Missiles and their Physics: Do you understand it?

Sat Apr 26, 2003 5:55 am by joemolley

this isn't a really big issue, its just a pet peeve of mine and i got to vent the irritation, so bear with me.

i've searched the forums a bit looking for editing stuff, but i repeatedly get sidetracked by people who claim that missiles are too slow and they suck. I have seen a few, like 1 or 2 people, mention that the missile speed is not an absolute.

people need to understand that in physics, the speed of a projectile is modified by the speed of its launcher. a missile has a speed rated at, say, around 90 m/s. that would be the speed of the missile if you were not moving at all yourself. under normal circumstances you would be moving at around 80 m/s, so the effective missile speed would be about 170 m/s, enough to catch up fairly quickly. if you happen to use a thruster burst when firing, that could push a missiles speed up to about 290 m/s, fast enough to easily catch any ship that wasn't cruising.

another thing about this speed increase, in my experience, is that the turing radius of missiles seems dependant on the actual speed of the missile. the faster the missile goes, the faster it also seems to turn. i have had so much more success with all missiles, even torpedoes, in dogfights, even when the enemy is spinning, turning, or whatever, when i use the thruster to give my missiles some more oomph, that i am surprised that more people do not jump up in indignation.
does anyone else experience this increase in turning speed?

soo... in conclusion i state this-
Using the thruster when firing a missile improves:
1. the speed of the missile, nearly impossible to outrun
2. the turning ability, making it much harder to outmanuever the missile
3. the overall effectiveness of the missile; it improves dramatically

i acknowledge that many people probably already know this to one degree or another, and i ask to not be flamed, please, and try to respond intelligently.

whew. thanks for bearing with me through my windy speech here. it got a bit longer than i expected but i tend to get into details. sorry about the length.

PS - i know that only missiles, maybe mines and countermeasures too, are affected by your ship speed, but are your energy weapons affected too? i don't know, and i would guess that only the tachyon and photon weapons should have an absolute speed, not affected by your ship's velocity. all the other weapons, neutron, plasma, etcetera, should be affected by your ship. is there some way to edit this sort of thing?

Sat Apr 26, 2003 6:28 am by Chandrasekhar Limit

Well, FL has never claimed to be accurate when it comes to physics and the bulk of the combat centers on the gee-whiz-looks-cool visuals of the gun fight, so perhaps to most players missile performance is kind of moot.. I'm willing to bet that 9 out of 10 FL players hardly ever uses missiles after acquiring one of those three "top-end" VHFs and mounted class-10 guns on them.

If one wants to really get into missile physics then there would be other effects that would be nice to incorporate, like a dynamic launch zone that takes into account target aspect and speed (head-on shots would be effective at longer ranges than tailchase shots). Maneuverability of the missile will depend on its time-in-flight (very good while the rocket motor is burning, loses energy after the rocket motor burns out and won't be so maneuverable), proximity detonation effects, and a padlocking feature so you can keep an enemy missile on your 90 to outmaneuver it.

Heck, I'd love to play a "Falcon 4.0" of space sims that makes an attempt at realistic space combat physics, but unlike myself I think most gamers would be bored to death with such a thing..

Sat Apr 26, 2003 8:06 am by milod

If one wants to really get into missile physics then there would be other effects that would be nice to incorporate, like a dynamic launch zone that takes into account target aspect and speed (head-on shots would be effective at longer ranges than tailchase shots). Maneuverability of the missile will depend on its time-in-flight (very good while the rocket motor is burning, loses energy after the rocket motor burns out and won't be so maneuverable), proximity detonation effects, and a padlocking feature so you can keep an enemy missile on your 90 to outmaneuver it.

In space? You are thinking of aerodynamic effects of air-to-air missiles losing turning ability due to drag and speed loss in coast phase. Not relevant in space. A real spaceborne missile would need to turn using lateral manuevering thrusters in addition to a gimballed main engine. Something like the ASAT or GBI KKVs from the SDIO program.

Except for that, all the other features you mention (and several others such as antiship missiles with laser warheads) are implemented in Starshatter.

Heck, I'd love to play a "Falcon 4.0" of space sims that makes an attempt at realistic space combat physics, but unlike myself I think most gamers would be bored to death with such a thing..

Then you should definitely check the link in my signature. And it's not as boring as you make it sound. It's easy to find a balance between accuracy and action, and you can always include ease-of-use features to make the game more accessible.

--milo
www.starshatter.com

Sat Apr 26, 2003 8:14 am by RK-47

Hhohoho so I was right after all ^_^ it's nice to hear that i'm not the only who thinks missile speeds are not max. 90!

BECAUSE:
While i was burning away from the hessians, they shot me with a missile. I thought, nah can't hit me. I'm going at 200. it's max speed is 90. I swear to thee it aint Cruise Disruptor cause it hits and my burner speed remains. From then on, I always assumed that Ship's Speed + Missile Spd = Actual Missile Spd after launched.

