8 results on '"Francesca Letizia"'
Search Results
2. Statistical analysis of conjunctions in Low Earth Orbit
- Author
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Dennis Weber, Francesca Letizia, Benjamin Bastida Virgili, and Stijn Lemmens
- Subjects
Atmospheric Science ,Geophysics ,Space and Planetary Science ,Aerospace Engineering ,General Earth and Planetary Sciences ,Astronomy and Astrophysics - Published
- 2022
3. Assessment of orbital capacity thresholds through long-term simulations of the debris environment
- Author
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Francesca Letizia, Benjamin Bastida Virgili, and Stijn Lemmens
- Subjects
Atmospheric Science ,Geophysics ,Space and Planetary Science ,Aerospace Engineering ,General Earth and Planetary Sciences ,Astronomy and Astrophysics - Published
- 2022
4. Identifying the 50 statistically-most-concerning derelict objects in LEO
- Author
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Stijn Lemmens, Liu Jing, Darren S. McKnight, Rachel Witner, Chris Kunstadter, Francesca Letizia, Alessandro Rossi, Wang Dongfang, Hugh G. Lewis, D. A. Grishko, Mike Nicolls, Satomi Kawamoto, Shen Dan, Juan-Carlos Dolado Perez, Luciano Anselmo, Vincent Ruch, Vladimir S. Aslanov, Carmen Pardini, and A. A. Baranov
- Subjects
Debris remediation ,020301 aerospace & aeronautics ,Computer science ,Process (engineering) ,Aerospace Engineering ,02 engineering and technology ,Space (commercial competition) ,01 natural sciences ,Space sustainability ,International Action ,Space safety ,0203 mechanical engineering ,Risk analysis (engineering) ,Low earth orbit ,Ranking ,Hazardous waste ,0103 physical sciences ,Sustainability ,Orbit (dynamics) ,010303 astronomy & astrophysics ,Active debris removal - Abstract
著者人数: 19名, 形態: カラー図版あり, Number of authors: 19, Physical characteristics: Original contains color illustrations, Accepted: 2021-01-14, 資料番号: PA2110015000
- Published
- 2021
5. Space sustainability in Martian orbits — First insights in a technical and regulatory analysis
- Author
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Holger Krag, Francesca Letizia, Vitali Braun, and Isabell Suchantke
- Subjects
Martian ,020301 aerospace & aeronautics ,Planetary protection ,Computer science ,media_common.quotation_subject ,Spacefaring ,Aerospace Engineering ,Outer space ,02 engineering and technology ,Mars Exploration Program ,Space weather ,01 natural sciences ,Astrobiology ,0203 mechanical engineering ,Physics::Space Physics ,0103 physical sciences ,Orbit (dynamics) ,Astrophysics::Earth and Planetary Astrophysics ,Safety, Risk, Reliability and Quality ,010303 astronomy & astrophysics ,media_common ,Space debris - Abstract
Hazards from the outer space environment either natural (space weather and asteroids) or artificial (space debris and the growing number of satellites launched to orbit) pose a rising risk to space flight activities. The awareness for space sustainability and space safety has seen a continuous increase in recent years and does not stop at the Earth's sphere of influence. The first spacefaring nations start thinking about sustainability in cislunar space and the Martian environment. This work deals with the issue of space debris in Martian orbits in the light of planetary protection. A Mars Sustainability Framework has been developed. This includes a study on the orbital and regulatory environment of Mars, long-term propagation of orbits of artificial objects and the two natural moons, and the analysis of objects evolution and first approaches for collision probability computation. With this work, the issue of space debris beyond Earth orbit is analysed at an early stage.
- Published
- 2020
6. Environment capacity as an early mission design driver
- Author
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Francesca Letizia, Stijn Lemmens, and Holger Krag
- Subjects
020301 aerospace & aeronautics ,Collision avoidance (spacecraft) ,Spacecraft ,Computer science ,business.industry ,Aerospace Engineering ,02 engineering and technology ,01 natural sciences ,0203 mechanical engineering ,Work (electrical) ,0103 physical sciences ,Systems engineering ,Satellite ,Environmental impact assessment ,Metric (unit) ,business ,010303 astronomy & astrophysics ,Space debris ,Constellation - Abstract
In recent years, several metrics have been proposed to quantify the impact of a mission on the space debris environment. In our previous work, we introduced the environmental capacity as the number and typology of missions that are compatible with the stable evolution of the debris environment. This concept enables the evaluation of the effectiveness of mitigation guidelines by looking at the use of environmental capacity due to existing missions. The current work will investigate how the same concept can also be applied as a tool during the design of a mission, facilitating the comparison of different mission architectures depending on their overall contribution to the debris environment. First, the paper will present the latest updates to the debris index used as a metric of the environment capacity, including the inclusion of a penalisation for objects with low trackability and an improved model for the break-up probability. Then, several application cases will be discussed to demonstrate its use as design driver. First, the relevance of adopting operational best practices (i.e. collision avoidance and disposal manoeuvres) will be studied for different spacecraft classes as a way of quantifying better than required behaviour. Then, the environmental impact of a mission will be analysed considering the case when the mission is realised through a single large satellite or through a constellation of smaller satellites. Finally, different end-of-life scenarios will be assessed to demonstrate the use of the method to discriminate between various technologies on a case-by-case basis. The adoption of passive de-orbiting systems will be compared to conventional disposal through de-orbit burns or operations at lower altitudes to gain insight into how two different options, both compliant to existing guidelines, differ in terms of the resulting environmental impact. Finally, a scenario with active-debris-removal will be considered, showing how the quantification of the impact on the debris environment can support the selection of parameters such as the rendez-vous altitude, based on the expected success rate of the capture and final disposal phase.
