my solution to an engine fitting problem

[Kianykin]

I wanted to have a nuke engine on a small spaceplane. So i tilted the nuke engine downward. Gets into orbit just fine.

[kiwi1960]

You sir, are either a legend.... or totally insane.

I have yet to make up my mind.

[Goldham]

Wait what about the fact that it isn't inline with the command module? also you have .02 units of intake air left in space.

[Pbhead]

I kinda like my solution better...

My space planes would always want to flip over backward in the super upper atmosphere... so now I just let them.

[Kianykin]

For some reason it always shows a little intake air when scoops are closed, not sure why. The engine is inline with center of mass. I just tilt the plane forward as i burn to circularize

[wooaa]

best. idea. ever.

[tstehler1]

I wanted to have a nuke engine on a small spaceplane. So i tilted the nuke engine downward. Gets into orbit just fine.

True kerbalism. Using the little tiny game bugs to one's advantage.

[Brofessional]

Seems to me that putting a NERVA on an SSTO is hardly worth it, it's so heavy and has poor TWR.

I prefer using 48-7S', but if you're going to spam intakes you may as well just use ions.

[RogueMason]

Seems to me that putting a NERVA on an SSTO is hardly worth it, it's so heavy and has poor TWR.

I prefer using 48-7S', but if you're going to spam intakes you may as well just use ions.

I actually disagree here. The nuclear engine will work very well on SSTOs if you have an adequate number of jets and intakes to get you up to a high speed. I built the Cosmic Flyer, an SSTO with a nuclear engine, and it's done more than any other of my SSTOs have without any refuelling whatsoever:

Minmus landing (no VTOL equipment at all), with a Mun flyby later on in the mission. The 4 jet engines and their countless intakes (I plead guilty to intake spam) got the Cosmic Flyer up to speeds that allowed the nuclear engine to nudge the plane up into space. Once there, it had tons of rocket fuel left over.

I was sceptical about using the nuclear engine on SSTOs at first, but the range is increased so much in comparison to spaceplanes that use aerospikes, for instance. Seeing the Cosmic Flyer work was pretty incredible.

[Psycix]

The point Brofessional makes is it is likely that a lighter engine with more fuel in most situations weighs less than a nuke+fuel that features the same amount of delta-V.

This is especially true if you want to have a appreciable TWR.

As your total amount of deltaV increases and your desired TWR decreases, the nuke becomes more favored, but contrary to popular belief, for most practices it is usually not worth it!

Proof:

http://imgur.com/a/iNqmQ

http://imgur.com/a/yuUH4

Most people "default" to nukes, completely forgetting how much extra fuel they could have carried were they to use a lighter engine.

Engine weight matters!

@OP

Although I find it very creative, a set of radial engines and a perhaps a tad more fuel will likely grant you more delta-V for less weight.

That nuke is half your plane's mass.

Edited October 11, 2013 by Psycix

[rodion]

I'll agree here, it needs to be remembered that engine mass is still mass that has to be dragged around at a cost. One NERVA on its own has the same mass as a fully fueled 180-unit fuel tank, so if your total craft mass is equivalent to not more than a few of those, it's probably a waste to use a non-chemical engine. The 909 has half the Isp, but less than a quarter of the mass, and the little red one is even more extreme in the difference.

[M5000]

OP, I have no idea how you managed that but I really like your craft, and that idea for space saving... Top notch!

[Kianykin]

I modified it and tried LV-909 and those little rockmax engines. I couldn't make orbit with either, but I can consistantly get the nuke engine into orbit. I may just be piloting it wrong though.

[Warmblood]

I happened to be testing this yesterday. For mid size craft (15-25 ton fully loaded range-the one posted is a tad small) nukes are the way to go if you can fit one. Anything 2 jet engines and above should qualify. I flew an aircraft with a nuke stuck to the front, the same way one of the earlier posters had set his up. In this configuration you will likely need an extra engine at the back for the phase immediately after jet engine shutdown, but even then the efficiency gained from nuclear is high enough to offset that wasted mass.

As a test, I sent up the aforementioned plane. It made it to stable orbit with about 2500 delta-v. The atomic engine was only used in circularization, not the main burn. And I didn't even jettison the rear rocket engine, so it really could have been more efficient.

For comparison, I flew a very similar plane with the same fuel loading. All I did was remove the nuke, change the rear engine to a single aerospike, and adjusted the aerodynamic surfaces to suit the new CG position. It made it to orbit just fine, and indeed, was a little easier to fly. It had substantially more fuel once in orbit as well. But, it's calculated delta-v was only 1800.

ISP matters. A lot. 800 is clearly superior to 390. As long as the weight of the engine is offset by the overall mass of the spaceship, (and there's fuel ofc!) efficiency becomes the dominating factor in delta-v calculations. Furthermore, if you refuel a rocket plane, that element of efficiency with the nuclear engine will increase even further. It may be extremely awkward, but if you really need to go far with medium to large spaceplane, a nuke is the way to go!

[Captain Sierra]

OP, I have no idea how you managed that but I really like your craft, and that idea for space saving... Top notch!

I think this is supposed to be a subtle hint to yall to get back on subject.

M5K, that might have been a bit too subtle.

[M5000]

I think this is supposed to be a subtle hint to yall to get back on subject.

M5K, that might have been a bit too subtle.

No, it wasn't really off topic to begin with, I genuinely like the idea and am curious as to how he managed that... I can't tell if it's one of those radial adapters.. Or schnazzy use of Editor Extensions mod... No idea..

[Col_Jessep]

I genuinely like the idea and am curious as to how he managed that...

You can do it even without activating part clipping. Just use a small cubic octagonal strut and attach it at an angle. After that you can attach one part to the strut at an angle and another one to the parent part:

http://imgur.com/a/Ynk1F#0

[M5000]

You can do it even without activating part clipping. Just use a small cubic octagonal strut and attach it at an angle. After that you can attach one part to the strut at an angle and another one to the parent part:

http://imgur.com/a/Ynk1F#0

Hmm. I know the trick well, but it just seems weird since the NERVA is such a long engine... There seems to be a LOT of it hidden..