In December 2022, the first commercial flight of the lightweight Vega-C failed to reach orbit and lost two satellites, delivering a fresh blow to a continent already struggling to blast its missions into space.

The rocket was grounded for two years while the nozzle of the Zefiro 40 rocket motor -- which caused the failure -- was redesigned.

Vega-C's return flight, carrying the Sentinel-1C satellite for the European Union's Copernicus Earth observation programme, was initially scheduled for Tuesday from Europe's spaceport in Kourou, French Guiana.

That launch was postponed by one day to allow for "additional checks on electrical connections in the upper stage" of the rocket, the ESA's space transportation director Toni Tolker-Nielsen said.

But hours before the launch, it was again delayed another 24 hours.

This time it was "due to a mechanical problem preventing the removal of the Vega-C mobile gantry," French space agency CNES said in a statement on Wednesday.

A gantry is a movable frame that supports the rocket on the launch pad.

The next attempt to finally fire Vega-C off the ground is planned for 6:20 pm local time (2120 GMT) on Thursday, according to the ESA.

Earlier on Thursday, the ESA's Proba-3 mission to probe the Sun's outer atmosphere successfully launched on an Indian rocket.

Europe has struggled to find a way to independently launch missions since Russia withdrew its rockets in 2022 over the war in Ukraine.

Four years of delays to Europe's new Ariane 6 rocket compounded the issue, forcing the continent to turn to rivals such as Elon Musk's SpaceX.

However, the heavy-lift Ariane 6 had a successful first flight in July, offering some relief to European space efforts.

The lighter Vega-C was designed to send small satellites into low Earth orbit.

Its predecessor Vega had its last launch in September, placing more importance on Vega-C returning to active duty.

Four launches using Vega-C are planned for next year, followed by five more in 2026, Tolker-Nielsen said.

The Sentinel-1C satellite will use radar to monitor Earth's environment as part of the EU's Copernicus programme to provide climate and other data to governments and businesses.

gr-esp-dl/bc

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