Learn to let go of space missions

InSight array

When dust builds up on InSight’s solar array, it can significantly reduce the power it can generate. This means that the mission can be completed in a few months. (Credit: NASA / JPL-Caltech)


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The end of InSight has come to light.

At a press conference last month, NASA officials admitted that they had been afraid for a long time. The dust that accumulated on the lander’s solar panels quickly reduced its output until the spacecraft did not generate enough power to operate its equipment. And by the end of this year, the panel will not generate enough power to keep the spacecraft alive.

“We don’t really know how well the spacecraft will work when it goes down. It exceeded our expectations on almost every turn on Mars,” Banerdt said of InSight. ..

The announcement was not a surprise. Since last year, project leaders have said they are aware that dust buildup will reduce power levels. They wanted a “cleaning event” that would allow a dust devil to pass through the lander and remove dust. This is similar to what happened to the Spirit and Opportunity Rover, which has been in operation for years. However, no such cleaning event took place, and other measures were taken, such as using the lander’s robotic arm to drop the regolith near the panel, causing the wind to bounce pebbles off the panel and kick up dust. Only short-term measures were provided. repair.

NASA used briefings to outline how the lander spends its final Mars sol on Mars. The arm will be placed in the final “retirement pose” and the camera attached to the arm will be able to observe the seismograph, which is the main equipment of the lander. The seismograph goes into intermittent operation and shuts down completely in July as soon as the power level continues to drop.

It may last a little longer. “We are in an unprecedented operational system,” Bruce Banerdt, JPL’s Principal InSight Researcher, said in a briefing. “We don’t really know how well the spacecraft will work when the power goes down. On almost every turn on Mars, it exceeded our expectations. It may last longer. . ”

Due to this issue, some wondered why the mission had no way to clean the array. Some people put a brush on the edge of the robotic arm and wiped the array like dusting home furniture. Banerdt explained that it’s not as easy as it sounds and it’s cheap. “The more money we put into solar arrays, the less money we put into scientific equipment, so we tried to find the right balance,” he said. (InSight, as part of NASA’s Discovery Program, had to meet cost limits, had problems developing seismographs, and had problems such as a two-year delay in launch.)

NASA claimed that the problem with the solar array was successful, even though it had reached the end of its life. It worked far beyond its main mission of one year on Mars (a little less than two years on Earth) and, despite its problems, achieved its scientific goals with a spectrometer. A heat flow probe that could not sneak into the surface of the earth. A few weeks before the briefing, NASA announced that InSight had measured the strongest quake to date. This is equivalent to magnitude 5.

But even successful long-term missions must someday be completed. Almost at the same time that NASA held a briefing on InSight, problems with the Voyager 1 spacecraft, which was launched nearly 45 years ago and is now slowing down from the solar system, were also reported. The spacecraft attitude control system returned data that did not match the actual behavior of the spacecraft.

“A mystery like this is one of the courses at this stage of the Voyager program,” Dodd said.

The spacecraft itself appears to be functioning well in other respects, and the strength of the signal received by Deep Space Network suggests that the spacecraft is properly oriented. However, the problem of what is called AACS may be a sign that more serious problems will occur in the future.

“Such a mystery is one of the courses at this stage of the Voyager mission,” said Susanne Dodd, Voyager Project Manager at JPL, in a statement. “Both spacecraft are almost 45 years old, far beyond what mission planners expected. We are also in interstellar space. This is what spacecraft has ever been. It’s a highly radiant environment that has never been flown. Therefore, the engineering team faces some major challenges. ”

Originality and ingenuity

The Ingenuity Mars helicopter, which was originally planned to fly five times, has flown 28 times, but has not flown since late April. (Credit: NASA / JPL-Caltech)

The Ingenuity Mars helicopter is only a short age on Voyager 1, but far beyond its lifespan. The experimental helicopter was initially designed to fly up to five times in a few weeks in April 2021, but then the project was completed and the Perseverance Mars probe was able to continue its mission. increase.

However, the ingenuity worked so well that it was extended. “Scientists said,’This is really useful. Let’s adopt it and make it an operational support element,'” said Thomas Zurbuchen, NASA’s Deputy Director of Science, last week at the National Academy of Space Research. I recalled at the committee meeting. Ingenuity was a Perseverance scout and completed his 28th flight in late April.

However, the beginning of winter at Jezero Crater on Mars is affecting Ingenuity. The helicopter lost communication with Perseverance, and thus the Earth, for several days in early May as the heater to keep the electronics warm drained the battery. This project was adapted by lowering the threshold temperature at which the heater was turned on, but probably due to exposure to low temperatures, the inclinometer used to measure its orientation before the start of the flight was lost. rice field.

Limited sunlight, and thus the power available during the winter, keeps ingenuity mainly on the ground until spring if it survives. After speaking at the International Space Exploration Conference in late May, Ingenuity Chief Engineer Jaakko Karras said: The engineer has come up with a workaround to allow the flight to continue without an inclinometer.

However, the mission has a long bonus time, and no one expected it to work after more than a year, so we are dealing with undesigned conditions. Zurbuchen wanted to speak at the Space Research Commission and set expectations accordingly.

“If it happens now, it’s a huge success, and it’s over,” he said of ingenuity. “We have achieved all the success we have hoped for. Celebrate this. We don’t care what happens next. This is a success.”

“Death is inevitable for all of us, and it is inevitable for all spacecraft,” Zurbuchen said.

He had a similar view on the Voyager 1 and InSight issues. “This mission is doing great science. We are exploring an environment close to the galaxy,” he said of Voyager. He said the project team has solved similar problems in the past, but one day they may run into problems that they can’t solve. When that happens, “don’t take out the champagne and pretend to be problematic for some reason.”

As for InSight, he said he was in line with Banerdt on how to organize the mission. “We intend to maximize science, not the life of the mission,” he said.

Banerdt said the same thing at a briefing last month. “The team didn’t have that much fate and darkness. We’re still focused on spacecraft operations,” he said. “We are still looking for ways to get the most out of science.”

Ultimately, no matter how long it lasts, all missions will eventually fail for some reason. “Death is inevitable for all of us,” Zurbuchen said during the meeting. “And that is inevitable for all spacecraft.”

However, it can be revived. NASA’s extended missions or InSight will end this year, assuming power levels are below critical levels. However, if the landing site is exposed to sunlight in the spring and the situation improves, and InSight finally reaches the long-awaited cleaning event, the spacecraft may be revived. NASA will check in the signal from InSight next year.

“The environment on Mars is very uncertain. I don’t know what will happen,” said Kathya Zamora Garcia, Deputy Project Manager at InSight, at a briefing last month. “We listen.”


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