Experiments and simulation of a net closing mechanism for tether-net capture of space debris

• Published in: Acta astronautica Vol. 139; pp. 332 - 343
• Main Authors: Sharf, Inna, Thomsen, Benjamin, Botta, Eleonora M., Misra, Arun K.
• Format: Journal Article
• Language: English
• Published: Elmsford Elsevier Ltd 01.10.2017; Elsevier BV
• Subjects: Closing mechanism; Closing mechanisms; Computer simulation; Containment; Debris removal; Deployment dynamics; Design; Detritus; Ejection; Experiments; Gravitation; On-ground test-bed; Simulation; Space debris; Space debris mitigation; Spacecraft; Tensioning; Tether-net; Validation studies; Closing mechanism; Space debris; On-ground test-bed; Debris removal; Tether-net; Experiments; Deployment dynamics
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2017.07.026

This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission. •Tether-actuated cinch-cord mechanism for closing net around debris is proposed.•Performance of the mechanism is demonstrated in laboratory experiments.•Simulated model with realistic debris confirm functionality in space conditions.•Experimental test-bed is suitable for range of studies on tether-net debris capture.