India's and Israel's moon-landing attempts both failed during descent - here's why the '15 minutes of terror' are so difficult
- India's Vikram moon lander, part of its Chandrayaan-2 mission, crashed into the lunar surface last week. It was the country's first attempt at a soft landing on the moon.
- The landing of Israeli nonprofit SpaceIL's Beresheet lander also failed in April.
- Descent and landing are difficult stages of a mission to the moon or any other planetary body - especially the final stages, which India's space-program director referred to as "15 minutes of terror."
- That's because landers must successfully carry out a series of complex commands with little room for failure, while contending with the moon's wonky gravity, uneven terrain, and pesky dust.
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India's attempt at a soft lunar landing appeared to end in a crash on September 6 (September 7 in India), making it the second failed moon landing this year.
The mission's main spacecraft, Chandrayaan-2, has since spotted the Vikram lander's hapless hardware from its vantage point orbiting the moon. The lander arrived at the moon's south pole, seemingly in one piece, but India's space agency said it has been unable to restore communications.The crash came just five months after an Israeli nonprofit's lander, called Beresheet, crashed into the moon's surface. In both cases, the fatal errors occurred the final stages of descent.
Robert Braun, dean of the College of Engineering and Applied Science at the University of Colorado, has worked on landing and descent teams for multiple NASA missions to Mars.
"Among all the things we do in space, landing is one of the more challenging aspects, because time gets greatly compressed," he told Business Insider. "There's very little margin to try something again if it didn't happen as planned."
Here's why the final stages of a moon landing are so challenging.