NASA to study two alternative architectures for Mars Sample Return

ORLANDO, Fla. — NASA will spend the next year and a half studying two different approaches for returning samples from Mars, one leveraging technologies used on previous Mars missions and the other new commercial vehicles.

NASA leadership announced Jan. 7 that it would pursue studies of two architectures for its Mars Sample Return effort that would take samples currently being collected by the Perseverance rover and bring them back to Earth as soon as 2035.

The main difference between the two options would be how to deliver a redesigned sample retrieval lander to the surface of Mars, which would take the samples from Perseverance and launch them into orbit on a rocket called the Mars Ascent Vehicle (MAV). The samples would then be picked up by a European spacecraft, the Earth Return Orbiter, and brought back to Earth.

The first option, which NASA Administrator Bill Nelson said would cost between $6.6 billion and $7.7 billion, would use the “sky crane” technology previously developed by Jet Propulsion Laboratory for landing the Perseverance and Curiosity rovers. The second option, with projected costs of $5.8 billion to $7.1 billion, would use a commercially provided “heavy lander”.

The first option appears similar to what JPL proposed to NASA last year when the agency solicited studies from within and outside the agency on alternative approaches to MSR. JPL said it would be possible to use the sky crane technology for landing a scaled-down sample retrieval lander with a smaller MAV, estimating it would reduce in half NASA’s estimates of $11 billion to carry out MSR.

NASA did not disclose details on what commercial landers would be used the second option. Nicky Fox, NASA associate administrator for science, declined to discuss specifics about what companies proposed, citing proprietary information. Both Blue Origin and SpaceX did receive study contracts in June 2024 for concepts that would incorporate technologies they are developing for Blue Origin’s Blue Moon and SpaceX’s Starship lunar landers.

“The main difference is in the landing mechanism,” she said of the two options being considered.

Both systems would deliver a redesigned sample retrieval landing platform. It would use a radioisotope thermoelectric generator (RTG) for power rather than solar panels, a move intended to simplify operations of the lander and better deal with dust storms that would impair solar panels. It would also use a smaller MAV, although NASA did not release details on changes in the design of the rocket that was one focus of the study contracts awarded last June.

The landing platform will also include a redesigned sample loading system for transferring sample tubes from Perseverance to the lander in a way that maintains backward planetary protection, or prevention of contamination back on Earth from Martian dust on the outside of the tubes. That is intended to simplify a NASA-designed capture and containment system on ESA’s Earth Return Orbiter that had also been a challenge to develop.

Fox said NASA will work through roughly the middle of 2026 to refine the two architectures. The JPL-developed sky crane, she noted, needs to handle a lander about 20% heavier than what was used for earlier rovers, while other work will focus on the design of the MAV. “It’s almost the normal engineering that we would do to get it up to the preliminary design review level of maturity,” she said.

Budgets and schedules

That initial work, Nelson said, requires Congress to provide at least $300 million in a fiscal year 2025 appropriations bill. NASA originally zeroed out MSR in its 2025 budget request last March, then requested $200 million. A House spending bill introduced last year would have provided $650 million while a Senate version offered $200 million. Congress has yet to pass a final 2025 spending bill, more than three months into the fiscal year.

Fox said that the revised plans would allow for a launch of ESA’s orbiter in 2030 followed by the sample retrieval lander as soon as 2031, allowing samples to be returned no earlier than 2035 but potentially as late as 2039. Nelson said how quickly the samples can be brought back will depend on how much Congress is willing to spend now.

“A bottom line of $300 million is what the Congress ought to consider,” he said. “If they want to get this thing back on a direct return earlier, they’re going to have to put more money into it, even more than $300 million.”

Nelson said he had not directly discussed MSR plans with the incoming Trump administration, saying he has deferred to the “formal transition apparatus” for discussions. However, he defended the decision to study two options and defer a final decision to the next administration. “I think it was a responsible thing to do not to hand the new administration just one alternative if they want to have Mars Sample Return, which I can’t imagine that they don’t.”

The revised plans make it in increasingly likely that the first samples brought back from Mars will be by a Chinese effort that could launch as soon as 2028. Nelson, though, was dismissive of the “grab and go” Chinese plan that would grab samples accessible only at the landing site, rather than the science-driven NASA-led effort to collect samples specifically designed to provide insights in the habitability of Mars early in the planet’s history.

“They’re just going to have a mission to grab and go,” he said. “That does not give you the comprehensive look for the science community. So, you cannot compare the two missions.”

Speaking at the AIAA SciTech Forum here Jan. 6, Laurie Leshin, director of JPL, emphasized the science the samples being collected by Perseverance can provide. She cited an example of one sample that she said contained characteristics that, on Earth, would be considered ancient biosignatures. “That sample is now in the belly of Perseverance, waiting to come home and for us to tear apart in our labs and answer this question about life on Mars,” she said. “Our job is to go get it.”

She outlined the sky crane approach that JPL proposed, but provided no hints about whether it would be selected. She added that she was open to other ways to get the samples back. “If we’ve got Starships going to Mars, great. We’d love to put our lander inside of one of those.”

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