Surveyor 4

Infobox Spacecraft
Name=Surveyor 4


Caption=Surveyor model on Earth
Organization=NASA
Major_Contractors= Hughes Aircraft
Mission_Type=Lander
Satellite_of= Moon
Launch= July 14, 1967 11:53:29 UTC
Launch_Vehicle= Atlas-Centaur
Decay=Impacted on moon July 17, 1967, 02:05:00 UTC at Lunar coords and quad cat|0.45|N|1.39|W
Mission_Duration= 65 hours
Mass= 282 kg after fuel used
NSSDC_ID= 1967-068A

Surveyor 4 was the fourth lunar lander in the Surveyor program that explored the Moon.

*Launched July 14, 1967; landed July 17, 1967
*Weight on landing: 625 lb (283 kg)

This spacecraft crashed after an otherwise flawless mission; telemetry contact was lost 2.5 minutes before touchdown.

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. After a flawless flight to the moon, radio signals from the spacecraft ceased during the terminal-descent phase, approximately 2.5 min. before touchdown. Contact with the spacecraft was never reestablished, and the mission was unsuccessful. The solid fuel retro rocket may have exploded near the end of its scheduled burn.

Like Surveyor 3, Surveyor 4 was equipped with a surface claw (with a magnet in the claw) to detect and measure ferrous elements in the lunar surface. The mission was completely successful until all communications were abruptly lost 2 seconds prior to retrorocket cutoff at 02:03 UT on 17 July 1967, with only 2.5 minutes left to landing on the Moon. The landing target was Sinus Medii (Central Bay) at 0.4° north latitude and 1.33° west longitude. NASA concluded that the lander might have exploded when contact was lost.

External links

* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690027073_1969027073.pdf Surveyor Program Results (PDF) 1969]