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[1.12.x] 'Project Orion' Nuclear Pulse Engine


RoverDude

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17 hours ago, Starfire70 said:

So total delta-V is insane, about 600 thousand. This is a propulsion system meant for multiple voyages but also NOT meant for fine orbital maneuvering. Getting a close-in orbit around Pol and Bop was a bit of a challenge but with proper attitude to offset some of the acceleration from prograde/retrograde I was able to do it.

I agree with this - my 100k estimate is when loaded pretty heavy - enough for a TWR<2.  As for fine orbital maneuvering, I use Kerbodyne+ as my "insanely BIG stuff" mod, and there's a great LFO RCS module in that with a thrust of 40 - and by adjusting it on the fly, it's been more than adequate for fine orbital maneuvers of large ships.  USI's 5m SAS module is also great on the giant ships.

I've got a last-minute module addition I'm putting up there - this is a sandbox game, and not career, so lofting large modules on insanely-sized boosters is not a problem:

i6Oq1m3.png

The giant tanks are from Kerbodyne+, my second stage becomes an orbital refueling station and comm relay, and has gigantic solar panels and radiators, with 2 of the USI SAS modules to turn the thing.  You can also see the RCS blisters on the upper stage.

I had another design that I scrapped which had a Medusa on the front and a "standard" Orion on the back, mostly to get it into orbit - this was before Roverdude reduced the efficiency of standard Orion in atmo.

With the new aux module (adds comm antennae and a DeepFreeze unit), it looks something like this:

RG8xaow.png -(Download full res here: http://imgur.com/RDAAC9t - warning, it's HUGE)

16 hours ago, DStaal said:

Thanks.  I'll admit what I'm aiming for is probably closer to Panachrist's ship: The plan is a full OPM tour, in one shot.  I'll probably have some other engines for fine orbital maneuvering, but with calculating in habitation and supplies, I suspect a couple of my lander designs are pushing 200t, or close.  (Though I'm only planning on carrying a couple of landers, and reusing them.)  So the mothership that's going to be hauling them around is going to be huge.  Still, 100,000 m/s should be enough.

Mine has a MKS Orbital Shipyard on the back, and I have EL and Workshop installed.  The idea is to build what I need once I get out there.  The ship will have about 12-20 crew, with 10 frozen on the trip.  12 crew non-frozen would be a Habitation timer of 12 years, which is enough to get there but not back. So I think the trip will be capped at 16 crew, with 10 frozen each way.

EDIT: I just tested a modified version of the current trip: Vessel Mass about 1,400 tons.  150 tons of fuel (NPU-500) gives about 42km/s of DV.  So a ballpark figure would be as Isp of roughly 37,000s.  Delta-V calculation then becomes:

ΔV = g0 * Isp * ln[R]  (from Atomic Rocket)

g0 = 9.8066 m/s2

Isp = 37,000s

ln[R] is the natural logarithm of mass ratio (R), which is M/Me (mass with fuel / mass without fuel) - in my example, 1.12

Using an Isp of 37,000 gives a Delta-V of 41km/s, which is 2% under what I tested, which I would consider a healthy safety margin.

Each Pulse Unit Magazine is 100 tons of fuel, so in a given ship design it should be easy to determine R.

( @DStaal : note new math )

Edited by panarchist
added formulae
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16 hours ago, DStaal said:

Thanks.  I should be able to calculate from that.  :wink:

I had a lot of fun yesterday building small Orions and blowing them up in atmosphere while launching them to get ballpark ∆V numbers.  37,000s is a really good number - all my experimental tests fell right there.  The people getting 600km/s ∆V have some really good fuel/mass ratios.

 

4 hours ago, RemoteRadical said:

Ha, it will be weeks until I have a need for those, but what a great part.

Yep, definitely the JX2 - I needed something that might actually reach out to Cercani.  DMagic, has an even larger antenna, the Radio Signals Intelligence Dish, which has 20x the strength of the JX2, but it's 100m in diameter when unfurled, and draws 689 EC/second.  I didn't feel like redesigning with a bigger reactor.

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On 1/29/2017 at 4:08 PM, panarchist said:

I agree with this - my 100k estimate is when loaded pretty heavy - enough for a TWR<2.  As for fine orbital maneuvering, I use Kerbodyne+ as my "insanely BIG stuff" mod, and there's a great LFO RCS module in that with a thrust of 40 - and by adjusting it on the fly, it's been more than adequate for fine orbital maneuvers of large ships.  USI's 5m SAS module is also great on the giant ships.

@DStaalI've got a last-minute module addition I'm putting up there - this is a sandbox game, and not career, so lofting large modules on insanely-sized boosters is not a problem: <snip>

Holy crap, I am clearly not dreaming big enough with this mod. That's an incredibly impressive ship.

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On 2/4/2017 at 1:48 PM, Starfire70 said:

Holy crap, I am clearly not dreaming big enough with this mod. That's an incredibly impressive ship.

Thanks, it's been through several iterations of design.  My profile pic has an earlier version, which is also on KerbalX:

https://kerbalx.com/panarchist/DSE-02B-William-Klark

That version had a Tweakscaled heat shield to act as a shield against interstellar particles.  I launched that one to Cercani some months back, but wasn't happy with the results.  The Klark used a standard Orion drive instead of the Medusa - it took about 11 Kerbin years to travel the 7.265Gkm to Cercani.  The real trick is getting enough resources onto the ship (and a shipyard) to build all the ISRU components to be self-sustaining and refuel for the trip home. (the Klark wasn't really built for that)

@RoverDude - Could there possibly be a resource chain to manufacture fuel pellets and ablative oil in the future?  ;-)

I may be dreaming a bit TOO big - I haven't succeeded yet in a self-sustaining base on Duna, and I'm trying to bootstrap one 7 billion km away with no real chance for resupply.  If I can do it in sandbox, then I'll probably try to replicate it in a career game, in which case I'll probably Manley up and teach myself how to do a video series. :-D

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13 minutes ago, panarchist said:

Oh, cool - how did I miss that?

