Surveyor 1
Encyclopedia
Surveyor 1 was the first lunar soft-lander
Lander (spacecraft)
A lander is a spacecraft which descends toward and comes to rest on the surface of an astronomical body. For bodies with atmospheres, the landing is called atmospheric reentry and the lander descends as a re-entry vehicle...

 in the unmanned Surveyor program
Surveyor program
The Surveyor Program was a NASA program that, from 1966 through 1968, sent seven robotic spacecraft to the surface of the Moon. Its primary goal was to demonstrate the feasibility of soft landings on the Moon...

 of the National Aeronautics and Space Administration (NASA, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

). This lunar soft-lander gathered data about the lunar surface that would be needed for the manned Apollo Moon landings that began in 1969. The successful soft landing of Surveyor 1 on the Ocean of Storms was the first one by an American space probe
Space probe
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...

 onto any extraterrestrial body
Astronomical object
Astronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...

, and it occurred just four months after the first Moon landing by the Soviet Union's Luna 9
Luna 9
Luna 9 was an unmanned space mission of the Soviet Union's Luna program. On February 3, 1966 the Luna 9 spacecraft was the first spacecraft to achieve a soft landing on any planetary body other than Earth and to transmit photographic data to Earth.The automatic lunar station that achieved the...

 probe. This was also a success on NASA's first attempt at a soft landing on any astronomical object
Astronomical object
Astronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...

.

Surveyor 1 was launched May 30, 1966, from the Cape Canaveral Air Force Station
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

 at Cape Canaveral, Florida
Cape Canaveral, Florida
Cape Canaveral is a city in Brevard County, Florida, United States. The population was 8,829 at the 2000 census. As of 2008, the estimated population according to the U.S. Census Bureau was 10,147...

, and it landed on the Moon on June 2, 1966. Surveyor 1 transmitted 11,237 still photos of the lunar surface to the Earth by using a television camera and a sophisticated radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

-telemetry
Telemetry
Telemetry is a technology that allows measurements to be made at a distance, usually via radio wave transmission and reception of the information. The word is derived from Greek roots: tele = remote, and metron = measure...

 system.

The Surveyor program was managed by the Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...

, in Los Angeles County, but the entire Surveyor space probe was designed and built by the Hughes Aircraft Company in El Segundo, California
El Segundo, California
El Segundo is a city in Los Angeles County, California, United States. Located on the Santa Monica Bay, it was incorporated on January 18, 1917, and is one of the Beach Cities of Los Angeles County and part of the South Bay Cities Council of Governments...

.

Mission description

The Surveyor series of space probe
Space probe
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...

s was designed to carry out the first soft landings on the Moon by any American spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

. No instrumentation was carried specifically for scientific experiments by Surveyor 1, but considerable scientific data was collected by its TV camera and then returned to the Earth via the Deep Space Network
Deep Space Network
The Deep Space Network, or DSN, is a world-wide network of large antennas and communication facilities that supports interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the solar system and the universe, and supports selected...

 in 1966 - 67. These spacecraft carried two TV cameras - one for its approach -- which was not used in this case -- and one for taking still pictures of the lunar surface. Over 100 engineering sensors were on board each Surveyor. Their TV systems transmitted pictures of the spacecraft footpad and surrounding lunar terrain and surface materials. These spacecraft also acquired data on the radar reflectivity of the lunar surface, the load-bearing strength of the lunar surface, and the temperatures for use in the analysis of the lunar surface temperatures. (Later Surveyor space probes, beginning with Surveyor 3
Surveyor 3
Surveyor 3 was the third lander of the American unmanned Surveyor program sent to explore the surface of the Moon. Launched on April 17, 1967, Surveyor 3 landed on April 20, 1967 at the Mare Cognitum portion of the Oceanus Procellarum...

carried scientific instruments to measure the composition and mechanical properties
Mechanics
Mechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment....

 of the lunar "soil".

Surveyor 1 was launched May 30, 1966, and sent directly into a trajectory to the Moon without any parking orbit
Parking orbit
A parking orbit is a temporary orbit used during the launch of a satellite or other space probe. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory...

