|Proton K/Block DM-3|
|Launch vehicle||Proton K with Block DM-3 upper stage|
|Launch site||Baikonur, Kazakhstan|
|Description||Fourth stage partial failure|
|Payload||Astra 1K (Television satellite)|
|Desired orbit||Geostationary transfer orbit|
SES Astras 1K satellite was left in a 176-km circular low-Earth orbit with 51.6 degrees inclination after the Proton K rockets Block-DM 3 upper stage failed to put the satellite into the desired geostationary transfer orbit.
The Russian State Failure Commission investigating the flight said in a preliminary conclusion that the engine of the Block-DM upper stage experienced excessive temperatures and was destroyed during its second ignition, resulting in the separation of the spacecraft into the wrong orbit. Indications are that there was excessive fuel in the main engine at the time of the second burn, leading to the burn-through.