Mars 7

Launch data: Designation 06776 / 73053A Launch date 09 Aug 1973 - 17:00:17 UT Launch site B, LC-81/24 Launch vehicle Proton-K/D 8K82K (#281-02/11S824) Satellite type  3MP N° 51P Mission Mars probe Heliocentric orbit Perihelion / Aphelion  1.01 x 1.69 AU Eccentricity  0.25 Inclination  2.2? deg Period  574 days

Specifications:

Description:

• Mars spacecraft series built for 1973 missions. Due to unfavorable position of Mars during that campaign, separate versions built: two intended to orbit Mars and map the surface, and two to land capsules. The orbiters were equipped with instrumentation to study the composition, structure, and properties of the Martian atmosphere and surface, including an imaging device, a 256 channel gamma-ray spectrometer mounted on a boom and a Lyman-Alpha photometer. The landers would have separated from their uninstrumented bus, entered the atmosphere, where a parachute opened, slowing the descent. The lander equipment included a Lyman-Alpha photometer and a Bennett mass analyzer. Unfortunately, this entire series of spacecraft experienced failures on arrival at Mars due to pre-flight test of the electronics with helium, which resulted in degradation of the computer chips during the journey to Mars. Orbiters had a launch mass of 3444 kg, and landers 3260 kg.

Mission details:

• Passed 1300 km behind Mars on 1974 Mar 09.
• Capsule 73053D (07224) in Heliocentric orbit.
• Mars probe intended to make a soft landing on Mars. Mars 7 reached Mars on 9 March 1974. Due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) the landing probe separated prematurely and missed the planet by 1,300 km. The early separation was probably due to a computer chip error which resulted in degradation of the systems during the trip to Mars. Ended up in a final heliocentric orbit 1.01 x 1.69 AU, 2.2 degree inclination, 574 day period.