of asteroid mining, the orbital siphon represents an efficient...

The present study investigates the feasibility of deploying multiple CubeSats from low Earth orbit to near-Earth asteroids for an increased scientific return and reduced mission costs. It is found ...

Depletion of minerals and other non-renewable resources has long been a source of worry to industrial economies. This worry waxes when markets are tight and wanes when they are not. However, evidence has continued to mount that there are staggering amounts of minerals in space that are technically within our grasp. Scientific work has considered mineral availability and technical ability to mine on near earth objects. Within the last decade, a number of space related industries have gained attention. While availability and technical feasibility are both necessary conditions for this industry to develop, they are not sufficient. Rather sufficiency also requires financial feasibility. Although studies have considered the costs of mining asteroids, we are aware of no papers that model the effects on terrestrial mineral market structure with the injection of extra-terrestrial minerals. Our contribution is to consider the current state of mineral markets and provide a model of firm entry to derive implications to the market from space mined minerals entering the market. We provide a numerical simulation to demonstrate what prices asteroidal entrants might face for the injection of a variety of metals and provide an online model for others to change inputs to their asteroid and metals of choice.

A modified method for identifying and studying secular resonances in the dynamics of near-Earth objects is described. Unlike the traditionally used approach based on approximate analytical formulas for calculating secular frequencies that are valid only for small eccentricities, the proposed method uses exact values obtained in the process of numerical simulation of the motion from the Newton–Euler equations. This technique can be used to analyze the dynamics of objects with any arbitrary eccentricities of the orbits, but its application to the study of the motion along orbits with large or rapidly growing eccentricities is most interesting. Testing is carried out on the example of research of the Lidov–Kozai resonances in the dynamics of near-Earth objects.

Objectives The subject of the study are space threats – Near-Earth Objects (NEO) and Potentially Hazardous Asteroids (PHA). Methods The research methods employed in this article included the classic theoretical methods used in security sciences and a practical method – a quantitative study of social media. Results At present, space threat studies aim to resolve the terminological confusion related to NEOs, determine currently and potentially hazardous space objects and estimate the potential threats they could cause. Another expected result of the research is to present two literature methods for estimating NEO threats, the Palermo and Torino scales. The practical result is to evaluate public mood regarding NEO threats. Conclusions Studies have shown that certain active space objects are capable of reaching the Earth's surface or impacting human-made in-space objects and devices, such as communication satellites. Should it happen, it could cause substantial social damage and destabilise state security, particularly if elements of critical infrastructure of the state were to be affected. Continuous monitoring of NEOs may play a central role in the provision of security. Furthermore, the public should be kept abreast of the threats.

Fifteen orbital clusters (associations) were identified among ~20000 near Earth asteroids (NEAs). All associations were found with a high statistical reliability using a single linkage cluster analysis algorithm and three orbital similarity functions. The identified groups constitute a small fraction (4.74 %) of the entire sample. Nonetheless they may be hazardous to the Earth and its inhabitants. As it happens with meteoroid streams, every year the Earth comes very close to the orbits of each association. In two cases (2008TC3 and 2017FU102) the distance between the asteroid's and the Earth's orbits was smaller than our planet's radius. Among the members of the identified associations we found 331 objects larger than the Chelyabinsk asteroid and all of them approach the Earth's orbit at a distance smaller than 0.05 [au]. Two of the identified groups (4179) Toutatis and (251430) Itokawa support catastrophic origins of Toutatis and Itokawa asteroids. This study does not focus on the origin of the NEA associations, but on tracing them. Regardless of their origin, the identified groups pose a serious threat to the Earth. Hence, to facilitate their monitoring of we calculated coordinates of the theoretical radiants and calendar dates of their potential activity., Comment: 14 pages, 19 figures

As one of the secondary payloads on the space launch systems vehicle, the Near-Earth Asteroid (NEA) Scout will demonstrate a low-cost and innovative approach to deep space reconnaissance missions. The main objective is to image and characterize a Near-Earth asteroid. The spacecraft packages a full deep space mission into the volume of a 6U CubeSat. To enable long-term sustained propulsion to the target, a solar sail is utilized as the main propulsion system. The spacecraft bus is single string, with compact avionics. Guidance and control performance meets science requirements with margin, but limited power impacts the amount of science data that can be returned, an aspect that is in part mitigated by the introduction of novel on-board data analysis software. Following in the recent footsteps of the Mars Cube One (MarCO) mission, the first deep space CubeSat demonstration, which included the infusion of the Iris radio; the NEA Scout will continue to blaze the trail for small CubeSats for interplanetary science and reconnaissance missions. This article will provide an overview of the mission, flight system design, and unique features needed for science and propulsion.

