A Day in Astronomy: Launch of the Orbiting Solar Observatory 7

Image (Credit): Artist’s impression of NASA’s Orbiting Solar Observatory 7 circling the Earth. (NASA)

On this day in 1971, NASA launched the Orbiting Solar Observatory 7 satellite to study the Sun. It successfully completed its mission and remained in orbit through July 9, 1974.

According to a December 31, 1972 report by Ball Brothers Research Corporation, the goal of the Orbiting Solar Observatory program was to make observations and measurements contributing to:

  • Determination of details of the sun’s atmospheric structure, composition and physical state and the process of energy transport radially outward and inward;
  • Determination of origin, energy supply, and solar/terrestrial consequences of transient solar phenomena such as sun spots, flares, radio bursts, and particle bursts;
  • Prediction of transient solar events and their consequences by combining data with those from other spacecraft, rockets, balloons, and ground-based observations; and
  • Secondary objectives including study of the earth and celestial objects.

You can read more about the Orbiting Solar Observatory 7 mission here.

NASA launched eight successful Orbiting Solar Observatory missions in all, but the program had some problems along the way. One satellite launched in 1965 failed to reach orbit, with the satellite burning up in the atmosphere. In another case, a rocket motor test in 1964 went awry, killing three men and wounding eight others.