Stratolaunch: Roc and Spirit of Mojave

Microsoft co-founder Paul Allen announced Stratolaunch in December 2011 with a plan to air-launch rockets from the biggest aircraft ever built, and Burt Rutan's Scaled Composites built it in Mojave from two gutted 747-400s and an all-new composite wing and fuselages. It rolled out in May 2017 and flew for the first time on April 13, 2019, six months after Allen's death; the company nearly closed that year, was bought by Cerberus Capital Management in October 2019 and refocused on hypersonic flight testing for the US military and research customers.

Roc's job now is to carry the Talon-A, a rocket-powered vehicle the size of a business jet, to about 35,000 feet and release it to fly at more than Mach 5 before landing on a runway. The first powered Talon-A flight was in March 2024 and the first fully reusable hypersonic flights followed in 2024 and 2025, with the vehicle landing at Vandenberg. Roc flies only for those missions and for the occasional test, usually a few times a year, each one out of Mojave and over the Pacific range.

The 747 was built in 2001 for Virgin Atlantic as G-VWOW, named *Cosmic Girl* after the Jamiroquai song, and flew passengers out of Heathrow and Gatwick for fourteen years. Virgin Galactic bought it in 2015, re-registered it N744VG and fitted a pylon under the left wing, where a 747's spare-engine mount sits, to carry the LauncherOne rocket. Virgin Orbit flew it from Long Beach and put satellites in orbit on four missions between January 2021 and July 2022, then failed on its first launch from Newquay, England, in January 2023 and went bankrupt that April. Stratolaunch bought the aircraft at auction, renamed it *Spirit of Mojave* and converted the pylon to carry Talon-A, giving it a second launch platform that is far cheaper to operate than Roc.

There is nothing to confuse Roc with: two fuselages, a wing wider than a football field is long, six engines and a cockpit only in the right-hand fuselage. It is white with blue Stratolaunch titles. Spirit of Mojave is a standard-looking 747-400 in white with a Stratolaunch tail and a pylon under the left wing between the fuselage and the inboard engine. On the tracker they broadcast N351SL and N744VG, climbing out of Mojave toward the coast and flying a racetrack over the Pacific before the drop.