Abstract
The EC FP7 RemoveDebris mission aims to be one of the world's first Active Debris Removal (ADR) missions to demonstrate key technologies in-orbit in a cost-effective ambitious manner, including: net capture, harpoon capture, vision-based navigation, dragsail de-orbitation. The mission will utilise two CubeSats as artificial debris targets to demonstrate the technologies. In early 2018, the main 100 kg satellite will launch to the International Space Station (ISS) where it will be deployed via the NanoRacks Kaber system into an orbit of around 400 km. The mission comes to an end later in 2018 with all space entities having been de-orbited.
The mission contains several mechanisms and inflatable systems that will be addressed in the paper: CubeSat deployable, dragsail mechanisms, harpoon target extender. One of the ejected CubeSats, DS-1, which acts as the artificial debris and is used in the net experiment, deploys an inflatable structure to maximise volume and enable faster de-orbitation. The dragsail system utilises a two stage deployment - firstly using a 1 metre inflatable rigidisable mast to move the sail system away from the main platform - then deploying a series of coiled carbon fibre booms to draw out a 10 metre squared aluminised Kapton sail. Finally, the harpoon is fired at a deployable target plate, which is extended 1.5 metres away from the platform by a deployable carbon fibre boom. The varying mechanisms technologies in the mission form a mix of core technologies (such as the dragsail) and in-space support technologies (such as the target extender).
The paper will examine for the selected mechanisms the design of the systems and details of the testing methodology and results for ground (both functional and environmental). The paper will also detail some in-flight mission results with regards to the experiments. Examination of mechanism performance will also be addressed, along with usage and scalability potential for future ADR missions.
Future mega-satellite constellations are now being proposed, where hundreds to thousands of satellites are being launched into orbit. A coherent strategy, along with technological and platform developments, is needed for de-orbiting, re-orbiting, or servicing of such constellations. The RemoveDebris mission is a vital prerequisite to achieving the ultimate goal of a cleaner Earth orbital environment, and is a core step in the development of active removal vehicles, or on-orbit servicing vehicles of the future.