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Missile Drive velocities

Posted: Sun Nov 12, 2017 10:42 pm
by phavoc
I know this was debated a lot before the first book was published, but I was reading an article about Turkey's S400 purchase and the size of the launcher and missile made me think that the Traveller version is still broken - especially since we regularly have designs popping up that have starships outrunning missiles on reaction thrusters. That shouldn't be possible in a rational setting.

Missiles are designed for offense, therefore a designer will use the best materials, in this case rocket propellant, available. If a ship can put out 15G with reaction thrusters, then a missile designer will ensure that their missiles utilize the same propellants as well. One could argue that the different speeds are based upon propellant volume, but that wouldn't hold up to common sense. And missiles have no need to worry about protecting their fleshy passengers, so their engines should be pushing out the maximum velocity. Even the size of the missile (standard ones are pretty tiny compared to an S400 round) wouldn't make a difference. Larger missiles would have comparably larger nozzles and more fuel to maintain the same level of thrust as smaller ones.

Anyways, back to your regularly scheduled discussions. :)

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 9:40 am
by Condottiere
It's two stage, if you consider (and use) the spaceship as a missile bus.

Other than that, you have to assume they're limited by the prevailing technology, manoeuvre factor nine by technology level thirteen, though this seems a drive form more suited to a torpedo or a drone.

Or sixteen gees acceleration with a burnout measured in hours.

You don't have a separate design system for space vehicles under ten tonnes, specifically for tiny kamikaze drones, so it's off the shelf rather than customized.

You also don't have the option to stage them, nor strap on boosters.

Unless it's the High Burn Thruster, whose mysteries in this edition I've consciously decided to deal with last.

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 9:42 am
by msprange
I am not sure about standard missiles changing, but I think a Very High Velocity Missile could be an interesting addition...

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 11:25 am
by Infojunky
phavoc wrote:
Sun Nov 12, 2017 10:42 pm
I know this was debated a lot before the first book was published, but I was reading an article about Turkey's S400 purchase and the size of the launcher and missile made me think that the Traveller version is still broken - especially since we regularly have designs popping up that have starships outrunning missiles on reaction thrusters. That shouldn't be possible in a rational setting.
Or the model you have in your head is broken. The vast majority of Air to Air missiles aren't all that much faster than the airframes that carry them. There are a number of ground based Anti-Air Missile that are significantly faster that their target airframes, but they have to overcome both range and speed of the target, but even in that case they won't win a drag race. . As with everything there are exceptions, but those are the fringe issues.

So the question becomes what do you want a missile to do? I mean if you fire a missile at a target and they run away isn't that almost as good as damage ing them. It's not like they can easily turnaround once your missiles burnout.

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 11:34 am
by baithammer
Ground based mobile SAM are constrained by the design weight and are more use versus helicopters, where as larger platforms have missiles of a larger and faster design, often to the point of being upwards of 3 to 4 times the speed of fighter craft but with a far more limited range.
I mean if you fire a missile at a target and they run away isn't that almost as good as damage ing them. It's not like they can easily turnaround once your missiles burnout.
Your not taking into account m-drives which provide thrust so long as energy is devoted to it, which means yes a fighter can in tandem with r-drives outrun the missiles and can come back to attack the target.

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 2:12 pm
by Rikki Tikki Traveller
WAY back, missiles usedt the same M-Drive technology and were limited to 6-Gs.

Later in MGT1, ships were 6-Gs but missiles were 10-G.

Now they seem to be back to missiles and ships being the again, but at higher thrust.

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 9:46 pm
by Condottiere
It’s unclear what technologies and concepts researchers have developed for the new missile. But there are some hints. In April 2017, Chuck Perkins, the principal deputy to the assistant secretary of defense for research and engineering, circulated an artist’s impression of an Air Force F-22 launching a hypothetical LREW.

The missile in the image features two stages — a warhead and sensor up front and a rocket booster in the back. In the artwork, the F-22’s main weapons bay — the one designed to accommodate the 12-foot-long AIM-120, is open. By implication, the LREW can be no longer than 12 feet and still be compatible with the F-22.

