7:55pm ET Update: After launching right on time, the Inmarsat spacecraft reached low-Earth orbit, and after two successive burns by the Falcon 9’s second stage, the satellite deployed successfully into geostationary transfer orbit. This means SpaceX has now performed six successful missions in 2017, all in the last four months.
Original post: Tonight, SpaceX will attempt to launch its sixth Falcon 9 rocket of 2017. If successful, this take-off would put SpaceX on course to launch more than a dozen missions this year and, possibly, as many as eighteen. The 49-minute launch window opens at 7:21pm ET Monday (0:21am UK Tuesday), and the rocket will deliver an Inmarsat-5 F4 communications satellite to a geostationary transfer orbit. Weather is near ideal for a launch from Kennedy Space Center this evening, with a 90-percent chance of favorable conditions.
Because the satellite is so heavy—more than six metric tons—and going to a higher orbit, the Falcon 9 rocket won’t have enough fuel to make a return attempt, even at sea. The company has not disclosed whether it will make another experimental attempt to recover the rocket’s payload fairing.