A giant six-engine aircraft with the world’s longest wingspan landed its first flight after some two hours in the air Saturday.The behemoth, twin-fuselage Stratolaunch jet lifted off from Mojave Air and Space Port and climbed into the desert sky 70 miles (112 kilometers) north of Los Angeles. Founded by the late billionaire Paul G. Allen, Stratolaunch is vying to be a contender in the market for air-launching small satellites.The aircraft is designed to carry as many as three satellite-laden rockets at a time under the center of its enormous wing, which stretches 385 feet (117 meters) – a longer wingspan than any other aircraft. At an altitude of 35,000 feet (10,668 meters), the rockets would be released, ignite their engines and soar into space.The advantages of such air-launch systems include being able to use numerous airports and avoid the limitations of fixed launch sites which can be impacted by weather, air traffic and ship traffic on ocean ranges. Allen, the co-founder of Microsoft, founded Stratolaunch Systems Corp. in 2011 after emerging in aerospace by funding the development of the experimental air-launched SpaceShipOne, which in 2004 became the first privately built manned rocket to reach space.After Allen’s death in October 2018, Stratolaunch dropped plans to develop its own type of rocket engine and a family of launch vehicles, focusing instead on getting the giant plane airborne and launching Northrop Grumman’s proven Pegasus XL. The Stratolaunch aircraft emerged from its Mojave hangar for the first time in May 2017 and proceeded through ground tests, including taxiing and rolling down a runway at near-takeoff speeds.Powered by the same type of engines used by Boeing 747s, the aircraft is designed to take off at a maximum weight of 1.3 million pounds (589,676 kilograms). Its twin fuselages – sort of the airplane equivalent of a catamaran – are 238 feet (72.5 meters) long. The previous wingspan leader was Howard Hughes’ World War II-era eight-engine H-4 Hercules flying boat – nicknamed the Spruce Goose. Surviving in an aviation museum, it has an approximately 320-foot (97.5-meter) wingspan but is just under 219 feet (67 meters) long.While Stratolaunch calls its aircraft the world’s largest, other airplanes exceed it in length from nose to tail. They include the six-engine Antonov AN 225 cargo plane, which is 275.5 feet (84 meters) long, and the Boeing 747-8, which is just over 250 feet (76.3 meters) long.