Spacecraft Concept for Active De-Tumbling and Robotic Capture of Ariane Rocket Bodies

Zusammenfassung (Abstract) :

Active debris removal (ADR) has been recognized for now some time as the only way of reducing the current growth of the space debris population. Rocket bodies (R/Bs) in particular appear as the most attractive targets given their high concentration in certain Low Earth Orbits (LEOs) and high mass and collision probability product. However, being able to safely approach and de-orbit such targets is not an easy task, especially if we take into consideration their non-cooperative nature and unknown rotational state. Moreover, multiple ADR concepts are being studied at the same time, since the community has failed to achieve consensus about the most optimal technique to employ. In fact, a multitude of techniques are being investigated, including both contact and contactless solutions. To support that global research effort, we propose a robotic spacecraft concept able to actively de-tumble its target, capture it, with a semi-rigid clamping mechanism, and de-orbit it, by using a de-orbiting kit. The underlying mission, entitled Agora (Active Grabbing & Orbital Removal of Ariane), is conceived to demonstrate technologies and techniques to autonomously remove an Ariane R/B. To assess the key technologies on-board the chaser, Agora will de-orbit the upper stage used to launch it. This choice was driven by the desire to lower the risk of failure of the overall mission, given the low TRL (Technology Readiness Level) of the considered technologies. The cost cap of the mission is set to ¤200M FY2015 and the launch date to 2025. In this poster, we present the payload system and GNC concept, considered the two most critical systems of any future ADR mission. The spacecraft's payload consists of a de-tumbling device, a semi-rigid clamping mechanism and a robotic arm. The de-tumbling device uses eddy currents, induced onto the target by a magnetic field, to actively reduce the tumbling rate of the target and enable the grabbing mechanism to capture it. The semi-rigid clamping mechanism is used to safely secure the target, once the relative motion has been compensated, while the robotic manipulator is used only to deploy a de-orbiting kit and attach it to the main nozzle of the target R/B. For the preliminary assessment, we assumed a free-flying (or active attitude controlling) mode of the base spacecraft during the operation of the robotic manipulator. In conclusion, we present a promising concept design of a spacecraft and its mission that would raise the TRL of necessary technologies and enable robotic ADR to be used in future removal missions safely and cost-effectively.

Stichworte :

gnc; space debris; agora; on-orbit robotics; active de-tumbling; demonstration mission; stardust itn

Files:

20150929-ASTRA2015_Poster-MJankovic.pdf

Links:

http://robotics.estec.esa.int/ASTRA/Astra2015/index.html