Well, I don't know when you looked, and it hasn't been around that long. (I submitted it as a PR a few months ago when I started planning to build an orion-drive ship in orbit, and realized I couldn't fuel it...)

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  • 2 weeks later...
On 1/26/2017 at 5:50 PM, Temperus Maximus said:

I built this trying to see how heavy a vessel the orion could put into orbit on it's own, this is the result.

 

takes about a thousand of the biggest nuke pellets to get off the pad and into orbit, barely enough power to get off the pad, not to mention heavy enough to classify as an asteroid, enough reaction wheels to spin a small moon, and can build a base as big as you want wherever you want in the kerbol system, except maybe eve.

 

Thanks for the mod Rover

How long is that?

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  • 2 weeks later...
On 6.02.2017 at 7:55 PM, panarchist said:

Thanks, it's been through several iterations of design.  My profile pic has an earlier version, which is also on KerbalX:

https://kerbalx.com/panarchist/DSE-02B-William-Klark

That version had a Tweakscaled heat shield to act as a shield against interstellar particles.  I launched that one to Cercani some months back, but wasn't happy with the results.  The Klark used a standard Orion drive instead of the Medusa - it took about 11 Kerbin years to travel the 7.265Gkm to Cercani.  The real trick is getting enough resources onto the ship (and a shipyard) to build all the ISRU components to be self-sustaining and refuel for the trip home. (the Klark wasn't really built for that)

@RoverDude - Could there possibly be a resource chain to manufacture fuel pellets and ablative oil in the future?  ;-)

I may be dreaming a bit TOO big - I haven't succeeded yet in a self-sustaining base on Duna, and I'm trying to bootstrap one 7 billion km away with no real chance for resupply.  If I can do it in sandbox, then I'll probably try to replicate it in a career game, in which case I'll probably Manley up and teach myself how to do a video series. :-D

Hey Man, any chance for a list of parts on this:

http://imgur.com/RDAAC9t

 

I dont recognise some parts in the section with the antennas - trying to get inspiration :wink:

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9 hours ago, Jasseji said:

Hey Man, any chance for a list of parts on this:

http://imgur.com/RDAAC9t

 

I dont recognise some parts in the section with the antennas - trying to get inspiration :wink:

Science/Comm Section:

The large batteries are from Near Future Electrical.  Agro bits are from MKS or USI-LS (can't recall which at the moment). JX-2 antennae, hub from NF Structural, Freeze chamber from DeepFreeze, science instruments from SCANsat and DMagic Science, remaining bits are stock.

Rest of Ship:

USI bits: FTT, MKS, Kontainers, Konstruction, Nuclear Rockets, etc.  Inline solar is from DarkStar Technologies, some structural bits, RCS, and I think the 5m SAS are all from Kerbodyne Plus.  There might be a couple of habs from SXT Continued (Lack's SXT under new management).  I think that covers all of them.  The KerbalX page that I uploaded it to has a complete parts list:
https://kerbalx.com/panarchist/DSEV-01-FULL-SHIP/parts

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  • 1 month later...

Hi all - I've been trying out this amazing mod (thanks RD!), but the behavior is a little different than videos I've seen which were recorded in the last year or so (ie presumably recent iterations):

  • Throttle doesn't seem to have any effect on bomb frequency.  It's a constant 4-5 bombs/second regardless of throttle settings.  Tested primarily on Orion using the various propellant categories
  • Medusa engine doesn't seem to generate any thrust at all.

If anyone can shed some light on these oddities, I'd be grateful.  Otherwise, this a very fun mod for building giant, interstellar arks :)

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1 hour ago, RoverDude said:

Throttle is now all or nothing, you change thrust by varying what size bombs you use. Are you using the Medusa in orbit?

Understood re throttle - makes sense.  For the Medusa, I had to toggle retract/extend a couple of times then it worked fine.  Seems like the graphic and the actual state were out of sync at launch or something.

Thanks again for the assistance and the all the fantastic content.

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On 27/03/2017 at 5:15 PM, Chilkoot said:

Understood re throttle - makes sense.  For the Medusa, I had to toggle retract/extend a couple of times then it worked fine.  Seems like the graphic and the actual state were out of sync at launch or something.

Thanks again for the assistance and the all the fantastic content.

I've got erratic behavour with the medusa by not having it staged properly. You need to stage it via the spacebar command for it to generate trust. 

Meanwhile my humble megarocket:

 

Spoiler

EMYM358.png

I call it the Conestoga (as a reference to Outpost 2). It carries enough material to be a "seed factory" for a duna colony. Carries everything needed for a duna colony to bootstrap itself. Kerbals aare taken frozen. Once I finish it I'll post some proper screenshots or a big render.

Edited by Djohaal
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  • 1 month later...
2 minutes ago, A_beholder said:

Can you make more nukes with MKS, and if so, how?

Not sure if you can do it with Ground Construction, as I haven't tried - but I know you can make fuel canisters w/fuel using EL - as long as you have a lot of Enriched Uranium lying around...

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Just now, DStaal said:

Not sure if you can do it with Ground Construction, as I haven't tried - but I know you can make fuel canisters w/fuel using EL - as long as you have a lot of Enriched Uranium lying around...

All I needed to know, thanks!

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