Stratolaunch Systems Corporation, founded by Paul G. Allen, last week successfully completed the maiden flight of the world’s largest all-composite aircraft, the Stratolaunch.
With a dual fuselage design and wingspan greater than the length of a Rugby field, the Stratolaunch took flight at 06:58 local time from the Mojave Air & Space Port on Saturday 13 April. Achieving a maximum speed of 189 miles per hour, the plane flew for 2.5 hours over the Mojave Desert at altitudes up to 17,000 feet. As part of the initial flight, the pilots evaluated aircraft performance and handling qualities before landing successfully back at the Mojave Air and Space Port.
“What a fantastic first flight,” said Jean Floyd, CEO of Stratolaunch. “Today’s flight furthers our mission to provide a flexible alternative to ground launched systems. We are incredibly proud of the Stratolaunch team, today’s flight crew, our partners at Northrup Grumman’s Scaled Composites and the Mojave Air and Space Port.”
The Stratolaunch is a mobile launch platform that will enable airline-style access to space that is convenient, affordable and routine. The reinforced centre wing can support multiple launch vehicles, weighing up to a total of 230 Tonnes.
Stratolaunch's carrier aircraft has a wingspan of 117 m this would make it the largest airplane, by wingspan, ever to fly. It weighs in at over 540,000 kg including the fully fuelled launch vehicle and will require a runway at least 3,700 m long. It is larger than the the Spruce Goose and the Antanov AN225.
The aircraft is powered by six Pratt & Whitney PW4000, 205–296 kN thrust-range jet engines, sourced from two used 747-400s that were cannibalized for engines, avionics, flight deck, landing gear and other proven systems to reduce initial development costs. The carrier is designed to have a range of 2,200 km when flying an air launch mission.
Over the course of 2018, the Stratolaunch carrier aircraft performed taxi tests of increasing speed at the Mojave airport. On January 9, 2019, the Stratolaunch carrier aircraft completed a 110 knot taxi test, during this test the nose gear lifted off the ground.
Originally SpaceX was intended to provide a liquid-fuelled rocket to serve as the means of lifting the Stratolaunch payload delivery vehicle into space by launching it at high altitude from under the carrier aircraft, but collaboration with SpaceX was abandoned in late 2012.
In November 2012, Stratolaunch retained Orbital ATK on a "study contract" to develop and evaluate "several alternative configurations" for the vehicle to be launched from the carrier aircraft. By early 2013, Orbital ATK was under contract to develop the Pegasus II for the Stratolaunch space vehicle launch component: The Pegasus II was expected to be able to deliver up to 6,100 kilograms to low Earth orbit.
It was announced on September 13, 2017 that Stratolaunch had signed an agreement with NASA to provide testing services to support propulsion for a vehicle. Stratolaunch hired Jeff Thornburg as vice president of propulsion, Thornberg had worked both on the J-2X engine for NASA and helped develop the Raptor rocket engine at SpaceX. The implication is Stratolaunch has decided to go its own way in developing a launch vehicle. The NASA agreement stated that Stratolaunch plans to deliver the test device for "testing of its propulsion system test article element 1" at NASA's Stennis E1 test stand by the end of May 2018. The test series is scheduled to be completed by the end of 2018.
On November 2, 2018, Stratolaunch completed the first hot-fire test of the "pre-burner" portion of its engine at NASA's Stennis Space Centre.
All Stratolaunch development work on its own family of launch vehicles ended in January 2019, but the company continues to plan to launch the Pegasus XL rocket from the carrier aircraft.
An internal Stratolaunch concept, the Black Ice spaceplane was revealed in early 2018, as a possible payload for the Stratolaunch system. It would be a fully reusable rocket- plane the size of the NASA Space Shuttle orbiter, and initially be unmanned, with possible future manned variant.