Project Long Duration Deep Space Vessel

[Sky Captain]

An addon I started to make about 3 months ago but didn't have time to finish. Now I have more free time again and I hope to release it to O-H maybe at the beginning of next week.

Long Duration Deep Space Vessel (LDDSV) is big interplanetary spacecraft designed to send large crew (~100 people) on a multi year exploration missions to outer Solar system.

Propulsion is electric with variable ISP and thrust powered by advanced fission reactors. Acceleration at higher ISP modes (200 000 m/s and above) is going to be low ~1 km/s per day or less depending on ship mass so navigation will be tricky and require careful planning. Propellant is LH2. With on board electrolysis plant it is possible to make H2 from local ice which is plentiful in outer solar system.

Here is some images

general overview.


Forward section houses reactors, radiators and propellant tanks



Engines and habitation modules placed at the rear shielded from reactors by shadow shields and propellant tanks.




main engine test





Things to do:
Some upgrades to mesh and textures
Add docking ports
Add RCS exhaust animations
Hab and antenna rotation once I figure out how to make animated parts with spacecraft3.

 

[silent_protagonist]

Very nice.

Of course, ever since I read about Valkyrie I've been convinced that all these deep space vessels have their engines pointing the wrong way, but that's just me. It's nice to see a craft with good large radiators; I don't think Clarke and Kubrick realized the curse they laid on humanity's perception of spacecraft when they took the radiators off of Discovery.

Looking forward to flying this baby!

 

[Yoda]

VERY NICE !!!!
Can't wait to take this one on a spin !

Is this going to be UMMU compatible ???
How many docking ports will it have for landers and such ?

LOOKING GOOD !!!

 

[Sky Captain]

Very nice.

Of course, ever since I read about Valkyrie I've been convinced that all these deep space vessels have their engines pointing the wrong way, but that's just me. It's nice to see a craft with good large radiators; I don't think Clarke and Kubrick realized the curse they laid on humanity's perception of spacecraft when they took the radiators off of Discovery.

Looking forward to flying this baby!

Well, the acceleration is so low even at lowest ISP and highest thrust setting that structural loads from main engines are similar to loads from RCS thrusters so if the structural frame can withstand RCS firing so it can withstand main engines.

How many docking ports will it have for landers and such

Currently it has 8 docking ports, but there is space for up to 16 docking ports which IIRC is the maximum number spacecraft 3 allows.

Is this going to be UMMU compatible ???

It's spacecraft3 vessel because I don't know how to code dll based vessels, but I think there was an addon somewhere that can make any vessel UMMU compatible.

 

[Izack]

It's spacecraft3 vessel because I don't know how to code dll based vessels, but I think there was an addon somewhere that can make any vessel UMMU compatible.

That would be [ame="http://orbithangar.com/searchid.php?ID=3509"]UMMUFA[/ame].

 

[Slice N Splice]

An addon I started to make about 3 months ago but didn't have time to finish. Now I have more free time again and I hope to release it to O-H maybe at the beginning of next week.

Long Duration Deep Space Vessel (LDDSV) is big interplanetary spacecraft designed to send large crew (~100 people) on a multi year exploration missions to outer Solar system.

Propulsion is electric with variable ISP and thrust powered by advanced fission reactors. Acceleration at higher ISP modes (200 000 m/s and above) is going to be low ~1 km/s per day or less depending on ship mass so navigation will be tricky and require careful planning. Propellant is LH2. With on board electrolysis plant it is possible to make H2 from local ice which is plentiful in outer solar system.

Here is some images

general overview.
http://img42.imageshack.us/i/lddsv1.jpg/

Forward section houses reactors, radiators and propellant tanks

http://img811.imageshack.us/i/lddsv3.jpg/

Engines and habitation modules placed at the rear shielded from reactors by shadow shields and propellant tanks.
http://img42.imageshack.us/i/lddsv4.jpg/



main engine test
http://img4.imageshack.us/i/lddsv7.jpg/




Things to do:
Some upgrades to mesh and textures
Add docking ports
Add RCS exhaust animations
Hab and antenna rotation once I figure out how to make animated parts with spacecraft3.

All the deep space traveling ships look the same in my opinion.

They are all long and thin and look the same.

The habitation modules are so freaking small that living in them would be quite a challenge.

