So basically they almost landed. The mission’s main spacecraft, Chandrayaan-2, has since spotted the Vikram lander’s unfortunate 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.
This isn’t the first moon fuck up for humankind. The Indian crash was just five months after an Israeli nonprofit’s lander, called Beresheet, crashed into the moon’s surface. In both cases, the fatal errors occurred in the final stages of descent.
So close, yet so far. 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. He explains that landing is one of the more challenging aspects because time gets greatly compressed. One chance,- one shot.
If India’s Vikram lander, part of its $140 million mission to the moon, had touched down successfully, the country would have become the fourth to soft-land on the moon. But no. The lander diverged from its intended path 1.3 miles above the lunar surface and lost communication with spacecraft operators shortly after. Later on, operators discovered that a command telling Vikram to shut off its engine was incorrectly sent.
There was nothing new in this scenario as the The Beresheet lander, part of Israeli nonprofit SpaceIL’s private moon mission, met a similar fate when it lost communications during its descent in April. Beresheet hurtled toward the moon’s surface at 310 mph. All because a manual command entered into the spacecraft’s computer led to a technical glitch that caused the spacecraft’s main engine to malfunction, rendering it unable to slow down.
After such grand snarl-up, a logical thing to ask is: “How the fuck can you successfully land that crap”. And the answer is wrapped with a thick layer of details. At the most basic level, a lunar lander begins its descent by propelling itself out of the orbit of the moon and orienting itself in the right direction. Often, a lander deploys the legs it will land on during this phase. From there, it continues re-configuring and re-orienting itself as it looks for the safest landing spot on the moon’s cratered, rocky surface.
As it gets very close to the surface, the spacecraft must slow down. This may be the point at which India’s communications loss doomed its lander. Vikram was supposed to touch down at a speed of less than 5 mph, but Doppler data from a radio telescope in the Netherlands indicated that it was moving at over 110 mph as it approached the lunar surface.
Braun makes a really accurate definition of his work: “You basically work on something for four or five years, and then it takes four or five minutes in real-time for that landing to occur, and it’s very dramatic. You’re gathering with all the people that you’ve been working with, who you’ve become typically pretty close to,” he said. “You’ve done all you can for the spacecraft well before the landing. These systems are all autonomous.”
Next time India will team up with Japan in 2023. They will try to send a rover to the south pole of the moon. We can only wish the poor bastards good luck!