Mission Extension Using Sensitive Trajectories and Autonomous Control

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Mission Extension Using Sensitive Trajectories
and Autonomous Control

• Edward Belbruno
• Princeton University and Innovative Orbital
  Design, Inc.
• AISRP PI MEETING 2005
• April 3-6, NASA Ames

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Goal- Enable spacecraft to linger about a planet
for extended time spans in a cost effective
manner, and autonomously

• Data collection is maximized for a given mission
• Accomplish goal by using new sensitive/chaotic
  trajectories
• Dynamic sensitivity saves fuel -gt do more with
  less
• Theory is weak stability boundary (WSB) theory
  developed by EB, 87-90
• Idea Transition region about a planet, eg Moon,
  between capture and escape gtchaotic weak capture
• Can achieve ballistic lunar capture
  transfers(surfer catching wave)

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Operational Demonstrations

• Used in 1991 to salvage Japans Hiten and bring
  to Moon
• -gt First application of chaos to
  space travel
• -gt New 90 day ballistic
  capture transfer
• Used in 2004 to get ESAs SMART-1 captured into
  lunar orbit
• Ideas played a key role in 1998 salvage of Hughes
  HGS-1 using Moon

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Approach

• Two key applications
• a. Motion about planet in WSB region
• b. Newly discovered Quasi-stationary
  motion
• Focus on a. using Moon
• WSB transfer to Moon -gt ballistic capture in WSB
  region
• Can maintain weak capture for tiny DeltaV
• Demonstrated in Februarys work, DeltaV is very
  small
• 20 m/s for 3-4 months
• Smaller the DeltaV, more unstable/complicated the
  motion
• Idea- Reduce DeltaV, require more
  frequent control
• Optimize -gt will yield control algorithm thats
  autonomous