Falcon 9 passed hotfire tests today at the Kennedy Space Center, Florida. The rocket booster will be used for SpaceX's NRO mission for the National Reconnaissance Office to launch a reportedly spy satellite. The Falcon 9 boosters were rolled up the ramp at Launch Complex 39A, were fired without a glitch and then shut down. This is SpaceX's most important mission so far, says reports.

After flying a used Falcon 9 booster a month ago, SpaceX has finished hotfire tests for an unused Falcon 9 today, Space Flight Insider reported. Called the NROL-76 mission, the booster was taken to the launch platform and was readied for the static test which had a 6-hour window which started noon EDT. The nine Merlin 1D engines were ignited as the booster's first stage and was confirmed successful after a plume of smoke appeared from the launch site.

Elon Musk, owner and founder of SpaceX has confirmed via SpaceX Twitter account that the hotfire tests were successful. He said that the static fire test were to prepare the Falcon 9 for the NROL -76 launch on April 30, Sunday. Teslarati reported that this was a clandestine mission for the NRO which is a classified agency in the United States Department of Defense. A lot of information about the mission was kept secret and what is only known so far is that SpaceX will launch a spy satellite in orbit.

Preparing all its rockets through static fire tests is SOP for SpaceX. This is to make sure that the Falcon 9, rockets, the staff and all launch equipment are ready for missions ahead of time. Static fire tests include fueling first and final stages of the rockets with rocket grade kerosene and liquid oxygen. The two ingredients are chilled to their respective freezing points just before the launch and any remaining fuel drained from the rockets.

Falcon 9 will liftoff on Sunday, April 30, with a launch window starting at 7 a.m. EDT (11:00 GMT). This is the first NRO launch by SpaceX; previous launches were done by the United Launch Alliance.