Sirio 1 (Satellite Italiano ricerca industriale orientato) was primarily a geostationary communications satellite. It included experiments measuring the local plasma and field environment and the flux of low-energy cosmic rays.
The satellite was launched on a Delta-2313 and was located at 15 deg w longitude.
The Sirio-2 geostationary spacecraft carried two independent payloads:
The cylindrically shaped spacecraft measured 144 cm in diameter and 240 cm in length including the apogee boost motor. The primary structural members are equipment platforms and a central thrust cone carrying conventional housekeeping electronics in addition to payloads. Attitude, orbit and spin rate control were performed using a hydrazine propulsion system including four thrusters. The spin rate would have been maintained at 90 rpm throughout the two-year nominal lifetime. A mechanically despun antenna relayed S-band telemetry (meteorological and housekeeping), while a traditional omnidirectional turnstile system supported VHF ranging and telecommands, as well as housekeeping telemetry in transfer orbit and as backup geostationary orbit.
Sirio-2 was lost in a Ariane-1 launch failure in 1982.
|Type / Application:||Communication|
|Contractors:||Compagnia Nazionale Satelliti per Telecommunicaziono SpA|
|Power:||Solar cells, batteries|
|Sirio 1||1977-080A||25.08.1977||CC LC-17B||Delta-2313|
|Sirio 2||1982-F06||09.09.1982||Ko ELA-1||F||Ariane-1||with MARECS B|