Nasa pulls plug on Mars rock return mission as costs skyrocket

After years of delays, budget battles, and dwindling hope, Nasa’s bold plan to bring pieces of Mars back to Earth has officially run out of air. The ambitious Mars Sample Return (MSR) mission, once hailed as the ultimate quest to answer whether life ever existed on the Red Planet, has been effectively cancelled.

A new US spending bill released this week backs the White House’s move to end the costly programme, which has been on life support for months. Although the bill still needs final approval from Congress and the President’s signature, it’s now clear that MSR’s journey has reached its final stop.

“This is deeply disappointing,” says Victoria Hamilton, chair of Nasa’s Mars Exploration Program Analysis Group, reported Science journal. “When we talk about being the dominant power in space, it’s hard to understand how we walk away from something this ambitious,” she added.

The end of an era

The decision leaves behind Nasa’s most prized planetary science goal, and the 30-plus rock cores that the Perseverance rover has spent years carefully drilling, sealing, and storing on the Martian surface. These tiny tubes of red dust were meant to be fired into space and ferried home for study, possibly holding clues to ancient life.

The MSR mission had been in trouble for a while. Originally expected to cost about $5 billion, its estimated budget ballooned to a staggering $11 billion by 2024. Even after Nasa revised its plan and trimmed the figure to $7 billion, the project remained too expensive for lawmakers already worried about overruns in other missions.

The new compromise bill offers no comfort. “The agreement does not support the existing Mars Sample Return programme,” it states. Instead, $110 million will go to a new “Mars Future Missions” fund, aimed at preserving technologies developed for MSR, like advanced landing systems for Mars.

Global consequence

Killing MSR could free up funds for other long-delayed missions in Nasa’s science portfolio, such as the long-awaited Venus probes and a proposed Uranus explorer.

The overall science budget is being cut by just 1 per cent, to $7.25 billion, far less severe than the White House’s original plan to halve it. For planetary scientists, that’s a small relief amid the disappointment.

But the cancellation also comes with diplomatic and scientific fallout. The project was a joint venture with the European Space Agency (ESA), which had been developing an “Earth Return Orbiter” to collect and transport the samples home.

ESA may now turn its nearly finished spacecraft into a standalone Mars mission, leaving Nasa without a partner should the US ever revive the sample-return idea. That could make any future reboot even more expensive.

Meanwhile, the scientific value of Perseverance’s samples keeps growing. In 2024, the rover drilled a rock called Cheyava Falls that contains curious mineral patterns, nicknamed “leopard spots”, which resemble microbial traces found in ancient Earth rocks. Scientists suspect it could be the most promising hint of past Martian life yet. But without bringing it back to Earth, there’s no way to be sure.

For now, Nasa’s challenge is figuring out what to do with Perseverance itself. The rover is approaching its fifth year on Mars, nearly done collecting its planned set of samples. Without a mission to retrieve them, those precious tubes could remain stranded forever.