Novel Technologies for Spacecraft Deorbiting
- Paper number
IAC-07-A6.3.07
- Author
Dr. Wolfgang Griethe, Kayser-Threde GmbH, Germany
- Coauthor
Dr. Manfred Leipold, Kayser-Threde GmbH, Germany
- Coauthor
Mr. Carsten Wiedemann, Institute of Aerospace Systems, Germany
- Year
2007
- Abstract
The space debris environment is of great complexity and difficult to characterize due to the dynamic behaviour of the debris population. However, the principles of spacecraft interferences are well-understood by spacecraft designers, satellite manufacturers and service providers, and a lot of constructive and operational techniques have been implemented meanwhile in order to minimize mission-related debris during the deployment of space infrastructures. Nevertheless, as a matter of fact, the hazard of potential collisions could not be significantly decreased by the implemented measures, unfortunately. On the contrary, today the debris flux in some orbital regions exceeds a critical threshold, as for instance at altitudes between 900 km to 1100 km respectively at 1500 km, and ultimately in that orbital regions an increased debris population has to be recognized, amongst others caused by collisions of debris particals themselves. In other words, there is a cascade effect which creates more debris in these orbits than will decay naturally downwards to Earth by atmospheric drag and other perturbing forces. This led to the conclusion that, if no effective steps will be seized at last, it is only a question of time until orbital regions will become inhospitable to space operations. Although experts estimated presently the probability of colliding with debris in LEO at least 100 times greater than in GEO, a collisional growth in GEO is unavoidable as well. In fact, all effort has to be done to keep the collision hazard as low as possible regardless of the orbit, whether LEO, MEO or GEO. Since the total mass of objects in orbit is causal for the growth of the debris population, the deorbiting of spacecrafts after their functional lifetime as an appropriate measure can mitigate the debris problem. The currently practised method to move GEO spacecrafts at the end of their lifetime into a “disposal orbit” is easy but not forward-looking. Thus, the paper examines innovative mechanical interventions for the deorbiting of useless space infrastructures, based on (1) advanced servicing vehicles, (2) deployable structures and (3) inflatable systems. The basic concept of the suggested innovations, the possible mission scenarios and its effectiveness are discussed at research level. Finally, possible risks will be assessed from a practical point of view. The discussed technologies are promising not only for deorbiting of spacecrafts but offer a wide range of applications with revenue potential: Reuse of geostationary slots, recovery of spacecrafts being launched into incorrect orbits, space asset protection, etc. This nourishes the hope that the feasibility of the proposed technologies can be demonstrated in the near future.
- Abstract document