Sophonts live on planets, but ships and stations operate in space. For ships that do not land, they typically take up orbit around the planet of interest. Orbits, however, vary dramatically. Most orbits are circular or nearly so to make everything easier for space traffic control. Elliptical orbits are the general case and may be very eccentric (ie. comets). In all cases, orbits closer to the planet have a shorter period (time to go around the planet) than orbits further out. Low orbits are those that occur close to the planet's atmosphere. While definitions can vary somewhat, low orbits are those above the atmosphere and out to about 1/3 of the planetary radius. Medium planetary orbits go out from 1/3 of the planetary radius to a particular location known as geostationary orbit where the time to orbit the planet equals the period of rotation. Low and medium orbits have periods that are shorter than the rotation of the planet and, depending upon the altitude, may make many orbits per planetary day. Geostationary orbits (if centered over the equator) will have the object in the same sky position all the time. If inclined from the equator, objects appear to move north-south along a line of longitude, with larger variations for those orbits more inclined away from the equator. High orbits are those above GEO, and have longer periods than the rotation of the planet. Objects in high orbit appear to move backward through the sky in a retrograde orbit.
Orbits require 3 peices of information: d (the diameter of the actual planet), g (the gravitational field of the planet), and t (the period of rotation for the planet). Some planets, particularly those that are tidally locked such as Venus or Mercury, have very long rotational periods and nothing will be in high orbits. Most moons are in high orbits around their planet, although some smaller moons are in medium orbits. All moons in the M317 Cluster (and most moons anywhere) are tidally locked to their planet and everything will be in a very low orbit around any moon (to avoid being stripped away by the larger planetary body or other moons). Click here to calculate the travel time from your chosen orbit to the surface.
Planetary diameter: km (rounded to 100 km)
Planetary gravity: g (rounded to .01g with g=10.0 m/s)
Rotational time: hours (rounded to the nearest hour)