Mash up of the specs of an SIV-B rocket, plus the X-33 ( VentureStar SSTO), plus the Shuttle. The Shuttle gave me the idea of putting the X-33 on top of a 747 and air launching the X-33 to orbit. Feasible?
The 747 can manage the weight, I believe, but would it be airworthy? Secondly, would the additional altitude be enough to allow it to get to orbit without additional weight?
A jet power requirement for the microwave powered x-33 aeroshell to orbit is also provided. Another question is what if you were to incorporate this idea into the final design ( somehow)?
Rather than use a catapult to get airborne, instead put the X-33 type larger shell which has the real X-33 inside it or on top of it. The X-33 larger shell would be an airbreather with no fuel tank. It would utilize superheated atmosphere provided by microwave energy from the ground for thrust.
Operationally, the 747 releases the X-33 larger shell, which in turn lifts the still attached X-33 to a higher altitude and velocity. From there, the larger shell releases the X-33, which then flies to orbit.
Probably too complicated and too much mass, though.
Why lift the X-33 at all? Wasn't it supposed to be SSTO? Well, the idea is to get maximum efficiency out of a hydrogen/oxygen engine. At lower altitudes, you lose a lot of ISP. It is much more efficient at a vaccuum or near vacuum. That saves mass and therefore makes it easier to get to orbit with a smaller vehicle. But the 747 doesn't fly high enough or fast enough, so that's why you add the second ( larger X-33 shell). You make that an airbreather in order to avoid carrying any fuel. The energy would be provided from the ground.
The boost would hopefully get it up to an altitude and velocity equal to a first stage conventional rocket.
|sources: Parkins thesis, Wikipedia X-33, Shuttle, Boeing 747|