Surveyor 3
Encyclopedia
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
(S3º 01' 41.43" W23º 27' 29.55") . It transmitted a total of 6,315 TV images to the Earth.
As Surveyor 3 was landing (in a crater, as it turned out ), highly reflective rocks confused the spacecraft's lunar descent radar
. The engines failed to cut off at 14 feet (4.3 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 meters). The second bounce reached a height of about 11 feet (three meters). On the third impact with the surface — from the initial altitude of three meters, and velocity of zero, which was below the planned altitude of 14 feet (4.3 meters), and very slowly descending —Surveyor 3 settled down to a soft landing as intended.
This Surveyor mission was the first one 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 seven inches (18 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, which was able to be reactivated twice after lunar nights, but then never again.
The television camera on Surveyor 3 consisted of a vidicon tube, two 25 and 100 millimeter focal length
lenses, shutter
s, filter
s, and an iris
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 (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
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
. 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-persistency phosphor
. Its persistency had been selected to match the nominal maximum frame rate
. 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 the Earth itself during a solar eclipse
.
The Apollo 12 Lunar Module landed near Surveyor 3 in November 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
in Washington, D.C.
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
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
following landing on the lunar surface. However, estimations were possible. The small spring constant 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 Surveyor 3 landing site was later selected also as the landing target for the Lunar Module of the Apollo 12
manned 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 man-made objects and materials. Although space probes have returned to Earth in the decades since Apollo 12, this remains the only occasion in which humans have visited a probe that had been sent to another world.
It is widely claimed that a common type of bacteria
, Streptococcus mitis
, accidentally contaminated
the Surveyor's camera prior to launch, and that bacteria survived dormant in the harsh lunar environment for two and one-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, but more importantly, it led NASA to adopt strict abiotic procedures for space probes to prevent contamination of the planet Mars
and other astronomical bodies that are suspected of having conditions possibly suitable for life. Most dramatically, the Galileo space probe
was deliberately destroyed by sending it to crash into Jupiter
to avoid the possibility of contaminating the Jovian moon Europa
with bacteria from earth.
However, independent investigators have challenged the claim of surviving bacteria in Surveyor 3 on the Moon. (See Reports of Streptococcus mitis on the moon
.)
In 2009, the Lunar Reconnaissance Orbiter
photographed the Surveyor 3 landing site in some detail, in which surrounding astronaut foot tracks could also be seen. In 2011, the Lunar Reconnaissance Orbiter
returned to the landing site at a lower altitude to take higher resolution photographs.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
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...
sent to explore the surface of the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
. Launched on April 17, 1967, Surveyor 3 landed on April 20, 1967 at the Mare Cognitum
Mare Cognitum
Mare Cognitum is a lunar mare located in a basin or large crater which sits in the second ring of the Procellarum basin. The basin material is of the Lower Imbrian epoch, while the basaltic mare material is of the Upper Imbrian epoch...
portion of the Oceanus Procellarum
Oceanus Procellarum
Oceanus Procellarum is a vast lunar mare on the western edge of the near side of the Earth's Moon. Its name derives from the old superstition that its appearance during the second quarter heralded bad weather...
(S3º 01' 41.43" W23º 27' 29.55") . It transmitted a total of 6,315 TV images to the Earth.
As Surveyor 3 was landing (in a crater, as it turned out ), highly reflective rocks confused the spacecraft's lunar descent radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
. The engines failed to cut off at 14 feet (4.3 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 meters). The second bounce reached a height of about 11 feet (three meters). On the third impact with the surface — from the initial altitude of three meters, and velocity of zero, which was below the planned altitude of 14 feet (4.3 meters), and very slowly descending —Surveyor 3 settled down to a soft landing as intended.
This Surveyor mission was the first one 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 seven inches (18 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, which was able to be reactivated twice after lunar nights, but then never again.
Television
Focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
lenses, shutter
Shutter (photography)
In photography, a shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene...
s, filter
Filter (optics)
Optical filters are devices which selectively transmit light of different wavelengths, usually implemented as plane glass or plastic devices in the optical path which are either dyed in the mass or have interference coatings....
s, and an iris
Diaphragm (optics)
In optics, a diaphragm is a thin opaque structure with an opening at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture...
