Cosmic Ray Satellite "Option B"
Description
The Cosmic Ray Satellite was a non-optical space based telescope that used a specially developed spark chamber to detect gamma-ray emissions. This spark chamber was designed to convert an incoming gamma ray emission into an electron and positron, which collided causing a “spark.” Its successes included completely cataloging gamma-ray sources from the disc of the Milky Way as well as capturing the first detectable emission from outside the galaxy, object 3C273. The COS-B scientific satellite was developed by the European Space Agency (ESA) to study extraterrestrial gamma radiation in the 25-MeV to 1-GeV energy range from a highly elliptical orbit of roughly 100,000-km apogee, 350-km perigee, and near-polar inclination. The satellite’s highly eccentric orbit keeps it outside of the Earth’s radiation belts. NASA provided, on a fully reimbursable basis, the Delta launch vehicle and the associated launch services. Communications, command, and control of the COS-B satellite in orbit were provided by the ESA Estrack network. The COS-B spacecraft was cylindrical with a diameter of 140 cm and a height of 121 cm. Four monopole antennas, protruding 51.2 cm below the bottom of the cylindrical body, gave the spacecraft a total effective height of 172.2 cm. The spacecraft obtained orientation of its angular momentum vector with respect to inertial space using data from an earth albedo sensor and a solar sensor. Spacecraft attitude was adjusted by a nitrogen cold-gas attitude control system (ACS). The ACS included two spin-rate-adjust nozzles to maintain the spin rate at 10 rpm and two precession nozzles to adjust the momentum vector. The spacecraft had a pcm/psk/pm telemetry system with 6.5-W real-time-only transmitter providing a switchable bit rate of 160 and 320 bps and a pcm/psk/pm, up-link/down-link, range-tone command system. Power was supplied by 9480 solar cells mounted on 12 subpanels on the cylindrical body of the spacecraft. (NASA - National Space Science Data Center and ESA) |
Facts
Spectrum Studied: Gamma Rays Launch Date: 1975-08-09 Termination Date: 1982-04-25 Orbital Location: Earth orbit (100,000 to 350 km) Launch Vehicle: Delta Launch Site: Vandenberg AFB, United States Mass: 277.5 kg Funding Agency European Space Agency |