Of course, it’s possible to fit a range of different boosters to a two-stage weapon. Industry could design LREW with a variety of front and back ends to produce different versions of the weapons with different seekers and ranges. For example, F-15s could carry larger and longer-range LREWs externally, while F-22s and F-35s stick with smaller, shorter-range versions of the weapon that fit inside their bays.

Re: Missile Drive velocities

Posted: Mon Nov 13, 2017 10:30 pm
by Infojunky
baithammer wrote:
Mon Nov 13, 2017 11:34 am
I mean if you fire a missile at a target and they run away isn't that almost as good as damage ing them. It's not like they can easily turnaround once your missiles burnout.
Your not taking into account m-drives which provide thrust so long as energy is devoted to it, which means yes a fighter can in tandem with r-drives outrun the missiles and can come back to attack the target.
Actually you are half right, I forgot that MgT uses speed rather than velocity in it's combat system. Thus I am correct in the traditional Traveller model but not in the MgT cinematic model.

Re: Missile Drive velocities

Posted: Tue Nov 14, 2017 11:05 am
by Condottiere
Part of the reason has to be that any speed a missile can go, so can a spaceship, since we have inertial compensation.

Re: Missile Drive velocities

Posted: Wed Nov 15, 2017 2:46 am
by baithammer
Part of the reason has to be that any speed a missile can go, so can a spaceship, since we have inertial compensation.
Missile has fewer components per unit than a manned space ship, even inertial compensation doesn't change the extra displacement life support takes up.

Re: Missile Drive velocities

Posted: Wed Nov 15, 2017 9:09 am
by Condottiere
Missiles also have a payload that needs to be delivered, but one significant difference is duration and cost of the respective propulsion.

Re: Missile Drive velocities

Posted: Thu Nov 16, 2017 2:51 pm
by phavoc
We have no specs on what the upper limit is of a inertial compensator tech. We do know that with the addition of reaction drives the upper limit on speeds has dramatically increased. But we also know that non-fleshy objects can take FAR more G's than people. So unless the inertial compensators can offset hundreds of G's, a missile or other device that is not carrying a human will always have the upper hand.

Re: Missile Drive velocities

Posted: Thu Nov 16, 2017 4:09 pm
by Condottiere
Some parts of High Guard appear to have been redacted, because the degree of inertial compensation appears to be a highly classified secret.

The other aspect would why not strap additional rockets on a missile or torpedo, to increase acceleration in the initial launch?

Re: Missile Drive velocities

Posted: Fri Nov 17, 2017 4:17 am
by baithammer
Increases mass without increasing warhead load and the cost factor.

Besides, you could throw a spacecraft missile rack on a drone for similar and more cost effective delivery.

Re: Missile Drive velocities

Posted: Fri Nov 17, 2017 9:41 am
by Condottiere
I miss missile packs.

Re: Missile Drive velocities

Posted: Tue Nov 28, 2017 5:16 pm
by steve98052
Condottiere wrote:
Mon Nov 13, 2017 9:46 pm
. . .
The missile in the image features two stages — a warhead and sensor up front and a rocket booster in the back. In the artwork, the F-22’s main weapons bay — the one designed to accommodate the 12-foot-long AIM-120, is open. By implication, the LREW can be no longer than 12 feet and still be compatible with the F-22.
. .
If length is the only issue, strap-on boosters would solve the problem.

Re: Missile Drive velocities

Posted: Wed Nov 29, 2017 11:34 am
by Condottiere
Which adds volume in odd places, probably requiring a modified and larger launcher.

Re: Missile Drive velocities

Posted: Sun Dec 03, 2017 5:01 pm
by Linwood
I think you could assume that inertial compensator tech evolves in step with maneuver drive tech - if your world can build a 6G maneuver drive the inertial compensation comes in as part of the package. Which leads to thought that reaction drives don’t follow this model and thus would subject their crews to multi-G stresses when used. But YMMV.