
Mission Details
Mission Name: Explorer 49 |
Mission Type: Lunar Orbiter |
Operator: NASA (National Aeronautics and Space Administration) |
Launching State: United States |
Location: Unknown |
Latitude: N/A |
Longitude: N/A |
Launch Date: 10 June 1973, 14:13:00 UT |
Landing Date: N/A |
Objects on or Related to Site: Explorer 49/RAE-B |
Image Source: NASA |
Description
The Radio Astronomy Explorer B (RAE-B) mission was the second of a pair of RAE satellites. It 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.

Read more:
https://solarsystem.nasa.gov/missions/explorer-49/in-depth/
Heritage Consideration
The spacecraft was the largest human-made object to orbit the Moon to date—with its deployed antennas measuring about 1,500 feet (457.2 meters or nearly half a kilometer!) tip-to-tip. These antennas, as well as a 630-foot (192-meter) long damper boom and a 120-foot (36.6-meter) dipole antenna, were all stored away on motor-driven reels which allowed them to unfurl in lunar orbit.
Object on or Related to Site
Object Name: Explorer 49/RAE-B | |
Cospar: 1973-039A | |
Norad: N/A | |
Location: Precise location unknown or undisclosed. | |
Launch Date: 10 June 1973, 14:13:00 UT | |
Landing Date: N/A | |
Deployment: N/A | |
End Date: August, 1977 | |
Function: To provide radio astronomical measurements of the planets, the sun, and the galaxy over the frequency range of 25 kHz to 13.1 MHz. | |
Image Source: NASA |
Description
The spacecraft, part of a duo of Radio Astronomy Explorer (RAE) missions (the other being Explorer 48), was designed to conduct comprehensive studies of low-frequency radio emissions from the Sun, the Moon, the planets, and other galactic and extragalactic sources, while in a circular orbit around the Moon. Its location was driven by the need to avoid terrestrial radio interference.

Read more:
https://solarsystem.nasa.gov/missions/explorer-49/in-depth/