Phobos 2
Phobos 2 — Phobos 1's twin, in Mars orbit from 29 January 1989. It studied Mars and photographed its moon Phobos from as close as 191 km, covering about 80% of its surface. On 27 March 1989, days before it was to fly within 50 m of Phobos and release two landers, contact was lost; the probable cause was a failure of its onboard computer.
Key facts
Mission & specifications
Mission
- Operator
- Lavochkin / IKI (USSR)
- Launched
- July 12, 1988
- Status
- Completed
Trajectory
- Distance from the Sun
- 1.58 AU
- Computed from the cached position
- Distance from Earth
- 1.56 AU
- Computed from cached positions
- Distance from Mars
- 6,471,330 km
- Computed from cached positions
Mission
Phobos 2 was Phobos 1's twin, launched five days after it on 12 July 1988, and it carried an extra passenger: a small hopping lander meant to bounce across the surface of Phobos, measuring as it went. One of its two radio transmitters failed on the way, and its onboard computer was known to be unreliable. On 29 January 1989 it entered orbit around Mars. Over the next two months it studied the planet — its surface, atmosphere and the solar wind around it — and was steered toward Phobos, photographing the moon from 860 km, then 320 km, then 191 km, covering about 80% of its surface. Its landers were to be released on 4–5 April. On 27 March, at a routine session, the craft did not answer. A weak signal came back later that day, the sign of a spacecraft that had lost its orientation and was spinning, and then nothing more. The mission was declared lost on 14 April 1989. The probable cause was a failure in the power supply of its computer, which had happened once before, in January.
- 1988Phobos 2 launches toward Mars on a Proton rocketLaunch
Phobos 1's twin, carrying an extra hopping lander.
It studies the planet and closes in on Phobos.
Together with earlier passes, covering about 80% of the moon.
- 1989Contact lostMission end
Days before its landers were to be released.
Images
Images from open archives · credit shown per image