India's first lunar module, dying on its way to the lunar surface on Friday, has been found out of orbit, according to the country's space agency. This has raised the hope that it could be revived.
If it did indeed land in a working state, that would be an impressive achievement. In the history of spacecraft, robotic probes that malfunction when landing on another world are no longer audible.
The Indian Space Exploration Organization – India's equivalent to NASA – tweeted Tuesday that its efforts to contact the lander have not yet been completed.
The ISRO Declaration d has not been confirmed News reports in India cite a nameless official who said the lander is intact, inclined only at an angle.
"It's hard enough to land on another planetary body if everything works perfectly," said Mark Johnson, the head of Lockheed Martin's team during the successful landing of the NASA spacecraft InSight on Mars November, "but to have done it in the presence of a major anomaly would have been startling."
Chandrayaan-2 – India's second mission to The Moon is made up of two parts: an orbiter conducting orbital research for up to seven years, and a lander named Vikram (which also included a rover Pragyan). The lander and orbiter parted last week, leaving the orbiter in a circular orbit 60 miles above the moon, moving the lander into an elliptical path that was within 20 miles of the surface.
During most stages of a mission, when a spacecraft goes awry. It is programmed to go into "safe mode", ie to be largely shut down, to avoid major problems and to wait for new instructions from Earth. That's not unusual. However, a spacecraft parked in a stable orbit or on the surface of another world is usually not in immediate danger, requiring engineers days or even weeks or months to fix the problem.
A problem during the landing is more like jumping out of an airplane and finding out that something is wrong with the parachute. There is little time left and the floor will not get out of the way.
"Landing is the hardest thing we do in planetary exploration," said Robert D. Braun, Dean of the College of Engineering and Applied Science at the University of Colorado, who has worked on NASA missions, the Rover to the surface of Colorado sent Mars.
When Vikram, who worked autonomously, fired his engines to slow down to landing, he was on a course that crossed the moon in 15 minutes.
The first phase seemed to be going well, but at a height of about 1.3 miles, their trajectory deviates from the planned route. There was little or no time for help from the earth. If that was possible, the spaceship had to recover quickly by itself.
"You only have one chance," said Mr. Johnson of Lockheed Martin. "You can not stop or go back and repeat it."
Whether the landing was successful or not, "It's a great first try," Dr. Brown. "You can not get so close without learning a lot of things that will help you next time."
Consider NASA's Mars Polar Lander disappearing when it tried to land near Mars's South Pole in 1999. An investigation found several possible explanations, including the fact that sensors accidentally interpreted the vibrations as surface spacecraft and shut off the engine when deploying the lighters.
The engineers who had written the state software could have added instructions to restart the engine if the spacecraft noticed that it crashed, but no one had expected it. In general, machines can only handle the problems expected of engineers.
Dr. Rather than trying to write software for all sorts of hardware failures, it makes more sense to invest money and time to make the hardware as reliable as possible.
For NASA Phoenix Mars and Mars InSight For missions, the spaceships were largely designed by Polar Lander, but were modified to avoid potential pitfalls. For example, the computer was instructed to ignore any vibration signals that occurred when the landing legs were deployed. Through testing, the engineers have made sure that everything works. Both Phoenix and InSight made it to the surface with ease.
Now that the Indian Space Agency knows Vikram's location, she can try to contact the lander more closely.
But any optimism to bring the spaceship back to life could be premature.
Jonathan McDowell, an astrophysicist at Center for Astrophysics in Cambridge, Massachusetts following space missions, announced on Twitter that the small lander, which is about two meters wide, would be barely visible in photos from the Chandrayaan 2 orbiter.
ISRO has not posted any pictures of the landing site. Another orbiter, NASA's Lunar Reconnaissance Orbiter, is said to fly over the part of the moon where it could be found on September 17th.
"NASA will share all images before and after the overflight of the area around the targeted Chandrayaan-2 Vikram Lander landing pad in support of analysis by the Indian Space Research Organization," a NASA spokesperson said in an e-mail.
Amateurs used an old 25-meter radio telescope from the Dutch Radio Astronomy Institute to track Vikram's descent. The frequency of the radio transmissions of the lander changed in relation to the earth, depending on the speed. This phenomenon, known as the Doppler effect, is similar to the changing pitch of train whistles and police sirens as they pass.
Cees Bassa, an astronomer from the Dutch institute involved in the effort, calculated the speed of the lander, the matching predictions during the first phase of the firing of the engines.
But then the speed of the spacecraft fluctuated, which was not to be expected.
"It confirms that something was wrong." Bassa.
He could not say what caused the oscillations, but he now believes the end of the radio transmission coincided with Vikram's impact on the ground. It should start at less than five miles an hour.
The Doppler data shows that Vikram moved at more than 110 miles per hour instead.