Atmospheric operation of small craft, incorrect assumptions

[Ishmael]

I think what they're trying to say is that, compared to atmospheric flight, all Traveller spacecraft are ungainly in space flight -

I don't think the Mongoose game designers are THAT brain dead.

Spacecraft are optimized for space
Aircraft are optimized for atmosphere

Take either out of the environment that they were designed to operate at, the will be ungainly when compared to their normal operational environment.

Multi-role vehicles are a compromise

As I've shown, grav ships will be limited in speed, even if it is still greater than modern jets ( mach 3 at sea level is nothing to sneeze at ). I've also shown that yawing without slowing down will cause huge increases in profile drag and in the case of the example I gave, created 10e6 newtons of drag/deceleration.
Given how previous incarnations of Traveller describe thrusters ( DGP's Starship Operator's Manual), they have only a limited amount of vectored thrust ( relative to thrust along the roll axis ) thus, they would act in a similar manner to a Harrier in terms of control.
But the grav ship would be limited to 6 g's of thrust ( lower for vectored-thrust maneuvers) regardless whereas a modern jet can call upon 12 G's for turning and looping maneuvers.

The grav ship is faster, better rate of climb and a larger speed envelope, but worse in a turning fight. I doubt that they would be able to avoid an AIM-120 except to outrun it IF it saw it coming early enough. Faster missiles do exist however.

It seems to me that the grav ship would have the advantage if it used 'bounce' tactics and NOT a turning battle.
Vertical maneuvers would be its strong point.

The grav ship would be ridiculously easy to spot and to target ( ECM capabilities not withstanding ) due to its huge size when compared to a modern fighter.
Its huge amount of drag at speed would make for a good IR target as well as radar contact; huge profile drag makes for a huge wake and pressure waves. The ship would be traceable from its sonic boom.

If this is what the design rules create, then I doubt that they are brain dead.

 

[Nidhogg]

At this point it may be worth noting that Traveller is a space opera RPG and intended to simlate interesting dramatic effects as one expects to see in a space opera and not 100% realistic simulation of real world physics...

 

[DFW]

If one goes by the MGT rules it's even worse. Since no vector thrust is mentioned it would be 100% out the back and nothing anywhere else.

Actually not. If not mentioned, it could any direction as "M-drives" aren't reaction rockets... So, it wouldn't be "100%" anything. So, as I pointed out, MT doesn't limit the direction...

 

[DFW]

Take either out of the environment that they were designed to operate at, the will be ungainly when compared to their normal operational environment.

You didn't read the quote I was responding to;
"all Traveller spacecraft are ungainly in space flight"

Try again.

 

[DFW]

And MGT (Mongoose Traveller) says nothing about vectored thrust. So "if not mentioned, it does not exist" is a valid assumption. More valid IMHO than "I want it to exist so it does no matter that I have no source"

Nope. Not when it it flies in the face of logic and would contradict/make illogical other rules of the game. Ie: a non airframe ship being able to land on a world. THAT requires vectored thrust. Therefore, your argument that MT ships 100% don't have it is illogical per the MG rules as the ships couldn't land without it.

 

[DFW]

It does not. Try reading the thread and you might understand why it does not require vectored thrust.

I started the thread and read all of it. There is NOTHING in the rules that indicates no vectored thrust. Put up or...

 

[DFW]

As said: NO mentioning means...

As I knew already, nothing in this thread OR the rules indicates that vectoring doesn't exist. Although, it would be impossible to land a non-airframe ship without it, including on a planet with NO atmoshere. Logic is a beautiful thing.

 

[MarkB]

Take either out of the environment that they were designed to operate at, the will be ungainly when compared to their normal operational environment.

You didn't read the quote I was responding to;
"all Traveller spacecraft are ungainly in space flight"

Space flight is ungainly compared to atmospheric flight, simply due to the nature of the medium (or lack of medium).

In space, barring the occasional gravity-slingshot where circumstances permit, the only way to alter your velocity is through sheer brute-force application of thrust.

