Office of Surveys and Statistics

Feel free to add a page and provide some statistics for use with article writing and general game play. System briefs also welcome.

Space Stations: Rotation Speeds & Size Specifications

With a standard of 1g of gravity at the wheel, the rotation speed per 1 revolution computed as a function of station size along with how fast the wheel is moving linearly around the hub.

Station Size
Time for 1 Revolution
Wheel Velocity
 1 19.87 sec
 31.62 m/s
 2 24.18 sec
 44.72 m/s
 3 34.41 sec
 54.77 m/s
 4 39.74 sec
 63.25 m/s
 5 44.43 sec
 70.71 m/s
 6 48.66 sec
 77.46 m/s

A size 6 station spins 2 1/2 times slower than a size 1 station. For comparison, 50 m/s is 112 mph.

Original discussion here:

The table below charts space station diameter, circumference, and the types of ship that can dock at the hub (by ship's Hull Size).

Station Size
Ship Types in Dock
 1200 m
 628.3 m
 2 400 m
 1256.6 m
 3 600 m
 1885 m
 4 800 m
 2513.3 m
 5 1000 m
 3141.6 m
 6 1200 m
 3770 m

Stealth Doesn't Work

Poster: Unknown

STEALTH DOESN’T WORK: Space is vast, but mostly empty. Space is also dark and cold; the average background temperature of space is 2-5 Kelvin. Ships with habitable life support sections, even with the engines off, will have a surface temperature of at least 200 to 250 Kelvin (ice melts at 273 Kelvin). For a typical habitable section of a ship, the radiated heat signature is in the range of a few hundred kilowatts, which is generally detectable out to 30,000 km in under a day using a full spherical search pattern with a broad-field IR-band telescope with an aperture of 3 meters. In addition to the waste heat generated by life support, a ship’s power generation system generates heat. A perfect Carnot heat engine produces 2 watts of waste heat for every watt of electricity it produces, where waste heat dissipation is free (like in an atmosphere). In space, waste heat has to be radiated. Minimizing radiator size (to make them retractable in combat, and to make them mass less) means running them at a higher temperature, which reduces the efficiency of the Carnot cycle. Each radiator in AV:T is roughly a 25m x 25m surface radiating from both sides at around 1600 K. Each radiator disposes of roughly 44 GJ of waste heat in 128 seconds, for a signature strength of roughly 340 megawatts, which is detectable (easily) out to around 10 light seconds (3 million kilometers) under the same conditions as the crew’s waste heat. (The distance from the Earth to the Sun is 500 light seconds, as a point of comparison.)

Beyond that, for a 5,000 ton ship using a reaction drive, even in cruise mode, it’s producing a minimum of a 340 gigawatt signature at about 2800 K, which gives a 1 day spherical search pattern “guaranteed” detection radius of a bit over 1,000 light seconds, or roughly 2 AU. In low thrust fuel economy mode, it takes roughly 10-16 weeks to cross 1 AU. During this entire time, the people attempting detection need only look for a 14th magnitude star with measurable proper motion. (A ship in combat thrust puts out drive signatures 10 times as bright, and would be easily detectable out at roughly triple the ranges listed above, or around 6 AU) Finally, any ship using a reaction drive reveals its mass by the correlation between observed rate of thrust and the temperature and brightness/mass spectroscopy of the exhaust plume.

Art Eaton says:

Want real stealth? Get your vector set way, way out where it is harder to detect you. Use a large body to mask your burn, and then use ti to deflect your course to your intended heading. Then you set out a parabolic or corner reflector front of you to reflect radiation away from the direction of your target. The reflectors outward face is probably black RAM to absorb energy coming in, and will be attached to radiators on the BACK SIDE of the reflector (and out of the focused beam of the reflector). This makes the "mask" absorbent in two ways on the inbound side, making it quite well hidden, yet radiates the heat directionally. On one side it is a mask, on the other it is a beacon. You simply cannot have yin without yang in a semi-closed system Vacuum is great for insulation.

Time to Void Jump Speed

Time to Void Jump Speed computed by ADF with a jump speed of 1%C or 180 hexes. All times listed in Galactic Standard Time.

 1 180 30 1.5
 2 90 15 .75
 3 60 10 .5
 4 45 7.5 .375
 5 36 6 .3

Of course based on the map scale, 1 ADF equals an acceleration of 27.77 m/s/s or about 2.8g.  So you could do it at those speeds but you'd be stuck in an acceleration couch the entire time, even at an ADF of 1 and could do nothing else during the trip.

If we take 1g to be 10 m/s/s (rounding up a bit for simplicity), c to be 300,000 km/s and one day to be 20 hours, you get the following chart:

Accel (g)
 1 500 83.33 4.17
 2 250 41.67 2.08
 3 166.7 27.78 1.39
 4 125 20.83 1.04
 16.67 0.83

Most ships will only move at 1g of accleration for the entire trip as that is the average, standard gravity most of the beings are used to.  To do otherwise would either make the trip take longer (at a lower acceleration) or limit the mobility of crew and passengers and may have a negative effect on crew performance.  Thus at 1g, a typical jump takes about 8.5 days, just over 4 days to accelrate to jump speed and the remainder to decelerate on the far end and maneuver to your final destination.