News Brief

On an episode of Planetary Radio released today, SpaceIL engineer Yoav Landsman said the first few minutes of Beresheet's descent perfectly mirrored simulations. The first sign of trouble began when one of the spacecraft's Inertial Measurement Units, which provide velocity vector and acceleration data, suddenly shut down. The reason for the failure is still unknown.

According to a report by The Jerusalem Post, it was the first time SpaceIL flight controllers had experienced an IMU failure during the mission, and they sent an "activation command" to restart the unit. Landsman said an IMU failure on its own would not have caused Beresheet to crash, as the spacecraft has redundant units.

The Post report, as well as a SpaceIL press release from today, said the command kicked off a chain reaction in the spacecraft that ultimately caused an engine shutdown as Beresheet sped towards the lunar surface. Landsman confirmed to me that the command was sent in response to the IMU failure.

SpaceIL is still investigating how the command caused the failure cascade, and hopes to issue a final report in the coming weeks. They have also issued what they say was the very last image received from Beresheet, from a height of just 15 kilometers above the Moon. (Our previous "final image" was apparently not the last, after all!)