The Beresheet spacecraft executed a perfectly choreographed space hop on Thursday evening, allowing the car-sized spacecraft to jump from an orbit around Earth to one around the moon.
The maneuver makes Israel the seventh country in the world to bring a spacecraft into lunar orbit, placing it on track to attempt a landing on the moon next month.
The spacecraft is aiming to have Israel become the fourth country to land a spacecraft on the moon on April 11.
“This was a milestone and it actually gives us a real shot at the moon,” said Yonatan Winetraub, co-founder of SpaceIL, the Israeli nonprofit that built the spacecraft.
The NIS 370 million ($100 million) spacecraft is a joint venture between the Israeli nonprofit SpaceIL and Israel Aerospace Industries, funded almost entirely by private donations from well-known Jewish philanthropists.
Up until now, engineers have on several occasions activated the engines in short bursts of about a minute or two in order to nudge the spacecraft into increasingly larger elliptical orbits of the Earth.
In order for the spacecraft to successfully enter into an orbit around the moon, Beresheet needed to slow down from 8,500 kilometers per hour to 7,500 kilometers per hour. Although that still seems fast to mere humans, according to engineers, it is the orbital equivalent of slamming on the brakes. The engineers accomplished this by turning the spacecraft so that its engines thrust it in the opposite direction, slowing down the speed.
It took about nine minutes for eight different engines to slowly maneuver the spacecraft in the right direction, and a little less than six minutes for the engines to slow the spacecraft down to the correct speed.
On Thursday, engineers said they believed that the moon’s gravity had successfully captured the spacecraft, though it would take a few hours for them to be sure that the craft is heading in the right direction.
About 25 engineers at the control room in Yehud, a suburb of Tel Aviv where Israel Aerospace Industries is housed, burst into applause at the end of the planned maneuver.
A failure to slow down would have brought the mission to an abrupt end.
“The price of a mistake here would have been infinite,” said Opher Doron, space division general manager at Israel Aerospace Industries, which worked with SpaceIL on the project. “We would have been spinning in space toward some sun orbit that no one wants to go into.”
“After six weeks in space, we have succeeded in overcoming another critical stage by entering the moon’s gravity,” said SpaceIL CEO Ido Antebby. “This is another significant achievement our engineering team achieved, while demonstrating determination and creativity in finding solutions to unexpected challenges. We still have a long way until the lunar landing, but I‘m convinced our team will complete the mission to land the first Israeli spacecraft on the moon, making us all proud.”
Amusingly, though the engineers successfully executed the spacecraft’s maneuver, the press team had difficulty pulling off the powerpoint presentation explaining next week’s lunar landing for journalists, and were forced to abandon the effort midway, turning the presentation off.
Thursday was the longest period that engineers have activated the engines since the spacecraft’s launch on February 22.
Now drawn into lunar orbit, Beresheet will trace smaller and smaller loops around the moon before attempting to land.
“There is a significant chance we have a crash landing,” said Doron. “It’s very dangerous, and it’s difficult to predict we’ll succeed.”
Engines have so far been fired seven times to widen the elliptical orbits. Beresheet has made 12.5 trips around the Earth since launching on February 22. The lunar orbits are much smaller, and some will take no longer than 14 hours. In the coming week, the spacecraft will make smaller and smaller circles around the moon until it reaches an altitude of around 15 kilometers above the surface. The landing gear will then engage to hopefully bring the spacecraft to rest in the Sea of Serenity.
In total, the spacecraft has traveled around 5.5 million kilometers and still has about a million left to go. This is the slowest and longest trip a spacecraft has made to the moon. The distance from the Earth to the moon is an average about 385,000 kilometers (239,000 miles).
By utilizing the gravitational pull of the earth and the moon and only activating the engines at the nearest and farthest points on the ellipses, engineers were able to drastically reduce the amount of fuel needed on the spacecraft. Fuel still accounts for the majority of Beresheet’s weight. At launch, the spacecraft weighed a total of 600 kilograms (1,300 pounds), of which about 440 kilograms (970 pounds) were fuel.
Beresheet, which means “Genesis” in Hebrew, lifted off on February 22 from Cape Canaveral in Florida atop a Falcon 9 rocket from the private US-based SpaceX company of entrepreneur Elon Musk.
Last month, Beresheet sent back a photo taken with its “selfie camera,” in which the Israeli flag can be seen 37,600 kilometers (23,000 miles) above Earth.
The project launched as Israel’s entry into the Google LunarX challenge for nongovernmental groups to land a spacecraft on the moon. Google ended the contest in 2018 with no winners, but the Israeli team decided to continue its efforts privately.
With Beresheet, Israel hopes to become the fourth country in the world to land a spacecraft on the moon, following the US, Russia, and China.
If successful, Beresheet will make history twice: as the first private-sector landing on the Moon, and the first craft from Israel to reach the orb.
If Beresheet successfully lands on April 11, the spacecraft is expected to carry out two or three days of experiments collecting data about the moon’s magnetic fields before shutting down. There it will stay, possibly for eternity, on the moon’s surface, joining approximately 181,000 kilograms (400,000 pounds at Earth weight) of manmade debris strewn across the moon’s surface.
The Associated Press contributed to this report.