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Mission record

Mars 6

Also known as M-73 No.50P, Mars6

U.S.S.R · Launched

Explore trajectory

Partial success · Partial success

The third of the four Soviet spacecraft launched towards Mars in July and August of 1973. The Mars 6 interplanetary station consisted of a flyby bus and an attached descent module; the descent module separated from the bus on reaching Mars and was designed to enter the martian atmosphere and make in-situ studies of the Mars atmosphere and surface. Contact with the descent module was lost in direct proximity to the surface, probably either when the retrorockets fired or when it hit the surface. The descent module transmitted 224 seconds of data before transmissions ceased, which NSSDCA records as the first data returned from the atmosphere of Mars, although much of it was unreadable due to a flaw in a computer chip which led to degradation of the system during its journey to Mars.

Destinations
Launch vehicle
Proton Booster Plus Upper Stage and Escape Stages
Launch site
Tyuratam (Baikonur Cosmodrome), U.S.S.R
Countries
Soviet Union
Mission types
Lander, Flyby

Chronology

Mission timeline

  1. Launch

    Launched into an intermediate Earth orbit

    NSSDCA's launch/orbital information page gives the launch date and time as 1973-08-05T17:45:48Z and an Earth orbit with a periapsis of 154.00 km, an apoapsis of 193.00 km, a period of 87.90 minutes and an inclination of 51.500°. Mars 6 successfully lifted off into an intermediate Earth orbit on a Proton SL-12/D-1-e booster and then launched into a Mars transfer trajectory. Total fueled launch mass of the lander and bus was 3260 kg. That page disagrees with itself on the epochs and the disagreement is recorded rather than resolved: it starts both the Earth-orbit and the interplanetary-cruise rows on 1973-07-05, a month before the launch date printed at the head of the same page.

    Earth

  2. Milestone

    Course correction, then a telemetry failure

    After one course correction burn on 13 August 1973, there was a failure of the telemetry system on 3 September.

  3. Flyby

    The bus passed within 1600 km of Mars

    The bus continued on into a heliocentric orbit after passing within 1600 km of Mars. NSSDCA's launch/orbital information page prints a Decay Date of 1974-03-12 for this object, which the master catalog's heliocentric orbit contradicts; the disagreement is recorded rather than resolved. Recorded at day precision because neither page publishes a time for the bus flyby.

    Mars

  4. Deployment

    Descent module separated 48,000 km from Mars

    It reached Mars on 12 March 1974. The descent module separated from the bus at 5:01:56 UT on 12 March 1974 at a distance of 48,000 km from Mars.

    Mars

  5. Loss of contact

    Contact lost in direct proximity to the surface

    The descent module entered the atmosphere at 09:05:53 UT at a speed of 5.6 km/s. The parachute opened at 09:08:32 UT after the module had slowed its speed to 600 m/s by aerobraking. During this time the craft was collecting data and transmitting it directly to the bus for immediate relay to Earth. Contact with the descent module was lost at 09:11:05 UT in "direct proximity to the surface", probably either when the retrorockets fired or when it hit the surface at an estimated 61 m/s. Mars 6 landed at 23.90 S, 19.42 W in the Margaritifer Sinus region of Mars, and NSSDCA's launch/orbital information page records a Lander row for Mars with the same coordinates and the same epoch. The landed mass was 635 kg. The descent module transmitted 224 seconds of data before transmissions ceased.

    Mars

Mission architecture

Vehicles

  • Mars 6 flyby bus · Spacecraft

    Destinations: Mars

    • Mars 6 descent module · Lander

      Destinations: Mars

Trajectory record

Trajectory dataset not yet available

No verified trajectory dataset is committed for this mission, so Mission Atlas renders no path.

Provenance

Sources

Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.

Data verified through September 2, 2026