Later in the day, Endeavour carried out the deployment of a solar cell experiment Picosat on behalf of the Department of Defence (DOD). The tiny satellite was sent on its way via a spring release system on the cargo bay’s sidewall.
The satellite will test two types of new solar cells in the harsh environment of space, with the performance of the solar cells - and their degradation over time - to be used to determine if they are fit to use in flight.
“Space Shuttle Picosat Launcher 5510/Picosat Solar Cell Experiment (SSPL 5510/PSSC). PSSC has picosatellites designed to test solar cells in space,” noted STS-126 SSP Flight Readiness Review (FRR) documentation on L2. “Picosatellites are ejected after ISS undock using a Non-Explosive Actuator (NEA) via spring force.
“SSPL 5510/PSSC is attached to PLB sidewall using the Adaptive Payload Carrier (APC). Deployment command/telemetry provided by crew via standard switch panel. Weight: 126 lbs; picosats deployed weight: 16 lbs.”
In a month’s time, its 8D model rocket motors - the same used by some rocket model rocketeers - will fire to adjust its orbit.
“Unused space being used to study micro satellite propulsion with solid rocket motors via ground command and tracked by radar,” added the presentation. “Picosat has ability to adjust its own orbit and will do so at end of primary mission. Burn is no earlier than 30 days after deploy.”
Note: A reader points out that these could be composite D motors vs. BP D11/12s. I'm sure someone will dig up the answer.
Update: Someone actually joined the site (i.e. laid out some of their hard-earned cash) to look at the background documents, but unfortunately these didn't provide any more information on the motors being used.