Photos: More Atlas 5 launch shots

A powerful European Ariane 5 rocket blasted off from French Guiana late Friday and boosted a pair of satellites into space for a seven-year plunge into the inner solar system, a voyage requiring seven planetary flybys to slow down enough in the sun’s gravitational clutches to slip into orbit around hellish Mercury.

SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral on Thursday evening, heading due east over the Atlantic Ocean to deliver the BulgariaSat 1 communications satellite into orbit 35 minutes later.

The step-by-step stacking of United Launch Alliance’s final Delta 2 rocket was completed in June at Vandenberg Air Force Base in California for liftoff Sept. 15 with an Earth science satellite for NASA.