Needing more detailedway to calculate orbits

[briansommers]

Im wanting a simple formulaic approach to calculating 4 orbits of a given planet size diameter

Low orbit
Medium orbit
Geosynchronous orbit
High orbit

Im looking for a multiplier of the planets diameter, for example
Safe jump didtance is 100 * diameter

Low is X*d etc

Once i haveghe figure i can vary it a little along with a navigation role, etc.

 

[NOLATrav]

Here's what I've been using for quite a while now... YMMV

Low World Orbit (LWO) is closest to the surface of the world, ranging from 0.1 to 0.25 diameters. Immediately below LWO is the world's thermosphere, the first substantial atmospheric layer of a world, where ships become subject to the world's weather patterns and full surface gravity. General LWO traffic includes surface interface vehicles, small orbital stations, low power satellites and planetary rings. LWO exerts 0.75*surface gravity on ships and installations.

Medium World Orbit (MWO) is the next higher zone, extending from 0.25 to 1.00 diameters. MWO holds the planet's exosphere, its most tenuous, outermost layer of atmosphere. General MWO traffic includes planetary rings, occasional comms beacons and weather satellites. In moderate tech systems (TL 9 and 10) this region also contains observatories, space telescopes and patrol and research installations. Beyond TL 10 most worlds can cheaply place scientific, support and patrol installations where ever they may be desired or needed. MWO exerts 0.5*surface gravity on ships and installations.

Semi-Sync Orbit (SSO) extends from 1.00 to 3.00 planetary diameters and is generally occupied by major comms and weather satellites and global positioning satellites. Heavy ring systems may extend into this region as well. Semi-sync stations and satellites make a full orbit of their host world twice each local day. SSO exerts 0.25*surface gravity on ships and installations.

Geo-Sync Orbit (GSO) occurs at 3.00 planetary diameters and is occupied by geo-synchronous and geo-stationary satellite systems that often form the basis of real-time electronic communications on the surface of the world. Geo-sync satellites orbit over a particular spot on the planetary surface and orbit at the rotational rate of the world below it. GSO also defines the beginning of orbit and de-orbit operations and gas giant refuelling. GSO and higher exerts 0.0*surface gravity on ships and installations.

High World Orbit (HWO) marks the edge of interplanetary space, from GSO to 10.00 planetary diameters. Traffic is generally local patrols, if they exist, and ships entering and leaving the system. In the OTU setting, ten planetary diameters is the end of local planetary law and the beginning of Imperial law; thus in many systems the Imperial highport will be found at the ten diameter limit and the HWO region will be filled with planetary interface vehicles and streamlined ships travelling to and from the world surface.

Hope that helps.

 

[briansommers]

Exactly what i wanted.

Thanks so much.

BTW, I noticed you mention the percentage of the planets gravity in each zone.
how are you using the gravity in game? (Game mechanic)

 

[NOLATrav]

I went down a rabbit hole thinking about 1G/Thrust1 ships refueling from 1.5+G gas giants. And the canonical High Guard maneuver, where ships refueling from gas giants are watched over by guard ships higher up in the gravity well.

Basically I’ve ruled that an M-Drive produces twice its rating - half for acceleration and half for inertial compensation. And that ships have to somehow counteract local gravity or be drawn off course or into the well. Or lose Thrust equal to the gravity their fighting.

So a Thrust 1 ship can’t take off from a 1G world. Unless they turn off the inertial compensators. Which is clearly dangerous. But vacc suits to a limited extent, acceleration couches/benches (standard at shipboard workstations and in staterooms) and also G-drugs can alleviate the stresses on passengers and crew. So you can turn off 0.5G inertial compensation and get Thrust 1.5 out of your engines, boosting out at Thrust 0.5 against the 1G gravity well. Acceleration couches can provide the 0.5G in compensation so as long as everyone’s strapped in you’re good to go.

It’s fun to play with the numbers, and as you gain altitude you’re subject to lesser gravity from the world as I described above.

It doesn’t seem to be a popular idea but our group likes the crunch and it’s pretty simple to implement.

