Andrew Boulton
The Adminator
Yeah, those are very nice ships.
A Universe without Artificial Gravity...
- Thread starter Scarecrow
- Start date
You need a very efficient fuel to thrust mechanism for traveller's mode of flight.
Local+1G will get you to orbit rather nicely, even if the first bit of the strip is limited by atmospheric drag.
It is even doable by modern technology; it is NOT practical.
Something similar to White Knight and SS1, but scaled up seems a pretty reasonable mode. Envision a 727 orbital lighter, and a 747-sized launch carrier. The useful payload is some 20-30 tons.
Now, as for long term thrust in system, Ion or Plasma drives will be nearly requisite; nothing else has ISP's high enough, save maybe Orion drives. Expect underway G's from Ion to be 0.1-0.5...
Traveller's gravitic based thruster plates make long-haul possible; gravitic dampening of thrust makes long trips safe.
BTW, 0.1G continuous thrust would cut earth-mars times drastically from modern coasting.
Local+1G will get you to orbit rather nicely, even if the first bit of the strip is limited by atmospheric drag.
It is even doable by modern technology; it is NOT practical.
Something similar to White Knight and SS1, but scaled up seems a pretty reasonable mode. Envision a 727 orbital lighter, and a 747-sized launch carrier. The useful payload is some 20-30 tons.
Now, as for long term thrust in system, Ion or Plasma drives will be nearly requisite; nothing else has ISP's high enough, save maybe Orion drives. Expect underway G's from Ion to be 0.1-0.5...
Traveller's gravitic based thruster plates make long-haul possible; gravitic dampening of thrust makes long trips safe.
BTW, 0.1G continuous thrust would cut earth-mars times drastically from modern coasting.
Scarecrow
SOC-14 1K
Colin, I hope that you were contacting this man when it comes around to doing the artwork for Ships. Simply amazing, this is what I would want to see more in Traveller! I know this is akin to Jessie's style but we see to few of that and this simply blows me away for starships. </font>[/QUOTE]I believe Hunter has him doing work for 2320. I could be wrong!
Crow
mike wightman
SOC-14 10K
Don't give up on it, I think it's a really good idea.
mike wightman
SOC-14 10K
Don't worry, there will be plenty of volunteers to do thatI just didn't want to have to rewrite the entire Traveller ships system.
First of all, you don't have to do away with artificial gravity to use a perpendicular deck plan: look at the Azhanti Hight Lightning or my "Clipper" and Type M designs
Even if you don't like deck gravity (I don't ) contra grav drives are a couple of orders of magnitude easier. Also is acceleration is dependent on the strength of the grav field you are working againts, porportional the square of dikstance. So a drive that can give you 4 G in LEO yields only 0.00001 G at 100 diameters.
So I can see grav drives for planet-to orbit vehicles, but jump vehicles are low-g only vehicles with centrifuges. Military vehicles might have some kind of plama drive to get 0.01 G at a distance from a planet.
Even if you don't like deck gravity (I don't ) contra grav drives are a couple of orders of magnitude easier. Also is acceleration is dependent on the strength of the grav field you are working againts, porportional the square of dikstance. So a drive that can give you 4 G in LEO yields only 0.00001 G at 100 diameters.
So I can see grav drives for planet-to orbit vehicles, but jump vehicles are low-g only vehicles with centrifuges. Military vehicles might have some kind of plama drive to get 0.01 G at a distance from a planet.
Scarecrow
SOC-14 1K
Fair comment. I guess what I'll do is take a standard Traveller ship design spec (200-300 dTons) and simply do perpendicular plans for it. The rest is up to the end user, as they say.
My plan is for three designs. One conical, based on the Banking Clan starship from Attack of the Clones ('Aim for the fuel tanks.' 'Good call, My young Padawan') which inspired this burst of creativity in the first place.
Another in a similar vein that would unite essentially three rocket shapes in a triaxial layout and finally, a transformer-like, streamlined vessel that would have fold out arms with hab modules on allowing them to rotate and create centripetal gravity whilst outside a gravity well.
I've just had an idea for a cruciform shape too.... so many ideas, so little time!!!!!
Crow
My plan is for three designs. One conical, based on the Banking Clan starship from Attack of the Clones ('Aim for the fuel tanks.' 'Good call, My young Padawan') which inspired this burst of creativity in the first place.
Another in a similar vein that would unite essentially three rocket shapes in a triaxial layout and finally, a transformer-like, streamlined vessel that would have fold out arms with hab modules on allowing them to rotate and create centripetal gravity whilst outside a gravity well.
