You could just cover your behind and say that going to full impulse interacted with some "trinimbic turbulence" or something and presto:
Environmental effects of various propulsion systems
- Thread starter Nerys Ghemor
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You could just cover your behind and say that going to full impulse interacted with some "trinimbic turbulence" or something and presto:
I'm not sure what full impulse while in atmosphere would be, speed-wise. I've already established it as being really, really damn fast in space, perhaps even near light speed. (However, I can certainly say that impulse is nowhere near as effective in atmosphere, and would not reach such speeds.)
Under your theory of impulse, would you expect damage to anything unshielded (and possibly to shielded facilities) on the ground? I'd figure even the sonic boom alone would be pretty nasty.
Heh...I KNEW someone was going to post that...
Given the acceleration rates of impulse engines, I think it would be no problem for any starship to escape the piddly gravity of a planet. Even if it were actually on the surface. Or in the core, really.
If impulse engines are just opened fusion reactors using a deuterium-deuterium cycle, then Timo's right, you've just got ionized hydrogen and helium. The former will burn with the oxygen in the atmosphere, I suppose, so the ship would likely leave a trail of really really hot steam.
Would we see EMP effects from this?
Incidentally, is it really correct to treat impulse as an acceleration and not a speed?
I know the show does it all the time, but it could still represent an acceleration level--technically speaking, the speed of the object can be anything between 0 and arbitrarily close to c, it just depends on the amount of the acceleration.
D'oh, this is what I get for not reading whole threads or dates.
I do think there might be an electromagnetic pulse from the operation of an impulse engien inside a planetary magnetic field. If you're not looking for real numbers (and I don't blame you), I'd say run with EMP.
And if you really want to go nuts, we are talking about a drive system which may propel a starship up to high relavistic velocities in a matter of minutes... that's incredible force. Have the exhaust blow off the atmosphere.
Definitely not looking for real numbers. Like the show itself, I'm looking more to tell a good character and action story with a veneer of science just thick enough to avoid serious mockery. 
So I see four or five possible effects, some of which might be seen simultaneously, if I'm reading this correctly:
1) An EMP in a high-altitude burst, which would disrupt any electronic equipment not heavily shielded, for hundreds of miles around the site and probably get even more destructive since it's sustained as the ship gains altitude, to the point where an entire continent could be affected.
2) Possible plasma discharges from the ship (shields may be involved as well) in the form of such phenomena as St. Elmo's fire, ball lightning, or maybe even flat-out LIGHTNING lightning, as seen in thunderstorms. These would be disruptive to other atmospheric craft nearby, as well as to buildings and vegetation in the immediate area should any of it go ship-to-ground and set anything on fire.
3) Sonic boom. And we're talking about something a lot bigger than the space shuttle here, and (in my unprofessional estimation) something even more likely to generate some very destructive booms due to not being aerodynamically designed. It would seem to me that even with the Intrepid-class, which is designed to land (and is probably sized fairly similarly to the Galor), that aerodynamic properties must come (in-universe) from some trick of shield configuration and possible antigrav units rather than from any sort of aerodynamic design. So this warship certainly would not be designed for mitigation of sonic booms.
4) (And this one I'm still debating on) You seem to suggest another form of shockwave as a result of hitting relativistic velocities. I'm not sure I want to go with blowing off the entire planet's atmosphere, but is it possible for there to be a shockwave severe enough that you could be looking at meteorological disruptions for years after the event? (Is asteroid damage, such as the Cretaceous extinction event, a reasonable precedent or no?)
5) (Also debating this) It's been suggested the superheated exhaust itself could do damage on the ground in the immediate area of the maneuver.
And one last one that pops into my head.
6) HOW did the Probe in Star Trek IV do its damage to Earth's weather patterns? One thing I distinctly remember is that it's said that the atmosphere was ionized. Could the mechanism that caused all that damage be at all similar to the effects of going to impulse in atmosphere?
Basically...I want there to be reasons this maneuver would be banned by many governments and that, like going to warp in a gravity well, only a very desperate individual would do it even if they hailed from one of those worlds that didn't have an outright ban.
So I see four or five possible effects, some of which might be seen simultaneously, if I'm reading this correctly:
1) An EMP in a high-altitude burst, which would disrupt any electronic equipment not heavily shielded, for hundreds of miles around the site and probably get even more destructive since it's sustained as the ship gains altitude, to the point where an entire continent could be affected.
2) Possible plasma discharges from the ship (shields may be involved as well) in the form of such phenomena as St. Elmo's fire, ball lightning, or maybe even flat-out LIGHTNING lightning, as seen in thunderstorms. These would be disruptive to other atmospheric craft nearby, as well as to buildings and vegetation in the immediate area should any of it go ship-to-ground and set anything on fire.
