Encyclopedia Astronautica
Mariner 1-2



mariner2.jpg
Mariner 1, 2
Credit: NASA
American Venus probe. 2 launches, 1962.07.22 (Mariner 1) to 1962.08.27 (Mariner 2). The world's first successful interplanetary spacecraft.

The objective of the mission was to fly by Venus and return data on the planet's atmosphere, magnetic field, charged particle environment, and mass. It also made measurements of the interplanetary medium during its cruise to Venus and after the flyby.

Mariner was based on the Ranger lunar spacecraft. Mariner 2 consisted of a hexagonal base, 1.04 meters across and 0.36 meters thick, which contained six magnesium chassis housing the electronics for the science experiments, communications, data encoding, computing, timing, and attitude control, and the power control, battery, and battery charger, as well as the attitude control gas bottles and the rocket engine. On top of the base was a tall pyramid-shaped mast on which the science experiments were mounted which brought the total height of the spacecraft to 3.66 meters. Attached to either side of the base were rectangular solar panel panels with a total span of 5.05 meters and width of 0.76 meters. Attached by an arm to one side of the base and extending below the spacecraft was a large directional dish antenna.

The Mariner 2 power system consisted of the two solar cell panels, one 183 cm by 76 cm and the other 152 cm by 76 cm. A 31 cm dacron extension (a solar sail) was used to balance the solar pressure on the panels. These powered the craft directly or recharged a 1000 Watt-hour sealed silver-zinc cell battery, which was used before the panels were deployed, when the panels were not illuminated by the sun, and when loads were heavy. A power-switching and booster regulator device controlled the power flow.

Communications consisted of a 3 Watt transmitter capable of continuous telemetry operation, the large high gain directional dish antenna, a cylindrical omnidirectional antenna at the top of the instrument mast, and two command antennas, one on the end of either solar panel, which received instructions for midcourse maneuvers and other functions.

Propulsion for midcourse maneuvers was supplied by a monopropellant (anhydrous hydrazine) 225 N retro-rocket. The hydrazine was ignited using nitrogen tetroxide and aluminum oxide pellets, and thrust direction was controlled by four jet vanes situated below the thrust chamber. Attitude control with a 1 degree pointing error was maintained by a system of nitrogen gas jets. The Sun and Earth were used as references for attitude stabilization. Overall timing and control was performed by a digital Central Computer and Sequencer. Thermal control was achieved through the use of passive reflecting and absorbing surfaces, thermal shields, and movable louvers.

The scientific experiments were mounted on the instrument mast and base. A magnetometer was attached to the top of the mast below the omnidirectional antenna. Particle detectors were mounted halfway up the mast, along with the cosmic ray detector. A cosmic dust detector and solar plasma spectrometer detector were attached to the top edges of the spacecraft base. A microwave radiometer and an infrared radiometer and the radiometer reference horns were rigidly mounted to a 48 cm diameter parabolic radiometer antenna mounted near the bottom of the mast. All instruments were operated throughout the cruise and encounter modes except the radiometers, which were only used in the immediate vicinity of Venus.

Scientific discoveries made by Mariner 2 included a slow retrograde rotation rate for Venus, hot surface temperatures and high surface pressures, a predominantly carbon dioxide atmosphere, continuous cloud cover with a top altitude of about 60 km, and no detectable magnetic field. It was also shown that in interplanetary space the solar wind streamed continuously and the cosmic dust density was much lower than the near-Earth region. Improved estimates of Venus' mass and the value of the astronomical unit were made.

Gross mass: 200 kg (440 lb).
First Launch: 1962.07.22.
Last Launch: 1962.08.27.
Number: 2 .

More... - Chronology...


Associated Countries
See also
  • Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...

Associated Launch Vehicles
  • Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...
  • Atlas Agena B American orbital launch vehicle. Atlas D with improved, enlarged Agena upper stage. More...

Associated Manufacturers and Agencies
  • JPL American agency;manufacturer of rockets, spacecraft, and rocket engines. Jet Propulsion Laboratory, Pasadena, USA. More...
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...

