Incoming Hurricane Irma is menacing Florida, USA, prompting mandatory evacuations – and threatening to ruin Elon Musk's week too.

On Wednesday, SpaceX is due to deliver the US Air Force's secretive X-37B pocket space shuttle into orbit, using a Falcon 9 rocket blasting off from Cape Canaveral in the usually Sunshine State. The X-37B is usually launched by SpaceX's bitter rival the United Launch Alliance, but the Musketeers have convinced the US Department of Defense to let them try it.

"The many firsts on this mission make the upcoming [orbital test vehicle] launch a milestone for the program," said Randy Walden, the director of the Air Force Rapid Capabilities Office, before the weekend. "It is our goal to continue advancing the X-37B [orbital test vehicle] so it can more fully support the growing space community."

This is the fifth mission for the X-37B: the last one kept the space plane aloft for nearly two years. As ever, the Department of Defense isn't saying what the shuttle's payload is other than that it's carrying "small satellite ride shares and will demonstrate greater opportunities for rapid space access and on-orbit testing of emerging space technologies."

With a catastrophic category-five hurricane bearing down on the US coast and the rocket's launchpad, though, it's now highly unlikely the scheduled takeoff will go ahead on the date planned, unless the storm either slows, weakens, or diverts its course. Even so it'll be chucking out swathes of cloud and rain, both of which can disrupt launches.

It's a pain for SpaceX because not only has it stolen one of the ULA's prime plums, but the Falcon was also going to be used to launch the X-37B into a higher inclination orbit than was managed in the past, when it was lifted using a smaller Atlas V rocket.

If the hurricane does track into Florida, SpaceX and NASA could have bigger problems on its hands. Cape Canaveral is basically built on a large sandbar and the high winds and tidal surges a mega-storm produces could damage the facility.

Since Hurricane Andrew in 1992, all new buildings at the location have been built to withstand wind speeds of up to 130mph. However, Irma is, right now, producing winds in excess of 180mph and may pick up more strength before it hits the coast.

In such conditions the space center goes into lockdown. Non-essential staff are evacuated and a core team of volunteers stays on site until the storm is past, safe in the launch bunkers. For safety reasons they aren't allowed out in wind speeds higher than 58mph, but they can still be on site for immediate repairs and cleanup. ®