How does a grav flyer maneuver? And other military questions

[ShadowDrake]

Hi folks,

I was thinking about combat once grav tech becomes widespread for my MTU, and something is bugging me. It might be rather silly, really, my knowledge of physics is limited to high school several years ago.

Once fighters and gunships (atmospheric) are given grav units, how does this change the way they maneuver? For example, take two fighters dogfighting over an area clear of air defense (I guess a massive advantage of grav is being able to hover at nap of the earth to avoid the frighteningly effective AA of the future). To an observer watching, does it look like a modern fight? a WWII fight? Something absurdly different?
For example, will fighters be able to spin around on their axis like they can in space? Do Traveller antigravs cancel out the G-forces of turning that fast at high speeds?

Now I know that it makes sense that these craft would engage at range with stand-off weapons like guided missiles. But lets assume for arguments sake that all missiles have been shot down by the crafts point defense. Or missed.

Which brings me to my second (unrelated) question. How effective do you think point defense is in the TU? It would seem easy to put a small laser or VRF gauss gun on all armored vehicles to engage incoming guided ordnance. Hell, they can practically do this today with CIWS and VIRSS systems. The laser weapon, in particular, should be able to engage incoming ordinance at very far ranges without accuracy issues.
Which would make aerospace craft even less welcome on the battlefield, as it seems somehow impractical to mount a tank cannon on a grav flyer. At that point, just stick extra armor on it and call it a tank.

So...any suggestions? Comments? Disparaging remarks about my character and intelligence?

 

[rust]

In my view "dogfights" between grav vehicles would probably be similar
to such fights between attack helicopters - which does not help much to
visualize them, because such fights have been extremely rare in the real
world, I am afraid.

One reason why many real world armies have given up research on la-
sers is the fact that they are too easy to disable by fog, rain, dust, smo-
ke and any other particles in the air. They look nice in movies, but are
near useless under battlefield conditions in the real world.

Therefore I would expect air to ground missiles to become "intelligent"
and able to aquire targets, maneuver, and all that, and point defense
to be something like miniguns, also "intelligent" - and the attack a kind
of "tactical chess" between the computer of the missile and the compu-
ter of the minigun.

 

[Rikki Tikki Traveller]

The answer will also depend on how you view Gravitics in your setting.

Does Gravitics provide LIFT only or LIFT and THRUST?

Most people seem to assume that gravitics will provide lift and thrust (no other propulsion system is needed other than gravitics). If this is how you view gravitics then vehicles will be able to spin around, ignore g-forces and have no need of any kind of control surfaces (but they will still be smooth to reduce drag). Flying Saucers are a good example of this type of design.

If you believe that Gravitics only provides LIFT, then all vehicles will have to have some other kind of propulsion system to make them "go". It won't have to be nearly as big as modern plane engines, since much of the power from the engine is used to generate lift via the wings. These types of vehicles will still have wings and other control surfaces, but they will be considerably smaller than those of a plane. There will also be secondary thrusters located all around the vehicle that will let it move sideways etc. The X-Wings from Star Wars and the Colonial Vipers from BSG would probably fit into this category.

Lift and Thrust gravitics will lead to fights that are going to be hard to visualize. Ships will essentially 'Turn on a dime' with the only limits being how strong your gravitics are.

Lift gravitics will be much more like the "helicopter duel" described by Rust.

MGT seems to use the "Lift and Thrust" model of Gravitics.

IMTU I use the "Lift Only" model for TL 9-11 and the "Lift and Thrust" model at TL 12+.

 

[Infojunky]

Watch Blue Thunder.... It has a great Helo fight in it.

 

[Sir Brad]

Grav tech can be used to provide both Lift and Thrust, but early Grav Tech is normally used to only provide one or the other or provide some of both wile still using more established Tech, also Grav Craft have G compensators in their design reducing or eliminating G Stresses caused by Maneuver on the Pilot, Crew and Equipment.

