Europe’s space programme does not yet have a reliable replacement for Russian launch rockets, the head of the European Space Agency said on Monday.
Josef Aschbacher said this was a “huge problem” for Europe’s space ambitions.
Russian Soyuz rockets launched more than two dozen missions from Europe’s spaceport in French Guiana between 2011 and 2022, but ties were severed after the invasion of Ukraine.
Europe’s workhorse Ariane 5 launcher is on the brink of retirement and there have been problems with next-generation rockets.
The agency is scrambling to have the delayed Ariane 6 launch vehicle into space by the end of this year to fill the gap.
“As of the middle of this year, we do not have guaranteed access to space by European launchers,” said Mr Aschbacher on Monday.
“This is a huge problem for all of us, for me personally, for ESA altogether, for Europe altogether, and we need to really work on this.”
One new launcher, the Vega-C, suffered a failure last month in which two Airbus reconnaissance satellites were lost.
Europe could turn to the older Vega rocket while engineers investigate what went wrong with the Vega-C, Mr Aschbacher said.
In addition, experimental mini-launchers could be handed ESA contracts before they have even completed a flight.
A British Virgin Orbit mission suffered a failure own on January 10, foiling hopes of achieving the first launch from Western Europe. The UK remains a member of ESA after Brexit.
There was better news when the heavier Ariane 6 performed well in testing last week, in what ESA official Daniel Neuenschwander called a “big milestone”.
Engineers are still working to resolve some outstanding technical issues with the launcher, Mr Aschbacher said.
“We are trying to advance as quickly as possible. With Ariane 6 we need to re-establish European access to space,” he said.
The older Ariane 5 is expected to carry out two final launches this year, including a mission to explore Jupiter’s icy moons.
But other missions were expected to launch on Soyuz rockets until Russia withdrew its staff from the ESA launch pad in French Guiana.
One mission known as Euclid, which will investigate dark matter in space, will instead launch on a Falcon 9 rocket built by Elon Musk’s SpaceX.
The changed political landscape in Europe has also prompted ESA to strengthen its cyber security, Mr Aschbacher said.
“We have a very tense situation in Europe from security perspective and therefore we also contribute within the means we have,” he said.
Another effect of the war was that some Russian space equipment was left behind in French Guiana. Some ESA gear was still on the Russian launchpad in Baikonur, Kazakhstan.
There have been “working-level discussions” with Russia about a possible exchange, said David Parker, the agency’s director of human and robotic exploration.
The former Soyuz area in French Guiana could be converted into a new pad for mini-launchers or used as a storage area, Mr Neuenschwander said.
Russia has separately announced that it will quit the International Space Station after 2024 and plans to build its own space laboratory.