I think if i was going into deep space, being crammed and stuffed in those modules for what? 50 years or so would drive me crazy...


Needs bigger habitation modules and stuff.


But it is still cool.

Cheers!

 

[Izack]

All the deep space traveling ships look the same in my opinion.

They are all long and thin and look the same.

Form follows function.

 

[Polaris]

This is just what I need to travel out and beyond! Here's a name suggestion: SS Carl Sagan, after the famous astronomer. May he rest in peace.

 

[Slice N Splice]

Here's a name suggestion: SS Carl Sagan, after the famous astronomer. May he rest in peace.

Amen.

 

[Sky Captain]

That would be UMMUFA.

Yeah that's what I was looking for.

The habitation modules are so freaking small that living in them would be quite a challenge.

I think if i was going into deep space, being crammed and stuffed in those modules for what? 50 years or so would drive me crazy...


Needs bigger habitation modules and stuff.

Hab modules have total volume of ~20 000 m3 or 200 m3 per person assuming crew of 100 (actual living volume would be less because hab also houses laboratory facilities for various research) which should be plenty even for multi year missions.

This is just what I need to travel out and beyond! Here's a name suggestion: SS Carl Sagan, after the famous astronomer. May he rest in peace.

That should be easy enough.

 

[Talon1]

Now that's another beautiful ship I can crash into the sun :lol: Well, At least I'll try not to

 

[T.Neo]

Well, the acceleration is so low even at lowest ISP and highest thrust setting that structural loads from main engines are similar to loads from RCS thrusters so if the structural frame can withstand RCS firing so it can withstand main engines.

Actually it isn't an issue of being strong enough, it's an issue of reducing mass. So even if the spacecraft is under a very low acceleration, you'll be able to reduce mass by putting the main structural components under tension rather than under compression. :thumbup:

Though at an acceleration of a 845th of a G, I think there are going to be navigation issues... TransX and IMFD don't deal well with low accelerations.

 

[jedidia]

TransX and IMFD don't deal well with low accelerations.

But the navigator will do quite fine.

 

[T.Neo]

But the navigator will do quite fine.

As fine as one would do trying to drill a hole with a hacksaw.

 

[Sky Captain]

Actually it isn't an issue of being strong enough, it's an issue of reducing mass. So even if the spacecraft is under a very low acceleration, you'll be able to reduce mass by putting the main structural components under tension rather than under compression. :thumbup:

But if you have structural frame so weak that it can withstand even very weak thrust from main engines only when put at tension it would break when RCS are used because that would introduce bending loads on structural frame which is worse than compression loads from main engines. So the frame has to have some rigidity or RCS would have to be so weak that it would take forever to orient vessel at desired attitude. Anyway most massive components are propellant tanks when full, nuclear reactors and engines which keep the same mass no matter whether engines are at front or rear. Structural frame already is only tiny fraction of overall mass.

Puller type setup make most sense if engines are high thrust like some sort of fusion torch drive capable of 1 G or greater acceleration. In my case engines are VASIMR type.

Another problem with puller setup is exhaust hitting the hull if exhaust streams spread out too much.

Though at an acceleration of a 845th of a G, I think there are going to be navigation issues... TransX and IMFD don't deal well with low accelerations.

Well. I managed on a second attempt to get to the Moon from LEO. Trip took nearly 2 weeks, but I get there. Later I will try an interplanetary trip to Mars or Jupiter.

Now that's another beautiful ship I can crash into the sun :lol: Well, At least I'll try not to

Hehe I already crashed it into the Moon on my first Moon trip. When I noticed that my periapsis goes below surface it was too late to do something because of low thrust:lol:

 

[T.Neo]

But if you have structural frame so weak that it can withstand even very weak thrust from main engines only when put at tension it would break when RCS are used because that would introduce bending loads on structural frame which is worse than compression loads from main engines. So the frame has to have some rigidity or RCS would have to be so weak that it would take forever to orient vessel at desired attitude.

Of course, but that doesn't mean you can't still reduce mass. And the RCS can also be constructed in such a way as to reduce stresses on the structure, like the z-direction linear RCS putting the structure of the ship in tension as well.

Mind you, real spacecraft tend to take forever to orient anyway...

Though I have to say my main problem with your design is you've put the heaviest components out front (propellant tanks and fission reactors) on the truss, rather than the lighter crew modules and supplies. Is there any reason behind this?

