Orbiting Solar Observatory

Dr. Nancy Roman, with a model of the Orbiting Solar Observatory

The OSO 4 satellite

A Delta rocket launching OSO 8 on June 21, 1975, at Cape Canaveral

The Orbiting Solar Observatory (abbreviated OSO) Program was the name of a series of nine NASA satellites primarily intended to study the Sun, though they also included important non-solar experiments. Eight were launched successfully between 1962 and 1975 using Delta rockets. Their primary mission was to observe an 11-year sun spot cycle in UV and X-ray spectra. The initial seven, OSO 1 through OSO 7, were built by Ball Aerospace, then known as Ball Brothers Research Corporation (BBRC), in Boulder Colorado. OSO 8 was built by Hughes Space and Communications Company, in Culver City, California.

The basic design of the entire series featured a rotating section, the "Wheel", which provided gyroscopic stability to the whole. A second section, the "Sail", was driven electrically against the Wheel's rotation, and stabilized to point at the Sun. The Sail carried pointed solar instruments, and also the array of solar photovoltaic cells which powered the spacecraft. The critical bearing between the Wheel and the Sail was a major feature of the design, as it had to operate smoothly for months in the hard vacuum of space without normal lubrication. It also carried both the power from the Sail and the data from the pointed solar instruments to the Wheel, where most of the spacecraft functions were located. Additional science instruments could also be located in the Wheel, generally looking out on a rotating radius vector which scanned the sky, and also across the Sun, every few seconds.

As for a number of other NASA programs, the OSO spacecraft were labeled by letter designations before launch, and only given numbers when successfully placed in orbit. Thus OSO 1 was originally called OSO A, through OSO I, which became OSO 8. The OSO J was planned but never launched.

See also

• OSO 1
• OSO 2
• OSO 3
• OSO 4
• OSO 5
• OSO 6
• OSO 7
• OSO 8

External links

• OSO 1, OSO 2, OSO 3, OSO 4, OSO 5, OSO 6,
• OSO 7, OSO 8 at NASA

v • d • e Solar space observatory missions Current Pioneer 6, 7, 8, and 9 · GGS WIND · SOHO · ACE · TRACE · RHESSI · Hinode · STEREO · Koronas-Foton Spaceflight portal Completed Helios probes · ISEE 1–3 · SolarMax · Ulysses · Yohkoh · Pioneer 5 · Orbiting Solar Observatory Sample return Genesis Future Solar Dynamics Observatory · PICARD · Solar Orbiter · Solar Probe · Solar Sentinels Cancelled Pioneer H

This article about a specific observatory, telescope or astronomical instrument is a stub. You can help Wikipedia by expanding it. v • d • e

This spacecraft or satellite related article is a stub. You can help Wikipedia by expanding it. v • d • e