Program Overview

The SPHERES (Synchronized Position Hold, Engage & Reorient Experiment Satellites) project is a collaborative effort with the MIT Space Systems Laboratory to develop and operate a testbed for satellite formation flight on the International Space Station. The SPHERES system consists of three self-contained satellites, each with battery power, a cold gas propulsion system and onboard communications and navigation equipment.

Using Ultrasound transmitter beacons in a designated arrangement aboard ISS, the satellites individually measure their respective positions and attitudes in relation to one other and to the defined volume. SPHERES provides a unique opportunity for researchers on the ground to test control algorithms in the microgravity environment of space. once they receive testing data, researchers are able to refine and uplink new algorithms in a relatively short period of time, allowing for an accelerated iterative process unavailable in other testing environments.

Capabilities & Benefits

SPHERES is the only free floating experiment onboard ISS

Capable of rotation and translation in all directions

Maneuverability with great precision in zero gravity

Powered by AA batteries and compressed CO2

Can accommodate various mounting features and mechanisms

Ability to test physical and mechanical properties of materials in microgravity