Near Earth Asteroids (NEAs) have become a hot topic these years for their scientific interests and technological accessibility. Manned NEA mission is a good choice for asteroid on-site exploration as well as a stepping stone for future manned deep space missions. Focusing on manned NEAs mission architecture analyzing, this paper uses the mission architecture matrix (MAM) method to reduce mission mass scale, for available studies show that simple mission architectures achieving NEAs all require LEO launching mass exceeding available space carrying capacity. By developing a series of mission architectures based on manned spacecraft system design method, the mass scale is estimated according to mission data of 63 most accessible NEA targets. It is discovered that with advanced mission architectures, maximum LEO launching mass can be significantly reduced by separate launching, rendezvous, and docking. The original on-orbit mass about 300–400 metric tons (mT) is reduced to 200–250 mTs, and the maximum launching mass is reduced to only about 70–100 mTs in several cases. This provides us a high possibility to launch manned NEA missions in the near future. In addition, this method can be used in mission mass scale analysis to other deep space targets. Advanced mission architecture also brings challenges on reliability, which plays another key role in mission design. The balance between mass scale and reliability needs to be kept in future works.

Space-related hazards come from both natural and man-made sources; these hazards pose risks based on the likelihood of exposure and consequence of that exposure. The use of satellites in Earth orbit is now essential to the functioning of nation-states and commerce. The loss of these resources increases global risk as both the world population and global reliance on technology increase. Risks from natural cosmic threats from outside the confines of Earth include asteroids (i.e., Near Earth Objects, NEOs), solar flares, and coronal mass ejections (CMEs). Threats from Near-Earth Objects (NEOS) are becoming clearer as our ability to detect and characterize them improves. Space weather, driven largely by solar dynamics, and changes to the Earth's magnetic field that could decrease the natural protective shielding of Earth against solar storms, likewise threaten our planet. At the same time, the risk to the world's population from catastrophes originating from human activity, war, pandemics, geophysical phenomena, weather, and other Earth-based risks appear to be increasing. As the global population has increased from 800 million in 1800 to nearly eight billion in 2019, the number of people whose lives might be affected by these low probability and high consequence events has risen significantly. While it is difficult to precisely determine the effect of any of these risks individually, it can be instructive to create a common framework that allows comparison of a diverse set of hazards to evaluate risk awareness, mitigation, and remediation. These hazards span from high probability, moderate consequence events to low probability high consequence scenarios. The Global Risk Continuum (GRC) presents individual scenarios within these threat classes along a single risk scale. As a first step in this analysis, a GRC is created by independently determining the probability for each type of event, and the consequence of each as represented in an estimated economic impact. The risk is then determined by taking the product of these two terms. Assumptions and conversion factors needed to enable this common baseline and preliminary observations of the results are provided. This is a "work in progress" that will require significant cooperation and collaboration to refine over time into a useful tool for policymakers, scientists, and others. The process of establishing 'estimates' of risk is an iterative process that will evolve and improve over time. This paper describes a thought process and the beginnings of a methodology rather than a complete tool for global risk assessment.

A near-Earth object (NEO) is any small Solar system body whose orbit brings it to proximity with Earth. Currently, more than 20000 NEOs are detected, most of which have diameters less than 1 km. The study of NEOs is significant to understand the solar system. NEOs formed in the very early stage of solar system according to isotope dating, and remain most original material in proto-planetary disk. Thus, the study of NEOs can reveal the components of early solar system. Besides, NEOs are also important to explain the formation of Earth-Moon systems in giant impact hypothesis, i.e., a mar-size asteroid hit Earth 4.5 billion years ago and the fragments around Earth formed Moon via gravitational accretion. Furthermore, survey of NEOs is also important for human beings, because of the potentially hazardous objects (PHOs), which lead to the Cretaceous-Paleogene (K-Pg) extinction event, as well as the Tunguska event. Fortunately, we have lots of NEO survey programs, e.g., Catalina Sky Survey, Near-Earth Asteroid Tracking, Pan-STARRS, Zwicky Transient Facility in ground, and Near-Earth Object WISE in space with near infrared telescope, etc. These projects provide a nearly completed catalog for NEOs with diameter>1 km. We can determine the orbits of these NEOs via the astrometric time series data. However, lots of smaller NEOs with diameter millions tons) of the asteroid. Besides, the big fragments of the asteroid after explosion may lead to more impacts on Earth and make conditions worse. Better forethought plans need experts in astronomy, geology, life science, climatology etc., to discuss together. The NEOs may be harmful if it impacts Earth. However, the resources on asteroid, e.g., water, metal can be utilized by human beings. Utilizing the resources in space is the only way to break through the limits of Earth’s resources, and extend the footprint of human being further in space. Currently, some companies are set up and aim to mine on asteroids, e.g., the Planetary Resources Company and the Deep Space Industries. Chinese people also set up a company named Origin Space to study the plan in this field. Although, there is a long way to go, including lots of crucial techniques need to be studied, the success of development of the resources on asteroid would bring our technique and civilization in a new era.

In this study, we introduce a framework for planning and assessing multi-spacecraft asteroid deflection campaigns. In the scenario considered, a near-Earth asteroid (NEA) is nudged away from gravitational keyholes via a kinetic impactor (KI) technique, lest its passage should incur an Earth collision in the future. An asteroid orbiter or/and an impactor is/are used in the precursor stage to obtain uncertain information about the target asteroid, whose launch date and trajectory are optimized using Chebyshev's method and a genetic algorithm. The KI mass is optimized through Monte Carlo simulations to improve the robustness of the method and achieve the minimum required probability of success (PoS). Case scenarios targeting Apophis and Bennu substantiate the utility of the framework in optimizing different deflection campaign architectures and making decisions amongst them via newly proposed visualization methods.