ATS Homepage : Space : Reven's Warp Guide
This lesson is going ot start quite simply, with a basic explanation of flight dynamics, impulse and warp velocities, and move on from there. You may wish to skip forward if you understand the basic material. Also, this lesson is not going to give any code to turn this into MUSH commands. It will give you all the knowledge you need, though, to turn it into MUSH commands yourself.
"Space is big... really big. You might thing it's a long trip down the street to the chemist's, but that's just peanuts to space..." - Hitchiker's Guide to the Galaxy
Space is big. We use two measuring systems on ATS, depending on your range to your 'target'. For close ranges, we use SU's (which I belive stand for 'standard unit'). 1 SU is equal to 10,000 kilometers (or about 5450 miles for you Americans;). For long ranges.. between stars, the unit of measurement is the Parsec, abreviated PC. The unit of measurement you may be familiar with for long distances is the light year. We all hear how many light years something is from earth. Alpha Centauri is 4.6 light years from us. 1 PC is equal to a little more than 3 light years (3.261598 to be more exact). The Parsec was used instead of light years in order to make the numbers a little easier to manage. You may be interested to know, that distances in ATS are as accurate as possible. Alpha Centauri in ATS really is 4.6 light years (1.4PC) from earth. Great care has been taken to make our space system as 'lifelike' as science fiction can be.
Coordinates in ATS are almost always given in PC, and in X Y Z format. If you think of our galaxy as a circular piece of paper, the X and Y are determining your location on that paper, and the Z how far above or below the paper you are.
Impulse engines are our 'Sunday-Morning-Go-To-Meeting' engines. For short distances, or sometimes combat. Impulse engines are slower than light. The speed of light is 299792500 meters/second, or, in our ATS measurements, 29.97925 SU/second. Impulse speeds are always expressed as a percentage of the speed of light (sometimes said to be a "percentage of 'c'", as the letter 'c' is used to represent the speed of light in mathematical equations). So, 50% impulse means 50% of the speed of light, or 14.99 SU/sec. If you round up the speed of light to 30 SU/sec in your head, then figuring out speeds is relatively easy. 'IMP 50', or 50% impulse is 15 SU/sec, 'IMP 25' is 7.5 SU/sec. A few nice numbers to remember are IMP 34, IMP 3.4 and IMP .34. These speeds will take you very close to 10, 1, and .1 SU/sec respectively. This is handy for travelling the last few hundred SU in to dock.
"Sulu, Warp 1 now. Go!" - Kirk, Wrath of Kahn- Interesting how similar Kirk and Picard become when a star (or Genesis device) is exploding behind them.
"Data, Warp 1 now. Engage!" - Picard, Star Trek Generations
Warp speed can be confusing. The biggest confusion in the game stems from the fact that many people expect warp 1 to be equal to the speed of light. While some books and technical manuals state this, others state that the warp field generated by the ship taps into a set of natural laws where the speed of light is much faster. In any case, it doesn't matter the reasoning behind it, just as long as we understand how it works.
The formula for determining the actual velocity that a given warp factor takes us is this:
speed = speed of light * Cochrane Factor * (warp factor)^(10/3)
(the last part is my notation for 'warp factor to the power of
ten thirds)
What units you get our of this equation depend on what units you use on the speed of light. I use SU for all my code. It is the most accurate measurement that ATS supports. Thus, the following formula will return the velocity of a warp factor in SU/sec:
speed = 29.97925 * Cochrane Factor * (warp factor)^(10/3)
Learn this formula. It is not difficult to remember, though calculating it in your head will for most of you be impossible (it certainly is for me).
Now, for that warp 1 difficulty. Examining the formula, you will see that when the warp factor is 1, the last term in the equation is 1 (1 to the power of any number is always 1). Thus, the formula for determining your velocity at warp 1 becomes simply, the speed of light times the 'Cochrane Factor'.
That would make a nice book title. For us, though, what exactly is the Cochrane Factor. On ATS, it is a spacial property that changes depending on the area of space you are in. The average, so I've been told, is 1278. In general you probably won't see it deviate much from the 1100 to 1400 range. Generally, the cochrane value gets smaller as you travel 'up' or 'down' along the Z axis. You can see the value of the Cochrane factor in a 'NAV STAT'.
Looking at our warp formula after plugging in the cochrane value, you can see now that the actual valocity of warp 1 is the speed of light times the cochrane value. Or, if we use our 1278 average, 1278 times the speed of light, or about 38000 SU/second. And this is our slowest warp speed.
The question that first time flyers pose is generally 'how the $@%# do you expect me bring a ship within docking range if there isn't any speed between 30 SU/sec, and 38000 SU/sec. The answer isn't easy. Coming out of warp, even if you time it perfectly, is still a crap shoot. You can come out of warp anywhere from 0 to 38000 SU's from a planet or base. This can be very inconvenient, as 38000 SU is 21 minutes at the speed of light. Depending on your maximum inpulse, it can take up to an hour to travel that distance. Me, I'd rather be trading, cavorting with Deltans, heck, I'd rather be cavorting with Nausicaans than sitting in a ratty freighter limping along at IMP 50 waiting to get in range to dock.
