The Agile MicroSat Aims to Prove Autonomous Propulsion Systems for Very Low Earth Orbit Use
Equipped with a depth-sensing camera and laser system, AMS is the first truly autonomous micro-satellite for VLEO use.
The Massachusetts Institute of Technology's Lincoln Laboratory is hoping to prove the capabilities of micro-satellites in very low Earth orbit (VLEO), having launched a test-bed device dubbed the Agile MicroSat (AMS) earlier this year — a "pathfinder mission" for micro- and nano-satellite autonomy.
"AMS integrates electric propulsion and autonomous navigation and guidance control algorithms that push a lot of the operation of the thruster onto the spacecraft," explains Andrew Stimac, principal investigator for the project and leader of the Lincoln Laboratory Integrated Systems and Concepts group, "somewhat like a self-driving car."
The 23×11×36cm (around 9.1×4.3×14.2") AMS craft features an Enpulsion electric propulsion thruster controlled via the Bus Hosted Onboard Software Suite (BHOSS), developed specifically for autonomous operation — allowing the satellite to maintain and adjust its orbit even in the tumultuous and relatively thick atmosphere of a very low Earth orbit (VLEO), a maximum of 326 miles above sea level.
"One of the enablers for AMS is the way in which we've created this software sandbox onboard the spacecraft," explains AMS team member Robert Legge. "We have our own hosted software that's running on the primary flight computer, but it's separate from the critical health and safety avionics software. Basically, you can view this as being a little development environment on the spacecraft where we can test out different algorithms."
Besides its autonomous propulsion system, the satellite carries two scientific payloads: a depth-sensing camera system, which team member Rebecca Keenan points out could be repositioned quickly to respond to disasters like fires or floods, and Beacon, an adaptive optics system for tracking fast-moving targets — or, in the test-bed case, lighting up a ground station at Haystack Observatory.
The satellite launched in May, with the camera capturing its first image in June and the completion of thruster commissioning in July. At the time of writing, it was descending towards its VLEO orbit for a full test of the autonomous thruster system — and to see if it can live up to its "agile" moniker.
Main article image courtesyof SpaceX.