IT was once rumoured to be a base for top secret UFO investigations and has already served as an emergency landing site for a US space shuttle.

Now the community-owned airbase in Machrihanish in Kintyre has launched its official bid to be named the UK's first spaceport, citing the previous support of Virgin Galactic and the advantage of its 3000ft runway.

Three of the shortlisted sites are in Scotland, including Scottish Government-owned Prestwick Airport and Stornoway, but the agency behind its bid believe the Machrihanish is the leading candidate.

Tom Miller, chairman of Machrihanish Airbase Community Company (MACC) and director of Discover Space UK, said previous endorsements from NASA and Sir Richard Branson's pioneering space tourism outfit, Virgin Galactic, stood in its favour.

Mr Miller said: "Machrihanish has a long-history with space flight, going back to the launch of NASA's Space Shuttle in 1981.

"Machrihanish was an emergency landing site for the shuttle in Europe, with our 3,049m runway long enough to welcome the shuttle and get it airborne again aboard a Boeing 747 Shuttle Carrier Aircraft.

"Then in 2009, the last time the UK looked at establishing a spaceport, Virgin Galactic said Machrihanish was one of its preferred sites for the UK spaceport.

"That's not our only connection to the stars. Paul McCartney's Mull of Kintyre estate is just 15 minutes from the base and the airbase itself was rumoured to have been used for testing top secret aircraft - so it's only fitting that Machrihanish Airbase leads the way by becoming the UK's first spaceport."

The airbase was nicknamed 'the UK's Area 51' following rumours it was previously used by the US Airforce to test secret aircraft and investigate UFOs.

Machrihanish is the only potential spaceport site which already meets the Civil Aviation Agency's criteria for a minimum 3000ft runway length, while organisers believe its remote location on a 1000 acre stretch of land removed from densely populated areas also make it an ideal place to welcome the first wave of space tourists - likely to pay up to £200,000 per head for a sub-orbital trip.

The UK Government wants to establish the UK's first spaceport by 2018, with Stornoway Airport in Scotland also in the running along with sites in Newquay and Wales.

The preferred location is expected to be announced by the UK Government later this year.

Mr Millar added picking Machrihanish to become the UK's first spaceport would transform the area.

He said: "A spaceport would provide a significant jobs boost and would revitalise local businesses. It would also help drive tourism from all over the world, which would be a real boom for the whole of the UK."

It comes after Prestwick Airport launched its official bid to become the spaceport last week.

Prestwick Spaceport Director Stuart McIntyre said they would offer the global space industry "a highly capable facility" for polar orbit launches and research.

It has previously been said that securing spaceport status would be a "catalyst for transformational change" at the ailing hub, which was bought by the Scottish Government in 2012.