Orbiting Astronomical Observatory 2

Orbiting Astronomical Observatory 2

Orbiting Astronomical Observatory 2
Mission type Astronomy
Operator NASA
COSPAR ID 1968-110A
SATCAT № 3597
Spacecraft properties
Manufacturer Grumman
Dry mass 2,012 kilograms (4,436 lb)
Start of mission
Launch date 7 December 1968, 08:40:09 (1968-12-07T08:40:09) UTC
Rocket Atlas SLV-3C Centaur-D
Launch site Cape Canaveral LC-36B
End of mission
Last contact Did not recognize date. Try slightly modifying the date in the first parameter.
Orbital parameters
Reference system Geocentric
Regime Low Earth
Perigee 768 kilometres (477 mi)
Apogee 777 kilometres (483 mi)
Inclination 35.0 degrees
Period 100.30 minutes
Epoch 6 January 1969[1]

The Orbiting Astronomical Observatory 2 (OAO-2, nicknamed Stargazer) was a space observatory launched on December 7, 1968.[2] An Atlas-Centaur rocket launched it into a nearly circular 750 kilometres (470 mi) altitude Earth orbit.[3] Data was collected in ultraviolet on many sources including comets, planets, and galaxies.[2][4] It had two major instrument sets facing in opposite directions; the Smithsonian Astrophysical Observatory (SAO) and the Wisconsin Experiment Package (WEP).[4] One discovery was large halos of hydrogen gas around comets,[4] and it also observed Nova Serpentis.[2]

The Smithsonian Astrophysical Observatory, also called Celescope, had four 12 inch Schwarzschild telescopes that fed into Uvicons.[5] Various filters, photocathodes, and electronics aided in collecting data in several ultraviolet light passbands.[5] The experiment was completed in April 1970.[5] By the time it finished about 10 percent of the sky was observed.[5]

The Wisconsin Experiment Package had eleven different telescopes for ultraviolet observations.[6] For example, there was a photoelectric photometer fed by a 16 inch telescope with a six-position filter wheel.[6] WEP observed over 1200 targets in ultraviolet light before the mission ended in early 1973.[4]

See also


  1. ^
  2. ^ a b c Joseph A. Angelo - Spacecraft for Astronomy (2009) - Page 20 (Google Books)
  3. ^ Gunter - OAO-2
  4. ^ a b c d Orbiting Astronomical Observatory OAO-2
  5. ^ a b c d High-Resolution Telescopes
  6. ^ a b Wisconsin Experiment Package

External links

  • OAO 2 observations of the Alpha Persei cluster