The rest of this document is going to deal with my solution to this problem. Different people have come up with different solutions. Some deal with dropping out of warp, changing your pitch away from the target by a calculated amount, doing a 1 second warp skip, then pointing towards your target and doing another 1 second warp skip to get into range. My method is different from this. Some say it's harder. I know, because I'm one of them. However, if you master it, you'll be much better off, both for accuracy, the time it takes to dock, and even in combat.
The key to getting in docking range of your target is a short, well calculated warp skip. In olden days this was really easy. All you had to do is reverse the warp formula and calculate the warp speed needed to travel a given distance. We'll go though an old example step by step:
Warp factor = (Speed / (Speed of light * Cochrane factor)) ^ 3/10
= (42621 / (29.97925 * 1154)) ^ 3/10
= (1.231961) ^ 3/10
= 1.064582<
Alas, tis not so any more
But alas, if you've read the above expecting to have a free ride, you're wrong. The above was used for a combat technique that many started calling 'straffing'. Instead of coming up with a good defense against it (such as battling at warp), many people instead complained, and the space system was changed. The nasty word now is 'acceleration'. Here is the problem. The above example assumes that whatever magic speed the formula pops out with, can actually be attained as soon as the ship enters warp. This is no longer the case for most ships. Some small fighters may still be able to use the above method, but by far, most ships cannot. We now have a system called 'variable acceleration' in place. This means, the higher the warp speed your ship is accelerating to, the greater the ships acceleration. Unfortunately, with our warp skip scenario, we want low warp speeds. This means that most ships pop into warp when low warf factors are set at around warp 1.001. This means more complex math for our warp skip system.
The first step in our new system is to determine a special warp factor for the ship. I call this number the 'Warp Initiator'. Partly because it actualy vaguely means what it says, but mostly because I think it's a nice catchy technical term I can throw around to look smart. What the 'Warp Initiator' is, is the warp factor your ship will first break into warp at, at low speeds. Here is the method I sue to determine it.
NOTE: This number is highly dependant on your starting speed. For example, if you start from IMP 10, for example, instead of stop, the number could be totally different. Higherm or lower.. depending on your particular ship's acceleration pattern. The reason for this, is that acceleration is not smooth. In fact, no ship movement is smooth on ATS. It is broken up into 1 second chunks. So, if on the one second increment just before your ship breaks into warp, it was really really really close to warp speed... like 99.999% impulse, then on the next second, the warp factor it breaks out into warp at will be as high as possible. If, though, it was a little further away, like 99.1% impulse, then it may break into warp at a lower value. You can experiment with impulse speeds to start with to get the highest possible value for the warp initiator. Also note, that the power you have assigned to movement in navigation will also greatly affect your acceleration. That number will have to be the same every time you dock using this method, or, you will need multiple calibrations.
Ok, now what
You now have a value for my snazzily named 'Warp Initiator'. What do you do with it now. Well, here is the complete play by play. For this example, we will assume the value for the warp initiator is 1.0035
Warp factor = (Speed / (Speed of light * Cochrane factor)) ^ 3/10
= ( (84611 / 2) / (29.97925 * 1221) ) ^ 3/10
= ( 42305.5 / (29.97925 * 1221) ) ^ 3/10
= (1.155740) ^ 3/10
= 1.044379
Speed = speed of light * Cochrane Factor * (warp factor)^(10/3)
= 29.97925 * 1221 * 1.0035^10/3
= 37033.465
Second2 distance = Total distance - Second1 distance
Second2 distance = 84611 - 37033.465
Second2 distance = 47577.535
Warp factor = (Speed / (Speed of light * Cochrane factor)) ^ 3/10
= ( 47577.535 / (29.97925 * 1221) ) ^ 3/10
= 1.081832
Keep in mind, we are still making an assumption here, but in my experience it has never gone wrong. We are assuming that the ship can make the acceleration from the Warp Initiator value (1.0035) to our final speed (1.081832) in one second. I've never seen a ship for which this method fails because of insuficient acceleration, though I've never used it on a megafreighter (I have used it on superfreighters).
I highly doubt that any of you will regularly hand calculate any of this. You will write code to help you calculate it. There is also nothing saying that this technique cannot be adapted for longer than 2 second warp skips. In fact, it can be used for skips of arbitrary length. The code I have written for myself does this. To use it, though, you need to get /very/ good at warp skips... at counting how many seconds you are at warp. I have a clock with a second hand on my computer screen when I do this. You also need to get to know your ship very well. You need to know exactly how long it takes to break into warp. Get to learn how far your ship travels in the time before it braks into warp, and adjust for this. Get to learn how you need to adjust the numbers these calcualtions spit out when your power to movement is different, and adjust for it on the fly. In the end, there is no substitute for PRACTICE.
This page is <URL:http://www.trekmush.org/space/warpdyn.html>
Last update: June 28, 1998
email: Reven (Text)
email: Leo (Website)