Initially controllers tried to fall back to the plan of making a two-day rendezvous with the ISS, but this was also abandoned after ground stations were not able to communicate with the spacecraft during the next three orbits.
[11] On 29 April, Roscosmos officially announced that the spacecraft was out of control and its orbit would eventually decay to fall back into Earth's atmosphere, with multiple systems suffering from failure and the main engine's fuel lines depressurized.
Given [the altitude of the debris] and the fact that Progress was found 30 to 40 kilometres above its intended orbit, we can say with confidence that there was some kind of blast at the moment of separation from the third stage of the rocket".
[20] Postflight investigation found that the failure was caused by an unforeseen design flaw in the new Soyuz 2.1a Blok I stage — the propellant tanks were shaped differently than in the older Soyuz-U booster, which ended up producing resonant vibration when attached to the Progress spacecraft.
The normal flight program would vent out the nitrogen pressure gas from the Blok I tanks following spacecraft separation, but engine cutoff produced a hammer effect that sent a shock wave through the stack, rupturing the propellant tanks and blasting the Progress into a much higher than planned orbit, while also leaving it in an uncontrollable spin and having suffered structural damage from being struck by flying booster debris.