Project High Velocity Interplanetary Passenger Spacecraft

[Dambuster]

Simply brilliant!

Also, are the landers going to be 'human-rated', or for cargo only?

 

[T.Neo]

Also, are the landers going to be 'human-rated', or for cargo only?

They're purely unmanned lunar surface-to-orbit/orbit-to-surface cargo vehicles.

 

[Izack]

I'm wondering about those radiators on the front of the HIVPS. Are you sure they're large enough? There's a fusion core in there...

 

[T.Neo]

I'm wondering about those radiators on the front of the HIVPS. Are you sure they're large enough? There's a fusion core in there...

This is true, I can enlarge them quite easily.

 

[T.Neo]

Attached is HVIPS with completed RCS setup. On the left are the rear RCS booms aligned horizontally, on the right they are aligned vertically. I like the arrangement on the right a bit more, because it takes the RCS booms out of the path of the thrust entirely and it looks a bit cooler.

I'd probably have to reposition the habitation module radiators to keep them horizontally aligned though.

That is more or less it for the exterior of HVIPS, but the VC still needs work and texturing.

 

[Moach]

lookin' good!


i'd go with the second one as well :thumbup:

 

[pattersoncr]

Very interesting design T.Neo
I have always lamented the fact that while the orbiter add-on universe has more SSTO spaceplanes than you can shake a stick at, it's very thin on interplanetary craft.
This project fills a real need. Keep up the good work!

 

[Izack]

I'm holding off my second trans-Solar System flight (this time with TransX) in anticipation of this vessel. :thumbup:

 

[mc_]

Looks nice. But right one is better, i think.

Very interesting design T.Neo
I have always lamented the fact that while the orbiter add-on universe has more SSTO spaceplanes than you can shake a stick at, it's very thin on interplanetary craft.

I've been thinking about the same things. Orbiter missing many good things, not only interplanetary vessels.
Yeah, its really sad...

Hope this project will fill some "gap" in addons.

 

[Zachstar]

Is this the legendary tinfoil texture? :lol:

Seriously though, I like where this ship is going. A practical design and the product of an intelligent discussion. :thumbup:

Do not EVEN get me started on the state of "Foil" Textures in orbiter. I spent like 3 months one year on the topic of foil textures. Created a bunch of them by messing with photos from NASA. I dont know if they are still around tho sadly.

 

[T.Neo]

HVIPS dry mass breakdown

Dry mass breakdown. Can change at any time though, I'm still messing around with things.

 

[francisdrake]

On the left are the rear RCS booms aligned horizontally, on the right they are aligned vertically.

I think there are no RCS booms required at all. To spin the vessel around x and y only outward thrusters are needed. To rotate around its longitudinal z-axis I would use RCS engines at the main-engine booms. Most of the inertial moment is packed in the engine section anyhow. If this is rotated, the truss and crew compartment will follow.

Great project, by the way! :thumbup:

 

[jedidia]

27% of the mass for auxilary craft seems an awfull lot, considering this is supposed to be a passenger liner and not an exploratory vessel. I would expect to find a running starport with its own short-range vessels at the destination.

 

[T.Neo]

I think there are no RCS booms required at all. To spin the vessel around x and y only outward thrusters are needed. To rotate around its longitudinal z-axis I would use RCS engines at the main-engine booms. Most of the inertial moment is packed in the engine section anyhow. If this is rotated, the truss and crew compartment will follow.

My logic behind the rear RCS boom is that it allows finer control, as well as better translation capability and no unintentional translation while rotating.

Though you're right, most of the inertial moment is in the propulsion section anyway. Which leads to unfortunate consequences on where I put the center of spin... :shifty:

I'll see if I can fix that... and if fixing it doesn't lead to the exhaust streams frying my auxilliary craft.

27% of the mass for auxilary craft seems an awfull lot, considering this is supposed to be a passenger liner and not an exploratory vessel. I would expect to find a running starport with its own short-range vessels at the destination.

Good point... I originally envisioned this as a vessel capable of transporting two DGs, and thus acted as the accomodation and whatnot for their passengers.

I guess you could just leave the auxilliary craft off, increasing your Dv capability and your cruise speed even more. :thumbup:

Or, the auxilliary craft could be replaced with a sort of MPLM cargo module. Which now turns the passenger spacecraft into a light, high speed freighter.

