Following the launch, SpaceX landed the rocket's first stage at a nearby on-shore landing zone, marking the 16th time Elon Musk's pioneering space company has recovered one of its rockets. The main goal today was getting the reusable X-37B - also known as the Orbital Test Vehicle (OTV) - into orbit.
But what exactly the X-37B does in orbit is classified - aside from launch and landing dates and minor operational details, the Air Force provides little on the vehicle's objective.
A delay to Friday would diminish launch probabilities even further to 40 percent "go" as Irma churns about 650 miles to the southeast of the Eastern Range, which encompasses Kennedy Space Center and Cape Canaveral Air Force Station.
Air Force Secretary Heather Wilson disclosed during an early June congressional hearing that SpaceX, not ULA, would be launching X-37B this time around.
The exact objective of the X-37B was never revealed and the secrecy surrounding the project has led to speculation that the solar-powered X-37B can be used as a spy satellite or to deliver weapons from space. A deployable solar panel generates electricity for the mini-shuttle, and it does not rely on hydraulics for its aerosurfaces, unlike NASA's space shuttles, which were limited to missions lasting several weeks.
Randy Walden, director of the Air Force Rapid Capabilities Office, said the many firsts on this mission make Thursday's launch "a milestone" for the X-37B program.
Here is a listing of the X-37B's flight history compiled by Spaceflight Now's Justin Ray. Thursday's launch will be the 13th Falcon 9 liftoff this year, after being banned from launches late last year due to an explosion in their Cape Canaveral launch pad. DARPA transferred it to the Air Force in 2006.
About 2.5 minutes into the flight, the Falcon 9's two stages separated. We will keep a close eye on the progression of the storm and wish both the residents of Florida and the many tenants of the Space Coast the best of luck as they hope to weather yet another large hurricane.
"Everything proceeded nominally", SpaceX launch commentator Michael Hammersley said.