Spartan 101

Spartan 101 F1 [NASA]

Spartan 1 (Shuttle Pointed Autonomous Research Tool for Astronomy 1) consisted of low-cost, Shuttle-launched, short-duration, sounding-rocket-type payloads. The payloads were retrievable and reusable with a turnaround time of approximately 6 to 9 months. It operated as an autonomous sub-satellite, and the data were stored on an internal tape recorder. Pointing and stabilization were achieved by an attitude control system capable of three-axis stabilized pointing to any target within plus or minus 3 arcmin. Spartan-A, as the first of the series, was intended to demonstrate the low-cost approach and its ability to achieve the desired technical performance in the STS environment. The scientific objective of the spacecraft was to investigate the photon emission processes in clusters of galaxies and to explore the center of our galaxy in the photon energy range of 0.5 to 15 keV. The spacecraft allowed the instrument to scan various cosmic sources at rates of 10 to 20 arcsec per second.

This experiment consists of two large X-ray proportional counters equipped with collimators constructed from stacked, etched grids, plus aspect cameras, detector gas supply, and electronics. The photon energy range covers 0.5 to 15 keV. Because of alignment considerations, the collimators, aspect cameras, and the attitude control star tracker and gyro components are mounted on a common optical bench, which is attached to the spacecraft structure through kinematic mounts that eliminate flexing of the optical bench due to mechanical or thermal loads. The instrument has been flown numerous times on sounding rocket flights.