Speaker
Dr
Alexander Wittig
(ESA Advanced Concepts Team)
Description
The use of the gravity of celestial bodies for gravity assist maneuvers is quite common in astrodynamics. The spacecraft gravitationally interacts with the celestial body in such a way as to provide the desired delta-v to the spacecraft. While this works well for large bodies such as planets, the gravitational attraction of small bodies, such as asteroids, is typically too small to perform such maneuvers.
In this work we analyze a different type of fly-by orbit using a variable length tether. During a fly-by of the spacecraft at an asteroid, a tether is attached to the asteroid which is then reeled out maintaining a tension within the limits of the tether. A dynamical model describing such a tethered flyby is developed. Using this model, it is possible to perform fly-by maneuvers that conceptually are very similar to traditional gravity assist maneuvers. While current tether technology is not yet able to provide the required tension, these fly-bys provide a new class of orbits that can be utilized in future for missions.
We demonstrate a potential use of such tethered fly-by maneuvers for multiple rendezvous orbits. A spacecraft in the main asteroid belt has to visit a long sequence of asteroids via tethered fly-bys. The optimization is performed with the goal of maximizing the number of asteroids visited in a given time frame. The computation is performed using the PyKEP toolbox developed by the Advanced Concepts Team. Due to its flexible design, this Python based toolbox can easily be to allow for optimization of missions using these novel fly-by dynamics. The global optimization is performed using either evolutionary algorithms or a tree search strategy.
| Applicant type | First author |
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Primary author
Dr
Alexander Wittig
(ESA Advanced Concepts Team)
Co-author
Dr
Dario Izzo
(ESA ACT)
