Surveyor 3 was the third

lander Lander may refer to: Media and entertainment * ''Lander'' (computer game), computer game published by Psygnosis in 1999 * ''Lander'' (game demo), the 3D game demo provided with the Acorn Archimedes computer * Lander (Transformers), a fiction ...

of the

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

uncrewed

Surveyor program The Surveyor program was a NASA program that, from June 1966 through January 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. The Surveyor craft w ...

sent to explore the surface of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

in 1967. It was the first mission to carry a surface-soil sampling-scoop. Surveyor 3 was visited by

Apollo 12 Apollo 12 (November 14–24, 1969) was the sixth crewed flight in the United States Apollo program and the second to land on the Moon. It was launched on November 14, 1969, by NASA from the Kennedy Space Center, Florida. Commander Charles ...

astronauts

Pete Conrad Charles "Pete" Conrad Jr. (June 2, 1930 – July 8, 1999) was an American NASA astronaut, aeronautical engineer, naval officer and aviator, and test pilot, and commanded the Apollo 12 space mission, on which he became the third person to ...

and

Alan Bean Alan LaVern Bean (March 15, 1932 – May 26, 2018) was an American naval officer and aviator, aeronautical engineer, test pilot, NASA astronaut and painter; he was the fourth person to walk on the Moon. He was selected to become an astron ...

in November 1969, and remains the only probe visited by humans on another

world In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the worl ...

. The Apollo 12 astronauts excised several components of Surveyor 3, including the television camera, and returned them to Earth for study.

History

Launched on April 17, 1967, Surveyor 3 landed on April 20, 1967, at the

Mare Cognitum Mare Cognitum (Latin ''cognitum'', the "Sea that has Become Known") is a lunar mare located in a basin or large crater which sits in the second ring of Oceanus Procellarum. To the northwest of the mare is the Montes Riphaeus mountain range, par ...

portion of the

Oceanus Procellarum Oceanus Procellarum ( la, Ōceanus procellārum, lit=Ocean of Storms) is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Proc ...

(S3° 01' 41.43" W23° 27' 29.55"), in a small crater that was subsequently named

Surveyor Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ...

. It transmitted 6,315 TV images to the Earth, including the first images to show what planet Earth looked like from the Moon's surface. As Surveyor 3 was landing in the crater highly reflective rocks confused the spacecraft's lunar descent

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, Marine radar, ships, spacecraft, guided missiles, motor v ...

. The engines failed to cut off at 14 feet (4.27 meters) in altitude as called for in the mission plans, and this delay caused the lander to bounce on the lunar surface twice. Its first bounce reached the altitude of about 35 feet (10.6 meters). The second bounce reached a height of about . On the third impact with the surface — from the initial altitude of 3 meters, and velocity of zero, which was below the planned altitude of 14 feet (4.27 meters), and very slowly descending — Surveyor 3 settled down to a soft landing as intended. This Surveyor mission was the first that carried a surface-soil sampling-scoop, which can be seen on its extendable arm in the pictures. This mechanism was mounted on an electric-motor-driven arm and was used to dig four trenches in the lunar soil. These trenches were up to 7 inches (17.8 centimeters) deep. Samples of soil from the trenches were placed in front of the Surveyor's television cameras to be photographed and the pictures radioed back to the Earth. When the first lunar nightfall came on May 3, 1967, Surveyor 3 was shut down because its solar panels were no longer producing electricity. At the next lunar dawn (after 14 terrestrial days, or about 336 hours), Surveyor 3 could not be reactivated, because of the extremely cold temperatures that it had experienced. This is in contrast with the

Surveyor 1 Surveyor 1 was the first lunar soft-lander in the uncrewed Surveyor program of the National Aeronautics and Space Administration (NASA, United States). This lunar soft-lander gathered data about the lunar surface that would be needed for the cr ...

