SEATTLE — Microsoft co-founder Paul Allen and aerospace pioneer Burt Rutan are building the world's biggest plane to help launch cargo and astronauts into space, in the latest of several ventures fueled by technology tycoons clamoring to write America's next chapter in spaceflight.
Their plans, unveiled Tuesday, call for a twin-fuselage aircraft with wings longer than a football field to carry a rocket high into the atmosphere and drop it, avoiding the need for a launch pad and the expense of additional rocket fuel.
Allen, who teamed with Rutan in 2004 to send the first privately financed, manned spacecraft into space, said his new project would "keep America at the forefront of space exploration" and give a new generation of children something to dream about.
Allen and Rutan join a field crowded with Silicon Valley veterans who grew up on Star Trek and now want to fill a void created with the retirement of NASA's space shuttle. Several companies are competing to develop spacecraft to deliver cargo and astronauts to the International Space Station.
Allen bemoaned the fact that government-sponsored spaceflight is waning.
"When I was growing up, America's space program was the symbol of aspiration," he said.
Allen and Rutan last collaborated on the experimental SpaceShipOne, which was launched in the air from a special aircraft. It became the first privately financed, manned spacecraft to dash into space in 2004 and later won the $10 million Ansari X Prize for accomplishing the feat twice in two weeks.
The new rockets will eventually carry people, but the first tests, scheduled for 2016, will be unmanned. It should be another five years before people can fly on the system that Allen and Rutan are calling Stratolaunch.
The company, to be based in Huntsville, Ala., bills its method of getting to space as "any orbit, any time." Rutan will build the carrier aircraft, which will use six 747 engines.
The spaceship and booster will be provided by another Internet tycoon, Elon Musk of PayPal, who has built a successful commercial rocket.