In this regard, Compton was following in the footsteps of OSO (Orbiting Solar Observatory) 7 (1971-74) and the Solar Maximum Mission
(1980-81 and 1984-89), the only other space missions to see gamma-ray emission lines from solar flares.
Though representing only the current solar cycle, data from the Earth-orbiting Solar Maximum Mission
and Nimbus 7 satellites suggest the sun's activity rises and falls with changes in its magnetic field, Baliunas reports.
The high activity levels also raised the height of Earth's atmosphere enough to cause the Solar Maximum Mission
satellite to reenter it earlier than expected, wrapping up a 10-year career that yielded about 250,000 photos of the sun, identified more than 12,500 solar flares, provided the first evidence to support the idea that only supernovas are suitable sites for the formation of elements heavier than iron, and discovered 10 "sun-grazing" comets (136: 357).
Flight controllers long anticipated the demise of the Solar Maximum Mission
satellite as its orbit descended lower into Earth's atmosphere with each trip around the planet.
Although researchers have had opportunities to study some objects after various periods of space exposure -- such as the shuttles, Apollo return modules and components from the Solar Maximum Mission
satellite -- none of these was intended as an experiment for return and analysis in terrestrial laboratories.
But on June 20, an instrument aboard the Solar Maximum Mission
satellite took a series of photos showing a prominence that rose nearly 2 million miles, about 2.5 solar radii from the sun's edge, and then headed back down.
During each of the four newly analyzed flares, which occurred in 1980, instruments aboard the Solar Maximum Mission
satellite detected a wavelength decrease, or "blueshift," in X-rays emitted by ionized calcium.
Stron of Lockheed Palo Alto (Calif.) Research Laboratory, the abundances measured with the Lockheed-built X-ray polychromator (XRP) aboard the Solar Maximum Mission
satellite differ in different parts of the sun, sometimes varying even from minute to minute.