Artist's impression of ESA’s ExoMars rover.

The European Rosalind Franklin rover will have a 2-metre drill to probe the Martian surface.Credit: ESA/ATG medialab

Europe’s Rosalind Franklin Mars rover, part of the beleaguered €1.3-billion (US$1.35-billion) ExoMars programme, is now set to launch in 2028, after securing a reported €360-million investment from European countries.

The money will allow the European Space Agency (ESA) to start designing a new landing platform to lower its first Martian rover onto the planet’s surface. The work became necessary after ESA severed ties with its former partner on the mission, the Russian space agency Roscosmos, in March, following Russia’s invasion of Ukraine. Roscomos was in charge of designing and building landing gear for the rover, as well as launching the mission from its site in Baikonur, Kazakhstan.

“I am very relieved and incredibly happy that this great mission was not taken away from us, and that I can continue to hope to steer a rover on Mars one day,” says Daniela Tirsch, a planetary geologist at the German Aerospace Center in Berlin. Only the United States and China have so far placed working rovers on Mars.

The latest postponement is the third in the mission’s history. The ExoMars rover was originally intended to launch in 2018, but technical issues scuppered that plan. The COVID-19 pandemic then delayed a scheduled 2020 flight to 2022, before relations with Russia deteriorated. The cost of this second delay was on the order of €100 million, an ESA spokesperson told Nature.

Deep drilling

Despite the hold-ups and burgeoning costs, scientists remain excited about the ExoMars rover. It is the second part of the programme, following on from an orbiter that arrived at the red planet in 2016 and has been hunting for biological or geological origins of methane and other gases.

The Franklin rover carries a 2-metre drill that will burrow deep beneath the Martian surface to search for preserved signs of ancient life. “We will search for evidence of past life in the subsurface for the very first time,” says Jorge Vago, ESA project scientist for the mission, based at the European Space Research and Technology Centre in Noordwijk, the Netherlands.

“ExoMars is a really incredible mission that will be unique in method and scientific approach, even if launched in 2028,” says Francesca Esposito, a planetary scientist at the INAF Astronomical Observatory of Capodimonte in Naples, Italy, and member of the mission team.

“It’s the first mission which can probe the very early history of terrestrial planets,” adds Tirsch, noting that the rover’s intended landing site, a vast plain called Oxia Planum, records “unique information on ancient, water-rich Mars environments, prebiotic chemistry, and, perhaps, life”.

ESA expects that NASA will help by contributing the mission’s launcher, its braking engine — for use during landing — and its radioisotope-based heating units, said ESA director-general Josef Aschbacher at a press briefing on 23 November. The units are necessary for Rosalind Franklin to survive the harsh Martian nights. But European technology will replace the rest of Russia’s lost contribution, he said.

Member states promised the cash for the mission at the ESA ministerial conference in Paris on 22 and23 November, at which they committed a budget of €16.9 billion in total for projects over 5 years. This includes €2.7 billion for human and robotic space exploration, an increase of 16% over the last allocation in 2019, and €3.2 billion for the agency’s scientific programme, a rise of 19%.

As part of this commitment, ministers agreed to fund the Solaris project, a programme to scope out the viability of developing, from 2025, a space-based solar-power system that would transmit energy to Earth. Nations worldwide are exploring technology to beam down energy from a kilometres-sized solar array in orbit, an idea that has become more viable given the plummeting costs of space launches.