Currently, key pieces of the required technology for the single-target space debris capture and orbital removal of large scale satellites have been developed and tested by Obruta members during their respective graduate studies at Carleton University. This work has been completed through simulations and experimental validation using the Spacecraft Proximity Operations Testbed (SPOT) within Carleton’s Spacecraft Robotics and Control Laboratory (SRCL), and exists at a Technology Readiness Level (TRL) of 4 and 5 for the capture and stabilization phases respectively.

All current research and developed intellectual property (IP) as a part of graduate studies requirements at Carleton University are owned by the students. Program policies allow for a two year non-compete grace period post graduation to patent any developed IP, which begins in fall 2019. We have engaged the Carleton Innovation Transfer Office who provides assistance with the patenting process and accelerators to fully support the commercialization of our product.

Figure 1: Angular rates of a captured target relative to the tether with arbitrary initial angular rates about all three axis

Current Work

Current single-target tether-based orbital debris mission profiles contain a launch of the servicer satellite, a rendezvous with the target debris, the deployment of the target capturing payload, the stabilization of the tethered target and servicer satellites, and finally a maneuver to a lower orbit which will naturally decay the tethered satellite system (TSS) at a rapid rate.

Our design improves on the capture and stabilization phases. Using the visco-elastic material properties of our tether, we can passively dampen the angular rates of the target debris using the same deorbiting acceleration as the altitude lowering maneuver.

When compared to a currently proposed mission, this results in a lower overall amount of fuel required for attitude control of the TSS when attempting to dampen the angular rates of the tumbling debris in order to stabilize the system and preform the altitude reducing maneuver.

This effect is shown in Figure 1 as the stabilization comparison of a traditional single tether (Black) and Obruta's tether (Red) over one orbital period.

To date our team has accomplished:

    • Simulated the on-orbit capture and detumbling of a target spacecraft rotating about 3-axes using the Obruta tether design (TRL 5)
    • Simulated the on-orbit deployment and contact of a target spacecraft rotating about 3-axes using the Obruta tether design (TRL 5)
    • Simulated and experimentally validated the stabilization of a target spacecraft post-capture in a planar laboratory environment using the Obruta tether design (TRL 4)
    • Simulated the deployment and contact of the Obruta tether design in a planar laboratory environment (TRL 4)

Future Work

The Obruta team is continuing to develop our novel tether design for active single-target debris removal missions. We are also focusing on developing a multi-target debris removal payload using current technology, as well as the development of small-sat end-of-life deorbiting solutions for those seeking to comply with the 25 year deorbit requirements while operating at higher altitudes.