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Mission record

Mariner 9

Also known as Mariner-I, PL-712B, Mariner Mars '71, Mariner9

NASA-Office of Space Science Applications · Launched

Explore trajectory

Completed · Success

The Mariner Mars 71 mission was planned to consist of two spacecraft to orbit Mars on complementary missions, but due to the failure of Mariner 8 to launch properly, only one spacecraft was available. Mariner 9 combined mission objectives of both Mariner 8 (mapping 70 % of the Martian surface) and Mariner 9 (a study of temporal changes in the Martian atmosphere and on the Martian surface). NSSDCA records it as the first spacecraft to orbit another planet. Imaging was delayed by a global dust storm that began on 22 September 1971, and normal mapping operations began once the storm abated through November and December. A total of 54 billion bits of scientific data were returned, including 7329 images covering the entire planet, before the spacecraft was turned off on 27 October 1972.

Destinations
Launch vehicle
Atlas-Centaur
Launch site
Cape Canaveral, United States
Countries
United States
Mission types
Orbiter

Chronology

Mission timeline

  1. Launch

    Launched toward Mars

    Original TR32-1550 volumeI reports22:23:04GMT; navigation report table1 gives22:23:04.5GMT. The current catalog uses second precision, without asserting subsecond timing accuracy.

    Earth

  2. Milestone

    Planned midcourse maneuver

    A planned midcourse maneuver was executed on 5 June.

  3. Milestone

    A global dust storm began in the Noachis region

    Imaging of the surface of Mars by Mariner 9 was delayed by a dust storm which started on 22 September 1971 in the Noachis region. The storm quickly grew into one of the largest global storms ever observed on Mars. By the time the spacecraft arrived at Mars no surface details could be seen except the summits of Olympus Mons and the three Tharsis volcanoes.

    Mars

  4. Orbit insertion

    The first spacecraft to orbit another planet

    Mariner 9 arrived at Mars on 14 November 1971 after a 167 day flight. A 15 minute 23 second rocket burn put the spacecraft into Mars orbit, making Mariner 9 the first spacecraft to orbit another planet. The insertion orbit had a periapsis of 1398 km and a period of 12 hr, 34 min. Two days later a 6 second rocket burn changed the orbital period to just under 12 hours with a periapsis of 1387 km. NSSDCA's launch/orbital information page records the same two orbits, giving the first as 1398.00 x 17915.00 km at 754.02 minutes and 64.400° from 1971-11-14, and the second as 1387.00 x 17094.00 km at 718.23 minutes from 1971-11-16. Keep day precision: original navigation sections contain conflicting engine-start clock values and ET versus GMT conventions. The incoming unbraked hyperbola must not be continued through the capture burn.

    Mars

  5. Milestone

    First orbit trim

    The six-second trim reduced the orbital period toward twelve hours. This is distinct from the December30 trim; source orbit dimensions refer to different epochs.

    Mars

  6. Milestone

    Trim maneuver on the 94th orbit

    A correction trim maneuver was made on 30 December on the 94th orbit which raised the periapsis to 1650 km and changed the orbital period to 11:59:28 so that synchronous data transmissions could be made to the Goldstone 64-m DSN antenna. NSSDCA's launch/orbital information page records the resulting orbit as 1650.00 x 16860.00 km at 719.47 minutes and 64.400°, beginning at 1971-12-30.

    Mars

  7. Mission end

    Final communication

    NASA chronology reports final contact at22:32UT. This is not a measured atmospheric-entry time; historical predictions of later orbital decay remain predictions.

    Mars

Mission architecture

Vehicles

  • Mariner 9 · Orbiter

    Destinations: Mars

Trajectory record

Time-dependent navigation trajectory

Source states place the model at the selected time. Reconstructed flight, estimates, predictions and historical mission plans are identified by interval; gaps remain visible.

J2000 · Sun-centered display · positions interpolated between source states

Coverage: November 16, 1971 to October 16, 1972

Source records and sampling assumptions are retained with the repository data. Model attitude and surface appearance are illustrative.

  • Mariner 9: JPL navigation-derived Mars-orbit arcs · 1971-11-16 to 1972-10-16; source gaps and maneuver/leap-second boundaries remain open · November 16, 1971 to October 16, 1972

Provenance

Sources

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

Data verified through September 14, 2026