 

[Mithras]

Some SF movie over the past 30 years must have had a go at portyraying this kind of aerial combat between grav flyers.

But I can't think of any ... Independance Day? Stargate?

 

[Da Boss]

It might be worth looking at the old Renegade Legion games - in particular Centurion which was all about high tech Grav tank battles - there are even a couple of novels.....

 

[ShadowDrake]

Avatar has VTOLS vs. flying aliens, which gives at least some indication of how it might look. I can't think of other helicopter scenes that would be helpful.

As for my grav drives, I always assumed they only provided lift, thrust would be provided by separate, conventional, engines.

 

[dmccoy1693]

As for my grav drives, I always assumed they only provided lift, thrust would be provided by separate, conventional, engines.

Think of it like a helicopter. If you have it pointing straight up and down, it provides lift. Tilt it and it goes forward/backwards/side to side.

 

[Infojunky]

I thought the PS1 game Warhawks did a good job of it.

 

[alex_greene]

The way they move is likely to be similar to the movement of boats on water, only with a three dimensional component skewed by the unidirectional force of gravity.

Thrust is required to increase or decrease the magnitude of the vessel's velocity, as well as to alter the direction of motion. How tight the corners are will depend on whether or not you include the concept of "inertial dampers" - the calculated application of internal G sufficient to counteract inertial effects of rapid velocity change.

If you do have inertial dampers, your G-flyers will be able to come to a halt on a full stop.

 

[GJD]

IMTU I like a bit more science that the OTU so I split the drives and the Contra-Grav into two seperate systems, using the old HEPLAR thrusters from TNE for thrust and a less sophisticated CG system to reduce the weight of the craft (or more accuratly, the influence of gravity on the actual mass), so CG makes the craft easier to move through the atmosphere with the thrusters. Inertia is still retained, so you can't flip and turn on a dime, as it still requires thrust to alter the vector of the mass, but whilst the CG is active you only need minimal thrust to stay airborn. The CG won't cancel out all of the weight, only 90 - 95% or so, so you won't get tossed around by the slightest breeze. The split between weight and mass also means that CG has diminishing returns as you leave a gravity field, so you still need a good main drive.

Also, my interpretation of inertial dampners (a-la Star Trek) was not that they cancelled out the inertia of the vessel itself, but that they maintained a consistant internal gravity field, so that when you accelerate to 1/4 impulse (from 0 to 1/16 speed of light in 30 seconds, apparently), your bridge crew don't get smeared in a pink paste 1 molocule thick over the rear bulkhead. Being able to flip and skim and turn on a dime is more typically called an inertialess drive, as seen in the Lensman books.

G.

 

[Jon Brazer Enterprises]

your bridge crew don't get smeared in a pink paste 1 molocule thick over the rear bulkhead.

Dang. Can't we just turn those off before beaming out the whole crew except wes crusher?

 

[ShadowDrake]

IMTU I like a bit more science that the OTU so I split the drives and the Contra-Grav into two seperate systems, using the old HEPLAR thrusters from TNE for thrust and a less sophisticated CG system to reduce the weight of the craft (or more accuratly, the influence of gravity on the actual mass), so CG makes the craft easier to move through the atmosphere with the thrusters. Inertia is still retained, so you can't flip and turn on a dime, as it still requires thrust to alter the vector of the mass, but whilst the CG is active you only need minimal thrust to stay airborn. The CG won't cancel out all of the weight, only 90 - 95% or so, so you won't get tossed around by the slightest breeze. The split between weight and mass also means that CG has diminishing returns as you leave a gravity field, so you still need a good main drive.

Also, my interpretation of inertial dampners (a-la Star Trek) was not that they cancelled out the inertia of the vessel itself, but that they maintained a consistant internal gravity field, so that when you accelerate to 1/4 impulse (from 0 to 1/16 speed of light in 30 seconds, apparently), your bridge crew don't get smeared in a pink paste 1 molocule thick over the rear bulkhead. Being able to flip and skim and turn on a dime is more typically called an inertialess drive, as seen in the Lensman books.

