Session
Technical Session XII: Science/Mission Payloads II
Abstract
Asteroid capture and retrieval is a problem of significant scientific and commercial interest. However, de-spinning and de-tumbling massive asteroids with chemical thrusters will require hundreds of kilograms of propellant. In order to address this challenge, Tethers Unlimited, Inc. has developed a small satellite mission architecture called “Weightless Rendezvous And Net Grapple to Limit Excess Rotation” (WRANGLER), which enables significant size, complexity, and order-of-magnitude mass savings for asteroid capture, retrieval, or redirect missions. WRANGLER uses a tethered nanosatellite to de-spin a targeted asteroid by converting the asteroid’s rotational momentum into rotation momentum of the nanosatellite as it revolves around the asteroid. The leverage offered by using a tether to extract angular momentum from a rotating asteroid enables very small nanosatellite systems to de-spin massive asteroids. This paper details the analysis of the tether deployment from a spinning and tumbling asteroid, demonstrates that a tethered system can effectively de-spin and de-tumble large space objects while avoiding tether wrapping and other dynamic problems, and compares tethered de-spin mission concepts to baseline approaches. Additionally, the capture and de-spin of an upper stage rocket body is proposed as a validation demonstration of both the WRANGLER architecture and its alignment to active debris removal missions.
Nanosatellite Architecture for Tethered De-Spin of Massive Asteroids
Asteroid capture and retrieval is a problem of significant scientific and commercial interest. However, de-spinning and de-tumbling massive asteroids with chemical thrusters will require hundreds of kilograms of propellant. In order to address this challenge, Tethers Unlimited, Inc. has developed a small satellite mission architecture called “Weightless Rendezvous And Net Grapple to Limit Excess Rotation” (WRANGLER), which enables significant size, complexity, and order-of-magnitude mass savings for asteroid capture, retrieval, or redirect missions. WRANGLER uses a tethered nanosatellite to de-spin a targeted asteroid by converting the asteroid’s rotational momentum into rotation momentum of the nanosatellite as it revolves around the asteroid. The leverage offered by using a tether to extract angular momentum from a rotating asteroid enables very small nanosatellite systems to de-spin massive asteroids. This paper details the analysis of the tether deployment from a spinning and tumbling asteroid, demonstrates that a tethered system can effectively de-spin and de-tumble large space objects while avoiding tether wrapping and other dynamic problems, and compares tethered de-spin mission concepts to baseline approaches. Additionally, the capture and de-spin of an upper stage rocket body is proposed as a validation demonstration of both the WRANGLER architecture and its alignment to active debris removal missions.