Sat Apr 26, 2003 8:47 am by Chandrasekhar Limit

In space? You are thinking of aerodynamic effects of air-to-air missiles losing turning ability due to drag and speed loss in coast phase. Not relevant in space. A real spaceborne missile would need to turn using lateral manuevering thrusters in addition to a gimballed main engine. Something like the ASAT or GBI KKVs from the SDIO program.

Actually, DLZ still applies to space. Anytime you make a delta-v to a projectile in space, it takes reaction mass. A missile only has so much propellent aboard. In atmosphere, gravity and drag simply adds more parameters to DLZ.

Imagine a missile in space with its main rocket motor burning. To turn it, either some of the main rocket exhaust has to be deflected to cause the missile to skid-turn, or some sort of lateral thruster would have to fire and expend propellent to do so. Once a missile uses up its lateral thrust propellent it would have to rely solely on main engine vector thrusting to continue to maneuver, or vice versa. And once both supplies of reaction mass are gone, the missile goes ballistic and can no longer maneuver.

Head-on shots minimize time-in-flight, maximizes closure rate, as well as minimizing lateral thrust propellent expenditure if the target doesn't turn-tail and run outside the "no-escape zone." Tail chase against a maneuvering target still makes a missile expend all its main motor propellent first for the chase and once that's gone, no more forward acceleration and it ceases to close with the target if the overtake speed is not sufficient (and all the lateral thrust propellent in the world will NOT help in that case). This is still valid in an environment without drag or gravity, which is why DLZ still matters in space!

And turning to put a missile on your 90 still gives you the best chance to move out of a missile seeker's field of vision, whether you are in atmosphere or in space.

Remember ASAT and SDIO are basically gunning for NONMANEUVERING ballistic objects (either an MIRV warhead on a ballistic trajectory or a satellite in pretty much a fixed orbit) where the target geometry is not really dynamic. That's not the case with a maneuvering spacecraft which can change the parameters of intercept from moment to moment!

Edited by - Chandrasekhar Limit on 26-04-2003 10:13:18

Sat Apr 26, 2003 9:07 am by milod

Yes, of course. I was taking exception to the phrase:

loses energy after the rocket motor burns out and won't be so maneuverable

Now, I suppose you could say that this is merely a profound understatement

, but on first reading it sounded like the missile only had one motor and was relying on aerodynamic surfaces to turn.

Regarding SDIO - yes I know, I worked on the ASAT project briefly in my youth. I mentioned those system only as examples of how real spaceborne interceptors have to maneuver. From what I recall, ASAT did not rely on foreknowledge of the target's orbit for a solution. It would have had some kind of FLIR sensor to track and guide on the target optically. The fact that the target was in a stable orbit was kind of irrelevant to the need for the KKV to maneuver in space in order to score an impact. However, I do understand what you are getting at - the KKV range and velocity budget would not be affected by a satellite trying to perform evasive maneuvers.

Clever nickname you have there, by the way.

--milo
www.starshatter.com

Sat Apr 26, 2003 9:41 am by Chandrasekhar Limit

Hmm... I was under the impression that for an ASAT mission to work, the shooter flying the F-15 lugging that pylon and weapon under its belly actually needs some tracking support (i.e. foreknowledge of the target's path!) in order to pull off a successful intercept.

From what I understood of the procedure, NORAD had to provide the tracking data for the particular satellite so the F-15 on station with the weapon can initiate its climb after tanking from an optimum "initial point" and direction to send the ASAT booster "into the ballpark" so the MHV has the best view of the target with its FLIR sensor and does not have to correct its flightpath very much to line up for the intercept.

What I want to know is what aspect angle the F-15 had to approach from during that one test shot conducted for the ASAT program (I would have to guess as head-on as possible). I haven't found that piece of data in open sources but that would be understandable if the gubmint decided to keep that under wraps-- I think that piece of info would be quite telling on what the ASAT can or cannot do.

Well, I defer to you in that department if my info was not accurate, since you worked on that program and I did not.

Sat Apr 26, 2003 3:35 pm by Deramonic

i think, missles and shrapnel weapons in FL were designed to be the 1st weapon used at the face to face point of combat... it was also designed for bombardment of structures( tried and it is good way of killing those nomad generators)

Sat Apr 26, 2003 4:55 pm by milod

I must have been having a hard time expressing myself last night. I meant to say that ASAT did not rely only on knowledge of the target's orbit - especially during the terminal homing phase. In other words, it didn't work like some kind of orbital JDAM, just relying on the IMU to arrive at a predetermined point at a specific time. Once the KKV was within range to pick up the target on the FLIR, it was designed to guide on the signal and fly into where the target actually was.

