Multiple software issues and a poor radio link doomed a test flight of Boeing’s crew capsule late last year, NASA said Friday, revealing for the first time a glitch that could have destroyed the spaceship on its re-entry.

The Starliner’s December 20 mission, an uncrewed test flight, was ended early when it failed to engage its thrusters on time, due to a previously reported faulty timer.NASA said in a statement Friday that the problem arose because it incorrectly pulled time from its Atlas V launch rocket, creating an 11-hour mismatch.

The second problem was intermittent space-to-ground communications, impeding the flight control team’s ability to command and control the vehicle.A third issue was confirmed by NASA and Boeing for the first time: a coding error in the program that governs Starliner’s preparation for reentry into Earth’s atmosphere.

This could have resulted in impact, destabilizing the ship or damaging its heat shield, said Jim Chilton, senior vice president of Boeing’s Space and Launch division.

Douglas Loverro, a senior NASA official, said the multiple errors pointed to “insufficient” oversight by his agency, but he also added: “It looks as if there could possibly be process issues at Boeing. And so, we want to understand what the culture is at Boeing, that may have led to that.” Starliner’s failure was the latest serious setback for Boeing, which is still reeling from two fatal crashes of its 737 Max aircraft.

NASA officials have refused to be drawn on what it all means for the future of Starliner, which is scheduled to take its first astronauts to the International Space Station in the coming months.