NASA says it's revising the Mars Sample Return mission due to cost, long wait time

NASA announced Monday it is revising plans for its Mars Sample Return (MSR) mission due to the estimated cost and long wait time for samples to return to Earth.

The mission's goal was to collect samples of rock, soil, atmosphere and loose surface material and deliver them back to Earth via the Mars Perseverance rover. The rover, which landed in 2021, has been collecting and storing samples in specially designed tubes. The mission was a joint effort with the European Space Agency.

During a press conference, NASA administrator Bill Nelson said although the federal space agency is "committed" to retrieving the samples, independent reviews have estimated the project would cost between $8 billion and $11 billion and samples may not return until 2040.

"That is unacceptable to wait that long," Nelson said. "It's the decade of the 2040s that we're going to be landing astronauts on Mars ... 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."

To make the mission work, NASA is requesting assistance from the NASA community, including the Jet Propulsion Lab (JPL), to create a new, updated mission design that "has reduced complexity, improve resiliency and risk posture, and well as well as strong accountability and coordination," Nicky Fox, associate administrator for NASA's Science Mission Directorate, said during the press conference.

Nelson said he is asking NASA centers and JPL to report back in the fall for alternate plans to make the mission quicker and cheaper to carry out.

The sample retrieval orbiter was scheduled to launch in 2027 and the lander in 2028, the latter carrying a NASA-led Mars rocket and small Mars helicopters. It was scheduled to land in 2030 and Perseverance would bring the samples to the lander, attached to the lightweight rocket.

Next, the rocket -- carrying the samples -- would launch to meet the orbiter, the first to do so from another planet. Lastly, the orbiter would carry the samples the rest of the way to Earth, with plans to originally return in 2033, according to NASA.

The helicopters would be used as backups in case Perseverance is not able to bring the sample tubes to the lander or in case sample tubes are accidentally left on the Mars surface.

"Collecting compelling science samples that will help scientists understand the geological history of Mars, the evolution of its climate, and prepare for future human explorers," NASA wrote. "The return of the samples will also help NASA's search for signs of ancient life."

Despite the schedule set by NASA, the future of the mission has been in question after an independent review board reviewed the federal space agency's plans and goals for the MSR mission and presented a report in September 2023.

In the report, the mission was described as having "[an] unrealistic budget and schedule expectations from the beginning."

The authors of the report said the program would cost between $8 billion and $11 billion and that "technical issues, risks, and performance-to-date indicate a near zero probability" of the estimated launch dates. The report found the 2027/2028 date was more likely to occur in 2033, delaying the mission by a few years. Additionally, the Decadal Survey, conducted by the National Research Council said samples were unlikely to return until the 2040s.

"Independent review boards like the one we commissioned for Mars Sample Return help review whether we're on the right track to meet our mission goals within the appropriate budget," Sandra Connelly, deputy associate administrator for NASA's Science Mission Directorate, said in a statement after the report's release. "We thank the board for its work, and now our job is to assess the report and address if there are elements of the program that need to change."

Past missions to Mars have confirmed that certain areas of the planet were capable of supporting life in the past, according to NASA. Evidence indicates parts of Mars were warm and wet about three billion years ago, which would be around the same time early life was developing on Earth.

"This commonality raises the prospect that discoveries on Mars can give us important insights about the origin and evolution of life on Earth," NASA stated.