For the USMP-4 mission, two SAMS instruments are being flown, with a total of five acceleration sensor heads. Each sensor head is made up of three single-axis accelerometers oriented so that they are mutually perpendicular.
Electrical cables connect the sensor heads to the SAMS electronics package.
Two computer-driven data acquisition units in the electronics packages convert the signals into digital data. All this data is transferred to hard disk drive storage on board. According to the requests of the scientists, data from some sensor heads are transmitted to the ground through the orbiter s communications systems. This downlinked data is received, processed, and displayed for the experimenters by the PIMS team.