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Mission record

Mariner 4

Also known as Mariner-Mars 1964, Mariner4

NASA-Office of Space Science Applications · Launched

Explore trajectory

Completed · Success

The fourth in NASA's series of planetary flyby spacecraft, which NSSDCA records as the first successful flyby of Mars, returning the first pictures of the martian surface and the first images of another planet ever returned from deep space. After 7.5 months of flight involving one midcourse maneuver, it passed Mars at 01:00:57 UTC on 15 July 1965, taking 21 full pictures and part of a 22nd, covering about 1% of the planet's surface, and returned 5.2 million bits of data in total. Communications with Mariner 4 were terminated on 21 December 1967.

Destinations
Launch vehicle
Atlas-Agena D
Launch site
Cape Canaveral, United States
Countries
United States
Mission types
Flyby

Chronology

Mission timeline

  1. Launch

    Launched on an Atlas-Agena D from Cape Canaveral

    NSSDCA's launch/orbital information page gives the launch date and time as 1964-11-28T14:22:01Z. After launch the protective shroud covering Mariner 4 was jettisoned and the Agena D/Mariner 4 combination separated from the Atlas D booster at 14:27:23 UT on 28 November 1964. The Agena D first burn from 14:28:14 to 14:30:38 put the spacecraft into an Earth parking orbit and the second burn from 15:02:53 to 15:04:28 injected the craft into a Mars transfer orbit. Mariner 4 separated from the Agena D at 15:07:09 and began cruise mode operations.

    Earth

  2. Deployment

    Separated from Agena

    NSSDCA reports spacecraft separation at15:07:09UT. The original report native state at15:07:27GMT is a separate navigation epoch.

    Earth

  3. Deployment

    Solar panels deployed and scan platform unlatched

    The source reports deployment at15:15UT; no continuous motion or exact hinge history was recovered.

    Earth

  4. Milestone

    Midcourse maneuver

    JPL TR 32-881 reports motor ignition at 16:09:25 GMT and says a 16.70 m/s increment was required. The JPL handbook lists commanded values of 20.06 seconds, 16.699 m/s, -39.16 deg pitch and +156.06 deg roll, and actual performance of 20.06 seconds, 17.085 m/s, -39.63 deg pitch and +156.62 deg roll. Its event chronology lists burn end at 16:09:30 GMT, five seconds after the ignition time in TR 32-881; the event-time basis is unresolved. These scalar and spacecraft-body attitude values are not used as an inertial maneuver vector. The plasma probe had its performance degraded by a resistor failure on 6 December 1964.

  5. Flyby

    First successful flyby of Mars

    The closest approach was 9,846 km from the Martian surface at 01:00:57 UT 15 July 1965. The camera sequence started at 00:18:36 UT on July 15. NSSDCA reports 21 pictures plus 21 lines of a 22nd; NASA Science reports 21 images plus 22 lines of a 22nd, so the line count remains a source discrepancy. Both describe about 1% coverage of the planet's surface. At the time of closest approach the spacecraft was 216 million km from Earth moving at a speed of approximately 7 km/sec relative to Mars. At 02:19:11 UT Mariner 4 passed behind Mars as seen from Earth and the radio signal ceased; it was reacquired at 03:13:04 UT. NSSDCA's two pages do not reconcile on this encounter and the disagreement is recorded rather than resolved: the launch/orbital information page labels a Mars flyby with a closest approach time of 1964-11-28 15:04:28, which is the moment the master catalog gives for the end of the Agena D second burn, and puts 1965-07-15 01:00:57 on an interplanetary-cruise row about the Sun instead. The record follows the master catalog.

    Mars

  6. Milestone

    Signal acquisition halted at 309.2 million km

    The spacecraft performed all programmed activities successfully and returned useful data from launch until 22:05:07 UT on 1 October 1965, when the distance from Earth (309.2 million km) and the antenna orientation temporarily halted signal acquisition.

  7. Milestone

    Intermittent telemetry contact re-established

    Intermittent telemetry contact was re-established on 3 May 1966 showing that the spacecraft and instruments were functioning. Full data acquisition resumed in late 1967, and the spacecraft systems were reactivated in October 1967 for attitude control tests in support of the Mariner 5 mission.

  8. Milestone

    Dust impacts disturbed spacecraft attitude

    Seventeen dust-detector hits in15minutes accompanied attitude changes. Slight thermal-shield damage is a proposed consequence, not an observed detailed surface change.

    Sun

  9. Milestone

    Attitude-control gas exhausted

    NSSDCA reports nitrogen exhaustion; later dust impacts further degraded the signal. The last contact remains December21.

    Sun

  10. Mission end

    Communications terminated

    On 7 December the gas supply in the attitude control system was exhausted, and on December 10 and 11 a total of 83 micrometeoroid hits were recorded which caused perturbation of the attitude and degradation of the signal strength. On 21 December 1967 communications with Mariner 4 were terminated. The total data returned by the mission was 5.2 million bits. NASA chronology instead givesDecember31; this source conflict is retained in the review.

Mission architecture

Vehicles

  • Mariner 4 · Spacecraft

    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: October 1, 1965 to December 28, 1967

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

  • Mariner 4: Physically reconstructed based on publicly available data · date-tagged heliocentric arc, 1965-10-01 to 1967-12-28; earlier intervals remain open · October 1, 1965 to December 28, 1967

Provenance

Sources

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

Data verified through October 5, 2026