Another problem with puller setup is exhaust hitting the hull if exhaust streams spread out too much.

Of course, but that's why you angle your exhaust outwards. Granted, you lose thrust that way, but the exhaust should not spread out that much, especially if the exhaust velocity is high.

Well. I managed on a second attempt to get to the Moon from LEO. Trip took nearly 2 weeks, but I get there. Later I will try an interplanetary trip to Mars or Jupiter.

Hmm... how did you do that? Transfer MFD?

And an interplanetary trip is a good deal more difficult than a lunar one... it's stuff like this that makes me wish we had low-acceleration navigation tools for Orbiter.

 

[Sky Captain]

Of course, but that doesn't mean you can't still reduce mass. And the RCS can also be constructed in such a way as to reduce stresses on the structure, like the z-direction linear RCS putting the structure of the ship in tension as well.

That means more RCS propellant and more thrusters to tension the structure before rotation which again is more mass.

Though I have to say my main problem with your design is you've put the heaviest components out front (propellant tanks and fission reactors) on the truss, rather than the lighter crew modules and supplies. Is there any reason behind this?

Main reason for putting reactors on front was to make as much ship as possible radiation free, especially the engines. Propellant tanks are there to provide another layer of radiation protection. That way if something goes wrong at engine section it is accessible by human crew. In a setup where engines are behind reactors engine section can be accessed only by RMS which could make repairs in some cases more difficult or impossible. Mind you it comes with some mass penalty, but then again every design decision has some tradeoffs

Of course, but that's why you angle your exhaust outwards. Granted, you lose thrust that way, but the exhaust should not spread out that much, especially if the exhaust velocity is high.

At lower ISP higher thrust settings exhausst spreading too much might be a problem.

Hmm... how did you do that? Transfer MFD?

I used IMFD. In the evening I will try interplanetary mission.

 

[Izack]

Main reason for putting reactors on front was to make as much ship as possible radiation free, especially the engines. Propellant tanks are there to provide another layer of radiation protection. That way if something goes wrong at engine section it is accessible by human crew. In a setup where engines are behind reactors engine section can be accessed only by RMS which could make repairs in some cases more difficult or impossible. Mind you it comes with some mass penalty, but then again every design decision has some tradeoffs

And what if something goes wrong with the reactors?
I would think that a problem with one of the nuclear reactors would be a much more urgent issue than a problem with one of the engines. If one engine goes kaput, the other engines can compensate (you have 5.) If one of the reactors undergoes meltdown, you lose the ship.

 

[T.Neo]

That means more RCS propellant and more thrusters to tension the structure before rotation which again is more mass.

No... to point the z+ translation thrusters backward requires no extra propellant.

Main reason for putting reactors on front was to make as much ship as possible radiation free, especially the engines. Propellant tanks are there to provide another layer of radiation protection. That way if something goes wrong at engine section it is accessible by human crew. In a setup where engines are behind reactors engine section can be accessed only by RMS which could make repairs in some cases more difficult or impossible. Mind you it comes with some mass penalty, but then again every design decision has some tradeoffs

Ah ok... engine maintainance. I was wondering because you could always have the reactors at the back of the ship, behind the fuel tanks, with the payload/crew up front, but that would cut off the engines from a repair attempt.

At lower ISP higher thrust settings exhausst spreading too much might be a problem.

Sure, but without any math on the subject it's impossible to tell how far it would spread, really.

I used IMFD.

I must admit I know very little about IMFD... did you just go through the normal procedure, or was there some special magic to it?

If one of the reactors undergoes meltdown, you lose the ship.

How likely is a reactor meltdown though? Maybe it could be avoided altogether with some inherent failsafe like with a pebble-bed reactor. :hmm:

But then again, one must ask how often the engines would break down...

 

[jedidia]

As fine as one would do trying to drill a hole with a hacksaw.

Not sure I understand what you're saying. The navigator works very well for low-thrust trajectories...

And an interplanetary trip is a good deal more difficult than a lunar one...

For a low-thrust vessel, no. Hitting the moon is very difficult, hitting Jupiter or Saturn is relatively easy. I made a low thrust flight there once with IMFD, you can make do. But how he managed to hit the moon is beyond me... unless he extended the orbit and just waited for the moon to come by.