The stars haven’t been aligned for Europe’s first Mars rover ExoMars, but scientists still believe the aging vehicle can play a big role in answering one of Mars exploration’s biggest questions: Is- has there ever been life on the red planet?
The European Space Agency (ESA) ExoMars Rosalind Franklin Rover is probably the most high-profile victim of the space industry Russia’s War in Ukraine. Originally slated for a 2018 launch, the rover was finally declared ready to go (after several delays) for a September launch this year at the summit. The Russian Proton rocket from the Baikonur Cosmodrome in Kazakhstan. But Russia’s invasion of Ukraine put an end to those plans.
ESA officially cooperation ended on the ExoMars mission with Russia in July, leaving the rover, designed in 2004, once again in limbo, and most importantly, without a landing pad to land it on the surface of March. (This landing pad was built by Russia, which joined the ExoMars program in 2012 following the withdrawal of original partner NASA in 2012.)
ESA has not yet decided the fate of the mission. Having already spent $1.3 billion on the program, it will have to choose between ditching the rover altogether or shelling out another substantial sum to replace the Russian parts.
Related: A Brief History of Martian Missions
In the case of the latter option, the most optimistic estimates see the ExoMars rover go Earth in 2028. For many European scientists, abandoning the mission should not be an option at all, and not just because of the investment. Even though NASA perseverance broke his sample collection targets and plans for a mission that would bring these samples to Earth are already underway, the aging ExoMars rover can contribute a lot to our understanding of Mars, they say. And some of these questions, in fact, cannot be answered by stellar persistence.
“[The rover’s instruments] are going to age a bit,” John Bridges, professor of planetary science at the University of Leicester in the UK, told Space.com. ‘t use the most advanced technology. Even if we go by bike rather than the newer car, it doesn’t really matter, as long as we get there.”
The Promise of Exercise
The greatest strength and scientific promise of the Rosalind Franklin ExoMars rover is its 6.6-foot (2-meter) drill, which some astrobiologists believe may have a better chance of finding traces of past or present martian life on Mars than the agile Perseverance.
“The pieces of rock that Perseverance collects come from the immediate surface [of Mars]”, Susanne Schwenzer, an astrobiologist at the Open University in the United Kingdom, who is also an interdisciplinary scientist on the ExoMars mission and a member of NASA science teams Curiosity and the Mars Sample Return missions, Space.com told Space.com. “And that immediate surface is bombarded by cosmic raysand UV rays [from the sun]which destroy organic matter.
Unlike Earth, Mars has no protective magnetic field and a very thin atmospherethere is therefore nothing to filter this sterilizing radiation, some of which can penetrate several meters deep into the Martian rocks.
“[The effects of the radiation] decrease exponentially, so the first centimeters [inches] are the most affected,” Schwenzer said.
That doesn’t mean Perseverance can’t find traces of life, just that detecting organic molecules in the burnt surface layers might require more difficult scientific analysis, Schwenzer added.
“The advantage of the return samples is that we will have them in our labs here,” Schwenzer said. “If we find something that we can’t answer with the instruments we have, we can wait until the right technology is developed. It took until the late 1990s to find water in the Apollo samples because they didn’t have the right instrumentation at that time.”
The deep excavations for which the ExoMars rover was built can, indeed, help scientists understand the rocks of Perseverance and the weathering they have undergone due to radiation bombardment.
“[The ExoMars rover] will help us understand how organic matter degrades with depth or does not degrade and is preserved in deeper layers,” Schwenzer said.
Europe’s wrong turn
Bridges agrees with Schwenzer. But there are other reasons why continuing with ExoMars should be the only option on the table, he thinks. A generation of European scientists have tied their careers to the mission, which may always have been a moonshot for Europe, since its inception in 2004.
“When we launched ExoMars in 2004, it was far from the capabilities [of ESA and the European space industry] to do it,” Bridges said. “So we landed the Americans and when the Americans pulled out, ESA just looked around, and the Russians put their hands up, and it was done. “
Bridges describes the partnership with Russia, hastily put together by ESA management under Director General Jean-Jacques Dordain in 2012, as “a strategic mistake”.
“I think we should have hit the pause button at the time and had a more in-depth discussion in the European communities about what we were going to do,” he said.
At that time, the start of the conflict in Ukraine was still two years away, but Russia was already guilty of fomenting a bloody war war in georgia (opens in a new tab); his actions in the Caucasus country were massively ignored by the international community at the time.
“There’s frustration and disappointment because so much work has gone into ExoMars,” Bridges said. “The instruments, the science teams. But we should probably go on and try to recoup all that science investment, not just give up in disappointment and walk away from it.”
The call to confirm life on Mars
Schwenzer adds that to provide the ultimate answer to the big question, whether there ever was life on Mars, scientists would want to examine as much data as possible.
“Extraordinary claims require extraordinary evidence,” Schwenzer said, quoting a famous astrobiologist Carl Sagan. “We can’t just find a molecule that is generally produced by life on Earth and claim that we’ve found life on Mars. We can’t make that claim unless we absolutely rule out anything else. could have made this molecule. And in order to do that, we would need all the information we can get, not just that from a single mission.”
The planned ExoMars landing site at Oxie Planuman ancient clay-rich basin near the northern tropic of Mars, has been carefully selected by a pan-European scientific consortium because it offers the best conditions to harbor traces of life.
Formed about 4 billion years ago, the basin, covered in fine-grained sediments, has a catchment area of thousands of miles, Bridges said, where water once collected.
“It’s a very different area from Jezero Crater [where Perseverance roams]”, Bridges said. “But just because we’ve seen one, that doesn’t mean it’s not worth going to see the other. We’ve only explored a tiny fraction of the Martian surface yet and we shouldn’t fall into the trap of assuming we’ve seen this, done this.”
The ExoMars conundrum, suggests Bridges, highlights weaknesses in ESA’s strategy and undermines the agency’s aspiration to be the world-class player it wants to be.
The ESA, a partnership of 22 European member states, was beaten to the surface of Mars by China, which only revealed its plans for the Zhurong rover in 2014. Chinese landers, including the famous Rover Yutu, have dominated lunar exploration for the past decade. The Japanese space agency JAXA, in the meantime, has built a legacy of return of asteroid samples.
“ESA has this problem that they can be left in the breeze for a bit,” Bridges said. “If external factors change, they don’t quite seem to have the size or the strength to withstand the jolts. Part of that is because they haven’t really decided what their strategy is, what they want. really do, compared to JAXA or the China National Space Administration, who know exactly what they want to do and they go in and do it.”
ESA is currently evaluating options for the ExoMars rover, which it will present to its member states later this year. Among the possibilities is a return to the original NASA partner, which could land the rover using its proven technologies, Bridges said, but with a substantial financial contribution from ESA.
NASA’s recent decision to scrap European Mars sample retrieval rover and replacing it with NASA-built helicopters, may provide impetus to stay with the struggling ExoMars.