In atmosphere, there are other options available which can greatly improve your maneuverability - but only if your craft is built to take advantage of them.

 

[DFW]

Space flight is ungainly compared to atmospheric flight, simply due to the nature of the medium (or lack of medium).

Interesting. Atmospheric flight certainly LOOKS far more graceful, I'll give you that. However, space flight is MUCH more precise because of the lack of variables. So, your maneuver envelope is known and predictable. An aircraft, not nearly as much. Definitely trade-offs involved.

 

[far-trader]

If one goes by the MGT rules it's even worse. Since no vector thrust is mentioned it would be 100% out the back and nothing anywhere else.

Actually not. If not mentioned, it could any direction as "M-drives" aren't reaction rockets... So, it wouldn't be "100%" anything. So, as I pointed out, MT doesn't limit the direction...

You seem a bit selective about how you apply your assumptions of what the rules don't say. Above, the rules don't say you have vector thrust so you assume that means you can have it. While (in the VLS Missiles thread here)...

Has it ever been stated one way or another if the missile launcher provides any assistance to launch?

No, and since there isn't ANY indication that they do, the assumption is the negative.

The rules don't say missiles get a kick start so you assume that means you can't have it.

I think you're letting your own prejudices about how Traveller works mess with your logic.

Not that I'm all that sure about applying any kind of justifiable reasoning from a lack of data

Seems to me where the rules are silent on a point is where MTU and YTU begin to divert from the Core Rules and that's cool. Trying to come up with some universal application of "the right way" to interpret lack of defined characteristics is impractical if not impossible.

That said you seem back to a Flying Saucer interpretation of Traveller maneuver drives. That is, a drive that has no discernible interface or requirement for such to provide thrust. It could quite literally be buried in the core of the craft and provide its thrust in any direction. And you seem to be working on an instant on/off at full speed in any direction as well, also iconic of Flying Saucers. That's all well and good. In fact it's a cool interpretation in ways. But it's not the way Traveller has ever described or illustrated the maneuver drive. They have always been a singly directed thrust drive located with an obvious external interface.

 

[far-trader]

As said: NO mentioning means...

As I knew already, nothing in this thread OR the rules indicates that vectoring doesn't exist. Although, it would be impossible to land a non-airframe ship without it, including on a planet with NO atmoshere. Logic is a beautiful thing.

Actually no. Two words: Tail Sitter.

A non-vectored thruster would simply land by coming down on its thrusters. Atmosphere or no. Vectoring is not required. Period.

Even the one mention of semi-vectored thrust mentioned that it was only in the final approach that the ship would lay over from tail sitting to horizontal to land because overpowering the thrusters enough to stay in the air with the minimal off axis potential runs the risk of melting your drives if done for too long.

 

[DFW]

No, and since there isn't ANY indication that they do, the assumption is the negative.

The rules don't say missiles get a kick start so you assume that means you can't have it.

Well, again logic. A mass driver PLUS a missile wouldn't fit inside the turret. By the current rules. So, explain YOUR logic as to how a mass driver is fit into a 1 ton turret + the missiles... I'll wait...

 

[DFW]

A non-vectored thruster would simply land by coming down on its thrusters. Atmosphere or no. Vectoring is not required. Period.

So, why couldn't you apply thrust and go UP as well as DOWN? THAT is what the rules state, you can't apply thrust to up once you set down. Please explain....

Also, an airframe ship would have to land the same way on a world WITHOUT
atmosphere. So, this rule means NO starship can land on an airless world and take off again, WITHOUT an expensive, elaborate launch pad system. Logic is a b--ch I know. But, the designers weren't being logical when they wrote this part of the rules...

 

[far-trader]

No, and since there isn't ANY indication that they do, the assumption is the negative.

The rules don't say missiles get a kick start so you assume that means you can't have it.

Well, again logic. A mass driver PLUS a missile wouldn't fit inside the turret. By the current rules. So, explain YOUR logic as to how a mass driver is fit into a 1 ton turret + the missiles... I'll wait...

