Mission Overview

The Phobos 2 mission was launched on 12 July 1988 from Baykonur Cosmodrome. The primary objective of the mission, as with its sister probe Phobos 1, was to explore the larger of Mars' two moons, Phobos. In addition to instrumentation to explore the Martian satellites, Phobos 2 also carried instruments to study the Sun, Mars, the interplanetary medium, and gamma-ray burst sources.

The Phobos 2 spacecraft arrived at Mars on 30 January 1989, but was lost while maneuvering in Martian orbit to encounter Phobos on 27 March 1989. The loss was traced to either a failure of the on-board computer or of the radio transmitter (which was already operating on the backup power system).

Launch Information

Launch Date: 1988-07-12 at 17:01:43 UTC
Launch Vehicle: Proton-K
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R


Originally, both Phobos spacecraft were to carry identical instrument payloads. Mass limitations required some tradeoffs so that certain instruments were carried by only one spacecraft. Phobos 2 carried a total of 25 instruments. Of those, a few were high energy detectors. A diagram of the Phobos instrumentation is included in the Phobos images page.

• APEX Gamma-ray emission spectrometer.

• LILAS Low-energy gamma-ray burst detector.

• RF-15 X-ray spectrometer.

• VGS High-energy gamma-ray burst detector.

Due to the loss of the spacecraft, much of the original science objectives were not met. However, the two months of data which were obtained did yield a number of important results. These are summarized in Goldman (1990).