Systems Design of a Small Satellite Multiple Gravity Tractor (MGT) Formation for Asteroid Deflection
- Paper number
IAC-08.A3.I.8
- Author
Dr. Vaios Lappas, Surrey Space Centre, University of Surrey, United Kingdom
- Coauthor
Prof. Bong Wie, Iowa State University, United States
- Year
2008
- Abstract
Multiple gravity tractors in halo orbits as well as a hovering solar-sail gravity tractor is proposed as an option for towing a certain class of near-Earth asteroids which may not require high-energy deflection techniques employing nuclear explosions or kinetic impactors. A hovering GT in a static equilibrium standoff position requires canted thrusters to avoid plume impingement on the NEA surface. Recent work has recently investigated a GT spacecraft flying in a displaced non-Keplerian orbit (also often called a halo orbit) for a possible fuel-efficient way of towing asteroids. From a practical viewpoint, such a GT not requiring canted thrusters but in a displaced orbit does not have a significant fuel-efficient advantage over a hovering GT requiring canted thrusters. However, such a halo orbit simply allows many GTs near a target asteroid. This paper presents the preliminary systems design analysis of a small satellite design for a Gravity Tractor formation as applied to asteroid Apophis. A system of orbiting multiple gravity Tractors (MGT) has many advantages over the hovering gravity tractor. The proposed MGT system may consist of several GTs in a primary halo orbit as well as in a secondary/backup halo orbit. They include: its larger total ?V capability, multi-spacecraft redundancy, and mission design flexibility with smaller satellites equipped with lower-risk propulsion systems. For example, instead of using a single large 2500-kg hovering GT spacecraft, we may employ an MGT system consisting of five (or more) small, 500-kg satellites or two (or more) 2500-kg orbiting MGTs (if needed). The paper examines the technical feasibility of using small satellite technology for designing a cluster of small 500 kg satellites to be used in a gravity tractor formation to tow a near-Earth asteroid such as Apophis. A trade-off of the propulsion options based on electric propulsion technologies is presented amongst with a realistic and practical design for a hypothetical near term asteroid deflection mission.
- Abstract document
- Manuscript document
IAC-08.A3.I.8.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.