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Orion Drive

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bibliophile20 bibliophile20's picture
Orion Drive
The Orion Drive. One of the craziest awesome drive technologies available. Instead of containing a chemical or plasma-based explosion and sending the exhaust plume out to rocket you in the opposite direction, like in plasma or chemical rockets, dropping nukes out behind you and riding the shock wave. Now, needless to say, this is a very wasteful, very hazardous method of travel. But, if you have the spare uranium and a distinct lack of concern for the local traffic (and happen to be in a tearing hurry), you could make use of this sort of thing. So, three questions: A) is this sort of tech feasible in EP? B) Is it more efficient/faster than other forms of rocket transport? C) If yes to A & B, what kind of performance would it give? Game background:
Spoiler: Highlight to view
I have my players in an exoplanetary system via Pandora Gate; it's a t-tauri system, with a baby M-class star and a debris disc. In the debris disc are a bunch of habitats with captive transhumans inside, left there by a TITAN (which is currently en route to the baby star next door, 13 light months away, in a Bussard Ramjet with a cargo of a computational structure 2500 km in diameter. It's been merrily sucking down the nebula's ambient hydrogen on its way and is going a noticeable fraction of c, away from this system). My players have determined that they want to rescue all of the transhumans before the TITAN could get back. So, they're turning a Mercury-type planet that they found in another system into an exponentially growing mining colony, setting up breeder reactors, shipping the fissiles through the gate, and are going to be manufacturing fast transports loaded with hibernation pods (with a [url=http://www.farcastblog.com/2013/11/309-macroforge.html]Macroforge[/url] that they've named Galactus, because it eats planetesimals). So, rather than waste oodles of hydrogen gas as fuel for plasma rockets, they want to know if they can get away with wasting oodles of plutonium and uranium instead, and if that'll get them any performance increase while they fly around a spherical space of ~250 cubic AU to rescue ~300,000 transhumans scattered in 99 fragile habitats. If not, then they'll just mine the proto-planetary disc for hydrogen while saving the fissiles for a missile wave to send towards any hostile TITAN artifacts left in the system. My reaction to this plan: o_o -_- O_O ^_^ I love my players. (Also heard tonight: "This plan explains all of your e-rep scores." "I know! It's like we're burning e-rep." "Hey! We're fueling the rockets with burning e-rep!")

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

ORCACommander ORCACommander's picture
well considering the high
well considering the high demand for fissionables for energy production for colonies and habitats i'd say orion drives would be very uncommon and probably would be variants on the fast couriers that use antimatter propulsion [img]http://www.nasa.gov/centers/glenn/images/content/84510main_warp07.gif[/img] http://www.nasa.gov/centers/glenn/technology/warp/scales.html unfortunately at the time of writing eclipse phase we did not have that massive mathematical breakthrough in warp drive engineering that took the required energy mass down from a Jupiter mass to that of several tons plutonium so it never made it into the book. then again the books keep on saying we lost a lot of tech in the fall
nezumi.hebereke nezumi.hebereke's picture
The warp drive engineering is
The warp drive engineering is extremely theoretical. Even assuming it's possible, and I'm not convinced it is, it's a long way off. You could introduce a warp-drive experimental ship as a plot device, but as standard ships available to truckers and such? Not likely. Regarding Orion, my understanding is it's just 'detonate a bunch of bombs and ride the shock wave'. In which case the answer is yes, but that doesn't mean it's easy, even by transhuman standards. The mining and enrichment processes take a LOT of manhours and brain-work to set up, plus building a ship strong enough to withstand the acceleration (and worse, the radiation), a dependable nuclear bomb design ... Plus they're digging up virgin material, so there's time for the supply chain. Even at transhuman speeds, we're talking years for everything. I'd let them cut it down to months, but they're going to need some MAJOR resources, far more than five people and a few builder swarms.
Micah_Hakubi Micah_Hakubi's picture
First off, I envy your
First off, I envy your players. Second off, going by everyone's favorite site, Atomic Rockets, Orion Drives are best utilized for lifting heavy payloads into orbit.
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The sad little secret about Orion is that the mission it is best suited for is boosting heavy payloads into orbit. Which is exactly the mission that the enviromentalist and the nuclear test ban treaty will prevent. Orion has excellent thrust, which is what you need for lift-off and landing. Unfortunately its exhaust velocity is pretty average, which is what you need for efficient orbit-to-orbit maneuvers. Having said that, there is another situation where high thrust is desirable: a warship jinking to make itself harder to be hit by enemy weapons fire. It is also interesting to note that the Orion propulsion system works very well with the bomb-pumped laser weapons system. ... Each charge accelerates the spacecraft by roughly 12 m/s. A 4,000 ton spacecraft would use 5 kiloton charges, and a 10,000 ton spacecraft would use 15 kiloton charges. For blast-off, smaller charges of 0.15 kt and 0.35 kt respectively would be used while within the Terra's atmosphere. The air between the charge and the pusher plate amplifies the impulse delivered. A 5 kiloton charge is about 1,152 kg. ... In other words, if you can believe their figures, the advanced Orion could carry a payload of 1,300 tons (NOT kilograms) to Enceladus and back!
You can find out more here, just scroll down to 'Pulse:Orion' http://www.projectrho.com/public_html/rocket/enginelist.php
ORCACommander ORCACommander's picture
*finally reads over the game
*finally reads over the game section* ok they have a mercury type planet and instead of manufacturing antimatter they are enriching fissionables? on a side note i hope they have good psychosurgeons and quarantine procedures. I am a afraid i must agree with the environmentalists though. unless we can make fission happen without x-rays and hard gamma not to mention the fall out nuclear thrust would be a disaster within planetary confines.
bibliophile20 bibliophile20's picture
ORCACommander wrote:*finally
ORCACommander wrote:
*finally reads over the game section* ok they have a mercury type planet and instead of manufacturing antimatter they are enriching fissionables?
Yep. And I've got two PCs who have been actually cackling (well, one has, but he's been making up for the taciturn AGI in spades) about getting to use their "Profession: Prospector" and "Profession: Resource Extraction" skills. Another has massively high Hardware: Industrial and various other skills. Suffice it to say, I have no legit excuse to squashing their desires in that direction. (They're also getting the breeder reactors up and are going to use their output to make some rather epic antimatter factories, but that's further down the line--the thought was that fissiles will be easier and faster to produce in usable quantities than antimatter)
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on a side note i hope they have good psychosurgeons and quarantine procedures.
Yep. One PC spent a good chunk of last session making beta and delta forks of herself for psychotherapy, assessment and psychosurgery purposes.
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I am a afraid i must agree with the environmentalists though. unless we can make fission happen without x-rays and hard gamma not to mention the fall out nuclear thrust would be a disaster within planetary confines.
Well, fortunately, they're in a system that doesn't have any planets yet--and is being bombarded by x-rays and other radiation from the baby proto-star in the center.

