Project yet another scifi ssto


Aug 29, 2008
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Hi guys,

over the last weeks i've worked on a new concept for an SSTO vehicle using scifi technology that does obviously not exist yet but is currently being scientifically investigated. So the major focus is that it should all be physically possible. (no handwavium and unobtanium stuff :))

First of all here are some concept pics of the rough shape i have done so far:

Heres how its supposed to work:

The design is centered around small lightweit fusion reactor technology which is probably the biggest question mark in the whole thing. Here I am refering to some conceptual papers by Robert W. Bussard about what he thinks might be possible with Polywell Fusion Reactors (should they ever be made to work). See for instance SSTO to Saturns Moons.pdf or other stuff found under

The design would have 2 Polywell Fusion Reactors in the 2-8GW Range each and using a P-B11 Fusion Reaction with direct electric conversion as proposed by Bussard. These power 2 QED Engines using LH2 or Water as drive mass. The ISP would be variable between 1500 and 5000-6000s with the upper ISP Limit given by the fact that the reactor has to be cooled regeneratively by the flowing drive mass.

For atmospheric ascend and cruise flight i would like to use an electrically powered version of a TBCC engine. The TBCC engine is described in different variations in various papers for instance here An adaptation to this using electricity to heat the air in the "burner" for instance with an Arcjet kind of approach instead of using chemical propellant should be possible given enough electricity.
The resulting plasma could be further accelerated by an MHD drive approach as described for instance here This would also open up possibilities for higher cruise Mach numbers by slowing the Air before the intake extracting energy from it. Also the thermal load on leading edges of the craft could be eased by ionizing the air upstream and magnetically guiding it. Even Lift to Drag ratio of the plane can be improved greatly as has been pointed out in the paper above.
Now it might not be a good idea to ionize air and throw out hot plasma at sea level on a regular airport/spaceport-runway during takeoff and landing. So i thought of two ways for powering the craft during the initial takeoff and climb-out phase as well as the approach and landing phase.
First one would be to just use the TBCC in a hybrid mode burning LH2 during Takeoff and landing and switching over to electrically powered flight later.
The other approach is a little more far fetched and i don't know if this might be possible. The idea would be to exchange the Turbofans in the TBCC design by electrically powered Fans. I did some math and simulations in orbiter and found around 300MW of energy for powering some fans with an overall area of ~15m^2 and a pressure ratio of 4-5 to give sufficient thrust for takeoff and climbout to a few kilometers. An electrically powered fan has already been proposed here and i have found news of electric motors in the 35MW range using high temperature superconductors currently being developed for use in ships. So the question that remains open for me is, could such a motor with associated cooling be made light enough to be used here. I used NASAs engine simulator to figure out the mass of a LH2 powered Turbofan of the required size and it came out to be around 1-1.5tons so for 5-6 turbofans to produce the required thrust i would be well below 10tons, i'm not quite sure this can be beat using electrically powered fans.

Allright.. finally some intended design specs of the bird shown above:
Length ~80m
Wingspan ~40m
Maximum Takeoff weight 300-400tons
usable cargo weight 50-100 tons
Atmospheric range flight to intercept the target orbit then atmospheric acceleration to Mach 8-15. (not quite sure what would be realistically possible) Then pitchup maneuvre and use of the QED Engines set to low ISP/high Thrust to attain orbital velocity. From there further ascend to GEO or maneuvering at high ISP/low Thrust could be used as needed.

I'd be happy to hear your opinions on the concept and current shape of the craft. Also currently i could use someone knowledgeable in aeronautical engineering for getting the simulation of the TBCC engine right.