G.

All of this makes me happy. One wonders if CG is directional or not though. As in, does it simply cancel the pull of G on an object (a bubble of antigrav around the vehicle, as it were)? Or does it only do it from a certain direction, usually the bottom. Basically, I'm asking what happens when you flip a grav vehicle upside down. Nothing? Does it fall rapidly?

 

[alex_greene]

I do believe I said something about the concept in my post here:-

"inertial dampers" - the calculated application of internal G sufficient to counteract inertial effects of rapid velocity change.

Yup. Definitely.

If you do have inertial dampers, your G-flyers will be able to come to a halt on a full stop.

Of course, the ability to come to a halt rapidly is just as much dependent upon the ability of the vehicle to retain structural integrity: contemporary ground cars which come to a sudden stop, usually by impacting with trees and walls, tend not to be very roadworthy after the impact.

 

[GJD]

I do believe I said something about the concept in my post here:-

"inertial dampers" - the calculated application of internal G sufficient to counteract inertial effects of rapid velocity change.

Yup. Definitely.

If you do have inertial dampers, your G-flyers will be able to come to a halt on a full stop.

Of course, the ability to come to a halt rapidly is just as much dependent upon the ability of the vehicle to retain structural integrity: contemporary ground cars which come to a sudden stop, usually by impacting with trees and walls, tend not to be very roadworthy after the impact.

The highlighted part says nothing about allowing the vehicle to be inertialess itself, just that it counteracts the inertial effects of rapid velocity changes - i.e. you don't get tossed around inside. So, your Uberfighter X-1 iz zipping along under a constant 12G acceleration and you suddenly apply a 12g braking thrust, the inertial dampers mean that the pilot won't don't suddenly feel a 24g change of acceleration and have his eyeballs pop out.

A truly inertialess vehicle could go from 12g to 0 in an instant, turn 180 degrees on a whim, without having to worry about vector changes or gradual changes in heading. Of course, this idea violates the laws of physics in many, many ways.

G

 

[GJD]

IMTU I like a bit more science that the OTU so I split the drives and the Contra-Grav into two seperate systems, using the old HEPLAR thrusters from TNE for thrust and a less sophisticated CG system to reduce the weight of the craft (or more accuratly, the influence of gravity on the actual mass), so CG makes the craft easier to move through the atmosphere with the thrusters. Inertia is still retained, so you can't flip and turn on a dime, as it still requires thrust to alter the vector of the mass, but whilst the CG is active you only need minimal thrust to stay airborn. The CG won't cancel out all of the weight, only 90 - 95% or so, so you won't get tossed around by the slightest breeze. The split between weight and mass also means that CG has diminishing returns as you leave a gravity field, so you still need a good main drive.

Also, my interpretation of inertial dampners (a-la Star Trek) was not that they cancelled out the inertia of the vessel itself, but that they maintained a consistant internal gravity field, so that when you accelerate to 1/4 impulse (from 0 to 1/16 speed of light in 30 seconds, apparently), your bridge crew don't get smeared in a pink paste 1 molocule thick over the rear bulkhead. Being able to flip and skim and turn on a dime is more typically called an inertialess drive, as seen in the Lensman books.

G.

All of this makes me happy. One wonders if CG is directional or not though. As in, does it simply cancel the pull of G on an object (a bubble of antigrav around the vehicle, as it were)? Or does it only do it from a certain direction, usually the bottom. Basically, I'm asking what happens when you flip a grav vehicle upside down. Nothing? Does it fall rapidly?

IMTU it was a constant effect, a field if you will. You had a CG generator (I gave it some whacky name, the Tesserman-Sachs generator or something) that whilst it was on, you negated some of the gravity. Of course, since a 100 ton ship would still weigh between 5 and 10 tons with it on, you still needed something to generate llift - so the ships had vectored thrusters to keep themselves airborn. Flip a ship over and those thrusters aren't pointing in the right direction any more.....

G.