by NASA recently announced that it is looking for new ways to return rock cores drilled by the Perseverance Rover in Jezero Crater on Mars to Earth. This worries space scientists, who view the Mars Sample Return (MSR) mission as the cornerstone of plans to explore the Solar System.
But when you think about what’s at stake, scientifically and politically, it looks like NASA is going to press ahead with the mission to make it a success.
One key conclusion of the NASA review is that MSR was established with an unrealistic budget and schedule. It now expects to cost US$8-11 billion (£6.5-8.9 billion), after an initial estimate of $5.3 billion. This does not include the investment being made by the European Space Agency (ESA), which is likely to be around €2 billion (£1.7 billion).
There are also concerns that the timeline for returning the drill cores to Earth could slip into the 2040s, thereby starting to hold up the even more ambitious vision of human missions to Mars.
Despite these obstacles, NASA remains committed to MSR as one of its highest science priorities. In fact, it remains the agency’s highest priority for planetary science in a decade.
NASA puts a lot of emphasis on delivering what its ten-yearly public surveys intend – and it would be reluctant to abandon the recommendations. Esa is unlikely to want to lose the scientific investment it has already made in MSR.
Huge scientific importance
So why does the space science community consider MSR so important? Partly because the technologies are a step forward for future human exploration. For example, the mission needs a lift vehicle to launch the samples into orbit for capture by another spacecraft.
Persistence is already doing the first key step of this mission – drilling in Jezero Crater. This is step one of four. The next two steps are to collect at least some of the drilled samples and send them on a Mars ascent vehicle into orbit for capture by the Esa Return Orbit. One of the main technical challenges of MSR is a folding football-sized capsule in Mars orbit. Esa is taking a big role here and she leads the development of the return orbit.
The final step, assuming a successful landing at the Utah Test and Training Range, will be a rigorous program of organic, geochemical and mineralogical analyzes conducted under strict containment conditions. This phase will deploy the best equipment scientists have in laboratories around the world.
But these challenging steps come at a cost, which NASA now plans to reduce. For example, it can reduce the mass of an ascent vehicle. And a proposed UK-built Fetch rover has already been dropped to collect drilled samples. Even the option of using helicopters as shown by Ingenuity on Mars2020 is in jeopardy – it may be Ingenuity itself that delivers the drill tubes to an ascent rocket.
But these financial savings come at a scientific cost. Fewer of the 30 drill cores currently planned (each of the rock cores inside the 15cm tubes are about 6cm long) would be returned in that case to keep the ascent vehicle light.
The actual samples from an ancient delta, and a thick lava flow that preserved tracks altered by hot water, which are being drilled in Jezero Crater, were kept on board or left at a depot. These precious cores show the results of past Mars orbiter and landing missions, telling us where to land and making precise predictions of what we might find.
Ultimately, the samples waiting to be returned to Earth give us the best chance in the near future to identify traces of ancient life beyond our own planet. It is hard to imagine a more urgent task for space science.
If Persistence continues to work successfully – and the 12-year-old sibling rover Curiosity I’m working on suggests – then we have the tantalizing prospect of sampling the rim of Jezero Crater. This is a window into a new type of environment in Mars exploration: the deeply excavated crust where ancient microbial life may have been protected from harsh surface radiation.
China’s competition
There is another reason, less driven by science, that NASA and ESA will want to maintain their records of success in Mars exploration.
Cold war rivalry with the Soviet Union spurred the Apollo program. Tragically, a new collaboration with the Russian space agency Roscomos, and the full potential for space exploration that could be realized in a more peaceful geopolitical environment, is not currently possible.
Roscosmos could no longer mount a credible MSR mission on its own. The Esa Rosalind Franklin rover was scheduled to launch on a Soyuz rocket in 2023, but after the invasion of Ukraine that mission was quickly reconsidered.
China now has credible plans for a Sample Return mission to Mars called Tianwen-3. The Chinese Space Agency wants to launch it in 2028, with separate lander and ascent vehicle launches. If that challenging timeline can really be achieved, samples could be returned to Earth by 2031.
In 2020, I argued that there could be an era of new Chinese cooperation with the west. But four years later, I wonder if the history of the competition is repeating itself.
MSR is needed to address some of our most important questions about Mars and habitable environments beyond Earth. But it also looks set to become another symbol of competition in space. That being said, it could be an important reason why it succeeds.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
John Bridges receives UK Space Agency funding for the NASA-ESA Mars Sample Return planning groups tasked with identifying the best techniques for analyzing returned samples, and the closest terrestrial analogues of the samples this.
