Explorer 49

Explorer 49 (also called RAE-B) was a 328 kilogram satellite launched on June 10, 1973 for longwave radio astronomy research. It had four 230-meter long X-shaped antenna elements, which made it one of the largest spacecraft ever built.

Launch

Explorer 49 was launched after the termination of the Apollo program, and although it did not examine the Moon directly, it became the last American lunar mission until the launch of Clementine spacecraft in 1994.

Orbit

This mission was the second of a pair of Radio Astronomy Explorer (RAE) satellites, Explorer 38 or RAE-A being the first. Explorer 49 was placed into lunar orbit to provide radio astronomical measurements of the planets, the Sun, and the galaxy over the frequency range of 25 kHz to 13.1 MHz. Since the spacecraft's design used gravity gradient booms, the lumpy lunar gravity field made for some interesting problems for the mission scientists.

See also

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