Responding to an independent review of NASA’s ambitious Mars Sample Return mission, agency officials said Monday they will seek fresh ideas from agency engineers, researchers and the private sector to come up with alternative mission designs to reign in sky-rocketing costs and get the precious samples back to Earth earlier.

The independent review board concluded last September, the complex multi-spacecraft sample return mission could cost as much as $11 billion to pull off — $4 billion to $5 billion more than originally expected — and not get samples back to Earth before 2040, even by stretching out development.

“The NASA team that looked at the Independent Review Board conclusions has said that they could string it out over time, but you’re not going to get the samples back until 2040,” NASA Administrator Bill Nelson told reporters. “That is unacceptable to wait that long. It’s the decade of the 2040s that we’re gonna be landing astronauts on Mars.”

He said the estimated price tag, which could go up to $11 billion depending on the options pursued, also was “unacceptable.” The original target in a National Science Foundation decadal survey that recommended a sample return mission was just under $6 billion.

“The long and short of it then is that the current budget environment doesn’t allow us to pursue an $11 billion architecture, and 2040 is too long,” Nelson said. “So, what to do?

“I have asked our folks to reach out with a request for information to industry, to JPL, to all NASA centers (and) to report back this fall an alternate plan that would get (samples) back quicker and cheaper, and try to stay within those limits that the decadal survey said that we should.”

After the teleconference concluded, SpaceX founder Elon Musk said on X that his company’s Starship rocket, which NASA Artemis astronauts will use to reach the moon’s surface in the next few years, “has the potential to return serious tonnage from Mars within (about) 5 years.”

No immediate comment on that idea from NASA.

As originally envisioned, the Mars Sample Return mission, or MSR, is the most complex robotic planetary science mission ever attempted, one requiring a new NASA lander to bring a rocket to the surface capable of launching soil and rock samples gathered by another rover already on the red planet.

Once in Mars orbit, the sample container would be collected by a European Space Agency spacecraft and returned to Earth for detailed laboratory analysis to determine if any signs of past microbial activity might be present in ancient riverbed deposits.

NASA originally hoped to launch the MSR mission, with a projected life cycle cost of nearly $6 billion, in 2028. But in September 2023, the independent review board concluded the project was not feasible given current budget projections, unrealistic schedules and a management structure that was not up to the task of getting the spacecraft ready for launch in time.

The review panel concluded the project almost certainly could not get off the ground before 2030 and could cost between $8.4 billion and $10.9 billion depending on the final mission architecture.

“MSR is a deep-space exploration priority for NASA, in collaboration with ESA,” the review team concluded. “However, MSR was established with unrealistic budget and schedule expectations from the beginning. MSR was also organized under an unwieldy structure.

“As a result, there is currently no credible, congruent technical, nor properly margined schedule, cost and technical baseline that can be accomplished with the likely available funding.”

The team said “technical issues, risks and performance-to-date indicate a near zero probability of … meeting the 2027/2028 Launch Readiness Dates (LRDs). Potential LRDs exist in 2030, given adequate funding and timely resolution of issues.”

To launch in 2030, the NASA sample retrieval lander and ESA’s Earth Return Orbiter likely will requite between $8 billion and $9.6 billion, “with funding in excess of $1 (billion) per year to be required for three or more years starting in 2025.”

Alternative mission scenarios and launching the sample retrieval rover and ESA orbiter on different timetables between 2030 and 2035 might “yield an MSR program that is potentially able to fit within the likely annual funding constraints.” But costs could reach nearly $11 billion, more than NASA spent to build the James Webb Space Telescope.

Nelson said a major reason for the ballooning cost was a billion-dollar hit to NASA’s science budget that was part of a congressional deal to secure funding for the debt ceiling. NASA received $310 million for the sample return mission in the agency’s fiscal 2024 budget and plans to ask for just $200 million in the FY25 budget request while mission options are explored.

However the mission plays out, samples will be waiting. Since landing in Jezero crater in February 2021, NASA’s Perseverance rover has been collecting soil and rock samples, storing them on board in sealed tubes or dropping them to the surface in known locations for eventual retrieval. The samples were collected at or near an ancient delta where water once flowed into the crater, possibly depositing indicators of past biological activity.

While Perseverance is equipped with sophisticated instruments and lab gear, it was designed primarily to assess habitability, not to look for direct signs of past microbial life. For that sort of in-depth research, the samples must be brought back to Earth.

Under the initial MSR plan, a NASA retrieval rover would touch down near the Perseverance samples, collect them with a robot arm or small helicopters and put them inside a sample container atop a solid-fuel rocket known as the Mars Ascent Vehicle. The MAV would then blast off and release the sample container in Mars orbit.

At that point, ESA’s retrieval spacecraft would rendezvous with the sample spacecraft, capture it and head back to Earth. The sample container then would be released for a parachute descent to a U.S. landing site. From there, it would be flown to a laboratory at the Johnson Space Center for the start of detailed analysis.