3) Sonic boom. And we're talking about something a lot bigger than the space shuttle here, and (in my unprofessional estimation) something even more likely to generate some very destructive booms due to not being aerodynamically designed. It would seem to me that even with the Intrepid-class, which is designed to land (and is probably sized fairly similarly to the Galor), that aerodynamic properties must come (in-universe) from some trick of shield configuration and possible antigrav units rather than from any sort of aerodynamic design. So this warship certainly would not be designed for mitigation of sonic booms.
4) (And this one I'm still debating on) You seem to suggest another form of shockwave as a result of hitting relativistic velocities. I'm not sure I want to go with blowing off the entire planet's atmosphere, but is it possible for there to be a shockwave severe enough that you could be looking at meteorological disruptions for years after the event? (Is asteroid damage, such as the Cretaceous extinction event, a reasonable precedent or no?)
5) (Also debating this) It's been suggested the superheated exhaust itself could do damage on the ground in the immediate area of the maneuver.
And one last one that pops into my head.
6) HOW did the Probe in Star Trek IV do its damage to Earth's weather patterns? One thing I distinctly remember is that it's said that the atmosphere was ionized. Could the mechanism that caused all that damage be at all similar to the effects of going to impulse in atmosphere?
Basically...I want there to be reasons this maneuver would be banned by many governments and that, like going to warp in a gravity well, only a very desperate individual would do it even if they hailed from one of those worlds that didn't have an outright ban.
It stands to reason that the TOS Enterprise used her impulse engines to exit the atmosphere once she had beamed Captain Christopher from his F-104. Now, TOS didn't have the budget to show anything, but neither did anyone comment about untoward effects from operating such engines on what would be considered "primitive" technology (like EMP) so I am guessing you'd be okay...
^The only time I ever run real numbers is in time-of-travel calculations. Speed of plot annoys me. Also, for sublight, there a number of relativistic calculators available that make this a cinch. Anything beyond that is beyond my capabilities. More 
than 
I guess. 
The question here is whether the impulse engine has such fine control that it can be regulated to produce just enough acceleration to throw a half-million ton starship into orbit (and this is still a tremendous amount of energy that should have local impact) or if it has a certain specific fusion point where the lowest possible power at which it could be operated is enough to create damage on a regional scale.
If your guys are running from something, this might not even matter, as they would simply order full impulse power without considering the impact on the planet.
Unfortunately, we don't know precisely how powerful impulse drive is. There is substantial evidence to show that it utilizes a low-powered warp field (the most critical piece of evidence, to my mind, is that the ship would need so much deuterium fuel to get up to relativistic speeds the deuterium need be either super-compressed or the ship super-huge). The contravening suggestion is that if they're using a warp field, why bother with the impulse exhaust at all? We know warp fields are propulsive.
Actually, I know I said I didn't run the numbers, but if my reasoning is correct (it may not be), then a billion tons of starship would require 280 billion tons of deuterium fused at perfect efficiency to attain half the speed of light... yikes.
(For those interested, my reasoning is that the kinetic energy of a billion-ton starship at .5c is E = .5mv^2 is 7.5X10^25 Joules... and assuming a .03% mass-energy conversion of the deuterium, that amount of fuel would need be expended to feed that much kinetic energy into the ship. I might be approaching the problem from a flawed premise and would love to be corrected.)
This would require, for a fuel cell of 200,000 cubic meters, a density of 140 million kilograms per square meter... a tad less than ten times the density at the heart of the sun. But less than the density of a neutron star, so at least we wouldn't have to imagine they're keeping the fuel so compressed it's developing degeneracy pressure against the seal. But at such a density it's fusing all the time, unless in addition to being masters of gravity, Trek denizens are masters of the strong nuclear force.
But, of course I'm not factoring in the weight of fuel itself, which increases the weight of fuel required to push the fuel to be expended later! And... I've reached my limit for math for the evening.
On the plus side, we're not sure that impulse = .5c. It could be far lower.
That seems very reasonable, especially if the impulse engines are pointed directly at the ground.
than I guess. The question here is whether the impulse engine has such fine control that it can be regulated to produce just enough acceleration to throw a half-million ton starship into orbit (and this is still a tremendous amount of energy that should have local impact) or if it has a certain specific fusion point where the lowest possible power at which it could be operated is enough to create damage on a regional scale.
If your guys are running from something, this might not even matter, as they would simply order full impulse power without considering the impact on the planet.
Unfortunately, we don't know precisely how powerful impulse drive is. There is substantial evidence to show that it utilizes a low-powered warp field (the most critical piece of evidence, to my mind, is that the ship would need so much deuterium fuel to get up to relativistic speeds the deuterium need be either super-compressed or the ship super-huge). The contravening suggestion is that if they're using a warp field, why bother with the impulse exhaust at all? We know warp fields are propulsive.
