NASA SLI
Huntsville, April 2027
The vehicle
Ten feet of G12
122 inches long. Five inches inside, 5.15 outside. Ogive nose, three carbon-fiber through-the-wall fins, 75-millimeter motor. About 25 pounds before the payload is locked. Dual deploy. Target 4,500 feet.
The circle on the airframe is the air brake. Fiberglass carries the loads. Carbon stays on the fins.
Air brakes
Closed-loop drag
A high-torque servo opens aluminum petals on rails. The controller reads altitude and speed, predicts apogee, and commands extra drag so the vehicle lands on 4,500 feet.
Estimated flight state in, additional Cd out. Bench-tested before it goes in the airframe.
The controller
Predicted apogee
The Simulink model from the proposal. Thrust and mass decay feed a physics model of flight. Inputs are altitude, velocity, Cd, and the 4,500-foot target. Output is commanded Cd and predicted apogee.
Recovery
Dual deploy
Drogue near apogee. Main at 600 feet. This is the recovery CAD: 5.14 inches across, 13.39 long.
Payload
Stand up. Scan.
After landing, this cylinder leaves the airframe, stands on its legs, and looks for a target without GPS. Camera on the lid, timestamp, distance. Written to a card.
Weighted nose. Legs on a central screw. Springs hold it in the tube until a burn wire lets it out.
Electronics
Two boards
One board flies the camera. One fires the burn wires and the legs. GY-91 for IMU and barometer. Raspberry Pi or ESP32 for the image. Arduino Nano for deployment. 3S LiPo, bucked to 5 volts.
