<ul><li>SpaceX is preparing to launch an unidentified payload referred to as 'RRT-1' on a Falcon 9 rocket from Cape Canaveral.</li><li>The launch is scheduled for 8:05 p.m. EST with an 80 percent chance of acceptable weather conditions.</li><li>The first stage booster, B1085, will make its fourth launch and attempt to land on the SpaceX droneship.</li><li>The exact nature of the payload remains undisclosed, but speculation suggests it could be a GPS satellite.</li></ul>

Live coverage: SpaceX to launch RRT-1 on Falcon 9 rocket from Cape Canaveral

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