Phobos program
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The Phobos program was an unmanned space mission consisting of two probes launched by the Soviet Union to study Mars and its moons Phobos and Deimos. Phobos 2 became Mars orbiter and returned 38 images with a resolution of up to 40 meters. Both probes suffered from critical failures.
Phobos 1 and its companion spacecraft Phobos 2 were a new spacecraft design, succeeding the type used in the Venera planetary missions of 1975-1985, including the last used during the Vega 1 and Vega 2 missions to comet Halley. Phobos 1 was launched on July 7, 1988 and Phobos 2 on July 12, 1988, each aboard a Proton-K rocket. They each had a mass of 2600 kg (6220 kg with orbital insertion hardware attached). The objectives of the Phobos missions were to:
- conduct studies of the interplanetary environment;
- perform observations of the Sun;
- characterize the plasma environment in the Martian vicinity;
- conduct surface and atmospheric studies of Mars; and,
- study the surface composition of the Martian satellite Phobos.
Phobos 1 operated nominally until an expected communications session on 2 September 1988 failed to occur. The failure of controllers to regain contact with the spacecraft was traced to an error in the software uploaded on 29 August/30 August, which had deactivated the attitude thrusters. By losing its lock on the Sun, the spacecraft could no longer properly orient its solar arrays, thus depleting its batteries.
Phobos 2 operated nominally throughout its cruise and Mars orbital insertion phases, gathering data on the Sun, interplanetary medium, Mars, and Phobos. Shortly before the final phase of the mission, during which the spacecraft was to approach within 50 m of Phobos' surface and release two landers, one a mobile 'hopper', the other a stationary platform, contact with Phobos 2 was lost. The mission ended when the spacecraft signal failed to be successfully reacquired on March 27, 1989. The cause of the failure was determined to be a malfunction of the on-board computer.
It is likely that the spacecraft design was immature and technical design issues not fully resolved, problems not uncommon to early generation Soviet space hardware. The Phobos design was used again for the long delayed Mars 96 mission which ended in failure when the launch vehicle's fourth stage misfired.
Systems and sensors
Phobos 1 carried solar x-ray and ultraviolet telescopes, a neutron spectrometer, and the Grunt radar experiment designed to study the surface relief of Phobos. The lander had an x-ray/alpha spectrometer to provide information on the chemical element composition of the surface of Phobos, a seismometer to determine the internal structure of Phobos, and the "Razrez" penetrator with temperature sensors and an accelerometer for testing the physical and mechanical properties of the surface.
Phobos 2 carried an infrared spectrometer called ISM. Like Phobos 1, it had an x-ray/alpha spectrometer, a seismometer , and a "Razrez" penetrator. Phobos 2 also carried a small "hopper" that would have used spring-loaded legs to hop around on the moon's surface. It had an x-ray spectrometer, a magnetometer, and an accelerometer.
See also
| [http://encycl.opentopia.com/ edit ] Spacecraft to visit the Planet Mars | |
|---|---|
| Flybys: Mariner 4 > Mariner 6 | Mariner 7 | Mars 4 | |
| Orbiters: Mars 2 > Mars 3 | Mariner 9 | Mars 5 | Viking 1 | Viking 2 | Phobos 2 | Mars Global Surveyor | Mars Odyssey | Mars Express Orbiter | Mars Reconnaissance Orbiter | |
| Landers and Rovers: Mars 2 > Mars 3 | Mars 6 | Viking 1 | Viking 2 | Mars Pathfinder | Spirit rover | Opportunity rover | |
| Future: Rosetta space probe>Rosetta | Phoenix Scout | Phobos-Grunt | Mars Science Laboratory | | ExoMars | Mars 2011 | Astrobiology Field Laboratory | |
References
- http://nssdc.gsfc.nasa.gov/planetary/phobos.html
- http://www.astronautix.com/craft/fobos1f.htm
External links
- [Phobos mission images from the Space Research Institute (IKI)]
- [Raw image data from Phobos 2]
- [Images from Phobos 2]
- [Processed images from the Soviet Phobos 2 mission]
| [http://encycl.opentopia.com/ edit ] Failed & Cancelled missions to the Planet Mars | |
|---|---|
| Failed: | Marsnik program > Sputnik 22 | Mars 1 | Sputnik 24 | Mariner 3 | Zond 2 | Mars 1969A | Mars 1969B | Mariner 8 | Cosmos 419 | Mars 6 | Mars 7 | Phobos 1 | Mars Observer | Mars 96 | Nozomi | Mars Climate Orbiter | Mars Polar Lander | Deep Space 2 | Beagle 2 |
| Cancelled: | Voyager | Mars Surveyor 2001 Lander | NetLander | Mars Telecommunications Orbiter |
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