Why give it for 1G only, when there's a formula, and ships have a variety of acceleration factors?
I suspect the real answer is that they were trying to avoid saying, "yes, ships have artificial gravity" outright.
1g Ships and Size:7 worlds...
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I suspect the real answer is that they were trying to avoid saying, "yes, ships have artificial gravity" outright.
AnotherDilbert
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Yes, they are carefully not saying anything specific in LBB2, hence we don't know.
Would I assume some magic maintained an artificial gravity field in the ship? No.
Then comes LBB5, do we assume it discusses an entirely different reality, physics, and tech base? No, we don't, well at least I don't.
We still don't know anything more than that they exist. Whatever you assume is your assumption, not dictated by the game.
If I wanted to know more about them, I would look in MT or TNE where they are defined. Before they came out, I accepted that I didn't know.
Do you mean turning or spinning around it's own axis? If you spin them too quickly, I would guess bad things would happen, just as in current aircraft. I would not assume some unspoken magic would save the pilot from a blackout or crash.
If we have already read LBB5, we would know the tech existed, but we would not know how to implement it in our vehicles, either grav or winged.
Would you assume a current jet fighter has internal gravity, since it can easily incapacitate the pilot? Even a WWII fighter or dive-bomber could easily blackout the pilot.
Whatever you assumed, it would be your assumption, not dictated by the game.
We don't know is a perfectly valid state, and sadly true more often than not, especially about fictional technology.
mike wightman
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Well to be fair neither version of LBB2 mentions artificial gravity or acceleration compensation.
The supplements and adventures makes it clear that the Third Imperium setting has these technologies, but a strictly by the book LBB1-3 universe requires the referee to decide on such things.
As to modern jets, the fact that pilots do black out shows there is no grav compensation - take the pilot out of the machine and the machine is capable of sustaining a lot more gs. No pilot would also allow designing airframes that can pull and sustain much higher g loads - planes today are built to the tolerances of the meat sack piloting them.
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AnotherDilbert
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Acceleration is a well-defined concept. Why would they bother spell out a massive table with a large number of distances and accelerations, when the formula said it all? It was explicitly just a few examples.
If they insisted 1 G travel was the only common mode, that would rather indicate that there was no internal gravity, since 1 G is the only comfortable acceleration for humans.
See, we can both assume things that are not stated, and most likely, we would both be wrong...
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AnotherDilbert
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Agreed, after reading only LBB2 there is no reason (other than TV) to assume magic.
But after reading both LBB2 and LBB5, when was the last time someone actually insisted LBB2 ships didn't have internal gravity?
And after reading both LBB3 and Striker, do we assume they describe completely different types of grav vehicles, with completely different properties?
mike wightman
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It is that square root and the planetary template formulae that earned Traveller the reputation as hard science fiction lol.
Heaven help us if they had actually used the rocket equation...
Heaven help us if they had actually used the rocket equation...
mike wightman
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LBB3, A12, and Striker are as similar as HG79, HG80, or LBB2 77 and 81 - the same but different.
It's no wonder they wanted a second revision to cut through all this - sadly the DGP folks that made MT made some questionable choices. (pp fuel use rates - power in general - free armour - reducing jump fuel because of pp decisions
I often wonder if T2300 Star Cruiser plus grav modules (Striker based) and HG weapon systems would have been the best way to start with a 3rd edition Traveller ship design system.
AnotherDilbert
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Barely anyone would have bothered with the game if you had to solve PDAs.
So it would have been forgotten, and we would not have discussed this 45 years later...
AnotherDilbert
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Quite, but describes the same (imaginary) physics, e.g. jump drives are (presumably) the same tech with the same properties, even if one is 5 Dt and the other 10 Dt.
I haven't looked at T2300. More crunch would probably not be a good idea. Anything more than LBB5 and it's barely used.
I hope LBB5 with more chrome (payload options other than staterooms and cargo, cf. Safari ship) could be acceptable? Mongoose is played, T5 isn't.
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mike wightman
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Confession - I have never yet completed a T5 ship. For a simple system supposedly based on LBB2 it is anything but user friendly.
And yet I can happily crank out FF&S designs
Star Cruiser is worth a look - mass, volume, energy, cost , surface area are all variables but for some reason the design sequence is pretty easy to use - only the surface area consideration makes it slightly more complicated than a Striker vehicle.