, which was able to be reactivated twice after lunar nights, but then never again. Surveyor 3 became famous after the crew of

used it as a landing target site. Landing within walking distance on November 19, 1969, the astronauts took several pictures of the probe and removed a scoop from the probe's soil mechanics-surface sampler, a section of unpainted aluminum tube from a strut supporting the Surveyor's radar altimeter and Doppler velocity sensor, another section of aluminum tube that was coated with inorganic white paint and a segment of television cable wrapped in aluminized plastic film and the Surveyor 3's television camera which were returned to Earth. Surveyor 3 is the only probe visited by humans on another

Science instruments

Television

The television camera on Surveyor 3 consisted of a

vidicon Video camera tubes were devices based on the cathode ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes ...

tube, two 25 and 100 millimeter

focal length The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foc ...

lenses, shutters,

filter Filter, filtering or filters may refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Filter (software), a computer program to process a data stream * Filter (video), a software component tha ...

s, and an

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

mounted along an axis inclined about 16 degrees to the central axis of the spacecraft. The TV camera was mounted under a mirror that could be moved in

azimuth An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematical ...

(horizontally) and elevation (vertically). The operation of the camera was completely dependent upon the receipt of proper commands from the Earth. Frame-by-frame coverage of the lunar surface was obtained over the complete 360 degrees in azimuth, and from +40 degrees above the plane normal to the camera's Z-axis to −65 degrees below this plane. Both 600-line and 200-line modes of TV camera operation were used. The 200-line mode transmitted over an

omnidirectional antenna In radio communication, an omnidirectional antenna is a class of antenna which radiates equal radio power in all directions perpendicular to an axis (azimuthal directions), with power varying with angle to the axis ( elevation angle), declining ...

and scanned one frame every 61.8 seconds. A complete video transmission of each 200-line picture required 20 seconds and used a bandwidth of 1.2 kHz. The 600-line pictures were transmitted over a

directional antenna A directional antenna or beam antenna is an antenna which radiates or receives greater power in specific directions allowing increased performance and reduced interference from unwanted sources. Directional antennas provide increased performanc ...

. These pictures were scanned as often as once every 3.6 seconds. Each 600-line picture required a nominal one second to be read from the image vidicon, and its transmission required a 220 kHz bandwidth, using digital picture transmission. The TV photos were displayed back on the Earth on a slow-scan TV monitor that was coated with a long-persistence

phosphor A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or v ...

. Its persistence had been selected to match the nominal maximum

frame rate Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images ( frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also be ...

. One frame of TV identification was received for each incoming TV photo, and the picture was displayed in real-time at a rate compatible with that of the incoming image. These data were recorded on a video magnetic-tape recorder. The camera returned 6315 pictures between April 20 and May 3, 1967, including views of the spacecraft itself, panoramic lunar surveys, views of the mechanical surface digger at work, and of an April 24 eclipse of the Sun by the Earth. The

Lunar Module landed near Surveyor 3 on November 19, 1969. Astronauts Conrad and Bean examined the spacecraft, and they brought back about 10 kg of parts of the Surveyor to the Earth, including its TV camera, which is now on permanent display in the

National Air and Space Museum The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States. Established in 1946 as the National Air Museum, it opened its main building on the N ...

in Washington, D.C. File:Surveyor 3 Fig 7-41b1.jpg, Panorama of the mare surface File:Surveyor 3 Fig 3-44.jpg, Angular blocks, up to 2 meters in diameter, which form part of a strewn field of blocks that surround a sharp-rim crater 13 meters in diameter File:Surveyor 3 Fig 7-41b2.jpg, Similar view but with different lighting File:Surveyor 3 Fig 3-53.jpg, Blocky fragments on north wall of crater in which the spacecraft is located

Soil mechanics surface sampler

Details of Surveyor 3 Soil Mechanics Surface Sampler

The soil mechanics surface sampler was designed to dig, scrape, and trench the lunar surface and to transport lunar surface material while being photographed so that the properties of the lunar surface could be determined. The sampler was mounted below the television camera and consisted primarily of a scoop approximately 120 mm long and 50 mm wide. The scoop consisted of a container, a sharpened blade, and an

electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate f ...

to open and close the container. A small footpad was attached to the scoop door to present a flat surface to the lunar surface. The scoop was capable of holding a maximum quantity of approximately 32 mm diameter of solid lunar material and a maximum of 100 cm³ of granular material. The scoop was mounted on a

pantograph A pantograph (, from their original use for copying writing) is a mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen. If a line dr ...

