The Perseverance rover, which has been operating on Mars since February 2021, has covered a distance approaching that of a marathon and collected samples that could address crucial questions: what was the planet like billions of years ago, was it habitable, and did life ever exist there? One of these samples, named Cheyava Falls, contains iron-bearing minerals. On Earth, such minerals usually indicate microbes that used iron in metabolic chemical reactions. This sample was collected in March 2024 in the Bright Angel area and is stored in the rover’s container. Analysis on Earth with a full set of laboratory equipment could answer whether terrestrial analogies apply to Mars. However, the return of Cheyava Falls and other samples to Earth is under threat.
Perseverance is the first stage of the multi-stage Mars Sample Return (MSR) mission aimed at delivering Martian samples. The Trump administration, in May, proposed canceling the return stage in the NASA budget project for 2026, calling it “financially unsustainable.” The decision now rests with the U.S. Congress. In 2024, NASA already abandoned the original MSR plan due to high costs and delays, shifting towards seeking cheaper commercial options. By the end of 2024, about a dozen proposals were submitted, including a scenario from SpaceX with the Starship rocket, projects from Blue Origin, and Rocket Lab, the latter promising to perform the mission for $4 billion with a return by 2031.
Scientists are disappointed. “We’ve been working for decades to make this happen,” says planetary geologist Vicky Hamilton. After collecting valuable samples, leaving them on Mars is “hard to watch.” Perseverance mission scientist Ken Farley calls Cheyava Falls “the most interesting sample in the collection.” The rover landed in the Jezero Crater, where a river once flowed, leaving a dry delta visible from space. Perseverance is equipped with a manipulator with a drill and 43 sample cavities. Ten of the collected samples were left at Three Forks in December 2022–January 2023 as a reserve. The most valuable ones, including Cheyava Falls, are on board the rover.
On Earth, the samples will allow for the search for signs of life difficult to explain by non-biological processes. The samples will help determine if the warm and wet planet was habitable 3–4 billion years ago, when and why its magnetic field and atmosphere disappeared. Electrons in the rocks preserve a “fossil record” of the field, which X-ray scans can reveal precisely. NASA awaits a decision on the sample delivery mission by mid-2026.
Perseverance, with a power source lasting 10 years, continues to collect, but without launching the next stages in two years, the MSR mission could fail. Recent developments hint at the growing involvement of private companies in space exploration could offer a viable alternative to traditional government-funded missions.