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Decimator Decimator's picture
X-rays and such aren't an
X-rays and such aren't an issue, just don't stand next to the rocket. Even the fallout [url=http://nextbigfuture.com/2009/02/project-orion-nuclear-pulse-units-emp.h...'t a huge issue.[/url]
Chernoborg Chernoborg's picture
The whole campaign will be
The whole campaign will be running hot with a young star and lots of early planetesimals- no doubt nearly molten with isotopic decay! For getting things moving ASAP Orion would be ideal compared to production rates of antimatter or collection of hydrogen for plasma drives. For a down side , deceleration means lobbing clouds of fallout towards your evacuees! "Run for the shelter ! It's our rescuers!"
Spoiler: Highlight to view
Are you playing a Firewall game? Between the TITAN activity and making LOTS of nuclear bombs they might get flagged as an x-risk!
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ShadowDragon8685 ShadowDragon8685's picture
Chernoborg wrote:The whole
Chernoborg wrote:
The whole campaign will be running hot with a young star and lots of early planetesimals- no doubt nearly molten with isotopic decay! For getting things moving ASAP Orion would be ideal compared to production rates of antimatter or collection of hydrogen for plasma drives. For a down side , deceleration means lobbing clouds of fallout towards your evacuees! "Run for the shelter ! It's our rescuers!"
I'm familiar with his player's plans, as he bounced this off me before bringing it to the forum. They're planning to use metallic hydrogen for the close-in work when near a live habitat.
Quote:
Spoiler: Highlight to view
Are you playing a Firewall game? Between the TITAN activity and making LOTS of nuclear bombs they might get flagged as an x-risk!
Spoiler: Highlight to view
1: The group [i]are[/i] Firewall. 2: They've been sanctioned by Firewall to conduct this rescue op. 3: They're in an exosystem, so nobody gives a damn if they start lobbing nukes left and right. :)
Me, I have a theory as regards this whole scheme myself.
Spoiler: Highlight to view
They're harvesting almost all of the asteroid the Pandora Gate was on. That's going to leave it very small. After they're done with that, theoretically, their Orion heavy mover could cannibalize/cast off its no-longer nessessary rescue mission payload, abut and attach to the remaining rock the pandora gate is anchored to, and once they're all out system, start boosting it into a system escape trajectory. I reckon an orion drive should have a hell of a lot more delta-v than some cockamamie bushbot. If so, and if the gate tolerates being accelerated, that'd be a hell of a way to make sure they aren't followed.
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Hoarseman Hoarseman's picture
Usable during Fall Evacuation
As has been pointed out the Orion Drive works best for massive ships, it requires a lot of nukes and a total disregard for fallout. That sounds a bit like what desperate hyper-rich/hyper-corps/government-remnants might put together during the Fall. A massive spaceship would actually be easier as you could use more conventional heavy engineering techniques to slap it together, something like "if it doesn't hold together add more steel beams" as an engineering technique. If the Earth is already being taken over by TITANs and nukes have already been used, or are about to be used the fallout is not a big concern, after all the people on the ship are leaving and probably not planning on coming back anytime soon. Finally, a global breakdown and irregular war sounds like the perfect opportunity for those with connections and power to grab a bunch of low yield nukes or depending on the time scales just jack plutonium from a reprossessing facility. As an aside, one use for antimatter is catalyzing fusion reactions, ie. use small amounts of antimatter to trigger a fusion explosion. Matter/antimatter annihilation could produce the temps and pressures to fuse hydrogen and you would need much less antimatter per bang than a pure matter/antimatter explosion.