Genesis ("Beresheet" in Hebrew), Israel’s first spacecraft on its way to land on the moon, is having some complications. After the launch on Friday morning, engineers from the SpaceIL organization and Israel Aerospace Industries discovered that sensors on the craft needed for navigation are overly sensitive to sunlight. They discovered another problem with the robotic spacecraft on Monday which could delay its reaching the moon.
Around midnight between Monday and Tuesday, Genesis was scheduled to carry out another maneuver to increase the radius of its orbit around Earth. The maneuver was supposed to be carried out automatically while the spacecraft was in a region of the sky where it wouldn't have contact with its controllers on the ground. But while the preparations for the maneuver were underway, the spacecraft’s computer performed an unplanned reboot on its own. The restart cancelled the maneuver, and it continued in its original orbit. The engineers responsible for Genesis' operations are analyzing the data and trying to understand what caused the reboot, and what its implications may be.
Every time Genesis completes an orbit it executes another maneuver, designed to move it further away from earth, by firing its engines for three minutes. This is how it will eventually reach the moon, with orbits at successively increasing distances from Earth in a trajectory resembling an elliptical spiral. The advantage of this method, which relies on the Earth’s gravitational pull, is that it saves fuel. Missing a maneuver means postponing Genesis' moon landing.
Genesis was privately built by the non-profit group SpaceIL in cooperation with Israel Aeronautics Industries. SpaceIL CEO Ido Anteby told reporters in a conference call that before beginning the maneuver, Genesis' systems carry out an orientation movement and calibrate the navigation systems. “At this stage, the spacecraft’s computer conducted an independent reset, so the maneuver was cancelled,” he said.
Once the engineers understand what caused the problem with the computer, they will decide when to try to repeat the maneuver, said Anteby. Opher Doron, the head of the IAI’s space division, said that he is not especially worried at the moment: “The faster we understand what happened, we will be able to prevent the problem from happening again.”
The planning of the orbital maneuvers included a number of days for delays, so if the problem is fixed within the next two days, the spacecraft can reach the moon according to the original schedule, said the two.
The maneuver isn't the first setback that Genesis has faced: The first problem was with one of the positioning systems, called star trackers. These are sensors that locate stars around the spacecraft in order to determine its location. After the launch, it became apparent that the trackers are more sensitive than expected to sunlight, which could make it hard to detect other stars. For now, the star-trackers are focusing on areas of the sky where the sunlight does not interfere, and Doron explained that it is possible this change is related to the unplanned reboot of the spacecraft’s computer.
Genesis was successfully launched late Thursday night from Cape Canaveral. After 33 minutes it separated from the booster rocket and started circling the earth. It is expected to land on the moon on April 11 and would be the smallest vehicle to accomplish that. One of SpaceIL’s founders, Yariv Bash, said that “the launch was cool, but the hard part is ahead of us.”
It will travel 6.5 million kilometers, the longest trajectory of any spacecraft that’s gone from Earth to the moon. The $100 million price tag is significantly lower than previous expeditions. If successful, Israel will be the fourth country to land on the moon.