Though it could still concievably be used as a sort of ferry, for DGs or some other hopefully more realistic craft (what that would be I have no clue).

I've thought about a more realistic version of the DG... almost like Moach's G-42, but nucular powered and smaller. The XRs already have engines in the ISP and thrust capability as nuclear lightbulb engines, but they have other problems, like fuel density and aerodynamics. And it really doesn't make sense landing a spaceplane on some airless moon, let alone giving a spaceplane some parasitic weight like hover engines. It would only really make sense to use a winged vessel if you were going somewhere with an atmosphere, like Titan... or maybe Mars.

Some of the mass figures there I'm not too happy about either. The truss masses a lot, especially if we're considering some sort of hokey use of carbon nanotubes. And the propellant tanks are probably represented as too light. And there isn't any provision for my mini nuclear reactor, which is pretty much redundant anyway considering it would be more than easy for my engines to generate a few kilowatts during cruise or while in orbit... that's several thousandths of the power they produce while thrusting.

 

[jedidia]

for DGs or some other hopefully more realistic craft

I think the Specs of the DG go well with the specs of your engines

 

[T.Neo]

Actually it is not so much the performance of the engines of the DG that are problematic, but other things such as fuel density. The performance of the DG engines is in the range of gas core nuclear rocket proposals. The DG and DGIV are more in fitting with open-core GCNRs, and the XRs are more in fitting with closed core GCNRs (so called "nuclear lightbulb" engines). From what I can tell those proposals were supposed to use more-or-less conventional nozzles and materials, although I did calculate once that the DG's nozzles would have to have a 13 meter diameter or something stupid like that. And they might not be entirely realistic in terms of engine mass or size.

Of course with that sort of engine using hydrogen as propellant, the DG wouldn't be able to house it, even if it was slushed hydrogen. It would easily be able to house that amount of water, but a water-fueled GCNR would have a lower specific impulse.

I didn't just mesh some nozzles and then ignore the other ramifications of my engines. They are collectively the second most massive component on the spacecraft, and are themselves around the size of a DG. A person could comfortably stand within one of the RCS nozzles...

My engines have nearly 200 times the exhaust velocity of those of the DG though. So I don't think they're that comparable...

The key to the magnetic nozzles is that they do not shield off a portion of the energy from the engine structure like some sci-fi forcefield, they seperate the actual thrust stream from the physical components completely. This means that the particles in the thrust stream can not deposit heat onto the engine components. Photons emitted by the thrust stream can though, and a reflective material is used to mitigate this. The rest of the photons then escape to space, or hit the rest of the ship (which is why I have big mirrors along the ship near the engines).

Of course, that thrust stream is going to be emitting a lot of photons...

 

[T.Neo]

Of course, that thrust stream is going to be emitting a lot of photons...

Yeah... turns out, that with gas temperatures ranging in the millions of degrees and thrust powers of... a very very very large amount of watts, that the spacecraft would basically turn into a brilliantly bright flash of brilliant brightness as soon as the pilot flicked the switch.

So... disregard anything I said about high thrust propulsion in the past. You can't mess with science- I found out the hard way. :shifty:

Rather than be productive and reconfigure everything into something a little less capable: :lol:

I've decided to wallow in the shame of my "epic fail", and focus on other projects that hopefully involve watts and kelvins that are not in 6-figure numbers.

So unfortunately it doesn't seem like there's going to be a HVIPS or anything like it any time soon. :dry:

 

[RisingFury]

Guess it's time you put those new experimental HyperThrustium engines in her :thumbup:

 

[T.Neo]

Yeah, the 1 gram engine with a 1 cm wide nozzle, capable of 13 meganewtons at 4 billion seconds of ISP!

 

[Sky Captain]

Why not change the engine performance settings to something based on report about Discovery II spacecraft. Suppose Gen III (Discovery II would be Gen I) fusion engines capable of accelerating the vessel at 0.05 G with ISP of 1000 - 1500 km/s. It would still give fast interplanetary travel while keeping the engine power somewhere in few hundred GW range wihich is comparable to what large chemical rockets put out at liftoff.