Six days after the Israeli spacecraft Beresheet crashed on the moon, SpaceIL on Wednesday said it had concluded the first stage of its internal investigation into why the main engine failed during the landing attempt.
According to the investigation, a malfunction was discovered in an acceleration sensor called IMU. A command sent to the sensor led to a chain reaction that caused the main engine to turn off.
Without the main engine running as a braking mechanism, it was impossible to slow Beresheet’s speed from 1,700 kilometers per hour (1,000 mph) to 0 just above the moon’s surface. Engineers were able to restart the engine, but by that time the spacecraft was too close to the surface to slow down sufficiently.
The first stage of the investigation only deals with understanding the sequence of events, so it isn’t yet clear why the sensor malfunctioned.
“The command didn’t directly cause the main engine to turn off, but rather caused the computer to restart and things carried on from there,” SpaceIL CEO Ido Anteby told reporters at a briefing.
“We still don’t have an assessment as to why the malfunction happened,” he added. “We still haven’t examined the decision-making, just the sequence of events. The spacecraft tried to turn on the engine and it was shut down again. We can see five or six attempts to turn on the engine.
“When we finish the full and detailed investigation we will have many takeaways for the next mission,” Anteby said, adding that the process would take several weeks.
Engineers believe the first problems started at about 14 kilometers (8.5 miles) above the lunar surface. At 150 meters (500 feet) above the moon’s surface, communication was lost completely. At this point, the spacecraft was moving at 500 kph (310 mph), making a collision with the lunar surface “inevitable,” a spokeswoman for the Beresheet team said last Friday.
SpaceIL chairman Morris Kahn on Saturday announced he was launching project Beresheet 2, effective immediately, adding: “We started something and we need to finish it. We’ll put our flag on the moon.”
On Wednesday, SpaceIL said it has already begun working on Beresheet 2 and that Kahn and his team have had several meetings on the matter and are in the process of outlining the project and deciding ton he budget, timetable, manpower, fundraising and more.
“We hope we can complete the project within two years,” it said.
The first spacecraft was budgeted at $100 million (NIS 370 million), a fraction of the cost of vehicles launched to the moon by major powers US, Russia and China in the past. It was a joint venture between private companies SpaceIL and Israel Aerospace Industries, funded almost entirely by private donations from well-known Jewish philanthropists.
Melanie Lidman contributed to this report.