"This is actually the most critical maneuver our spacecraft will do during the mission," said Ido Anteby, chief executive of the nonprofit, SpaceIL. "Except, of course, the landing."
Beresheet, the robotic spacecraft built by an Israeli nonprofit, remains on track for landing on the moon next week. On Thursday, after already traveling more than 3.4 million miles, it is to pull off a crucial bit of gymnastics, swinging from a highly elliptical orbit around Earth to one around the moon. Since launching in February, Beresheet, which means "Genesis" or "in the beginning" in Hebrew, has fired its engine several times to nudge its looping orbit higher and higher.
On March 19, a 60-second burn pushed the highest point of Beresheet's orbit to more than a quarter million miles above Earth, or slightly beyond the orbit of the moon. This trajectory has been carefully choreographed so that on Thursday, the spacecraft will near that highest point again as the moon passes by, its gravity grabbing Beresheet and flinging it away from Earth.
The seemingly tricky maneuver of jumping from Earth's orbit to the Moon's orbit is going to require some skill. Beresheet must first slow down. "If we don't hit the brakes, it will slingshot away forever," said Opher Doron, the space division general manager at Israel Aerospace Industries, which partnered with SpaceIL in building the spacecraft. If Beresheet misses that rendezvous, it probably will not have another chance. "It's not a complex maneuver," Doron said. "It's just not a time to have a sudden small problem. We'll be nervous." If the maneuver works, Beresheet will rein into an elliptical orbit around the moon, passing within 310 miles of the surface and swinging out as far as 6,200 miles away.
This coming week Beresheet will fire its engine once more to pull into a circular orbit 124 miles above the moon's surface. If all goes according to plan, Beresheet is to attempt a soft landing on April 11. To date, that is a feat that has only been accomplished by the governmental space agencies of the United States, the former Soviet Union, and China. This landing could make Israel only the fourth nation to put a spacecraft on the moon.
SpaceIL's original goal was to win the Google Lunar X Prize competition, which offered 20 million dollars for the first privately financed venture to put a robotic spacecraft on the moon. But the prize expired last year before any of the teams could claim it. SpaceIL pushed on, with the hope that its mission would inspire Israeli students to pursue careers in science and engineering. Mr. Doron said Beresheet has done just that.
