nyrath
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Posts posted by nyrath
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There is no friction in space. Here on Terra, if you are driving a car and take your foot off the accelerator, the car will coast to a stop due to the friction of the road. In space, if a spacecraft turns off its engines it will maintain its current velocity for the rest of eternity (unless is crashes into a planet or something). In the movie 2001 A Space Odyssey, you may have noticed that the spacecraft Discovery was traveling to Jupiter with nary a puff coming out of the rocket motors.
This is why it makes no sense to talk about the "range" of a rocket. Any rocket not in orbit around a planet or in the Sun's gravity well has a range of infinity. In theory it can do a burn and travel to, say, the Andromeda Galaxy, it is only that it will take millions of year to get there. Instead of a rocket's range, one should talk about a rocket's delta V capacity.
The important thing is that a mission can be rated according to how much delta V is required. For instance: lift off from Terra, Hohmann orbit to Mars, and Mars landing, is a mission which would take a deltaV of about 18,290 m/s. If the spacecraft has equal or more delta V capacity than the mission, it is capable of performing that mission. The sum of all the deltaV requirements in a mission is called the deltaV budget.
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Sweet... make the shock plate animate over 1.0s and give to me, and I will build a plugin to make it work.
OK, ialdabaoth, I think I have the part with the animation for you. At this point all I know is that it will animate in Unity, and the part will appear in the Vertical Assembly Building, where it can be attached to a stack. That's all.
How can I get it to you?
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I have this sudden urge to try to get to the Mun and back with nothing but a slide rule
Or a Nomogram
http://forum.kerbalspaceprogram.com/showthread.php/27860-A-Kerbal-Nomogram
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I have my Blender model in Unity, along with the emission map. Unfortunately I'm having trouble getting the animation attached to the pivot part. And when I export it, the model.mu file is ony 91 bytes, which means I'm doing something seriously wrong. I'm still plugging away.
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The Galactic Cruiser Leif Ericson
followed by the Pilgrim Observer
and the iconinc "Umbrella Ships" from Walt Disney's "Mars and Beyond" segement.
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Interesting stuff. I wondered how the directional casing would survive the blast. The obvious answer - it doesn't! It only needs to survive for a few ms to be effective.
Got it in one. The casing does not survive, but it survives long enough.
Interesting stuff? Heh, you don't know the half of it.
The Orion propulsion unit is a nuclear shaped charge optimized for propulsion.
What if you optimized it as a weapon?
You'd have the dreaded Casaba Howitzer, a directed energy weapon that shoots spears of nuclear flame.
I'd like to find more information about this but the blasted thing is still classified after all these years.
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How exactly does nuclear pulse propulsion work anyway? Most of the damage from a nuclear bomb comes from the movement of the air, but in space there's obviously no medium to transfer the energy. Is it "just" the radiation pressure from the blast, or is the bomb wrapped in a medium that is vapourised to provide usable thrust?
http://www.projectrho.com/public_html/rocket/enginelist.php#id--Pulse--Orion
It is a nuclear shaped charge.
Most of the _blast_ from a nuclear bomb comes from the movement of the air. A nuclear detonation is a huge burst of x-rays. In an atmosphere, it heats the air, creating blast.
In the nuclear pulse unit, allowing the x-rays to radiate in all directions would waste 90% of the bomb's energy, only 10% would hit the pusher plate. So the bomb is encased in a thick shell of x-ray opaque material with a hole oriented in the direction of the pusher plate. On top of the hole is a channel filler which converts the x-rays into heat. On top of the channel filler is a slab of propellant. The propellant is vaporized by the heat and projected at the pusher plate.
By using the shaped charge, about 85% of the bomb's energy hits the pusher plate.
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There's an emissive tutorial you can use here.
I'm pretty sure you can just attach the animation you create to any module you wish, as long as you call the correct name inside the module itself.
Thanks!
I've made an emission map in Photoshop, I've downloaded and installed Unity + Parts Tools plug-in, and I'm starting at square one learning Unity.
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Sometimes it is a case of so many propulsion systems, so little time.
You should see the gigabytes of data in my "to be added" folders.
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Welcome Nachtengel !
Did you see how these gentlemen used KSP to do a mission control simulation?
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Hey, Nyrath, while we are at it, I always wondered why you didn't have Bussard's fusion engine concept up on your page. You have something on hydrogen-boron fusion, I know, but honestly this is a way cooler way to go about it. Basically, they use one Polywell reactor to directly drive relativistic electron beams to heat the propellant (which is simple, since the output of a Polywell is extremely high voltage current).
I was hesitant since there is still some question about the viability of the Polywell fusor.
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I'm still learning how to do this
https://secure.flickr.com/photos/nyrath/8719459802/in/photostream
https://secure.flickr.com/photos/nyrath/8719459836/in/photostream
https://secure.flickr.com/photos/nyrath/8719459892/in/photostream
I've made it a one second stroke cycle, with the plate slowing down the higher it gets.
I've initially made the pictured model with the same diameter as the standard engine, because I was not sure of the dangers of changing it. In the original Orion study, they were looking at pusher plate 10 meters in diameter. This is only for the plate, the fuel drum and shock absorbers can be contained in a smaller diameter.
Is there a tutorial for emmisive mapping?
I was looking at the stock gimbaled engine, and noticed the two parts plus the anchor. I do currently have the mesh in two submodels, not sure where to put the anchor.
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That's a lot of NERVAs...
