Stratolaunch, the Paul Allen/Scaled Composites/Dynetics venture to air-launch satellites, has a new look - and I think it is a big improvement.
All graphics: Stratolaunch
No explanation is given for the new design shown on the Stratolaunch website, but it has changed following SpaceX's decision in December to exit the project because the modifications required to air-launch its Falcon 9 booster would have been too much. The original design (below) looked a bit 1960s and showed more of its origins in the two Boeing 747s that are being disassembled in Mojave to contribute engines and systems for the 380ft-span mothership.
Orbital Sciences stepped up to take SpaceX's place and is working with Stratolaunch to define a winged air-launched booster that draws on its experience with the Pegasus, which is carried aloft under a modified Lockheed L-1011 TriStar airliner. Stratolaunch has indicated a new design for the booster is expected to be announced soon. Flight tests are planned to begin from Mojave in 2015, followed by test launches from Kennedy Space Center in 2017.
And - Thanks to my former Flight colleague Rob Coppinger, who brought this to my attention.