WRANGLER: this is a concept that involves capturing and de-spinning an asteroid using a satellite known as an Asteroid removal satellite that involves shooting a wrangler that wraps a net/bag around the asteroids or space debris.
This idea was birthed from the challenges for the capture and retrieval of Asteroid and space debris. NASA was working on how it could retrieve materials from near earth asteroids (NEAs) to enable investigations of the nature of the early solar system. This architecture considered in the Asteroid removal mission (ARM) program would utilize a single spacecraft to capture a small debris or asteroid from a boulder asteroid and then transport it to a cislunar space.
This method was good ideally but there were challenges that were considered when this was to be deployed, it includes that astronomical observations have identified that most NEAs that are small enough to be considered for relocation are rotating a very high speed. This then brought about the idea of using a WRANGLER.
The concept of operations for the Wrangler is as follows:
- The wrangler maneuvers to prepare to capture the target and the ARM spacecraft can back away
to a safe distance
- Wrangler deploys a bag
- Wrangler maneuvers GRAPS bag around asteroid
- Wrangler closes bag to attach itself to asteroid
- Wrangler deploys tether between the nanosat and the GRASP bag
- Tether deployment drains angular momentum from asteroid
- Wrangler separates tether from the GRASP bag and finally the ARM spacecraft docks to the GRASP
and takes it o the cislunar space.
This method depends on the tether to slow down the angular velocity of the asteroids as it elongates from the nanosat.
Conclusion: The demonstration of the feasibility and value was done by the TUI (researchers). Also detailed conceptual designs for then architectures have been used to help demonstrate the significant mass savings afforded by the WRANGLER CONCEPT.
Source: Robert Hoyt, Karsten James, Jeffrey Slostad, Todd Moser (2014). WRANGLER: Capture and De-Spin of Asteroids & Space Debris