Don't bother waiting, you completely missed my point and the answer is off topic for this thread.

 

[DFW]

Don't bother waiting, you completely missed my point and the answer is off topic for this thread.

No, I understood the point. However, do you see the point regarding any ship landing on an airless planet?

 

[rust]

... WITHOUT an expensive, elaborate launch pad system.

The MGT core rules state in the chapter on spacecraft operations under
the heading landing that a majority of the ships have landing gear - and
this implies that a minority of those not designed for planetary landings
does not have landing gear.

Thanks to gravitics they will be able to touch down without major dama-
ge, they only have to brake to zero speed and then to sink down the last
few meters, but afterwards their maneuver drives are now pointing in the
wrong direction and would make them move forwards instead of upwards,
so they need a kind of ramp to start again - and a ramp for a big starship
would be a serious construction project.

 

[DFW]

they only have to brake to zero speed and then to sink down the last few meters, but afterwards their maneuver drives are now pointing in the wrong direction and would make them move forwards instead of upwards, so they need a kind of ramp to start again - and a ramp for a big starship would be a serious construction project.

Thanks that's interesting, however, that doesn't address the question nor the inanity of the original rule I listed.

 

[Chuckhazard]

As written on pg. 56 High Guard:
"A standard–hull small craft may still enter atmosphere, but is
very ungainly and ponderous, capable of only non–lift generating
powered flight."

This is a VERY strange statement. A vehicle using a gravitic drive to maneuver in the atmosphere has much better options than a craft that requires lifting surfaces to operate. Our Air Force would LOVE to get rid of lifting surface fighters and exchange them for gravitic, non-lifting surface maneuver craft. Also, a cylinder rounded on both end with NO lifting surface would be much more aerodynamic than a craft designed as a lifting body due to induced drag.

The config section of the books needs to be rewritten.

Thanks that's interesting, however, that doesn't address the question nor the inanity of the original rule I listed.

In what way does your original post need to be addressed? You state it needs a rewrite. Some people (not Someone, oi how confusing!) disagree.

So the purpose of this thread, I say, is to generate conversation, thought, and reading material on the subject. So an interesting point is wholly appropriate.[/i]

 

[kristof65]

I gotta run, and will have to read the last 6 pages of this thread later, but I wanted to inject something into the coversation that may have already been covered. This is based on decades of wargaming with games like RL: Centurion, Full Thrust, 40k, Epic, etc, etc.

Regardless of whether or not you can hover or spin on a dime, the combat advantage goes to the one who can outmanuever his opponent. And 99% of the time, outmanuevering your opponent means going fast enough to keep up with them, but slow enough you can predict their trajectory and react to it.

Sitting still means a fast opponent can simply fly away from you or go around you. Going too fast gives you a predictable trajectory that the opponent can exploit. The ability to sit still and maneuver on a dime is not in and of itself an advantage - in fact, it can be a distinct disadvantage.

In a conventional airplane versus grav vehicle engagement, yes, a grav vehicle could use that to it's advantage - assuming, of course, that the faster plane couldn't simply avoid the hovering grav vehicle. But in a grav to grav vehicle engagement, that ability wouldn't have any more distinct advantage than using speed would.

Basically, what I'm trying to say is this - if I had to bet on an engagement between a flying brick grav vehicle and an F117, I'm not going to pick on of the technologys over the other - I'd want to know how many years of flying their respective vehilces and how much combat experience each had before I placed my bet.

 

[Chuckhazard]

Also, I know I'm like fifty pages behind on this... but regarding the talk of a gravitic dog fight with a regular jet.

There was all this talk about trying to get behind the fighter plane. I'd just have the gravitic vehicle spin around and shoot to rearwards it, while maintaining it's direction of travel. I'm thinking of the hover craft style behavior, although I think I saw similar maneuvers in BSG.

I'm also reminded by all this talk that the space fighting from star wars was modeled on world war dog fights, because it looked super awesome.