- 07.07.88 Launch
- 09.02.88 Contact Lost
- 11.03.88 End of Mars Mission
- Status: Contact Lost
- VSK videospectrometric system
- ISM infrared spectrometer
- GS-14 gamma-emission spectrometer
- IPNM neutron detector
- RLK radar system
- LIMA-D laser mass spectrometric analyzer
- DION secondary ion mass analyzer
- ISO optical radiation spectrometer
- MAGMA magnetometer
- FGMM magnetometer
- APV-F plasma wave analyzer
- ASPERA scanning energy-mass spectrometer
- SOVIKOMS energy-mass charge spectrometer
- TAUS proton and alpha-particle spectrometer
- HARP ion and electron spectrometer
- SLED energetic charged-particle spectrometer
- IPHIR solar photometer
- TEREK solar telescope/coronograph
- RF-15 x-ray photometer
- SUFR ultrasound spectrometer
- LILAS gamma-burst spectrometer
- VGS gamma-burst spectrometer
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. A total of 28 thrusters (twenty-four 50 N thrusters and four 10 N thrusters) were mounted on the spherical tanks with additional thrusters mounted on the spacecraft body and solar panels. Attitude was maintained through the use of a three-axis control system with pointing maintained with sun and star sensors.
Fobos 1 performed a course correction en route to Mars on 16 July 1988. On 29 August 1988, due to a programming error, a command was issued to turn off the orientation and stabilization system (instead of a routine command to switch on the gamma-ray spectrometer). Fobos 1 operated nominally until an expected communications session on 2 September 1988 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. The spacecraft flew past Mars without activating its science instruments or deploying its lander.