The sequence I find does everything I want most simply is the ship design system in GT ISW.
And yet I can happily crank out FF&S designs
Star Cruiser is worth a look - mass, volume, energy, cost , surface area are all variables but for some reason the design sequence is pretty easy to use - only the surface area consideration makes it slightly more complicated than a Striker vehicle.
The sequence I find does everything I want most simply is the ship design system in GT ISW.
Straybow
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Coming a bit late into this...
Shuttle was a dead-stick landing. A powered landing brick can control AoA and do a flare. With any kind of vectoring, deceleration and soft landing is a piece of cake. With grav propulsion, the brick can slow down below hypersonic before it enters the atmosphere, or even slow to synchronous and lower itself straight down.
Straybow
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With its listed 100 kph speed, if it has Cd and frontal area similar to a ground vehicle of the same size (4 Td = 26 foot Uhaul truck [Cd≈0.54, A≈6.95 m²]), 0.1G would only get you a top speed of 80 mph = 128 kph at STP. Maybe a 100 kph cruise speed is quite reasonable, allowing some reserve power for emergency maneuvers.
Baroun Tardis
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I always pictured it as letting one edge of the air/raft (or whatever) be affected by gravity, which would make the thing slide down the (virtual) hill
Make the (virtual) hill too steep, and the air/raft would flip over
Baroun Tardis
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I think we did the math once on the TML, and the top speed on the air/raft is pretty close to the terminal velocity of it falling nose first thru the atmo
The logic I pushed was that it moves by not cancelling the weight on the leading edge, which leads to it 'falling' in that direction... and thus top speed is terminal velocity when falling
Yah I recall that too.
This is the problem. The STS in a full flare landing set down at (at the top end) 150m/sec (540kph/335mph). However, the STS Orbiter was built like an airplane (a strike from ice and/or styrofoam insulation on launch caused eventually catastrophic damage) rather than a battleship, and weighed about 110 tons. A similarly-sized Type S weighs about ten times as much... and isn't nearly as aerodynamically capable.
ManOfGrey
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Obviously this is completely true. Traveller is fiction, and if you want to say a ship with 1 G acceleration can take-off from a planet with a surface gravity of 1.125 G, then feel free.
But if you want a little more science in your science-fiction, then the answer is calculable.
Before there were two suggested options to the problem of taking off from a "Super Earth" with a larger diameter than our homeworld. They were:
1) Get a bigger drive. 2 G, 1.5 G, 1.25 G... it doesn't matter. As long as the drive's acceleration is equal to, or greater than, the planet's gravity.
2) Use aerodynamic wings to fly high enough to escape enough of the planet's gravitational field so you can then continue at 1G.
Sadly, there is an equation in Physics (below) that does not allow that second option to work. In real life, it is impossible.
If you work the numbers, to climb high enough to get far enough away that a 1.125 G surface gravity is now only pulling at 1 G, the ship would have to climb to an altitude of 436 km from the surface of a size 9 world. That's above the orbit of the International Space Station, which orbits at 410 km.
There is simply no atmosphere that high to generate the lift needed for aerodynamic wings to work.
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mike wightman
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You only need lift and weight to balance, you keep accelerating "horizontally" until you have achieved enough velocity for an inertial orbital insertion above the 1g threshold.
Its an orbital mechanics problem which is a little bit more involved then the simple equation you posted.
Its an orbital mechanics problem which is a little bit more involved then the simple equation you posted.
I was going to use more words to say that.
Though it occurs to me that it would only need to be an elliptical orbit with an apogee above that point. The problem with that is that the corresponding perigee would be fairly deep into the atmosphere... But Traveller doesn't care about heat, at least from ship drives.
Note heat is less of a issue within a atmosphere... Just sayin'I was going to use more words to say that.
Though it occurs to me that it would only need to be an elliptical orbit with an apogee above that point. The problem with that is that the corresponding perigee would be fairly deep into the atmosphere... But Traveller doesn't care about heat, at least from ship drives.
Even with one g if you can get it to fly, you can get it into orbit.
Though, when I think of traveller ships I rarely worry about Supersonic speeds.
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