Photos: New GPS navigation satellite powered from Earth

The launch of a commercial Bulgarian television broadcast satellite from NASA’s Kennedy Space Center in Florida is set for Monday after SpaceX ran through a mock countdown Thursday and test-fired a previously-flown Falcon 9 rocket’s Merlin main engines.

A massive radio broadcasting satellite for SiriusXM is set for liftoff Friday on top of a Falcon 9 rocket, punctuating a busy week for SpaceX that included the debut of a new-generation cargo ship for the International Space Station and a spectacular atmospheric test flight of a prototype rocket over South Texas.

A SpaceX Falcon 9 rocket lifted off Tuesday with five communications satellites for Iridium’s commercial voice, data relay, and tracking network, and a pair of U.S.-German research craft to probe Earth’s climate and water cycle. Launch from Vandenberg Air Force Base, California, occurred at 12:47 p.m. PDT (3:47 p.m. EDT; 1947 GMT).