My work on ASAT was fairly brief, and limited to the seeker DSP, so I don't know anything about how the KKV was to be inserted into orbit. All we were worried about was being able to identify, stabilize, and measure the hot spot on the IR focal plane. In fact, I'm not even sure if the customer ended up selecting our DSP or a competing design for the final version before the project was killed. This was about ten or eleven years ago, and I haven't worked on a DoD project since then, so the details are a little hazy.

--milo
www.starshatter.com

Sat Apr 26, 2003 6:26 pm by Artic

4.two counter mesures rend ervery missel usless

Sat Apr 26, 2003 6:53 pm by Ahriman

up to 7,800 credits per shot???
thanks, but no thanks. i stay away from the missiles and i don't try to understand their physics. the mines if u're not carefull will hit u.
what if the target isn't the stupid AI and uses CM?

Mon Apr 28, 2003 12:49 pm by Sapient6

i've searched the forums a bit looking for editing stuff, but i repeatedly get sidetracked by people who claim that missiles are too slow and they suck. I have seen a few, like 1 or 2 people, mention that the missile speed is not an absolute.

I thought it was common knowledge that your speed was added to the missile's speed when you fire it. I think the complaint that "missiles are too slow and they suck" is still entirely true. It's not that they're not fast enough to catch up, it's that you don't get enough return on your dollar spent to make them worth it. They cost a lot of money, don't do much more (or in some cases any more) damage than an equally classed energy weapon (don't think "per shot", think "per second" ), don't home particularly well, are easily countered.

In short, missiles don't offer you anything in return for the requirement that you pay for each shot. If you have to pay money to fire a weapon then it should give you something back in return, whether it's devestating speed and range (like a cruise disrupter), devestating damage, a guaranteed hit, or something .

As it is, if you work at it you can make your missiles "effective", which is to say, you can hit your enemies with them fairly reliably and do some decent damage with them. But, and here's the problem, if you're handy with your energy weapons you can do the same amount of damage with your energy weapons in that amount of time and save a few $$ to boot. That, right there, is the real complaint. It's not that missiles can't get the job done, it's that they don't get the job done any faster than the alternative despite being much much more expensive.

Edited by - Sapient6 on 28-04-2003 13:49:44

Mon Apr 28, 2003 3:02 pm by Catscratcher

Why does AI not fire those missiles from 1500 k ? Because it knows missiles are not effective in long range in this game.

However missiles must be more effective in long range and they must last longer !
They miss one time and poof ! they are gone.

I ain't use missiles. Sometimes I use starkiller as a missile because it has its own hardpoint. Cruise disruptor is a total mess you don'T need it until you have an assasination mission. Don't take those missions, you don't miss much.

Now i'm trying to get a sunslayer torpedo launcher to use as a missile launcher. I wonder the effects on the ships

Mon Apr 28, 2003 3:25 pm by thefinn

I have to disagree with that. The high-level Javelin series missiles (Lancer and Cannonball) do a high amount of damage, and even hit quite consistently if you know how and particularly when to use them. After the enemy's shields are depleted, a Lancer will usually take out more than half of a ships hull, unless it's a Titan or Sabre. As I see it, this can save your bacon if you're badly outnumbered in a dogfight (say, 6 to 1), letting you take out the first couple of bogeys quickly to give yourself breathing space.

As I see it, most HF and VHF class ships don't have the power supply to properly support a full load-out of high-power guns such as Outcast or Corsair weapons. Thus, it's no great loss to dedicate one slot to a missile launcher, since putting a gun on it will only be an annoyance causing your weapons power to run out all the sooner. Now, some people are going to say that you can just put Nomad weapons on your ship to get past that problem. This is true, of course, but for me, getting there is 99% of the fun. Once I have a VHF with four Nomad guns and a class 10 shield, the game ceases to be fun, unless I start over and do it all over again.

Mon Apr 28, 2003 3:53 pm by Sapient6

Cruise disruptor is a total mess you don'T need it until you have an assasination mission.

Or if you're going to be a pirate. One of the best ways to take out a train without the law showing up and harrassing you is to pirate a good trade route that doesn't have tradelanes. When the train flies by in cruise, hit your cruise engines and follow it. Give it a scan, if it's carrying what you want then cut your engines and and fire a disruptor. When the disruptor hits you'll close in, guns blazing, at just under cruise speed. Blast their cargo containers, tractor, and you can get out of there without wasting time fighting anything.

Another good use for disruptors is when you're flying kill'em'all missions at a challenging difficulty for your current equipment. Occasionally when you're at your first waypoint and only one ship is left he'll cruise up the momemnt you kill his buddy and make haste towards the next waypoint. Hitting him with a cruise disruptor and taking him out (he won't bother even turning to fire on you) can help even the odds in the upcoming fight at the next waypoint.

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