Sling shot maneuvers?

jedion357's picture
jedion357
August 13, 2015 - 4:12am
How would we do a sling shot maneuver around a planet in KH
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!
Comments:

Shadow Shack's picture
Shadow Shack
August 13, 2015 - 7:47pm
The rules state pasing one hex from a planet causes an automatic facing change, as long as there is continued movement. So you get one extra MR point if you want to make a u-turn around a planet.
No, I'm not overly fond of Zeb's Guide. Nor do I have any qualms in stating why. Tongue out

My SF website

jedion357's picture
jedion357
August 13, 2015 - 9:51pm
Thats different than using a planet to gain accel.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Malcadon's picture
Malcadon
August 13, 2015 - 11:00pm
jedion357 wrote:
Thats different than using a planet to gain accel.
If you have not it figured out, the whole space combat/movement rules are broken with regards to simulating real-word physics.

jedion357's picture
jedion357
August 14, 2015 - 4:56am
Yeah, but I don't see why we can't develop a formula/mechanic to allow a player to gain speed from a large planetary body.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

jedion357's picture
jedion357
August 14, 2015 - 6:41am
Reading up on it
https://en.wikipedia.org/wiki/Gravity_assist

It looks like the big number is orbital velocity of the planet

according to NASA these numbers are
https://solarsystem.nasa.gov/planets/charchart.cfm

Mercury: 17 hexes, Venus 13 hexes, Earth 10 hexes, Mars 9 hexes, Jupiter 5 hexes, Saturn 4 Hexes, Uranus 3 hexes, Neptune 2 hexes

rough rule of thumb would be 2 X orbital velocity in hexes but it would require whipping around the planet.

Correct me if I'm wrong but does not KHs say that orbiting a planet is done at the speed of 1? So a Gravity Assist would have to be at better than orbital speed or at least 2 or higher

Thus a craft travelling speed 5 coming into orbit of a planet (though he cant orbit because he's going to fast) would execute a gravity assist. If that planet was similar to Jupiter with a orbital velocity of 5 hexes
 would plug into 2U+v as 15 hexes after the manuever with the caveat that this is executed in the direction of the orbital path of the planet. the same could be execute against the orbital path of the planet for some speed breaking (sathar destroyers coming in hot and planning to use a gravity assist to slow their ships right on top of a space station and blast it to bits).

One question I have is what if the ship doesn't exactly come in on the proper angle or intend to leave on the proper angle to be exactly in line with the orbital path of the planet. I would think this should impact the numbers some.

Now I'm currious about the orbital velocity for the moon and giving new life to system ships in KHs
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

TerlObar's picture
TerlObar
August 14, 2015 - 4:26pm
Haven't had a chance to look at this but the speeds you listed are hexes per hour so you'd have to divide by six to get hexes/turn.

When New Horizons flew past Jupiter in 2007, it picked up 14,400 km/h or a quarter hex per turn.
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jedion357's picture
jedion357
August 15, 2015 - 1:27pm
TerlObar wrote:
Haven't had a chance to look at this but the speeds you listed are hexes per hour so you'd have to divide by six to get hexes/turn.

When New Horizons flew past Jupiter in 2007, it picked up 14,400 km/h or a quarter hex per turn.


Dope Slap/ I missed that.

So for a gas giant then we're talking about a minor boost in speed
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Shadow Shack's picture
Shadow Shack
August 15, 2015 - 1:45pm
Based on the Star Trek movies if you accelerate around a planet you can travel through time. Wink
No, I'm not overly fond of Zeb's Guide. Nor do I have any qualms in stating why. Tongue out

My SF website

iggy's picture
iggy
August 15, 2015 - 8:05pm
Shadow Shack wrote:
Based on the Star Trek movies if you accelerate around a planet you can travel through time. Wink

I only remember them using stars in the movies.  I cannot vouch for the serieses because I am not that much of a Trek geek.
-iggy

Shadow Shack's picture
Shadow Shack
August 16, 2015 - 7:41am
You may be right, I'm even less of a Trekkie.

I just recall them sling-shooting around something to travel through time and figured they were out of ideas since the Flux Capacitor was already being used by another franchise. 
No, I'm not overly fond of Zeb's Guide. Nor do I have any qualms in stating why. Tongue out

My SF website

iggy's picture
iggy
August 16, 2015 - 12:01pm
In ST IV The Voyage Home they do it and it requires them traveling at warp speed toward the sun.  Not someting possible with SF non-warp speed.
-iggy

Stormcrow's picture
Stormcrow
August 17, 2015 - 6:50am
"I just recall them sling-shooting around something to travel through time and figured they were out of ideas since the Flux Capacitor was already being used by another franchise."

No, they were drawing from the TV show, where it was done accidentally in "The Naked Time" and "Tomorrow Is Yesterday" and on purpose in "Assignment: Earth."

In the case of "The Naked Time," the effect occurs because the Enterprise is suddenly hurled away from a collapsing planet, not a star.

jedion357's picture
jedion357
August 17, 2015 - 6:12pm
Well I dont know about the physics of time travel but real world space craft used gravity assist to gain speed in flybys of the system's gas giants to leave the system
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!