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\u201cIt\u2019s almost an understatement to say that it has surpassed expectations,\u201d said Lori Glaze, director of the planetary science division at NASA.<\/p>\n
In an interview, MiMi Aung, who shepherded the helicopter project from early out-of-control experiments on Earth through Ingenuity\u2019s first flights on Mars, said she felt \u201cA little sad, but, I must say, mostly super proud of the whole team.\u201d She recalled how Ingenuity\u2019s first flight was delayed by a software glitch. Back then, she and her colleagues took meticulous care to ensure that a fix did not cause more serious problems.<\/p>\n
\u201cIngenuity could die any day,\u201d she said. \u201cBefore or right after the first flight.\u201d<\/p>\n
The helicopter team had prepared for what they described as a 30-day sprint. \u201cSeventy-two flights was not in our imagination,\u201d said Ms. Aung, who left NASA in mid-2021 to work on Project Kuiper, Amazon\u2019s effort to beam internet from space.<\/p>\n
The mission instead turned into an open-ended marathon. Mr. Tzanetos said that in the back of their minds, team members knew that each passing day could be the last day for Ingenuity. But the helicopter seemed to always bounce back from any challenge.<\/p>\n
Other than one nonessential sensor that had failed, \u201cThe rest of the subsystems, from the solar panels to the battery, have been aging remarkably well,\u201d Mr. Tzanetos said. \u201cOur electronics, avionics, processor all seem to be doing just fine.\u201d<\/p>\n<\/div>\n<\/div>\n
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On Jan. 18, during its 72nd flight, Ingenuity fell out of touch with Perseverance while descending. Communications were re-established the next day, but then a shadow in a photo sent back a few days later revealed that about one-quarter of one of the rotor blades had broken off.<\/p>\n
\u201cThere was the initial moment, obviously, of sadness seeing that photo come down and pop onscreen, which gives a certainty of what occurred,\u201d Mr. Tzanetos said. \u201cBut that\u2019s very quickly replaced with happiness and pride and a feeling of celebration for what we pulled off.\u201d<\/p>\n
Mr. Tzanetos noted that on Thursday evening, it would be 1,000 Martian days, known also as sols, since Ingenuity had been dropped onto the surface of Mars by Perseverance.<\/p>\n
\u201cShe picked a very fitting time to come to the end of the mission here,\u201d he said.<\/p>\n<\/div>\n<\/div>\n
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Ingenuity had been flying over terrain that Mr. Tzanetos described as \u201csome of the most challenging\u201d \u2014 not because of obstacles but because it was so bland, with few rocks or other features. The previous flight had ended with an emergency landing because the navigation system was having trouble tracking its position.<\/p>\n<\/div>\n<\/div>\n
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The 72nd flight was intended as a 30-second up-and-down to check that everything was working, but again the bland terrain caused problems. \u201cBecause of the navigation challenges, we had a rotor strike with the surface,\u201d Mr. Tzanetos said. \u201cThat would have resulted in a power brownout, which caused the communications loss.\u201d<\/p>\n
With at least part of one blade broken off, the helicopter would not be able to generate enough lift, and the rotor would be unbalanced, meaning that the helicopter would be likely to shake itself apart if it tried to take off again.<\/p>\n
\u201cThere are some lessons in that for us,\u201d said Havard Grip, the chief pilot for Ingenuity. \u201cWe now know that kind of terrain can be a trap for a system like this.\u201d<\/p>\n
Dr. Grip said that a higher-resolution camera, able to pick out more details in even a bland landscape, would likely have helped.<\/p>\n
The Ingenuity team will conduct a few final tests on Ingenuity\u2019s systems and download images and data remaining in the helicopter\u2019s memory.<\/p>\n<\/div>\n<\/div>\n
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NASA engineers are investigating what caused the dropout in communication and whether the rotor blade hit the ground when Ingenuity landed.<\/p>\n
Future Mars helicopters are in the planning stages, including a couple that could accompany a mission to bring back to Earth rock and soil samples that Perseverance has been collecting. But that Mars sample mission, which has encountered technological and budgetary challenges, is being reconsidered, and the helicopters may be dropped.<\/p>\n
\u201cIngenuity was based off of theories,\u201d Mr. Tzanetos said. \u201cWe now have facts, and future aircraft designs are going to rely on all the data we\u2019ve collected from Ingenuity.\u201d<\/p>\n<\/div>\n<\/div>\n