SpaceIL releases initial findings behind failed lunar landing

The Genesis spacecraft crashed due to a sensor failure that created a cascading effect leading to the main engine shutdown minutes before touchdown.

By Batya Jerenberg, World Israel News

An initial investigation into last week’s failed landing of the Israeli lunar module Beresheet (or, “Genesis”) has found that a technical malfunction led to the main engine’s shutdown during the critical last minutes of descent, causing it to crash on the moon.

Dr. Ido Anteby, SpaceIL CEO, said one of the spacecraft’s inertial measurement units (IMUs), which gauges acceleration, malfunctioned during the landing maneuver, correctly sending a failure message to the control center. The engineers then commanded the sensor to restart, which reset the lander’s computer. This brought about a quick chain of events that caused the main engine to shut down.

Ground control engineers attempted to restart the engine six times. Two tries were temporarily successful, but by that point Genesis had closed the distance to the moon to the point where there wasn’t enough time to slow the craft. It hit the lunar surface at 500 km/hr.

“When the engine doesn’t work, the spacecraft cannot make a soft landing, and that’s how the fate of the mission was sealed,” Dr. Anteby said.

He said that until the malfunction everything had been working perfectly.

“When we finish the entire investigation, we’ll know if and how things should have been done differently,” he said, “But it seems that if this incident had not occurred, the spacecraft would have continued with its landing.”

The full investigation will take a few more weeks as the initial findings have come solely from an examination of the lunar lander’s telemetry readings, according to Dr. Anteby. The more in-depth look will include a search for the cause of the initial sensor malfunction, as the component had worked correctly during all the various maneuvers the spacecraft had performed on its way to the moon.

The human element has to be examined as well, he said. “We have not yet performed an analysis of the decision-making in the control room,” Dr. Anteby said.

Morrish Kahn, the main benefactor supporting the years-long project to make Israel only the fourth country to land a spacecraft on the moon, remains undeterred by the findings.

“These incidents are an inseparable part of such a groundbreaking and complicated project,” said Kahn, who serves as SpaceIL’s president.

“What’s important now is to learn the lessons in the best way possible, look at the mistakes courageously, and move on. This is our message to the Jewish people and this is the spirit behind the Beresheet project.”

Mr. Kahn announced on April 13, only two days after lander’s failure, that SpaceIL would attempt a second landing with Genesis 2.