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You can create the animation itself in Blender and then export using FBX (with include animation ticked).
I'll see what I can do.
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Hmm... That's odd, I can see them fine. They're hosted on google drive. Can anyone else see them?
Edit: as a test can anyone see this image? I think people who are logged into their google account may not be able to see the images...
I found that I could not see the images. I followed a link to one of them and wound up at Google Docs. There I was asked to log into my Goggle account. After than, then I could suddenly see the pictures.
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Sweet... make the shock plate animate over 1.0s and give to me, and I will build a plugin to make it work.
Well, that might take a while. I have not learned how to use Unity yet, that is where one creates animations, right.
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Spacecraft that are multi-staged are called either "stacks" or "disintegrating totem poles"
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Project Daedalus ftw!
It's "just" about 500m high and has an equivalnet diameter, it's a two stage fusion vessel, that could reach Barnard's star within 50 years with it's top-speed exceeding 12%c.)
Yes, and it has just enough fuel to delta-V to 12%c. It does not have any fuel to slow down.
So it goes streaking through the Barnard's Star system at 12%c. Take your pictures and get your scientific readings fast, you don't have a long time.
Yeah, and someone figuring out how to make inertial confinement fusion with lasers work. The last results from NIF are pretty much discouraging form what I've heard. I found this recently, however. If you buy what they are selling, it sounds neat and close to work:Yes, magneto-inertial-fusion. So crazy it just might work. It is sort of a hybrid approach combining inertial confinement with magnetic confinement.
As is often the case, it has fantastic Isp (like 5,000 seconds) but pathetic thrust (like 14 kiloNewtons).
What is interesting is that you can use it on Earth for electrical power generation. Just direct the exhaust through a magnetiohydrodynamic generatior, and you have a fusion power reactor.
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Thanks, Scoundrel!
I've uploaded a new version that fixes the Eve miscalculation, go back to the first post.
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I would be so happy that First Contact had been achieved.
Maybe it has. Have you ever seen "The Leader" from Marvel Comics?
http://marvel.wikia.com/Samuel_Sterns_(Earth-91119)
Remind you of somebody?
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Any plans for interplanetary transfer "porkchop plots" in the near future? I know someone else was talking about an interactive program that could generate some on the forums before the Forum Kraken came through, but it doesn't seem to have made much progress lately.
That would be nice but it is a task way above my pay grade. It would make mission planning so much easier.
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Yeah, Eve is around 10.5km/s for takeoff from sea level. For stopping in atmosphere, it's not much more than the amount you need to stop from terminal velocity so tends to be ~150m/s for kerbin.
It's also not at all clear what the mass ratio is refering to, is that the average ratio across the whole burn or the amount that would be required in a single stage? Neither seem to particularly match up.
The way I understand it the mass ratio is the effective starting mass ratio, with effective meaning with multi-staging taken into account and starting meaning at the start of the burn.
I made honorable mistake in the case of Eve. The source I was using said liftoff/landing was 12000 m/s, I programmed it as 1200 m/s. My mistake.
That's a great idea! It gives a great way of seeing how much delta-v you'll need. My only suggestion is to maybe remove some of the massively huge exhaust velocities/delta-v on the upper edge of the chart, as I don't think they're super necessary for the average player, as the nuclear engine makes it only halfway up the scale. Of course, I have no idea how you calculated this, so I don't know if you're able to chop off half of the chart and scale it.I also don't think that Eve requires only 1.2 km/s to take off, I believe it's harder to take off from than Kerbin. I don't know specific delta-v values, but I would think that it would be pretty high, around 10 km/s?
One last suggestion, maybe colour-code the values? Maybe have different colours for different planetary systems? i.e. Purple for Eve and Gilly, blue for Kerbin, Mun, & Minmus, etc.
Regardless, I think this is a fantastic map, and it gives a good benchmark to aim for when designing rockets!
The main reason for the massively huge values at the top of the Isp chart is so I could add the Ion drive (Isp 4200 seconds, exhaust velocity 41,200 m/s). The main reason for the massively huge values at the top of the delta V chart is because I thought it would be cute to list the liftoff/landing value for Jool, not that anybody could actually do that.
The main problem I have with the delta V chart is where exactly do I chop it off? You can use this chart for a "grand tour" mission, where you would add up the required delta V for each segment of the mission, and see if the spacecraft had enough delta V to do the entire mission. Right now the delta V chart is chopped of roughly at the point where the Ion drive isp is connected to a mass ratio of 10.
For that matter, what is the logical place to chop off the mass ratio scale? Keeping in mind that multi-staging can make the effective mass ratio pretty large.
I could color-code the values, but of course that makes it harder to print out. I was thinking about the poor elementary science teacher with no budget.
Thoughts?
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You list Eve Liftoff/Land at 1,200 m/s delta-v. That's very high for landing (because the atmosphere will do a lot of slowing for you) and very low for liftoff (because the atmosphere will do a lot of slowing against you). Eve also has the highest planetary surface gravity in the game.
Yes, aerobraking is a problem. What would you specify as average values for liftoff and landing?
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We'd have to be in awe at the speed at which they develop and the ease at which they launch moon missions/interplanetary missions.
Not to mention how relatively indestructible they are. Being marooned on an airless planet is more prolonged boredom instead of a death sentence.
Xb-70
in The Lounge
Posted
One airman said that the XB-70 looked like a cobra sitting on a crate.