A trike was a small and simple type of shuttle, used for quick transport and various maintenance duties in orbit around settled planets, particularly in and around various orbital habitats. A trike had a semi-open hull and often non-pressurized cockpit, compared to other shuttles and small craft, and was often piloted while still wearing a spacesuit. Trikes were not built for atmospheric flight and were reserved for vacuum operations only.
With some effort, trikes could be converted into small, impromptu fightercraft, up-gunned with moderately powerful weaponry and with added (though still weak) external armour. Duiring their pursuit of Nightshade and flight to Resurgam, the crew of the Zodiacal Light used the time to carry out extensive combat modifications on the large number of civilian trikes they had gathered aboard their lighthugger before departing Yellowstone. The armed trikes played a role in the standoff between the Zodiacal Light and the Nostalgia for Infinity in Resurgam orbit.
A common type of small, inexpensive shuttle, the type is only referred to as a "trike". It is entirely possible trikes can vary externally, depending on their manufacturer (some possibly being home-brewn vehicles, rather than any official brand).