Aero wrote:Yes exactly - so we get spacecraft energy that equals 7.454773666E+07 megatons.
No no. The multiplier applies to the rest mass energy, not the Newtonian kinetic energy.
E_k = m·c²/sqrt(1-v²/c²) - m·c², right?
So E_k = (1000000x299792458²)x(1/sqrt(1-0.9801) - 1)
which works out to E_k = 5.472x10^23 J = 130792337 Mt.
kurt9 wrote:The Philip Bono design would be for deep space craft that would lift off from a prepared space port. Say, a space craft that travels from Earth to Mars or the outer solar system. A winged craft would be better for regular air transport on Earth.
It's true that the Bono shapes take up less room on the ground for a given volume, which could be important at a commercial spaceport. For exploration or bush piloting, though, they're just not stable enough.
NASA is having this exact problem with the Altair lander; the choice of an Apollo-style vertical orientation combined with using the lander's descent stage for LOI means that the PLF has to be at least 10 metres wide, preferably 12 m or more, for a half-decent level of stability. Even then, the astronauts have to climb up and down a rather tall ladder... DIRECT v3.0 (which does support 12 m PLFs) could enable the EDS to be re-used for LOI, since its engines (6xRL-10B2 in the recommended configuration) are even more efficient than the lander's engines; this reduces the size of the descent stage (which in turn means the EDS doesn't have to get any bigger to do the extra burn) and ameliorates the problem. The recent EELV/depot-based ULA proposal uses a horizontal lander that fits in a much smaller PLF and lands with everything much closer to the ground, which might be a better idea regardless of the launch system...
Okay, so that was a bit of an off topic ramble, but there are definite disadvantages to going tall and thin. Even for a vehicle that's expected to only ever use prepared spaceports, there exists the possibility that the pilot may be forced to make an emergency landing somewhere with lots of rocks and hills, and not a lot of flat ground... and if a DC-X-style accident ever happened (failure of a landing leg), the potential damage and loss of life would probably be much less with a design like a flying saucer, or indeed anything with a vertical axis significantly shorter than the other two.
A Bono SSTO is about as short and squat as you can make a VTVL rocket due to aerodynamic considerations, but with unlimited delta-V who cares? A saucer could accelerate almost horizontally like a spaceplane, or just lazily rise up to the point where atmospheric drag ceases to be an issue. So could basically any ground-hugging design. I don't see much advantage in the Bono beyond footprint. And if we're going to be building twenty-thousand-ton interplanetary passenger liners, a small footprint turns into a
disadvantage real quick...