NASA is dedicating the next 18 months to evaluating two distinct strategies for retrieving samples from Mars. One relies on established technologies from past missions, while the other integrates new commercial vehicles.
On January 7th, NASA announced its pursuit of two architectural designs for its Mars Sample Return (MSR) endeavor. This mission aims to collect samples currently being gathered by the Perseverance rover and bring them back to Earth, ideally by 2035.
The primary difference lies in the delivery method for a redesigned sample retrieval lander to Mars. This lander will collect samples from Perseverance and launch them into orbit using a rocket called the Mars Ascent Vehicle (MAV). A European spacecraft, the Earth Return Orbiter, will then retrieve the samples and return them to Earth.
Option one, estimated to cost between $6.6 billion and $7.7 billion according to NASA Administrator Bill Nelson, utilizes the “sky crane” technology used to land the Perseverance and Curiosity rovers. Option two, projected to cost $5.8 billion to $7.1 billion, employs a commercially provided “heavy lander”.
Option one resembles a proposal from JPL last year, suggesting the “sky crane” could land a smaller sample retrieval lander with a smaller MAV, potentially halving the original $11 billion MSR cost estimate.
NASA hasn't disclosed which commercial landers are under consideration for the second option. NASA associate administrator for science, Nicky Fox, cited proprietary information when asked about specific companies involved. However, both Blue Origin and SpaceX received study contracts in June 2024 for concepts integrating their lunar lander technologies (Blue Moon and Starship respectively).
“The main difference is in the landing mechanism,” Fox stated, comparing the two options.
Both systems will utilize a redesigned sample retrieval landing platform. This will feature a radioisotope thermoelectric generator (RTG) for power instead of solar panels, simplifying operations and mitigating dust storm effects. A smaller MAV will also be used, although specific design changes haven't been released.
The landing platform will also include a redesigned sample loading system to transfer samples from Perseverance while maintaining backward planetary protection. This aims to simplify the ESA’s Earth Return Orbiter’s capture and containment system.
Fox indicated that NASA will refine these architectures until mid-2026. The JPL-developed sky crane must handle a 20% heavier lander than its predecessors, and further work is needed on the MAV design. “It’s almost the normal engineering that we would do to get it up to the preliminary design review level of maturity,” Fox said.
Nelson stated that this initial phase needs at least $300 million in the fiscal year 2025 budget. NASA's initial 2025 budget request omitted MSR funding, later requesting $200 million. A House bill proposed $650 million, while a Senate bill offered $200 million. A final budget is yet to be approved.
The revised plans suggest a potential 2030 launch for ESA's orbiter, followed by the sample retrieval lander in 2031, with sample return between 2035 and 2039. The timeline's speed depends on congressional funding.
“A bottom line of $300 million is what the Congress ought to consider,” Nelson emphasized. “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 stated he hasn't discussed MSR plans with the incoming Trump administration, deferring to the transition team. He defended studying two options and delaying the final decision: “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.”
This leaves a potential opening for China’s quicker “grab and go” mission, possibly launching as early as 2028. However, Nelson downplayed this, highlighting the scientific superiority of NASA's approach.
“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.”
At the AIAA SciTech Forum on January 6th, Laurie Leshin, JPL director, emphasized the scientific value of the samples. She mentioned a sample containing potential 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.”
Leshin outlined JPL’s sky crane proposal but remained open to alternatives. “If we’ve got Starships going to Mars, great. We’d love to put our lander inside of one of those.”