. Its retrorocket
Retrorocket
A retrorocket is a rocket engine providing thrust opposing the motion of a spacecraft, thereby causing it to decelerate.-History:...

s were turned off at a height of about 3.4 meters above the lunar surface. Then Surveyor 1 fell freely to the surface from this height, and it landed on the lunar surface on June 2, 1966, on the Oceanus Procellarum. This location was at about 2.45 degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...

s South latitude and 43.22 degrees West longitude.

The duration of the spaceflight
Spaceflight
Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

 of Surveyor 1 was about 63 hours, 30 minutes. Surveyor I's lunar launch weight was about 995.2 kilograms (2,194 lb), and its landing weight (minus expended maneuvering propellant, its solid-fueld retrorocket -- which had been jettisoned, and its radar altimeter
Radar altimeter
A radar altimeter, radio altimeter, low range radio altimeter or simply RA measures altitude above the terrain presently beneath an aircraft or spacecraft...

 system) was about 294.3 kilograms (648.8 lb).

Surveyor 1 transmitted video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

 data from from the Moon beginning shortly after its landing, through July 14, 1966 -- but with a period of no operations during the long lunar night of June 14, 1966, through July 7, 1966. Any radio communications with Surveyor 1 required a "line-of-sight" from its location to the Earth, and this is not available during the lunar nights. Also, since it was solar-powered, Surveyor 1 had no electricity with which to do anything at all during the two weeks of the lunar nights.

The return of engineering information (temperatures, etc.) from Surveyor 1 continued through January 7, 1967, with several long interruptions by the lunar nights, of course.

Science instruments

Television

The TV camera consisted of a vidicon tube, 25 millimeter and 100 millimeter focal-length lenses, a shutter, several optical filters, and and iris
Iris
Iris commonly refers to:* Iris , part of the eye* Iris * Iris , a feminine given name* Iris , a Greek goddess* Iris , a genus of flowering plantsIris may also refer to:-Places:...

-system mounted along an axis inclined approximately 16 degrees from the central axis of Surveyor 1. The camera was mounted under a mirror that could be moved in azimuth and elevation. This arrangement created a virtual stereo image pair so that adjacent overlapping images were stereo image pairs and could be viewed as three-dimensional images. This stereo capability permitted some photogrammetric measurements of various lunar features. The TV camera's operation was dependent on the receipt of the proper radio commands from the Earth. Frame-by-frame coverage of the lunar surface was obtained over 360 degrees in azimuth and from +40 degrees above the plane normal to the camera's axis to -65 degrees below this plane. Both 600-line and 200-line modes of operation were used. The 200-line mode transmitted over an omnidirectional antenna for the first 14 photos and scanned one frame every 61.8 seconds. The remaining transmissions were of 600-line pictures over a directional antenna, and each frame was scanned every 3.6 seconds. Each 200-line picture required 20 seconds for a complete video transmission and it used a radio bandwidth of about 1.2 kilohertz.

Each 600-line picture required about one second to be read from the vidicon tube, and they required a radio bandwidth of about 220 kilohertz. The data transmissions were converted into a standard TV signal for both closed-circuit TV and broadcast TV. The television images were displayed on earth on a slow-scan monitor coated with a long persistency phosphor. The persistency was selected to optimally match the nominal maximum frame rate. One frame of TV identification was received for each incoming TV frame, and it was displayed in real time at a rate compatible with the incoming image. These data were recorded on a video magnetic tape recorder. Over 10,000 pictures were taken by Surveyor 1's TV camera before the lunar sunset of June 14, 1966. Included in these pictures were wide-angle and narrow-angle panoramas, focus ranging surveys, photometric surveys, special area surveys, and celestial photography. Surveyor 1 responded to commands to activate the camera on July 7. and by July 14, 1966, it had returned nearly 1000 more pictures.

Strain gauge

Strain gauges were mounted on each leg shock absorber to record the peak axial forces at landing impact of the spacecraft. They were designed to accept a force of approximately 800 kgf
Kilogram-force
A kilogram-force , or kilopond , is a gravitational metric unit of force. It is equal to the magnitude of the force exerted by one kilogram of mass in a gravitational field...

 (7.8 kN).

External links

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