|| I think that space flight is a condition of Nature that comes into effect when an intelligent species reaches the saturation point of its planetary habitat combined with a certain level of technological ability... I think it is a built-in gene-directed drive for the spreading of the species and its continuation.
—Donald A. Wollheim, The Universe Makers, 1971
A Fenspace vessel can be anything from a Subaru hatchback with a space drive to a multimegaton floating city. This section is devoted to anything in Fenspace that can move under its own power.
|| Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards.
—Fred Hoyle, "Sayings of the Week," The Observer, 9 September 1979
The most common space transports by far, Space Craft are defined as any spacecraft that can be landed within a standard parking lot's parking spaces. The technical requirement is 'less than 18 feet along a viable direction of thrust and less than 9 feet horizontally perpendicular to this axis, with landing gear suitable to a flat surface'. Craft between 9 and 18 feet wide and less than 9 feet long will usually have to demonstrate that they can fly sideways with reasonable precision before anyone believes that they count as Space Craft, as otherwise they can't be relied upon to be able to navigate into the internal Space Craft docks of most really large facilities. Most Space Craft, for obvious reasons, began life as automobiles, and thus share the same top speed of 0.1c (inside the Limit, but only a fool would go interstellar in something this small) - larger Space Craft have lower top speeds, while smaller ones can have top speeds up to 0.2c.
Size comparison of the Adler class
Space Ship (foreground) and Bolitho class
Space Craft (background). The Alder is a relatively small Space Ship class.
In general, Space Ships are considered to be anything mobile that falls between the definitions of Space Craft and Space Vessels. There is considerable variation in size and type - modified aircraft are fairly common but probably not a majority. Typically they function as mobile homes or as medium cargo transports but many other purposes exist.
It's extremely rare for a Space Ship to have a top speed inside the Limit above 0.05c. The very fastest (mostly owned by the Roughriders) have top speeds of 0.12c.
|| That's no moon.
—Obi-Wan Kenobi, Star Wars
This designation is reserved for the largest of craft - heavy cargo haulers and semi-mobile stations being the most common. In general, any space vessel that has a longest dimension in excess of 250 feet is classed as a Space Vessel. Most docking facilities insist that they do not make close approaches, instead transferring crew, passengers and cargo by means of auxiliary craft.
It's extremely rare for a Space Vessel to have a top speed (inside the Limit) higher than 0.03c, and the larger Vessels don't even manage that.
A Space Station is defined as any space-going habitat or vehicle that has capability to dock Space Craft without the use of specialist gear on the part of the Space Craft, but that cannot usually make accommodation for most Space Ships. Many Space Stations have a 'parking lot' area and/or extendable airlocks that can make a tight seal around car doors or windows.
Most Space Stations have maneuvering thrusters only, for station-keeping. Those that are designed to be mobile have top speeds within the Limit under 0.015c.
Space Docks are space stations that have a reasonable chance of docking Space Ships internally. While there are no guarantees, designating yourself as a Space Dock implies that a good faith effort will be made to dock anything less than a Space Vessel if landing permission is needed, and that Space Craft are available for ferrying duty if docking is not possible.
Like the other Space Stations, Space Docks either have station-keeping thrusters only, or have top speeds within the Limit under 0.015c (usually far under, since they're the largest ships in Fenspace). Those that are designed to be mobile often use Hohmann orbits to travel between planets rather than bothering to travel under their own power.
- ↑ Stations that that require specialized docking gear to allow access without EVA are unofficially designated as b####y rude.