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Mission record

Phobos 1

Also known as Fobos 1, 1F No.101, Phobos1

Institut Kosmicheskich Issledovaniy · Launched

Explore trajectory

Lost · Failure

One of two 1F spacecraft launched in July 1988, the next-generation in the Venera-type planetary missions, succeeding those last used during the Vega 1 and 2 missions to comet P/Halley. 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 failed to occur. The failure of controllers to regain contact with the spacecraft was traced to an error in the software uploaded on 29/30 August which had deactivated the attitude thrusters. This resulted in a loss of lock on the Sun, resulting in the spacecraft orienting the solar arrays away from the Sun, thus depleting the batteries.

Destinations
Launch vehicle
Proton-K
Launch site
Tyuratam (Baikonur Cosmodrome), U.S.S.R
Countries
Soviet Union
Mission types
Orbiter, Lander

Chronology

Mission timeline

  1. Launch

    Launched on a Proton-K

    NSSDCA's launch/orbital information page gives the launch date and time as 1988-07-07T17:38:04Z on a Proton-K from Tyuratam (Baikonur Cosmodrome), U.S.S.R. The main section of the spacecraft consisted of a pressurized toroidal electronics section surrounding a modular cylindrical experiment section; below these were mounted four spherical tanks containing hydrazine for attitude control and, after the main propulsion module was to be jettisoned, orbit adjustment. The two spacecraft pages disagree about the mass and the Phobos Project page prints both numbers: Phobos 1's page prints Mass: 6220 kg, Phobos 2's prints Mass: 2600 kg, and the project page prints 2600 Kg (6220 Kg with orbital insertion hardware attached).

    Earth

  2. Milestone

    Erroneous command disabled attitude control

    The later NASA chronology dates the command error to August 29, 1988. Loss of Sun pointing exhausted available power; the September 2 contact attempt failed. No measured tumble rate or phase is supplied.

    Sun

  3. Milestone

    Spacecraft stopped functioning, according to the commission

    RGANTD quotes the 1989 commission as dating the end of spacecraft function to August 31, after the August 29 command error. The failed September 2 communication attempt revealed the loss. This finding does not supply a measured attitude or a final position.

    Sun

  4. Loss of contact

    Contact lost after a software upload deactivated the attitude thrusters

    Phobos 1 operated nominally until an expected communications session failed to occur. The failure of controllers to regain contact with the spacecraft was traced to an error in the software uploaded on 29/30 August which had deactivated the attitude thrusters. This resulted in a loss of lock on the Sun, resulting in the spacecraft orienting the solar arrays away from the Sun, thus depleting the batteries. TWO NSSDCA PAGES DISAGREE ON THE YEAR AND THE DISAGREEMENT IS RECORDED RATHER THAN RESOLVED: the Phobos Project Information page dates the session to 2 September 1988 and the Phobos 1 master catalog page to 02 September 1989, in sentences whose other words match exactly in the two committed excerpts. This record follows the project page, whose 1988 sits between the 7 July 1988 launch date both pages print and the 29/30 August software upload both pages print.

  5. Mission end

    Recovery attempts ended

    The NASA chronology reports that attempts to recover Phobos 1 ended November 3, 1988. This administrative endpoint does not provide the spacecraft position; Mars orbit and DAS deployment were never achieved.

    Sun

Mission architecture

Vehicles

  • Phobos 1 · Spacecraft

    Destinations: Mars

    • DAS (Dolgozhivushchaya AS) · Lander

Trajectory record

Trajectory dataset not yet available

Known dates and encounters do not uniquely determine a flight path. This mission’s sourced timeline is available above; no verified trajectory is currently published here.

What is needed to reconstruct this path?
  • A frame-qualified position and vector velocity at an epoch, or equivalent complete orbital elements.
  • Separate state histories and release epochs for the listed vehicles; a parent mission trajectory cannot be assigned to every component.
  • Finer event-time constraints where required by an orbital reconstruction; the stored day/month/year precision is retained.
  • The actual failed-flight state history. Intended destinations are not evidence that the spacecraft reached them.

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