High-Performance Deorbit Engine with Minimal Power Requirements

The two primary methods of deorbiting a spacecraft involve either applying drag or using a propulsion system. Atmospheric drag, tethers, and solar sails are examples of the former, and chemical propulsion and electric propulsion are examples of the latter. The orbit height, spacecraft mass, and spacecraft “frontal area” will determine the velocity change requirements and the time frame over which a system can deorbit a spacecraft. The minimum-mass solution for a given time frame will generally involve the use of both drag and propulsion: use a propulsion system to lower the spacecraft orbit and then let atmospheric drag further slow the spacecraft to complete the deorbit maneuver. In this project, Ultramet will investigate the propulsion and drag requirements for a minimum-mass system, and then focus on the development of a suitable propulsion system. Specifically, Ultramet will mature its existing green propulsion technology, and its high-reliability low temperature ignition system that is being developed for the Air Force, and apply them to the development of a high specific impulse (>300 sec) hybrid rocket with low size, weight, power, and cost (SWaP C) that can be used to lower the orbit of a small spacecraft to the point where atmospheric drag can complete the deorbiting process within the desired time frame.