Photo of the Day: Beresheet's Final Moon Photo and the Likely Cause of Its Lunar Landing Failure...

SpaceIL

Earlier today, SpaceIL released the photo above that was the last-ever image that the Beresheet lander took (from an altitude of 15 kilometers, or 9 miles) during its ill-fated attempt to touch down on the Moon last Thursday. According to these tweets by SpaceIL and a Planetary Society staff member below, a likely cause of the spacecraft's main engine shutting down prematurely was an errant command that was transmitted to it from the flight team during the landing maneuver. A software glitch caused by an attempt to fix a sensor problem aboard Beresheet led to a chain reaction that eventually led to its main engine deactivating during the descent towards the lunar surface. By the time the engine was finally reactivated, Beresheet was traveling at a velocity of 500 kilometers per hour (311 miles per hour)...making a collision with the Moon's surface unavoidable.

If it was indeed a software issue that prevented Beresheet from landing on the Moon safely almost a week ago, then this is good news! This shows that Beresheet itself was physically healthy (apart from that sensor issue)...and that no significant upgrades would need to be made to the Beresheet 2.0 spacecraft to increase its chances of mission success next time. The only real thing that would need to be corrected is the flight team's vigilance towards transmitting the wrong command at the worst possible moment to the lunar lander. The same thing that befell NASA's Mars Climate Orbiter in 1999 (Google this spacecraft and read about what happened to it) is the same thing that befell Beresheet: Human error. Correct this oversight next time, and Israel will finally become the fourth nation (behind the United States, Russia and China) to soft-land on the Moon. Happy Hump Day!

Here are the findings of the preliminary investigation of #Beresheet’s landing maneuver: ⁰It appears that during the landing process a command was entered that led to a chain reaction, which caused the main engine to switch off and prevented it from being reactivated.

— Israel To The Moon (@TeamSpaceIL) April 17, 2019

We now know why Beresheet crashed: A software command uploaded to fix a sensor problem inadvertently started a chain reaction that shut down the main engines, dooming the lander. https://t.co/5P3D37c10J pic.twitter.com/dazeM4nT3k

— Jason Davis (@jasonrdavis) April 17, 2019