 

[Condottiere]

Less rabbit hole, more fog bank.

Tee Five implies that lifters (presumably factor one) are integral to some gravitational based manoeuvre drives, so presumably, you only have to really worry once you try that at two gravities.

 

[NOLATrav]

Less rabbit hole, more fog bank.

Tee Five implies that lifters (presumably factor one) are integral to some gravitational based manoeuvre drives, so presumably, you only have to really worry once you try that at two gravities.

True but it’s an ironically lazy handwave. “Installing Lifters is sufficient.” Works fine if you don’t want to be fiddly about it or don’t care about that level of detail. Whereas much of T5 provides Ludicrous levels of detail.

We like it. It allowed me to figure out rules for gravity slingshots. Works for grav vehicles as well. And some engine hits are Compensators so losing internal gravity during a fight is a thing. A very very fun thing.

 

[Condottiere]

To clarify, Mongoose makes no such claims.

However, I interpret that you can have both lifters/orbitals and thrusters working at the same time.

 

[Arkathan]

I went down a rabbit hole thinking about 1G/Thrust1 ships refueling from 1.5+G gas giants. And the canonical High Guard maneuver, where ships refueling from gas giants are watched over by guard ships higher up in the gravity well.

Basically I’ve ruled that an M-Drive produces twice its rating - half for acceleration and half for inertial compensation. And that ships have to somehow counteract local gravity or be drawn off course or into the well. Or lose Thrust equal to the gravity their fighting.

So a Thrust 1 ship can’t take off from a 1G world. Unless they turn off the inertial compensators. Which is clearly dangerous. But vacc suits to a limited extent, acceleration couches/benches (standard at shipboard workstations and in staterooms) and also G-drugs can alleviate the stresses on passengers and crew. So you can turn off 0.5G inertial compensation and get Thrust 1.5 out of your engines, boosting out at Thrust 0.5 against the 1G gravity well. Acceleration couches can provide the 0.5G in compensation so as long as everyone’s strapped in you’re good to go.

It’s fun to play with the numbers, and as you gain altitude you’re subject to lesser gravity from the world as I described above.

It doesn’t seem to be a popular idea but our group likes the crunch and it’s pretty simple to implement.

You can overpower the M-Drive and take off from 1G worlds with a 1 G drive. I think it was in an old TAS Journal that discussed thrust plates. The thrust plates are most efficient perpendicular to the plane of the plate, and have to work up to four times as hard to maintain 1G thrust along the plane (i.e. up, down and sideways). The one or two space turns required would not strain the system overly much.

 

[Condottiere]

I think it was Mongoose First where you could order a temporary extra one gee acceleration, relatively consequenceless.

 

[Annatar Giftbringer]

I think it was Mongoose First where you could order a temporary extra one gee acceleration, relatively consequenceless.

You still can in 2nd Ed. Overload drive on p.160 (core rulebook)

EDIT: Solomani Rim discusses short-duration overthrusts on p.184-185 as well. Basically the same as in the rulebook, but just for a few moments, to enable take-off from worlds with higher gravity than the ship’s drives

 

[Condottiere]

As I recall, luck plays less a factor in the previous edition.

 

[Annatar Giftbringer]

As I recall, luck plays less a factor in the previous edition.

Possible/likely. Not sure where I’ve put my 1st Ed books, so I can’t double-check for you…

 

[NOLATrav]

I think it was Mongoose First where you could order a temporary extra one gee acceleration, relatively consequenceless.

You still can in 2nd Ed. Overload drive on p.160 (core rulebook)

EDIT: Solomani Rim discusses short-duration overthrusts on p.184-185 as well. Basically the same as in the rulebook, but just for a few moments, to enable take-off from worlds with higher gravity than the ship’s drives

Cool.

I like our crunch better

 

[Condottiere]

You only have to switch on the afterburners for a round, so depending how fine a margin is required, so that's a quarter percent hull volume of fuel by default, a tenth of a percent technological level ten for factor one, and you can incrementally go downwards on how fine a margin you'd actually need for that extra boost to reach orbit.