I've just had an idea for a cruciform shape too.... so many ideas, so little time!!!!!
Crow
Colin, I hope that you were contacting this man when it comes around to doing the artwork for Ships. Simply amazing, this is what I would want to see more in Traveller! I know this is akin to Jessie's style but we see to few of that and this simply blows me away for starships. </font>[/QUOTE]Laurent IS doing the starship illos for 2320AD. I've been in touch with him for months about it. In fact, I even changed some of the ships to match his illos.
Colin
Of course, since it is only a few hours until 100 diameters passengers can stay in airline-style seating the the crew walking on the "walls" until jump and spin-up of the hab.
1 rpm is needed for long term habitation and luxery liners. 2 rpm for "economy" accomodations, 3 rpm for cargo crews
1 rpm is needed for long term habitation and luxery liners. 2 rpm for "economy" accomodations, 3 rpm for cargo crews
Madarin Dude
SOC-13
A perpendicular layout of the decks would also have to take into account that for all the acceleration there must be deceleration. There are 3 approaches that I can think of.
1. Have both the floor and the ceiling habitable and have stairwells like out of a Escher painting. Upon changing from accel to decel mode you change which side you live on.
2. Have the engines able to rotate so they are firing in the opposite direction when you are slowing down. (or have seperate decel engines firing thru the front of the ship.)
3. Have the habitable levels reverse direction when the mode changes from accel to decel.
Now add spin grav and you have a mess.
1. Have both the floor and the ceiling habitable and have stairwells like out of a Escher painting. Upon changing from accel to decel mode you change which side you live on.
2. Have the engines able to rotate so they are firing in the opposite direction when you are slowing down. (or have seperate decel engines firing thru the front of the ship.)
3. Have the habitable levels reverse direction when the mode changes from accel to decel.
Now add spin grav and you have a mess.
mike wightman
SOC-14 10K
How about just rotating the ship through 180 degrees?
mike wightman
SOC-14 10K
And while I remember to ask, the old Star Frontiers game had ships with perpendicular deck arrangements, didn't they?
Yup.
Or, more correctly, the two or three published designs did.
The Assault scouts didn't, but the axis of thrust put the pilot on his back with his legs elevated, one of the better ways to take G's.
Madarin: None of the above are needed. Just like the Apollo mission, they'll just sing the rear around.
your options are problematic
#1: the transition THROWS people at the other side.
#2: added and unneeded additional complexity for gain of a minute or two, at most, in redirection of thrust, PLUS reduced certainty of thrust axis, essential for thrust level corrections.
#3: If you're doing spin grav, you can just pivot the spin pods at the arm end, such that the combination of thrust and spin reorients the floor. This is added complexity. It is, however, one where the benefit is useful.
All current spacecraft proposals use on-center-line thrust for a number of good reasons: it makes it easy to calculate expected trajectory. Podded thrusters on pylons give greater moement for turning, but are absolutely no benefit over CL thrust otherwise, and additionally are more subject to damage, add pylon weight, add fuel delivery complexity, and add another series of stress points.
If you're going to do perpendicular decks sans A/G, the best drive is the Ion Thruster. The ISP is absolutely INCREDIBLE, it's real world, and it works.
Drawback to Ion thrust is the low thrust to mass of the drive itself; assuming some TL breakthroughs, it should go up a couple orders. (Current 5+kg units are delivering low 3 digit newtons (1g/1m/s/s).) So peak thrust for "Fast Ion" is going to be around 2G, a point where sustained operations are possible, though not advisable.
Or, more correctly, the two or three published designs did.
The Assault scouts didn't, but the axis of thrust put the pilot on his back with his legs elevated, one of the better ways to take G's.
Madarin: None of the above are needed. Just like the Apollo mission, they'll just sing the rear around.
your options are problematic
#1: the transition THROWS people at the other side.
#2: added and unneeded additional complexity for gain of a minute or two, at most, in redirection of thrust, PLUS reduced certainty of thrust axis, essential for thrust level corrections.
#3: If you're doing spin grav, you can just pivot the spin pods at the arm end, such that the combination of thrust and spin reorients the floor. This is added complexity. It is, however, one where the benefit is useful.
All current spacecraft proposals use on-center-line thrust for a number of good reasons: it makes it easy to calculate expected trajectory. Podded thrusters on pylons give greater moement for turning, but are absolutely no benefit over CL thrust otherwise, and additionally are more subject to damage, add pylon weight, add fuel delivery complexity, and add another series of stress points.
