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SEDSat 1 (SO 33, OSCAR 33)


SEDSat 1 (Students for the Exploration & Development of Space - Satellite) is an american microsatellite. It was to obtain images of the Earth and distribute them through the Internet from the University of Alabama in Huntsville. It also served as a relay for amateur radio communications.

The 34 kg satellite was built on a 32.13 cm × 32.13 cm × 35.43 cm structure. Originally it was to be deployed via a SEDS tether system (similar to SEDS 1, 2) from the Shuttle under the name SEDS-3, but due to concerns with using the tether system with the Shuttle, the mission was first redesigned for a tetherless deployment from the Shuttle and then for a deployment from a Delta stage 2.

SEDSat featured following equipment:

  • Imaging camera (SEDS Earth Atmospheric and Space Imaging System [SEASIS],) Visible light camera with 10, 7 and 10 nanometer filters for measuring atmospheric extinction coefficients. Resolution was 60 m in telephoto mode and 10 kg in panorama mode.
  • Mode L (13 cm uplink, 70 cm downlink digital packet UoSat compatible)
  • Mode A (2 meter uplink, 10 meter downlink, analog SSB 70 Khz transponder)

SEDSat 1 was launched as a piggy back payload mounted on stage 2 of a three stage Delta-7326 launch vehicle, which sent the Deep Space 1 (DS 1) space probe into a solar orbit. SEDSat 1 suffered from problems in the power system, causing both the imaging payloads and the amateur radio transponders never becoming operational. Only some telemetry was received. It was designed with a lifetime of five years, but was still semi operational in 2013.

Nation: USA
Type / Application: Technology
Operator: SEDS
Contractors: SEDS
Equipment: SEASIS
Configuration: 32.13 cm × 32.13 cm × 35.43 cm structure
Propulsion: ?
Power: Solar cells, batteries
Lifetime: 5 years (design)
Mass: 34 kg
Orbit: 547 km × 1079 km, 31.4
Satellite COSPAR Date LS Launch Vehicle Remarks
SEDSat (SO 33, OSCAR 33) 1998-061B 24.10.1998 CC SLC-17A Delta-7326 with DS 1