High altitude winds have delayed the scheduled launch on Thursday of a heavy-lift Ariane-5 rocket from French Guiana for at least 24 hours, space officials said.
The rocket carrying two telecommunications satellites was set to be launched from Europe's space base in Kourou on the northeast coast of South America at 7:29 p.m. (2229 GMT).
"The results of our weather probe prohibited us from trying to launch tonight and we will try to launch tomorrow," Arianespace President Jean-Yves Le Gall said.
High altitude winds can, in case of the rocket's explosion, send debris into populated areas.
The rocket was carrying the Astra 1L satellite for Luxembourg-based satellite operator SES Global and Galaxy 17 for Washington-based communications operator Intelsat.