In December 2011, the company presented a project to create the Stratolaunch aerospace “air launch” system for delivering cargo into space. According to the American newspaper The Wall Street Journal , one of the company’s founders announced his readiness to invest up to $200 million in the project [2] .The new system should launch 6.12 tons of payload into low Earth orbit. It consists of three main components:a twin-body carrier aircraft that will be the largest aircraft in history;a multi-stage rocket suspended under the central part of the wing between the fuselages;a system that allows a carrier aircraft to safely carry a missile.In 2012, a special hangar was built in the Mojave Desert ( California ) intended for the construction of a carrier aircraft.In March 2012, the company acquired two decommissioned Boeing 747-400 airliners . The engines and some systems of these aircraft were used to reduce development costs.It was assumed that the first test flights of the carrier aircraft would begin five years after the start of the project, in 2016. However, the first rollout of the aircraft from the hangar, which marked the beginning of ground tests, was carried out only in May 2017. The first demonstration flight took place on April 13, 2019.In May 2021, Stratolaunch Systems conducted its second test flight. The plane was in the air for about three hours. During test tests, it reached a height of 4 thousand meters and a speed of 320 km/h. They decided to use the aircraft to test hypersonic technologies.