Surveyor 4

Surveyor 4 was the fourth lunar lander in the American uncrewed Surveyor program sent to explore the surface of the Moon. This spacecraft crashed after an otherwise flawless mission; telemetry contact was lost 2.5 minutes before touchdown. The planned landing target was Sinus Medii (Central Bay) at 0.4° north latitude and 1.33° west longitude.

Surveyor 4
Surveyor model on Earth
Mission typeLunar lander
COSPAR ID1967-068A
SATCAT no.02875
Mission duration62 hrs. 9 min. 1 sec. (launch to last contact)
Spacecraft properties
ManufacturerHughes Aircraft
Launch mass1,039 kg[1]
Dry mass283 kilograms (624 lb)[2]
Start of mission
Launch dateJuly 14, 1967, 11:53:29 (1967-07-14UTC11:53:29Z) UTC
RocketAtlas LV-3C Centaur-D
Launch siteCape Canaveral LC-36A
End of mission
Last contact17 July 1967, 02:02:30 (1967-07-17UTC02:02:31Z) UTC (approx)
Lunar impact (failed landing)
Impact dateJuly 17, 1967, 02:05:00 UTC
Impact site0.45°N 1.39°W / 0.45; -1.39

Surveyor 6 successfully landed near the crash site of Surveyor 4 a few months later in November of 1967.


This spacecraft was the fourth in a series designed to achieve a soft landing on the Moon and to return photography of the lunar surface for determining characteristics of the lunar terrain for Apollo lunar landing missions. Equipment on board included a television camera and auxiliary mirrors, a soil mechanics surface sampler, strain gauges on the spacecraft landing legs, and numerous engineering sensors. Like Surveyor 3, Surveyor 4 was also equipped with a surface claw (with a magnet in the claw) to detect and measure ferrous elements in the lunar surface.

After a flawless flight to the Moon, radio signals from the spacecraft ceased during the terminal-descent phase at 02:03 UT on 17 July 1967, approximately 2.5 minutes before touchdown. Contact with the spacecraft was never reestablished, and the mission was unsuccessful. The solid-fuel retrorocket may have exploded near the end of its scheduled burn.[3]

See also


  1. "Surveyor 4: The Impact of a Low Probability Event". Drew Ex Machina.
  2. "Surveyor 4". NASA Space Science Data Coordinated Archive. NASA.
  3. "Surveyor 4". NASA Space Science Data Coordinated Archive. NASA.

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