Is anybody aware of or have a calculator that will determine the time to intercept with matched velocities? I.e. A derelict vessel drifting at xG constant velocity needs to be intercepted by a rescue craft. How long will it take a rescue craft to reach the derelict and match velocity if the starting distance between the objects is D and the rescue craft is capable of aG acceleration. Assume no outside gravity affects, i.e. planets, stars, etc. If it calculated turn over (when the chase ship starts to decelerate) that would be a nice touch.
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- Thread starter D-Foxx
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Traveller calculates the time to get to the destination as a zero-zero formula (i.e. it assumes you boost half-way, the decelerate the other half of the time). But it's generalized, and avoids many realities.
I would say that for simplicity sake you take the distance at the intercept time and just assume the same thing, with the exception that the chase ship, instead of decelerating all the way would instead have cut their decel to match velocities of the target.
I would say that for simplicity sake you take the distance at the intercept time and just assume the same thing, with the exception that the chase ship, instead of decelerating all the way would instead have cut their decel to match velocities of the target.
^ I came across the need for this in my current rpg. I decided if its not applicable to any of the calculators here;
http://www.cthreepo.com/lab/math1.shtml
then you're best off handwaving it :wink: It all depends if what you want to do is important to the campaign/session.
The best thing to do would be to run a quick calculation of the speed of your derelict and how it accelerated to get moving first. You can then figure out using the calculators in the link above as to distance travelled based on speed.
Next total the capability of your shuttle. Eventually, if quicker than the derelict, it will catch up. If slower after accelerating, its not going to catch up whilst the derelict is drifting.
When you know the shuttle is fast enough after accelerating, use the calculators (the top ones the best for this) to find out how far it travelled (distance and speed) based on its acceleration, then how long it will take then to reach the target.
Speeds in metres per seconds will be needed, and Gs are a multiple of 9.81m/s (1G, so 2G is 19.62m/s for example).
Sounds tough but isnt really
http://www.cthreepo.com/lab/math1.shtml
then you're best off handwaving it :wink: It all depends if what you want to do is important to the campaign/session.
The best thing to do would be to run a quick calculation of the speed of your derelict and how it accelerated to get moving first. You can then figure out using the calculators in the link above as to distance travelled based on speed.
Next total the capability of your shuttle. Eventually, if quicker than the derelict, it will catch up. If slower after accelerating, its not going to catch up whilst the derelict is drifting.
When you know the shuttle is fast enough after accelerating, use the calculators (the top ones the best for this) to find out how far it travelled (distance and speed) based on its acceleration, then how long it will take then to reach the target.
Speeds in metres per seconds will be needed, and Gs are a multiple of 9.81m/s (1G, so 2G is 19.62m/s for example).
Sounds tough but isnt really
I posted the original question on both CoTI and here so I feel I need to close both loops. So here I go.
My trig is real rusty and I know my physics sucks, however, after much sweat and tears I think this works pretty good. It is still hammering a square peg into a round hole but I believe it is close enough for game play.
The issue: An object is moving through space at a constant velocity and needs to be intercepted and boarded. How long does it take to match velocities with the object if your ship has xG acceleration and at what point do you perfom turnover, i.e. start to decelerate.
Input into the calculator the following:
1. Target's Velocity (must be constant)
2. Bearing angle to the intercept vehicle (0-180 degrees)
3. Interceptor's G rating
4. Initial distance between the target and the interceptor
5. The Interceptor's initial speed
--- Note: Only works if the Intercepting ship has 0 initial velocity or if its initial vector is "pointing" at the target; approximately within the interceptors 45 degree forward arc, GM's descretion. If Interceptor is not in alignment, calculate how long it will take to decel to 0 and how far it will have traveled, then start intercept from that point.
6. Here is the square peg...input an estimated travel time of target.
Now the calculator will produce a Time to Intercept, however this needs to equal your Target travel time. Now go back and adjust the target travel time until it equals time to intercept. It hasn't taken me more then 3-5 quick changes to target travel time for the two to equal.
The Calculator will produce seconds, minutes, hours, and days to intercept as well as the same time frames for turnover and the "course" angle to reach the intercept.
Any inputs would be appreciated but please don't be critical just to be critical. Like I said, these are some math functions that I haven't had to use in a very long time.
Calculator
My trig is real rusty and I know my physics sucks, however, after much sweat and tears I think this works pretty good. It is still hammering a square peg into a round hole but I believe it is close enough for game play.
The issue: An object is moving through space at a constant velocity and needs to be intercepted and boarded. How long does it take to match velocities with the object if your ship has xG acceleration and at what point do you perfom turnover, i.e. start to decelerate.
Input into the calculator the following:
1. Target's Velocity (must be constant)
2. Bearing angle to the intercept vehicle (0-180 degrees)
3. Interceptor's G rating
4. Initial distance between the target and the interceptor
5. The Interceptor's initial speed
--- Note: Only works if the Intercepting ship has 0 initial velocity or if its initial vector is "pointing" at the target; approximately within the interceptors 45 degree forward arc, GM's descretion. If Interceptor is not in alignment, calculate how long it will take to decel to 0 and how far it will have traveled, then start intercept from that point.
6. Here is the square peg...input an estimated travel time of target.
Now the calculator will produce a Time to Intercept, however this needs to equal your Target travel time. Now go back and adjust the target travel time until it equals time to intercept. It hasn't taken me more then 3-5 quick changes to target travel time for the two to equal.
The Calculator will produce seconds, minutes, hours, and days to intercept as well as the same time frames for turnover and the "course" angle to reach the intercept.
Any inputs would be appreciated but please don't be critical just to be critical. Like I said, these are some math functions that I haven't had to use in a very long time.
Calculator
Not sure. That's why I'm asking for feedback. I'm trying to keep it as simple as possible and think of it in 2d only. I think the bearing angle is enough to keep it at least in the "close enough for a game" realm. Overall I still just want myself and my players to have fun, I just want to be close in these types of scenarios without "hand waving" things away.
Rick
Mongoose
I think No. 2 should be a combined vector/angle, so both the targets and ships angles are added? (or just take the targets angle as a baseline and derive a closing angle relative to it).
Plus, if you're just working out 1 target plus 1 ship, it doesn't need to be in 3d - 2d is fine, there are no other objects to consider!
Plus, if you're just working out 1 target plus 1 ship, it doesn't need to be in 3d - 2d is fine, there are no other objects to consider!
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