arm that could be extended about 1.5 m or retracted close to the spacecraft motor drive. The arm could also be moved from an azimuth of +40 to -72 degrees or be elevated 130 mm by motor drives. It could also be dropped onto the lunar surface under force provided by gravity and a spring. The surface sampler performed seven bearing tests, four trench tests, and 13 impact tests. The total operating time was 18 hours, 22 minutes on 10 separate occasions. Measurements of motor currents and forces applied to the surface were not obtained due to the state of the spacecraft

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...

following landing on the lunar surface. However, estimations were possible. The small

spring constant In physics, Hooke's law is an empirical law which states that the force () needed to extend or compress a spring by some distance () scales linearly with respect to that distance—that is, where is a constant factor characteristic of th ...

of the torque spring precluded the determination of density from the impact tests. Penetrations of 38 to 50 mm were obtained from the bearing tests, and a 175 mm depth was reached during trenching operations. The design of the mechanism and its electronic auxiliary was more than adequate for the lunar surface operations. The scoop was also returned to Earth by the Apollo 12 astronauts and is currently on display at JPL.

Apollo 12 and the possibility of interplanetary contamination

The Surveyor 3 landing site was later selected also as the landing target for the

Lunar Module The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed ...

of the

crewed lunar mission in 1969. Several components of the Surveyor 3 lander were collected and returned to the Earth for study of the long-term exposure effects of the harsh lunar environment on human-made objects and materials. Although space probes have returned to Earth in the decades since Apollo 12, this remains the only occasion on which humans have visited a probe that had been sent off-world. It is widely claimed that a common type of

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, '' Streptococcus mitis'', accidentally contaminated the Surveyor's camera prior to launch, and that the bacteria survived dormant in the harsh lunar environment for two and a half years, supposedly then to be detected when Apollo 12 brought the Surveyor's camera back to the Earth. This claim has been cited by some as providing credence to the idea of interplanetary

panspermia Panspermia () is the hypothesis, first proposed in the 5th century BCE by the Greek philosopher Anaxagoras, that life exists throughout the Universe, distributed by space dust, meteoroids, asteroids, comets, and planetoids, as well as by spacec ...

, but more importantly, it led NASA to adopt strict abiotic procedures for space probes to prevent contamination of the planet

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

and other astronomical bodies that are suspected of having conditions possibly suitable for life. Most dramatically, the ''Galileo'' space probe was deliberately destroyed at the end of its mission by crashing it into

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousand ...

, to avoid the possibility of contaminating the Jovian moon

Europa Europa may refer to: Places * Europe * Europa (Roman province), a province within the Diocese of Thrace * Europa (Seville Metro), Seville, Spain; a station on the Seville Metro * Europa City, Paris, France; a planned development * Europa Clif ...

with bacteria from Earth. The ''Cassini'' probe also impacted Saturn at the end of its mission in 2017. However, independent investigators have challenged the claim of surviving bacteria on Surveyor 3 on the Moon. There is a possibility the contamination was caused by using a non-airtight container, or by scientists not covering their arms in the clean room after Apollo 12.

Lunar Reconnaissance Orbiter

In 2009, the

Lunar Reconnaissance Orbiter The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic missions t ...

(LRO) photographed the Surveyor 3 landing site in some detail, in which surrounding astronaut foot tracks could also be seen. In 2011, the LRO returned to the landing site at a lower altitude to take higher resolution photographs.

References

External links

Surveyor Program Results (PDF) 1969Analysis of Surveyor 3 material and photographs returned by Apollo 12 (PDF, 24 MB) 1972Surveyor 3 images
at Lunar and Planetary Institute
Surveyor Site III Lunar Map
at Lunar and Planetary Institute
Surveyor Site III Lunar Photomap
at Lunar and Planetary Institute {{Use American English, date=January 2014 3 Spacecraft launched in 1967 Missions to the Moon Apollo 12 Spacecraft launched by Atlas-Centaur rockets Soft landings on the Moon Alan Bean Pete Conrad 1967 on the Moon