Surveyor 3

Surveyor 3
Surveyor 3 on the moon
NSSDC ID	1967-035A
Mission goal	Preparation of manned moon landings
Client	NASA
Launcher	Atlas - Centaur AC-10 / 290D
Course of the mission
Start date	April 17, 1967, 07:05 UTC
launch pad	CCAFS LC-36
End date	May 4th 1967
04/17/1967 begin 04/20/1967 Landing on the moon 05/04/1967 Abortion of the radio signals 11/19/1969 Disassembly of the camera and other parts by Apollo 12

Surveyor 3 was the third probe of the US space agency NASA as part of the Surveyor program . The Surveyor program was the successor to the Ranger program . The results of the program should prepare the first manned moon landing . Surveyor 3 was supposed to land undamaged on the moon and from there transmit images and data to earth. After Surveyor 1 , it was the second US probe that landed softly on the moon and was able to complete its mission.

mission

Astronaut Pete Conrad ( Apollo 12 ) examines Surveyor 3

Surveyor 3 was launched on 17 April 1967 aboard a Atlas - Centaur rocket from the launch pad LC-36 of the Cape Canaveral Air Force Station . In contrast to Surveyor 2 , a course correction went smoothly. On April 20th, the probe reached the moon. At a height of 76 kilometers above the surface of the moon and at a speed of 2626 m / s, the first brake rockets detonated, which slowed the speed to 137 m / s. After that, as with Surveyor 1, the Doppler radar and the altimeter took over the further approach. With Vernier engines , the probe should be braked in a controlled manner over the last few meters. Probably triggered by reflections, however, the nozzles switched off too late, so that Surveyor 3 did not touch down gently but made three more small "jumps". The distance between the first and second ground contact was approximately 20 meters, and between the second and third approximately 11 meters. After landing, the probe slipped about 30 cm, as the ground was inclined at 14 degrees. It landed 3 kilometers from the planned point in Oceanus Procellarum , about 370 km south of the Copernicus crater .

After a function test, Surveyor 3 transmitted the first of a total of 6326 images. In addition, data on the reflectivity of the lunar surface, the thickness of the surface and the temperature of the probe were collected and transmitted. The temperature of the probe should be used to draw conclusions about the surface temperature of the moon. An excavator arm dug a trench 18 cm deep. With this experiment, too, conclusions were drawn about the nature of the moon's surface. Images of a solar eclipse (triggered by the earth) were also taken.

Surveyor 3 survived the lunar night unscathed and sent data and images again the next lunar day. The last data was received on May 4, 1967 at 00:04 UT.

Apollo 12

About two years later, on November 19, 1969, Apollo 12 landed just 180 meters from Surveyor 3. Astronauts Pete Conrad and Alan Bean visited the spacecraft on its second field mission on November 20th. They took pictures of the probe and the surroundings and dismantled a total of almost ten kilograms of parts of the probe, including the TV camera.

Contamination of the moon by terrestrial microbes

In 1967, like all other probes at the time, terrestrial microbes found their way onto the earth's satellite in a camera housing of the probe . This process is known as forward contamination .

For decades it was a popular opinion that in Surveyor 3's camera, terrestrial microbes survived on the moon for several years . This camera, along with other components, was brought back to Earth from the Apollo 12 mission. However, recent investigations into historical documents in 2011 cast doubts on the results. The standards for the clean room used did not correspond to today's standards . So people wore gloves, but z. B. only short-sleeved shirts. Self-contamination cannot be ruled out.

Trivia

The Surveyor-3 camera can be viewed at the National Air and Space Museum in Washington, DC . The landing sites of Surveyor 3 and Apollo 12 can be seen in the images of the Lunar Reconnaissance Orbiter .

Web links

Commons : Surveyor 3  - collection of images, videos and audio files

• NASA: Surveyor 3 (English)
• Description of the surveyor program

Individual evidence

1. ^ Leonard David: Moon Microbe Mystery Finally Solved. Space.com, May 2, 2011, accessed March 13, 2016 .