- Published
- 2020
7. Application of a debris index for global evaluation of mitigation strategies
- Author
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Holger Krag, Benjamin Bastida Virgili, Stijn Lemmens, and Francesca Letizia
- Subjects
020301 aerospace & aeronautics ,Service (systems architecture) ,Index (economics) ,Operations research ,Computer science ,Process (engineering) ,Aerospace Engineering ,Context (language use) ,02 engineering and technology ,01 natural sciences ,Frequency allocation ,0203 mechanical engineering ,0103 physical sciences ,Metric (unit) ,010303 astronomy & astrophysics ,Management process ,Collision avoidance - Abstract
The current debris mitigation guidelines are formulated by considering single objects, so they cannot dynamically account for variations in the space traffic, or for the actual current level of implementation and success of post-mission disposal manoeuvres. To address this limitation, the concept of space traffic management based on the environment capacity was proposed. Following this approach, a mission (single or multiple satellites and launch vehicles) is evaluated, before its launch, not only with respect to existing mitigation guidelines, but also with respect to what can be accommodated by the environment (e.g. not exceeding a defined risk level), considering objects already in orbits and other planned future missions. In this way, similarly to the approach used for frequency allocation in GEO, each mission can use a share of the environment capacity through a process that may define, for example, a maximum capacity consumption per year. In order to implement such a scheme, a measure of the debris environment criticality is required. Different formulations for such a metric have been proposed and, in the present work, the ECOB index (Environmental Consequences of Orbital Breakups) is applied. This work will give a brief overview of the most recent changes in the formulation of the index and will discuss examples of applications to the current environment. Different Post-Mission Disposal success rates and future launch traffic scenarios will be analysed. In this context, the evaluation provided by the debris index will be compared to other formulations available in literature and to the one from other indicators such as number of objects and catastrophic collisions. A comparison with operational data from ESA's collision avoidance service will be also presented. Finally, it will be analysed how such an index can be connected to the concept of the environment capacity and a concept for its inclusion within a space traffic management process will be formulated.
- Published
- 2019
8. End-of-life disposal concepts for Libration Point Orbit and Highly Elliptical Orbit missions
- Author
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Markus Landgraf, Willem Johan van der Weg, Francesca Letizia, Massimo Vetrisano, Camilla Colombo, Stefania Soldini, Massimiliano Vasile, Elisa Maria Alessi, and Alessandro Rossi
- Subjects
Elliptic orbit ,010504 meteorology & atmospheric sciences ,TL ,Highly elliptical orbit ,Aerospace Engineering ,Context (language use) ,7. Clean energy ,01 natural sciences ,Disposal ,0103 physical sciences ,Libration ,Aerospace engineering ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,Libration point orbit ,Spacecraft ,business.industry ,End-of-life ,Trajectory design ,Technical feasibility ,Test case ,13. Climate action ,Orbit (dynamics) ,TJ ,business - Abstract
Libration Point Orbits (LPOs) and Highly Elliptical Orbits (HEOs) are often selected for astrophysics and solar terrestrial missions. No guidelines currently exist for their end-of-life disposal. However, as current and future missions are planned to be placed on these orbits, it is a critical aspect to clear these regions at the end of operations to avoid damage to other spacecraft and ensure on-ground safety. This paper presents an analysis of possible disposal strategies for LPO and HEO missions as a result of a European Space Agency study. The dynamical models and the design approach are presented for each disposal option. Five current missions are selected as test cases Herschel, Gaia, SOHO as LPOs, and INTEGRAL and XMM-Newton as HEOs. A trade-off on the disposal options is made considering technical feasibility, as well as the sustainability context.
- Published
- 2015
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