Actually, I know I said I didn't run the numbers, but if my reasoning is correct (it may not be), then a billion tons of starship would require 280 billion tons of deuterium fused at perfect efficiency to attain half the speed of light... yikes.
(For those interested, my reasoning is that the kinetic energy of a billion-ton starship at .5c is E = .5mv^2 is 7.5X10^25 Joules... and assuming a .03% mass-energy conversion of the deuterium, that amount of fuel would need be expended to feed that much kinetic energy into the ship. I might be approaching the problem from a flawed premise and would love to be corrected.)
This would require, for a fuel cell of 200,000 cubic meters, a density of 140 million kilograms per square meter... a tad less than ten times the density at the heart of the sun. But less than the density of a neutron star, so at least we wouldn't have to imagine they're keeping the fuel so compressed it's developing degeneracy pressure against the seal. But at such a density it's fusing all the time, unless in addition to being masters of gravity, Trek denizens are masters of the strong nuclear force.
But, of course I'm not factoring in the weight of fuel itself, which increases the weight of fuel required to push the fuel to be expended later! And... I've reached my limit for math for the evening.
On the plus side, we're not sure that impulse = .5c. It could be far lower.
That seems very reasonable, especially if the impulse engines are pointed directly at the ground.
If I recall the TNG tech manual right, the impulse engines use "mass driver coils" or some such thing to lighten the mass of the ship or something. I dunno. I don't think "Warp drive" as we know it is the solve-all answer to all propulsion needs.
Of course, if they were light-horsepower warp drives, it would justify the retarded impulse placement on some starship designs, as they would merely be heat dissipator thingies.
Hmm, when you would lower the mass of the ship you would lower the mass of your fuel and also that of the stuff of what comes out of the impulse exhaust so everything would remain the same, another point for them to be strictly a fusion reactor powered coil drive, also that would explain a few faster then light "incidents" while there was no warpdrive available etc, yes, it does explain the rather bogus placement of impulse engine exhaust on some ships and ships who don't have them like the D'Deridex class and the Nebula class for example. 
^The only time I ever run real numbers is in time-of-travel calculations. Speed of plot annoys me. Also, for sublight, there a number of relativistic calculators available that make this a cinch. Anything beyond that is beyond my capabilities. More
The question here is whether the impulse engine has such fine control that it can be regulated to produce just enough acceleration to throw a half-million ton starship into orbit (and this is still a tremendous amount of energy that should have local impact) or if it has a certain specific fusion point where the lowest possible power at which it could be operated is enough to create damage on a regional scale.
If your guys are running from something, this might not even matter, as they would simply order full impulse power without considering the impact on the planet.
Unfortunately, we don't know precisely how powerful impulse drive is. There is substantial evidence to show that it utilizes a low-powered warp field (the most critical piece of evidence, to my mind, is that the ship would need so much deuterium fuel to get up to relativistic speeds the deuterium need be either super-compressed or the ship super-huge). The contravening suggestion is that if they're using a warp field, why bother with the impulse exhaust at all? We know warp fields are propulsive.
That's why I'm not too sure of the theory that impulse = low-powered warp drive, and I think I'd rather stick to the theory that it's something else.
And you're right that this is a situation where the impact to the planet is not going to be given a lot of consideration. It's an outpost--no native sentient species, only colonists. Now, Feddies might have qualms about torching the flora and fauna, but I don't see just everyone in the galaxy getting their knickers in a wad about setting a forest fire, or perhaps even about causing an extinction to non-sentients.
Now, from what we've seen about the use of impulse drive, it seems they can set whatever speed they want when using it in space. But it seems the question is, what is minimum impulse? Is it the space equivalent of idling at a traffic light--or do you go straight from a standstill to relativistic speeds? I think that's where we'd get evidence that would tell us how precise the control over an impulse drive is.
So do you think we'd be looking at some kind of outright firestorm on the ground? Or something less than that?
Depends on the distance. If it's in the upper atmosphere already, no.
Yeah, but it can't just be a rocket, as the analysis shows... unless it is hugely slower than we think, in which case its environmental effects might be negligible.
Actually, it occurs to me, since we have a specified number on the power of a Constitution class impulse drive, we could really derive an accurate maximum acceleration for the Connie...
Yeah, but it can't just be a rocket, as the analysis shows... unless it is hugely slower than we think, in which case its environmental effects might be negligible.
Actually, it occurs to me, since we have a specified number on the power of a Constitution class impulse drive, we could really derive an accurate maximum acceleration for the Connie...
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One scifi concept I use frequently is called Jon's Law, which states that anything powerful enough to make an interesting propulsion system is also a weapon of mass destruction. As a practical application: if your ship is equipped with, say, some kind of enormously powerful fusion drive, you have to be careful that there's nothing valuable behind you when you fire up your engines, lest you accidentally vaporize your space dock at the moment of ignition.
