This article is more than 3 years old

This article is more than 3 years old

SpaceX launched the US air force’s super-secret space shuttle on Thursday, blasting off from Kennedy space center in Florida as schools and businesses boarded up for Hurricane Irma.

Mysterious space plane blasts off for secretive US air force mission Read more

The crewless aircraft, a technology testing mini-shuttle capable of spending years in orbit, rode an unmanned Falcon rocket on the fifth such flight.

There are two X-37B orbital test vehicles in existence, and between them they have already logged five and a half years in orbit. Officials will not say what the spacecraft are doing up there.

The last mission lasted almost two years and ended with a May touchdown at the runway formerly used by Nasa’s space shuttles. The first one launched in 2010.

As has become customary, SpaceX landed its leftover booster back at Cape Canaveral for eventual reuse.

This was the first time SpaceX has provided a lift for the experimental minishuttle. The previous missions relied on United Launch Alliance’s Atlas V rockets. Air force officials said they wanted to use a variety of rockets for the X-37B program, to be able to launch quickly if warranted.

The Boeing-built mini-shuttle is 29ft long, with a 14ft wingspan. By comparison, Nasa’s retired space shuttles were 122ft long, with a 78ft wingspan.

At the air force’s request, SpaceX stopped providing details about the X-37B’s climb to orbit a few minutes after liftoff. The booster’s return to SpaceX’s landing zone at Cape Canaveral air force station, however, was broadcast live.

“The Falcon has safely landed,” a SpaceX launch controller announced. Cheers erupted at SpaceX headquarters in Hawthorne, California.

It was SpaceX’s 16th successful return of a first-stage booster. Booster rockets are normally discarded at sea.