Mission typeAmateur radio
OperatorAMSAT / NASA
COSPAR ID1972-082B
SATCAT no.6236
Mission duration4.5 years (achieved)
Spacecraft properties
Launch mass18.2 kg (40 lb)
Dimensions16 cm × 30 cm × 44 cm (6.3 in × 11.8 in × 17.3 in)
Power3.5 watts
Start of mission
Launch date15 October 1972, 17:19 UTC
RocketDelta 300
(Delta 91 / Thor 575575)
Launch siteVandenberg, SLC-2W
ContractorDouglas Aircraft Company
End of mission
Last contact21 June 1977
Orbital parameters
Reference systemGeocentric orbit[1]
RegimeLow Earth orbit
Perigee altitude1,448 km (900 mi)
Apogee altitude1,457 km (905 mi)
Period114.93 minutes

AMSAT-OSCAR 6 (a.k.a. AO-6) was the first Phase 2 amateur radio satellite (P2-A) launched into low Earth orbit. It was also the first satellite constructed by the new AMSAT North America (AMSAT-NA) organization.


The satellite was launched 15 October 1972, by a Delta 300 launcher from Vandenberg Air Force Base, Lompoc, California. AO-6 was launched piggyback with NOAA-2 (ITOS-D).


AMSAT-OSCAR 6 was box-shaped, measuring 43 cm × 30 cm × 15 cm, with a mass of 18.2 kg. It had a near-circular polar orbit of 1,448×1,457 km with an inclination of 101.70°. It deployed two quarter-wave monopole antennas, one each for 144 and 435 MHz, and half-wave dipole antenna for 29 MHz. It remained operational for 4.5 years until a battery failure on 21 June 1977.[2][3]

Equipped with solar panels powering NiCd batteries, AO-6 provided 24 V at 3.5 watts power to three transponders. It carried a Mode A transponder (100 kHz wide at 1 watt) and provided store-and-forward morse and teletype messages (named Codestore) for later transmission. Subsystems were built in the United States, Australia, and Germany.[4]

AO-6 had a 1.3-watt transmitter into a half-wave dipole antenna. AO-6's receiver input sensitivity was approximately -100 dBm (2 μV per meter) and had an Automatic gain control (AGC) that provided up to 26 dB of gain reduction optimized for single-sideband modulation. The transceiver team consisted of Karl Meinzer DJ4ZC, Wallace Mercer W4RUD, Dick Daniels WA4DGU and Jan King W3GEY.


AO-6 demonstrated several uses of new technologies and operations.[4]

See also


  1. ^ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 16 June 2013.
  2. ^ "AMSAT P2A". Gunter's Space Page. 31 December 1999. Retrieved 12 February 2013.
  3. ^ "Oscar 6 1972-082B". NASA. 14 May 2020. Retrieved 7 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  4. ^ a b "AMSAT-OSCAR 6 Satellite Summary". AMSAT. 31 May 2003. Archived from the original on 18 June 2010. Retrieved 11 February 2013.
  5. ^ Klein, Perry (October 1975). "Intersatellite communication using the AMSAT-OSCAR 6 and AMSAT-OSCAR 7 radio amateur satellites". IEEE Proceedings. IEEE. 63 (10): 1526–1527. Bibcode:1975IEEEP..63.1526K. doi:10.1109/PROC.1975.9988.