A command uplinked by mission control to resolve an error in the guidance system on the Israeli Beresheet moon lander inadvertently triggered a chain reaction that led to the shutdown of the probe’s main engine during descent to the lunar surface April 11, officials said this week.
An update Wednesday from SpaceIL, the Israeli non-profit organization that developed Beresheet, said engineers investigating the lander’s crash determined a manual command entered into the spacecraft’s computer sparked a series of events that doomed the mission.
Controllers at the mission’s ground station in Yehud, Israel, transmitted a command intended to fix a problem with the inertial measurement unit on the lander, a sensor which determined the craft’s orientation in space, according to a report published by the Jerusalem Post quoting Ido Anteby, SpaceIL’s CEO.
But the command had an unintended consequence, SpaceIL said.
“This led to a chain reaction in the spacecraft, during which the main engine switched off, which prevented it from activating further,” SpaceIL said in a written statement.
According to the preliminary investigation, the first technical issue occurred when Beresheet was 14 kilometers, or about 46,000 feet, above the moon. Without the main engine to slow its descent, Beresheet plummeted to the lunar surface.
Ground teams received the last data from the lander at an altitude of about 150 meters, or 492 feet. At that time, Beresheet was moving vertically at 500 kilometers per hour, or about 310 mph, toward a crash on the moon.
Beresheet, which means “genesis” or “in the beginning” in Hebrew, was aiming to become the first privately-funded spacecraft to land on the moon. On April 4, the mission became the first backed by a non-governmental organization to orbit the moon, and Israel became the seventh nation or space agency to successfully place a spacecraft into lunar orbit, after Russia, the United States, Japan, the European Space Agency, China and India.
Teams from SpaceIL and Israel Aerospace Industries, which built the Beresheet lander, continue investigating the events that occurred during the April 11 landing attempt, “in order to understand the full picture of what occurred during the mission.” The final results of the investigation will be released in the coming weeks, officials said.
Officials acknowledged the risks of Beresheet’s landing attempt before the mission. The spacecraft was developed for roughly $100 million, a fraction of the cost of previous government-funded moon landing probes, without backup systems for many key components.
SpaceIL begins planning for Beresheet 2
While engineers continue examining what went wrong with the April 11 landing attempt, private donors and Israeli Prime Minister Benjamin Netanyahu have promised to try again.
Morris Kahn, SpaceIL’s president and Beresheet’s top financial backer, said April 13 that he intends to form a new group of donors to support a second Beresheet mission.
“We are actually going to build … a new spacecraft, we’re going to put it on the moon, and we are going to complete the mission,” Kahn said.
Kahn, an 89-year-old South African-born Israeli billionaire, contributed more than $40 million of his fortune to the first Beresheet mission.
“This is part of my message to the younger generation: Even if you do not succeed, you get up again and try,” Kahn said.
Speaking at the Beresheet mission control center moments after officials declared the landing attempt a failure, Netanyahu pledged another landing attempt within two years.
Founded in 2011 by three young engineers, SpaceIL attracted funding from billionaire entrepreneurs, philanthropists, and corporations, including millions of dollars in contributions in money and labor from IAI, Israel’s top aerospace contractor. The Israel Space Agency awarded SpaceIL $2 million, the Beresheet project’s only government funding.
SpaceIL originally intended to pursue the $30 million Google Lunar X Prize, which fostered a competition between international teams to land the first privately-funded spacecraft on the moon. The Google Lunar X Prize ended last year without a winner, but SpaceIL continued to develop their lunar lander.
The X Prize Foundation awarded SpaceIL a $1 million “Moonshot Award” after the Beresheet mission came close to achieving a successful landing last week.
“I am proud of SpaceIL’s team of engineers for their wonderful work and dedication, and such cases are an integral part of such a complex and pioneering project,” Kahn said. “What is important now is to learn the best possible lessons from our mistakes and bravely continue forward. That’s the message we’d like to convey to the people in Israel and the entire Jewish world. This is the spirit of the Beresheet project.”
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.