The launch of a French rocket called Ariane 5 which would have placed two communications satellites for Brazil and South Korea into orbit was delayed on Monday by striking workers.
The transfer of the rocket to its launch pad was postponed after striking workers erected a barricade of tyres and wooden pallets at the Kourou Space Center, which is in French Guiana, on the northeastern coast of South America.
"Due to a strike, the scheduled transfer operation to move the rocket from the final assembly building to the launching zone could not go ahead," Arianespace said in a statement.
"Arianespace has been obliged to postpone the transfer 24 hours," the statement added.
The VA236 rocket is set to put into orbit two communications satellites.
One satellite, called SGDC, will provide strategic communications for the Brazilian government and military services, and beam broadband services across all of the country's territory, helping to provide internet access to remote and underserved communities.
The other, KOREASAT-7, owned by South Korea's KTsat, will provide a range of video and data services over Korea, the Philippines, Southeast Asia, India and Indonesia.
The launch, which had been scheduled for Tuesday, is now set for Wednesday, between 1731 and 2020 local time (2031 and 2320 GMT), the Arianespace statement said.
The strike was mainly organised by workers for public energy company EDF Guyane and staff at the Kourou hospital, according to the local trade union.