JERUSALEM (AP) — The Israeli start-up behind last week’s failed lunar landing said Thursday that it is still investigating a malfunction that caused the spacecraft to plummet to the moon’s surface.

SpaceIL, the non-profit that undertook the lunar mission, said that engineers in mission control received a malfunction notification in the craft’s inertial measurement unit, a critical part of its guidance system, during the lander’s final descent.

The team issued an activation command, which triggered a “chain of events” culminating in the spacecraft’s main engine failing, sending it slamming into the moon.

“We need to go in and understand the technical details inside in greater depth, but that’s the sequence that happened in the telemetry,” SpaceIL Chief Executive Ido Anteby told reporters in a telephone briefing.

“We have no assumption about the reason why this error happened,” he said.

SpaceIL said it would continue to analyze the flight data to determine the cause of the fatal glitch and publish a formal assessment in the coming weeks.

The moonshot, the first by a privately funded venture, sought to make Israel the fourth country to land on the moon, after the Soviet Union, the United States and China.

SpaceIL was founded in 2011 and originally vied for Google’s Lunar Xprize, a $20 million challenge for private companies to try to land on the moon. But the competition was scrapped by the tech giant in 2018 when none of the five companies appeared in reach of a predetermined deadline.