Stratolaunch has finished the preliminary design review (PDR) of its space launch system, which it claims will be the largest aircraft ever built.
"The carrier aircraft conducted their preliminary design review on [27-28 August] in Mojave, California," says the company. "The team is currently reviewing the data package and presentation."
The aircraft will be used to haul large SpaceX-built rockets up to 9,140m (30,000ft) before air-launching them, allowing the rocket to carry payloads with greater efficiency than traditional, vertical-take-off rockets.
The massive carrier aircraft is modelled on Virgin Galactic's WhiteKnightTwo, which will one day serve as the first stage for a reusable suborbital vehicle. While WhiteKnightTwo is aimed primarily at the tourist market, the greatly scaled-up Stratolaunch carrier aircraft is meant to appeal to satellite manufacturers.
While the carrier aircraft will be custom-built, it will incorporate engines, hydraulics and other systems from the Boeing 747-400, two of which have been purchased from United Airlines.
"We have completed the disassembly of [aircraft] N196UA and have relocated the carcass to allow the team to pick through the assembly during the build process. The majority of the carcass will be cut and sold for scrap," says the company. "[Aircraft] N198UA is in long-term storage and will not be disassembled before next year."
Configuration of the rocket, built by SpaceX, has not yet been finalised.