A Small Satellite as an Attached Payload on ISS—The Merger of “Small” and “Very Large”

This paper describes the use of the Floating Potential Probe (FPP) as an “Attached Payload” on ISS. Background and motivation for building the FPP and well as detailed descriptions of its subsystems are described in another paper published in these proceedings (ref # SSC01-V-4b). With it’s solar arrays, primary/secondary power system, control/data processor unit, RF command/data link, thermal protection system, and two science instruments, the FPP displays most of the characteristics of a small spacecraft— with the exception of attitude control and propulsion subsystems. The FPP was attached to the top of the P6 truss during one of several Flight 4A EVAs. It uses an RF link to communicate with an antenna (deployed at the same time as the probe) which feeds though the module and into a transmitter/receiver and portable computer inside the habitable volume. Real time data on the ISS potential is displayed on the laptop and downlinked through the ISS server when requested. This paper will provide an overview of the major subsystems, discuss how such small satellites could be made to work within the ISS system, and the possibilities of using small satellites as attached payloads for short term science or technology experiments. We will provide insight into deployment and operational considerations, show examples of the use of such a low cost system, and discuss briefly the data and science impact of this small $1M class probe.