Paul Allen’s Stratolaunch satellite launch system appears to be getting closer to testing. The world’s largest aircraft, which will fly to a high altitude before launching three rockets affixed to its wing, is currently undergoing ground testing at its home at the Mojave Air & Space Port. The Stratolaunch wingspan of 352 feet is nearly 150 greater than a 747.

It is estimated that the Stratolaunch will be able to launch a payload of 5,000-10,000 pounds to low earth orbit — or around a tenth of a Falcon 9 launch. It should be much cheaper and more flexible, however, for microsatellites at low orbits. And there are a lot of uses for small satellites at low orbits.

Stratolaunch management is also reportedly considering the design of a reusable space shuttle vehicle which could deploy satellites or visit the space station.

It’s anticipated that flight testing will begin later this year. No dates are set for full operations.