Russia has confirmed that on August 19th, the Luna-25 lunar lander crashed during a maneuver to lower the spacecrafts orbit. Roscosmos said the spacecraft entered into an emergency condition that caused the main engines to fire for 127 seconds instead of 84 seconds. Roscosmos believes the cause of the crash was related to the BIUS-L which measures the angular velocity of the spacecraft.
The on board computer (OBC) was unable to turn on the BIUS-L which resulted in the OBC receiving no signals from the accelerometers. This in turn meant that when the required speed was reached, the OBC did not receive a signal to turn off the spacecraft propulsion system. This event highlights the fragility of spacecraft software. Roscosmos has not made mention of any signs of foul play in their system but with Russia’s standing in the world today it certainly is not out of the realm of possibility.