NASA says it needs better ideas about how to return samples from Mars

NASA's $11 billion plan to robotically return rock samples from Mars to Earth is too expensive and will take too long, so officials are tasking engineers from the government and the private sector to come up with a better plan, the agency's director said Monday.

The agency's decision on how to proceed with the Mars Sample Return (MSR) program comes on the heels of an independent review last year that found cost inflation and delays threatened the mission's viability. These efforts will likely cost NASA between $8 billion and $11 billion, and the launch will be delayed for at least two years until 2030, with the samples returning to Earth a few years later. The review board concluded.

But this is not the whole story. Like all federal agencies, NASA faces new spending limits imposed by the Fiscal Responsibility Act, a bipartisan budget deal reached last year between the White House and Republicans in Congress. With these new budget headwinds, NASA officials have decided that the agency's Mars sample return plan will not return samples from the Red Planet to Earth until 2040.

One of the primary goals of NASA's Perseverance rover, which has been orbiting Mars since 2021, is to collect and catalog more than 30 samples of Martian rockets, sediment and air to return to Earth in a future mission. Perseverance is sealing these samples in cigar-sized titanium tubes, and their combined mass will total about half a kilogram.

Returning original samples from Mars to Earth for analysis in terrestrial laboratories has been a top priority for the planetary science community's decadal survey. But retrieving those samples turned out to be much more difficult than NASA thought.

“The bottom line is $11 billion is too expensive, and not returning samples until 2040 is an unacceptably long time,” NASA Administrator Bill Nelson told reporters on Monday.

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So, NASA is changing the Mars sample return program. The pre-existing plan has been put together over the past seven years, with improvements from engineers at NASA's Jet Propulsion Laboratory, the organization charged with managing the effort.

The latest version of the Mars Sample Return mission includes two launches. One will be conducted in 2030 with a European spacecraft that will orbit Mars and wait for the second mission – which is NASA's responsibility – to leave Earth in 2035 using the Sample Retrieval Rover (SRL). The second launch will include the Mars Ascent Vehicle (MAV), the rocket necessary to launch samples from the Red Planet into space.

The lander will deliver the MAV to the surface of Mars, and the Perseverance rover, already on Mars, will deliver sealed tubes of rock and soil samples in a container for the trip back to Earth. The MAV will then launch the material into orbit around Mars, where a European-made Earth Return Orbiter will rendezvous with the sample container and pick it up for the trip home.

These launches were previously scheduled to take place two years apart in late 2020, but those target dates are no longer achievable with the current plan and budget, officials said Monday. Stretching the two launches over five years would spread out expenditures on the MSR program to match the agency's projected budget without “cannibalizing” NASA's other planetary science projects, such as the Dragonfly mission to explore Saturn's moon Titan.

The latest plan revealed Monday also includes removing two helicopters from the Lander Retrieval Vehicle. These helicopters, which would have picked up tube samples and delivered them to the chamber that would return them to Earth, were supposed to be based on NASA's Ingenuity helicopter that was successfully demonstrated on Mars with the Perseverance rover. Instead, the updated plan will rely entirely on Perseverance to deliver sample tubes to the Mars Ascent Vehicle.

There are also some other changes to NASA's MSR architecture, including replacing the solar arrays on the sample retrieval vehicle with a nuclear power generator. This would improve the reliability of the lander and provide better thermal conditions for the MAV, according to Sandra Connelly, deputy chief of NASA's Science Mission Directorate.

However, this architecture was largely dead on arrival.