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 (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
Omnidirectional antenna
In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often...
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
Directional antenna
A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources....
. 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-persistency phosphor
Phosphor
A phosphor, most generally, is a substance that exhibits the phenomenon of luminescence. Somewhat confusingly, this includes both phosphorescent materials, which show a slow decay in brightness , and fluorescent materials, where the emission decay takes place over tens of nanoseconds...
. Its persistency had been selected to match the nominal maximum frame rate
Frame rate
Frame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
. 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 the Earth itself during a solar eclipse
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
.
The Apollo 12 Lunar Module landed near Surveyor 3 in November 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
National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution holds the largest collection of historic aircraft and spacecraft in the world. It was established in 1976. Located in Washington, D.C., United States, it is a center for research into the history and science of aviation and...
in Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
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 motorElectric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
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
Pantograph
A pantograph is a mechanical linkage connected in a special manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen...
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
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...
following landing on the lunar surface. However, estimations were possible. The small spring constant 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.
Apollo 12 and the remote possibility of interplanetary contamination
Apollo 12
Apollo 12 was the sixth manned flight in the American Apollo program and the second to land on the Moon . It was launched on November 14, 1969 from the Kennedy Space Center, Florida, four months after Apollo 11. Mission commander Charles "Pete" Conrad and Lunar Module Pilot Alan L...
manned 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 man-made objects and materials. Although space probes have returned to Earth in the decades since Apollo 12, this remains the only occasion in which humans have visited a probe that had been sent to another world.
It is widely claimed that a common type of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, Streptococcus mitis
Streptococcus mitis
Streptococcus mitis is a mesophilic alpha-hemolytic species of Streptococcus that inhabits the human mouth. It is a Gram positive, coccus, facultative anaerobe and catalase negative. It can cause endocarditis...
, accidentally contaminated
Interplanetary contamination
Interplanetary Contamination is the hypothetical contamination of a sterile planetary body by human spacecraft, either deliberate or unintentional. This is considered a potential form of directed panspermia...
the Surveyor's camera prior to launch, and that bacteria survived dormant in the harsh lunar environment for two and one-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, but more importantly, it led NASA to adopt strict abiotic procedures for space probes to prevent contamination of the planet Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
and other astronomical bodies that are suspected of having conditions possibly suitable for life. Most dramatically, the Galileo space probe
Galileo spacecraft
Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. Named after the astronomer and Renaissance pioneer Galileo Galilei, it was launched on October 18, 1989 by the Space Shuttle Atlantis on the STS-34 mission...
was deliberately destroyed by sending it to crash into Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
to avoid the possibility of contaminating the Jovian moon Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...
with bacteria from earth.
However, independent investigators have challenged the claim of surviving bacteria in Surveyor 3 on the Moon. (See Reports of Streptococcus mitis on the moon
Reports of Streptococcus mitis on the moon
As part of the Apollo 12 mission, the camera from the Surveyor 3 probe was brought back to Earth. On analyzing the camera it was found that the common bacterium Streptococcus mitis was alive on the camera...
.)
Lunar Reconnaissance Orbiter
Lunar Reconnaissance Orbiter
The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon. Two LPRP missions, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite , were launched in June 2009...
photographed the Surveyor 3 landing site in some detail, in which surrounding astronaut foot tracks could also be seen. In 2011, the Lunar Reconnaissance Orbiter
Lunar Reconnaissance Orbiter
The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon. Two LPRP missions, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite , were launched in June 2009...
returned to the landing site at a lower altitude to take higher resolution photographs.
External links
- Surveyor Program Results (PDF) 1969
- Analysis of Surveyor 3 material and photographs returned by Apollo 12 (PDF) 1972
- Examination of Surveyor 3 surface sampler scoop returned by Apollo 12 mission (PDF) 1971
- Surveyor 3 parts and materials returned from the moon by Apollo 12 - Evaluation of lunar effects - Jan 1971 (PDF)