After entering lunar orbit, Israeli spacecraft Beresheet on Sunday morning successfully performed the first of a series of maneuvers to slow down and go into ever-smaller orbits around the moon before attempting to land on April 11 in the Sea of Serenity.
On Sunday, all of Beresheet’s engines were turned on for 271 seconds, burning 55 kilograms (120 pounds) of the fuel it has left.
The maneuver reduced the spacecraft’s farthest distance from the moon from 10,400 kilometers (6460 miles) to just 750 kilometers (465 miles). The nearest spot in its orbit has remained 460 kilometers (285 miles) from the surface of the orb.
In the four days remaining until the landing attempt, the engineers will perform several further maneuvers to turn Beresheet’s current elliptic orbit into a circular orbit 200 kilometers (125 miles) from the face of the moon.
On Thursday, Beresheet’s engineers executed the most complicated maneuver yet, a perfectly choreographed space hop allowing the car-sized spacecraft to jump from an orbit around Earth to one around the moon — making Israel the seventh country in the world to achieve the feat.
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 (5,280 miles per hour) to 7,500 kilometers per hour (4,660 miles 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 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.
The United States, Russia (as the USSR), Japan, China, the European Space Agency and India have all made visits to the moon via probes, though only the US, Russia and China have successfully landed on the moon; other probes lost control and crashed into the surface.
If Israel successfully lands as planned on April 11, it will also be the first time that a privately financed venture has landed there.
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.
“There is a significant chance we have a crash landing,” said Opher Doron, the space division general manager at Israel Aerospace Industries. “It’s very dangerous, and it’s difficult to predict if we’ll succeed.”
In total, the spacecraft has traveled almost 6 million kilometers and still has about half 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 on 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.
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.
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 until the death of the solar system, on the moon’s surface, joining approximately 181,000 kilograms (400,000 pounds at Earth weight) of human-made debris strewn across the moon’s surface.