EuroSpace E950 Minerva Executive Transatmospheric Vehicle

[Trojan Points]

A GURPS Spaceships stated 'orbital business jet' for your THS campaign

The Minerva, a GURPS Spaceships stated 'orbital business jet' for your THS campaign!

[Tzeentch]

The HEDM rocket cannot go in the core. Also note that HEDM rockets are still quite dangerous in Transhuman Space and would probably not be rated for commercial use. (You can swap a fuel tank with the rocket to fix).

Computer Complexity should be C6 with the TS mod.

After tank multiplier it gets 0.7 mps per tank, for a total of 7 mps for the HEDM rocket.

Load should be 0.7 (1 crew, 6 passengers).

I get $820K for price

[MatthewVilter]

Originally Posted by Owen Smith

I also wouldn't use a seperate rocket and jet engines for this, they're parasitic weight when the other one is in use. I'd go for the hybrid engines which are just starting research now, that can air breath in the atmosphere and switch to stored oxygen at higher altitudes.

I think it would be pretty hard to make an air breathing HEDM rocket, let alone a hybrid one.

But yeah HEDM rockets are not exactly civilian tech in January 2100. Makes building SSTO craft hard...

Outside of a laser powered rocket the only thing that really comes close is a nuclear thermal rocket (.5 G/.45 mps) which may or may not be useable in earth's atmosphere.

Side question: would a fusion powered NTR perform any differently then a fission one?

[Anthony]

Originally Posted by MatthewVilter

I think it would be pretty hard to make an air breathing HEDM rocket, let alone a hybrid one.

It doesn't even make sense, HEDM fuel isn't binary. You can only make a dual air/rocket design if you're making a thermal rocket (nope) or one that works by mixing oxygen with fuel (nope).

[vicky_molokh]

Originally Posted by MatthewVilter

I think it would be pretty hard to make an air breathing HEDM rocket, let alone a hybrid one.

But yeah HEDM rockets are not exactly civilian tech in January 2100. Makes building SSTO craft hard...

Outside of a laser powered rocket the only thing that really comes close is a nuclear thermal rocket (.5 G/.45 mps) which may or may not be useable in earth's atmosphere.

Side question: would a fusion powered NTR perform any differently then a fission one?

A Light Bulb provides at least 0.8 mps per fuel tank, and exhales pure hydrogen. I think this is as SSTO-friendly as one ever needs. The only thing that is meh is that you need something like 6 hours to reach orbit.

[MatthewVilter]

Originally Posted by vicky_molokh

A Light Bulb provides at least 0.8 mps per fuel tank, and exhales pure hydrogen. I think this is as SSTO-friendly as one ever needs. The only thing that is meh is that you need something like 6 hours to reach orbit.

Well, considering that typical LEO is, what? 90 minutes? I think you are going to need something with a bit more oomph...

[vicky_molokh]

Originally Posted by MatthewVilter

Well, considering that typical LEO is, what? 90 minutes? I think you are going to need something with a bit more oomph...

Why would that matter? You're trading cheap SSTO (something like 8 tanks of hydrogen) for having to spend several hours flying. That's something like $8000 per launch for a small TAV (say 1-6 people) to GEO, which is cheaper than the $24,000 per person you pay when buying orbital tickets from your friendly neighbourhood laser-launch facility to LEO.

In fact, if such a TAV can get 6 people to orbit, it is competitive with the Olympus Project due to being doable from any airport.

[MatthewVilter]

I'm saying that you can't get to orbit with that low a thrust. If it takes longer to get up to orbital speed then it does for your suborbital trajectory to intersect the planet you are in for trouble.

[vicky_molokh]

Originally Posted by MatthewVilter

I'm saying that you can't get to orbit with that low a thrust. If it takes longer to get up to orbital speed then it does for your suborbital trajectory to intersect the planet you are in for trouble.

Wha? How are the two related? You've got an altitude gain throughout your launch, and you've got velocity gain throughout the launch. If needed, you just go round and round around the planet until you reach orbital velocity (you'll also get orbital altitude in the process).

[MatthewVilter]

Originally Posted by vicky_molokh

Wha? How are the two related? You've got an altitude gain throughout your launch, and you've got velocity gain throughout the launch. If needed, you just go round and round around the planet until you reach orbital velocity (you'll also get orbital altitude in the process).

The point of reaching orbital velocity is so that can go round and round! Before you are at orbital velocity you expend energy to avoid falling back to earth. If you are boosting into orbit with a high thrust craft we just call that energy "gravity drag". If you are planing to fly around the planet slower then orbital velocity you will end up spending huge amounts of energy just keeping your altitude up (especially at the start when there is a large difference between your speed and proper free falling speed). I doubt that you would even be able to keep yourself up with 0.05 G of thrust.