Since warp drive is a reactionless drive, there shouldn't be any kind of recoil effects on the surrounding environment since the drive requires constant power to remain active. On the other hand, the amount of energy it takes to drive a starship at a million kilometers per second could easily drive a mountain at one kilometers per second; if you activate your warp drive within a planet's atmosphere or too close to the ground, there's bound to be some downwash as a mass of air is suddenly accelerated to close to the speed of light, and your ship warps into orbit to suddenly discover a five billion megaton fireball rising off the launch pad.
In the movie they mentioned something about intense electromagnetic waves emanating from the probe, but that couldn't be the cause because ionizing radiation of that intensity would kill everything on the planet pretty much instantly.
The follow-on book had as an explanation something to do with the probe's communication method; apparently it was using a type of intense tractor beam to physically vibrate distant materials to make those sounds. This would have had an unintended effect on the atmosphere and electrical systems which behave very strangely when being physically grabbed and shaken at the molecular level.
Gamma ray photons would provide about as much thrust as a very powerful flashlight. There is no reason whatsoever they would be allowed to escape from the engine. More likely they'd be captured to continue irradiating the fuel products in the fusion reactors or otherwise converted into electrical energy.
If you want a reactant mass for thrust, you're looking for some heavy particles with alot of mass, which photons have only miniscule amounts of it. Impulse engines have subspace driver coils which gives you a reltivistic bang for your buck, but even then, for gamma ray photons to be used as thrust you'd be putting out enough radiation to vaporize the empire state building ten times a second, continuously, as long as the engine is active.
And as for the bump question:
Same problem with the warp drive. The subspace driver coils are screwing with the local laws of physics around your ship, but OUTSIDE that subspace field, all bets are off. Even if your ship can move through space at, say, .25C, it can't propell everything around it at the same speed; at best, it can create a bubble of space around it in which .25C is actually something like sixty kilometers per hour, but that bubble and everything it it will eventually collide with whatever's outside it.
So if you go to full impulse in an atmosphere, you're generating a shock powerful enough to flatten mount everest, followed by a vortex that immediately blows everything on the launch pad into satellite orbit in your wake.
So it wouldn't be anything as subtle as Saint Elmo's fire... more like the backblast effect from Firefly, only large enough to incinerate a small continent.
Same problem with the warp drive. The subspace driver coils are screwing with the local laws of physics around your ship, but OUTSIDE that subspace field, all bets are off. Even if your ship can move through space at, say, .25C, it can't propell everything around it at the same speed; at best, it can create a bubble of space around it in which .25C is actually something like sixty kilometers per hour, but that bubble and everything it it will eventually collide with whatever's outside it.
So if you go to full impulse in an atmosphere, you're generating a shock powerful enough to flatten mount everest, followed by a vortex that immediately blows everything on the launch pad into satellite orbit in your wake.
So it wouldn't be anything as subtle as Saint Elmo's fire... more like the backblast effect from Firefly, only large enough to incinerate a small continent.
Which is why the driver coils are mounted in the engines themselves, not somewhere else entirely like, say, buried in the saucer or the nacelle pylons. Impulse engines always face the rearward direction for a reason.
More likely the relationship between the exhaust products and the ship is is a conservation of energy type business; lowering the mass of the ship means raising the mass of the propellant by the same measure.
Yes, though it noted such a coil was not necessary until the Ambassador Class, so the TOS Enterprise should not have it.
"...waste heat and helium thats been expelled..." Thats called Tritium or Helium 3?
Fusion Reactors are going no where because they give off neutrons that decay the fusion containment module.
Ok, I really like this notion...
Through what mechanism is that accomplished, I wonder? Are the beings of Trek not only masters of electromagnetism, but the higgs field as well.
Hey, why not.Although this makes impulse nearly as complicated as a warp drive, it permits a reasonable amount of fuel (several millions of tons) to drive a starship at the speeds we would prefer (quarter-c up to arbitrarily close to the speed of light).
As an aside, I never really got how a warp field was supposed to lower mass, and even if it could, so what? Even if mass is zero, it's still limited to the speed of light.
I dunno, I like to believe that warp, involving intense gravitational fields, has got to be immensely dangerous to planetary bodies. And yet Trek has been inconsistent on that to an extreme level, where in TMP and and Best of Both Worlds and DS9 going to full warp inside a solar system at all is dangerous, but in TVH it's cool to go to maximum warp not only inside a solar system but inside an atmosphere!
I like the ones where the exhaust strikes the nacelle struts. Genius. The Sovereign comes a little too close for comfort on that count, in that you have to assume the jet is a trapezoidal prism as it leaves the impulse engines.
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