>>1279805>What about that double-747?You mean Stratolaunch?
Well... since Stratolaunch cancelled the Medium Launch Vehicle, the Medium Launch Vehicle Heavy and Spaceplane, the only thing Stratolaunch can do now is launch 3 Northrop Grumann Pegasus rockets at once, and.... that's not the best, really.... SpaceX originally planned to build the Falcon 5
for Stratolaunch, however this was before SpaceX worked on their recoverable boosters, and after the decision was made to switch to recoverable boosters, the Falcon 5 and the collaboration with Stratolaunch was ended.
Virgin Orbital is using a a repurposed 747-400 which used to operate for Virgin Atlantic, however Virgin Orbital are going to manufacture their own rockets. They will initally operate from the Mohave Spaceport, but they have a contract with the UK government to operate from the UK Spaceport at sometime in the future with another 747-400. They will be operating alongside both RocketLabs and Orbex (a UK based rocket start-up) for launches from Sutherland in northern Scotland for Sun-Synchronous Orbits.
>>1279924In the case of the Epsilon and the newer rocket (is that the one which will be launched at an angle and will have an unguided gravity turn?), the main objective there comes down to the fact that Japan, much like ESA, wants to have an independent means of getting into space. There are also other aspects about this. 1 Yen spent in Japan stays in Japan and all that, but the main focus will be an independent launch platform which can continue to operate, regardless of whether or not there is a cheaper alternative, because that cheaper alternative could go away.
Remember: the UK once had a small sat launch vehicle in the 1950s, the Black Arrow, but after the United States offered free Scout Rocket launches for all payloads if the UK scrapped its own rocket programme, the US then turned around and removed all free Scout Rocket launches.
No country, or multinational space agency, wants to do that.
