AIRS
Autonomous Information Retrieval System
This project was run through the SURF (Summer Undergraduate Research Fellowship) program at the Jet Propulsion Laboratory and California Institute of Technology. I wrote a proposal in late February 2011 to build a vehicle designed to autonomously release and descend to earth from the HALO (High Altitude Lensing Observatory) balloon mission at 100,000ft. The proposal was accepted, and with Anthony Ransford as a partner we began to design and build the vehicle in late June.
Abstract
Automated Information Retrieval System (AIRS): An Economical Safeguard Against Data Loss for High Altitude Balloon Missions.
Russell Smith
Mentors: Jeff Booth, Jason Rhodes
Long duration balloon missions such as the High Altitude Lensing Observatory (HALO) acquire such high quantities of data that they exceed the downlink bandwidth which can be guaranteed. AIRS provides a backup data transfer mechanism so that flights need not be limited by fear of total data loss. An autonomous glider with GPS and autopilot carries a solid state hard drive to an approved location near the balloon’s position. For maximum safety, mass and final kinetic energy have been minimized. Accurate waypoint targeting both simplifies recovery and further mitigates risk. A low drag, low aspect ratio wing provides rapid penetration through high crosswinds, yet supports slow landings at a high angle of attack. The 800g laminated thin wall fiberglass and foam capsule includes a solid state drive rated to withstand 1500G, more than double the capsule's impact force in an unlikely control system failure. A radio signal is broadcast after landing to allow AIRS to be easily located with a directional receiver. AIRS has been designed, fabricated, fitted with an autopilot, and tested for functionality, accuracy and safety both in simulation and from a weather balloon drop, demonstrating the feasibility of safe and easy data retrieval at low cost.
Russell Smith
Mentors: Jeff Booth, Jason Rhodes
Long duration balloon missions such as the High Altitude Lensing Observatory (HALO) acquire such high quantities of data that they exceed the downlink bandwidth which can be guaranteed. AIRS provides a backup data transfer mechanism so that flights need not be limited by fear of total data loss. An autonomous glider with GPS and autopilot carries a solid state hard drive to an approved location near the balloon’s position. For maximum safety, mass and final kinetic energy have been minimized. Accurate waypoint targeting both simplifies recovery and further mitigates risk. A low drag, low aspect ratio wing provides rapid penetration through high crosswinds, yet supports slow landings at a high angle of attack. The 800g laminated thin wall fiberglass and foam capsule includes a solid state drive rated to withstand 1500G, more than double the capsule's impact force in an unlikely control system failure. A radio signal is broadcast after landing to allow AIRS to be easily located with a directional receiver. AIRS has been designed, fabricated, fitted with an autopilot, and tested for functionality, accuracy and safety both in simulation and from a weather balloon drop, demonstrating the feasibility of safe and easy data retrieval at low cost.
Planning
Great emphasis was put on safety, protection of the data load, and ease of recovery. The design of the capsule itself morphed over time to better suit our goals. While we were initially inclined toward making a missile shaped capsule to drop quickly through the high crosswinds between 5 and 25km, then aerobrake in the final approach, we decided a greater emphasis on autonomous control was necessary for easy recovery. The choice of a glider over a missile was inspired by the greater control over flight speed, smaller form, and less threatening appearance. The system was also simpler as a whole without worries over failure in mechanical joints for the missile's aerobreaks (parachutes tangle and drift, Mars Exploration Rover styled popcorn cushions come with all sorts trouble in transporting explosives).
Build Manual