Microsoft co-founder Paul Allen has spent the last six years working on a giant aircraft capable of launching rockets to space. Today, his company Stratolaunch Systems literally rolled that plane out of its hangar in the Mojave Desert for the first time ever.

Australian model and designer Madeline Stuart, who has Down syndrome, acknowledges attendees after presenting creations from her label 21 Reasons Why By Madeline Stuart during New York Fashion Week in Manhattan, New York, U.S., February 12, 2017. (Photo by Andrew Kelly/Reuters)

Crowds gather and watch the launch of NASA space shuttle Endeavour from Kennedy Space Center on the beach May 16, 2011 in Cocoa Beach, Florida. (Photo by Roberto Gonzalez/Getty Images)

Aerial dancers from Voloa, perform a dress rehearsal ahead of their performance at the opening night of Salisbury International Arts Festival on May 20, 2011 in Salisbury, England. The 39th Salisbury International Arts Festival runs from tonight until Saturday 4 June 2011 and features a programme of theatre, dance, circus, film, music, comedy and spoken word in locations around the historic city, from Salisbury Cathedral to Stonehenge. (Photo by Matt Cardy/Getty Images)

Playboy founder Hugh Hefner (not pictured) arrives at Stansted Airport on June 2, 2011 in Stansted, England. The photograph is a recreation of a picture originally taken in the 1960's, with ten of the new London Bunnies. Mr Hefner is back in the UK to mark the launch of the new Playboy Club in Mayfair, which opens on June 4. The clubs opening will welcome back the iconic Playboy Bunny to Londonafter a 30 year absence. Famous Bunnies have included Debbie Harry and Lauren Hutton. (Photo by Dan Kitwood/Getty Images)

Kit Cox wears a mustache umbrella in the Hendrick's Unusual Umbrella Emporium at the launch of London Cocktail Week on October 12, 2011 in London, England. The Unusual Umbrella Emporium is a pop-up bar in Seven Dials which will open for the duration of London Cocktail Week until October 15, 2011. The venue will showcase obscure umbrellas alongside a selection of cocktails and cocktail umbrellas designed by the top bartenders in the UK. (Photo by Oli Scarff/Getty Images)

Dr. Christopher Brown (R), the Director of the Ashmolean, talks with Colin Harrison, the Ashmolean's Senior Curator of European Art, in front of a painting by Edouard Manet entitled “Portrait of Mademoiselle Claus” from 1868 in the Ashmolean Museum on February 24, 2012 in Oxford, England. The painting has been sold to a foreign buyer for 28.35 million GBP, however the Government has extended a temporary export bar on the artwork until August to give the Ashmolean an opportunity to raise funds to retain the painting in the UK. (Photo by Oli Scarff/Getty Images)

A Russian Soyuz 2.1a rocket carrying Lomonosov, Aist-2D and SamSat-218 satellites lifts off from the launch pad at the new Vostochny Cosmodrome outside the city of Uglegorsk, about 200 kilometers (125 miles) from the city of Blagoveshchensk in the far eastern Amur region Thursday, April 28, 2016. The launch of the first rocket from Russia's new space facility has been delayed after a last-minute problem. (Photo by Kirill Kudryavtsev/Pool Photo via AP Photo)