Imagine the Universe!

OSO 1


photo of OSO


* Mission Overview

The first in a series of 8 successfully launched Orbiting Solar Observatories (OSO 1) was launched on 7 March 1962. The 200 kg spacecraft had a 9-sided spinning wheel section 1.2 m in diameter joined onto a fan- shaped sail section. It was put into a roughly circular orbit at ~ 575 km altitude, 32.8 degrees inclination. It s primary mission objectives were to measure the solar electromagnetic radiation in the UV, X-ray, and gamma-ray regions. Secondarily, it was to investigate dust particle in space. Data transmission ended on 6 August 1963. The satellite reentered the Earth's atmosphere 8 October 1981.

* Instrumentation

There were a number of X-ray and gamma-ray experiments aboard OSO 1 for performing solar observations. One instrument, however, the University of Minnesota Gamma-ray Experiment, was designed to provide preliminary measurements of the intensity and directional properties of low-energy gamma-rays in space. The detector operated in the 50 keV - 3 MeV range. For the 50-150 keV range, a NaI(Tl) scintillation crystal monitored radiation through a lead shield. The detector operating in the 0.3-1.0 MeV and 1.0-3.0 MeV energy regions used two scintillators connected as a Compton coincidence telescope.

* Science

The U. Minnesota gamma-ray experiment on OSO 1 produced a measurement of the extraterrestrial gamma-ray flux between 0.5-3.0 MeV, and an indication of its origin on the celestial sphere. Equally important, this experiment began to define the background problems encountered in gamma-ray astronomy.
[Gallery] (http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/images/oso_images.html) [Publications] (http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/biblio/oso_biblio.html)
Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Nicholas White (Director), within the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center.

The Imagine Team
Project Leader: Dr. Jim Lochner
All material on this site has been created and updated between 1997-2004.

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