Airbus engineers in white overalls prepare the ExoMars 2020 rover Rosalind Franklin for removal

The rover is equipped with a 2-metre drill to allow it to search for signs of life beneath the surface of Mars.Credit: Aaron Chown/PA/Alamy

The future of a €1.3-billion (US$1.4-billion) programme to explore Mars has been thrown into doubt by Russia’s invasion of Ukraine, after the European Space Agency (ESA) said that the launch of its rover this year is now “very unlikely”.

The plan to send a rover mission to Mars is the second part of the joint ExoMars mission between ESA and the Russian space agency Roscosmos. The rover was scheduled to take off on a Russian rocket from Baikonur, Kazakhstan, in September.

Following a meeting of ESA’s member states, the organization said on 28 February that the economic sanctions imposed by Western nations on Russia and the wider context of the war have made a 2022 launch unlikely. ESA’s director-general, Josef Aschbacher, will now analyse possible options for the mission’s way forwards.

ExoMars aims to deliver Russia and Europe’s first Martian rover, named Rosalind Franklin. It is equipped with a drill designed to detect any signs of organic life buried deep beneath the surface. This will be the third time the mission has been postponed from its original planned launch in 2018. Each delay comes with mounting costs.

Painful delay

In its statement announcing the probable delay, ESA said it deplored “the human casualties and tragic consequences of the war in Ukraine”, and that its decisions take into account not only its workforce but European values.

Not flying the ExoMars rover on a Russian rocket is “the morally right thing to do”, says Paul Byrne, a planetary scientist at Washington University in St. Louis, Missouri, who is not involved in the mission. But for the planetary-science community, the delay will be “painful”, he says. The next launch opportunity will be November 2024, he adds. “That’s a long time to wait for scientists who have worked on this mission for almost a decade already.” Early-career researchers who are relying on its data will be particularly affected.

To continue the mission, scientists might have to adapt it to fly on another rocket. If difficulties arise there, “then perhaps the project overall will face cancellation”, Byrne adds. “A cancellation would be a blow to ESA’s programme of planetary exploration, which is otherwise returning incredible findings about our Solar System.”

“If it will not be launched this year, it will not be launched ever,” says Lev Zelenyi, science adviser and former president of the Space Research Institute of the Russian Academy Of Sciences in Moscow, and a member of the mission. Zelenyi says that he understands ESA’s motivations, but thinks it is the wrong decision. “Tremendous efforts of scientists, engineers, technicians of many European countries, not even speaking about Russians, will be wasted.”

It would be difficult for ESA to remove Russia entirely from the project. Although in theory Europe has made the rover and Russia has made its descent module and landing platform, there is “no clean line” between the responsibilities of the two teams, ESA project scientist Jorge Vago told Nature in 2016.

“ExoMars 2022 is unprecedentedly complex in terms of interfaces,” adds Oleg Korablev, a member of the ExoMars collaboration at the Space Research Institute. Adapting the craft to use a NASA landing device would take more than two years, he adds.

ESA and Roscosmos already collaborate on the Trace Gas Orbiter (TGO), the first part of the mission, which reached Martian orbit in 2016. The TGO is designed to not only study Mars’s atmosphere, but also act as a relay station for the rover. A spokesperson for ESA could not say what the impact of the situation would be on TGO operations.

Collaborations affected

The war in Ukraine and sanctions against Russia have already affected other space-science collaborations. On 26 February, Roscosmos withdrew its staff from ESA’s main spaceport in Kourou, French Guiana — effectively ceasing launches on Russian Soyuz rockets, which ESA uses for medium-sized launches, including satellites in its Galileo navigation system. ESA says it will assess whether upcoming payloads can be launched on other rockets such as Vega-C or Ariane 6, which are both set to fly for the first time later this year.

Sanctions could also affect Roscosmos’s upcoming Luna moon missions. ESA plans to contribute a landing camera to Luna-25, set to launch in July, and a navigation system, drill and mini-laboratory for Luna-27, designed to study the composition of soil near the lunar south pole. An ESA spokesperson declined to comment on how the conflict might affect these plans.

As countries continue to shut down research collaborations with Russia, there could be a further division in space exploration between Western nations and a China–Russia collaboration. In a YouTube address on 26 February, director-general of Roscosmos Dmitry Rogozin announced that, in the face of sanctions, Russia will purchase any microelectronics it needs for spacecraft from China.

The two countries plan to collaborate on a raft of future projects, including building a human base on the Moon, according to China’s five-year plan for space.

Roscosmos has announced “a full-scale go-ahead” on collaborations with China, says Korablev, and institute scientists are already working on an instrument for a Chinese asteroid mission. “Still, science cooperation takes years and dozens of years to establish,” he says, and the effect of the conflict and sanctions on scientific cooperation is “enormous”.