WASHINGTON — NASA and the European Space Agency have revised their plans to return samples from Mars, removing a rover and its lander from the effort and replacing them with helicopters modeled on Ingenuity.
At a July 27 briefing, officials with the two space agencies discussed the latest version of the planned Mars Sample Return campaign, with the goal of returning to Earth in 2033 samples currently being collected by the Perseverance rover.
In March, NASA said it would split a sample retrieval lander into two separate landers. One would carry an ESA-provided “fetch rover” that would pick up samples cached by Perseverance and return them to the second lander, which contained the rocket called the Mars Ascent Vehicle (MAV) that would launch the samples into orbit. ESA’s Earth Return Orbiter would collect the sample package and return it to Earth in 2033. The two landers, NASA said then, were needed since a single lander that could carry both the MAV and the fetch rover had become too large to land using technologies demonstrated on previous landers.
The new concept, though, does away with the fetch rover and its lander. Instead, NASA and ESA will rely primarily on Perseverance to bring the samples to the lander with the MAV. An ESA-provided robotic arm will transfer the samples from Perseverance to the MAV.
“Key to our new architecture is a recent assessment of Perseverance’s reliability and life expectancy based on its performance to date,” said Jeff Gramling, director of the Mars Sample Return program at NASA. That assessment, along with the performance of the similar Curiosity rover, which will mark 10 years on Mars next month, led the agencies to conclude that Perseverance will be able to deliver samples to the lander.
“We have confidence that the rover will be available to deliver samples to the sample retrieval lander in 2030, when we need it to be,” he said.
As a backup, the lander will bring with it two helicopters similar to Ingenuity, the small helicopter delivered as part of the Perseverance mission and which far exceeded expectations. The helicopter was originally planned to conduct no more than five flights over a month, but has flown 29 times over more than a year.
Richard Cook, manager of the Mars Sample Return program office at the Jet Propulsion Laboratory, said the new helicopters would be slightly heavier than Ingenuity. Each would be equipped with robotic arms to grapple sample tubes and have wheels on their landing legs. The wheels, he said, would allow the helicopters to land near a sample tube and then roll up to it to grab it. The helicopters would then fly back to the lander and roll up to it.
“They would be used as a backup to bring the tubes back to the lander,” he said. “There’s also the possibility we could do other things with it, such as observing the area around the lander and potentially taking pictures of the MAV launch.”
Gramling said eliminating the fetch rover and its lander would reduce the risk of the overall Mars Sample Return campaign. “This mission is simpler. It’s less organizationally complex,” he said. “We believe now that we have an architecture that is simpler and will position us for success.”
It will also presumably be less expensive, but Gramling did not provide any estimates of the cost savings. “Obviously, one lander is much less expensive than two,” he said, but deferred any cost estimates until the mission reaches a milestone called Key Decision Point C, where the agency sets cost and schedule commitments, in about a year.
Two years ago, NASA and ESA estimated the overall cost to the agencies for all the missions in the full Mars Sample Return campaign to be at least $7 billion. An independent review several months later estimated that cost to rise by on the order of $1 billion. NASA did not disclose how much the two-lander approach considered earlier this year would cost.
ESA will save significant money by not building the fetch rover, which comes as it works to try to find a new way to launch its ExoMars mission and the Rosalind Franklin rover after terminating cooperation with Roscosmos. David Parker, director of human and robotic exploration at ESA, said the project has been working “at great speed” on alternative concepts for the mission.
“There’s been some excellent discussions between NASA and ESA to explore the different options getting Rosalind Franklin to Mars,” he said. However, ESA ruled out using Rosalind Franklin as the Mars Sample Return fetch rover because of significant differences in design. Parker said a decision on the future of ExoMars would come at ESA’s ministerial meeting in November.
Thomas Zurbuchen, NASA associate administrator for science, said on the call that he’s been giving talks recently about the James Webb Space Telescope, which released its first science observations earlier this month after a successful launch and commissioning that came only after years of delays and billions of dollars in cost overruns.
He said he sees comparisons between JWST and Mars Sample Return. “Both are historic missions. Both are international. They’re big missions that are both difficult but are very much worth doing.”
