Live coverage: Atlas 5 countdown and launch journal

A commercial communications satellite will blast off Thursday from French Guiana on top of a Soyuz rocket, on the way to a station over the Americas to supply bandwidth to airline travelers and broadcasters in the United States, Canada and Mexico.

Carrying a $2.7 billion NASA mission to Mars, a United Launch Alliance Atlas 5 rocket took off July 30 from Cape Canaveral and fired into a summer sky powered by four powerful solid rocket boosters and a kerosene-burning main engine.

NASA has partially restored the Hubble Space Telescope to science mode after a software error temporarily halted observations, but engineers continue studying a problem that kept the telescope’s aperture door from closing and a separate concern with Hubble’s main camera.