Associated Programs
  • Mariner Mariner spacecraft were built by the Jet Propulsion Laboratory for early exploration of the nearby planets. The Mariner series became the first spacecraft to return significant data on the surface and atmosphere conditions of Venus, Mars, and Mercury. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • Emme, Eugene M, Aeronautical and Astronautical Events of 1961 Report of NASA to the Committee on Science and Astronautics US House of Representatives 87th Cong 2d Sess, NASA, 1962. Web Address when accessed: here.
  • Bramscher, Robert G, "A Survey of Launch Vehicle Failures", Spaceflight, 1980, Volume 22, page 351.
  • Lockheed Martin Coporation, Atlas Family Fact Sheets, September 1998.. Web Address when accessed: here.
  • National Space Science Center Planetary Page, As of 19 February 1999.. Web Address when accessed: here.
  • NASA Report, Mariner-Venus 1962 Final Project Report, Web Address when accessed: here.
  • NASA Report, Mariner Journey Around the Sun, Web Address when accessed: here.
  • NASA Report, Tracking and Data Acquisition Support for the Mariner Venus 1962 Mission, Web Address when accessed: here.
  • NASA Report, A Summary Review of the Scientific Findings of the Mariner Venus Mission, Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC12 Atlas launch complex. The complex was built for the Atlas ballistic missile program. Launch sites 11 to 14 were accepted between August 1957 and mid-April 1958. Complex 12 supported its first Atlas launch on 10 January 1958, and it supported nine Ranger missions and four Mariner missions between 12 August 1961 and 15 June 1967. Complexes 11, 12 and 14 were deactivated in 1967, and Complex 13 was deactivated in April 1978. More...

Mariner 1-2 Chronology


1961 September 28 - . LV Family: Atlas. Launch Vehicle: Atlas Centaur LV-3C.
  • Mariner moved to Atlas-Agena due to Centaur delay. - . Nation: USA. Program: Mariner. Class: Venus. Type: Venus probe. Spacecraft: Mariner 1-2. Summary: NASA announced that instrumented Venus probe to be launched next year would be launched by an Atlas-Agena B rather than a Centaur rocket as originally planned..

1962 July 22 - . 09:21 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC12. LV Family: Atlas. Launch Vehicle: Atlas Agena B. LV Configuration: Atlas Agena B 145D (AA5) / Agena B 6901 (AA5). FAILURE: Destroyed by range safety.. Failed Stage: U.
  • Mariner 1 - . Payload: Mariner R-1. Mass: 200 kg (440 lb). Nation: USA. Agency: NASA. Program: Mariner. Class: Venus. Type: Venus probe. Spacecraft: Mariner 1-2. Decay Date: 1962-07-22 . COSPAR: F620722A. Summary: Venus probe..

1962 August 27 - . 06:53 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC12. LV Family: Atlas. Launch Vehicle: Atlas Agena B. LV Configuration: Atlas Agena B 179D (AA6) / Agena B 6902 (AA6).
  • Mariner 2 - . Payload: Mariner R-2. Mass: 201 kg (443 lb). Nation: USA. Agency: NASA. Program: Mariner. Class: Venus. Type: Venus probe. Spacecraft: Mariner 1-2. USAF Sat Cat: 374 . COSPAR: 1962-A-Rho-1. Mariner 2 was the first spacecraft to successfully flyby another planet. It was a backup for the Mariner 1 mission which failed shortly after launch to Venus. After launch and termination of the Agena first burn, the Agena-Mariner was in a 118 km altitude Earth parking orbit. The Agena second burn injected the Mariner 2 spacecraft into a geocentric escape hyperbola at 26 minutes 3 seconds after lift-off. Solar panel extension was completed about 44 minutes after launch. On 29 August 1962 cruise science experiments were turned on. A midcourse maneuver was initiated at 22:49:00 GMT on 4 September and completed at 2:45:25 GMT 5 September. On 8 September at 17:50 GMT the spacecraft suddenly lost its attitude control, which was restored by the gyroscopes 3 minutes later. The cause was unknown but may have been a collision with a small object. On October 31 the output from one solar panel deteriorated abruptly, and the science cruise instruments were turned off. A week later the panel resumed normal function and instruments were turned back on. The panel permanently failed on 15 November, but Mariner 2 was close enough to the Sun that one panel could supply adequate power. On December 14 the radiometers were turned on. Mariner 2 approached Venus from 30 degrees above the dark side of the planet, and passed below the planet at its closest distance of 34,773 km at 19:59:28 GMT 14 December 1962. After encounter, cruise mode resumed. Spacecraft perihelion occurred on 27 December at a distance of 105,464,560 km. The last transmission from Mariner 2 was received on 3 January 1963 at 07:00 GMT. Mariner 2 remains in heliocentric orbit. Scientific discoveries made by Mariner 2 included a slow retrograde rotation rate for Venus, hot surface temperatures and high surface pressures, a predominantly carbon dioxide atmosphere, continuous cloud cover with a top altitude of about 60 km, and no detectable magnetic field. It was also shown that in interplanetary space the solar wind streams continuously and the cosmic dust density is much lower than the near-Earth region. Improved estimates of Venus' mass and the value of the astronomical unit were made.

1962 December 14 - .
Home - Browse - Contact
© / Conditions for Use