If you're going to do perpendicular decks sans A/G, the best drive is the Ion Thruster. The ISP is absolutely INCREDIBLE, it's real world, and it works.
Drawback to Ion thrust is the low thrust to mass of the drive itself; assuming some TL breakthroughs, it should go up a couple orders. (Current 5+kg units are delivering low 3 digit newtons (1g/1m/s/s).) So peak thrust for "Fast Ion" is going to be around 2G, a point where sustained operations are possible, though not advisable.
mike wightman
SOC-14 10K
The plasma rocket is another viable contender.
Sig: Agreed, but the plasma rocket is going to be far more constrained by fuel than is the ion drive. The iod drive can conceivably have 3 YEARS of fuel on board, plus useful cargo space. The minimal amount of fuel carried aboard DS1 is a years worth of thrust... or more.
Of course, that is about a 1% drive, and is producing 0.001G, at TL8, with minimal power input (Drastic for a solar panel or Radio-thermal decay generator, but those are WEAK power sources). With a higher power power source, it could get up to about 10x more efficient with current tech, if I understood the whitepaper on it correctly.
So, given large, high energy reactors, and 10% drives, we could conceivably see a 0.1G CONSTANT thrust with a duration of over a year. More than adequate for TL8 expectations.
(FF&S numbers predate any real-world public use of ion drives in space).
Of course, that is about a 1% drive, and is producing 0.001G, at TL8, with minimal power input (Drastic for a solar panel or Radio-thermal decay generator, but those are WEAK power sources). With a higher power power source, it could get up to about 10x more efficient with current tech, if I understood the whitepaper on it correctly.
So, given large, high energy reactors, and 10% drives, we could conceivably see a 0.1G CONSTANT thrust with a duration of over a year. More than adequate for TL8 expectations.
(FF&S numbers predate any real-world public use of ion drives in space).
mike wightman
SOC-14 10K
Good point on the fuel requirements, but if you want to achieve 1G+ then I can't see an ion drive getting there without morphing into a plasma rocket.
I found a serious discussion while googling for constricting the plasma sufficiently to get a fusion reaction
- fusion rockets anyone?
I found a serious discussion while googling for constricting the plasma sufficiently to get a fusion reaction
- fusion rockets anyone?
1G+, in a context of space travel, is undesirable save as a take-off drive, wherein a plasma rocket is undesirable due to environmental concerns, and an Ion Drive is impractical (requires a very low atmospheric pressure).
Y'see, humans need gravity; we don't know scientifically just how much, but even 10% is medically far safer than micro. and a constant burn capability is essential; plasma drives will deprive useful payload if set for interplanetary use, or will require coasting along hohman transfer orbits; coasting is BAD.
Both are deep space drives. The Ion drive uses much denser fuels, and is using high-acceleration; by TL 15, I'd expect the end result to be not dissimilar to a plasma rocket. By using denser fuels, however, the Ion Drive saves on VOLUME, which saves on structural materials costs/weights.
Several methods exist for getting up there. Not the least of which is "unpowered displacement flight", better known as balloons, blimps, and dirigibles. Since balloons can get one to seriously thin air (20KM or roughly 65Kfeet, IIRC), you can ballon up to altitude, launch a reusable transfer rocket, ala SS1, and that transfer rocket-plane can then ion-drive once in low orbit. Cheap, replicable flight.
I'd figure many craft would have a small plasma drive for "critical maneuver", and a decent ion drive for long term thrust.
Y'see, humans need gravity; we don't know scientifically just how much, but even 10% is medically far safer than micro. and a constant burn capability is essential; plasma drives will deprive useful payload if set for interplanetary use, or will require coasting along hohman transfer orbits; coasting is BAD.
Both are deep space drives. The Ion drive uses much denser fuels, and is using high-acceleration; by TL 15, I'd expect the end result to be not dissimilar to a plasma rocket. By using denser fuels, however, the Ion Drive saves on VOLUME, which saves on structural materials costs/weights.
Several methods exist for getting up there. Not the least of which is "unpowered displacement flight", better known as balloons, blimps, and dirigibles. Since balloons can get one to seriously thin air (20KM or roughly 65Kfeet, IIRC), you can ballon up to altitude, launch a reusable transfer rocket, ala SS1, and that transfer rocket-plane can then ion-drive once in low orbit. Cheap, replicable flight.
I'd figure many craft would have a small plasma drive for "critical maneuver", and a decent ion drive for long term thrust.
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