steam engine in space

Spreading out away from the engine room were large, flat panels. Without any water tower for another million miles or so, the ship couldn't afford to loose a single drop of water--not if you asked Engineer Fred. These panels, which upon closer inspection revealed fine pipes arrayed across them, replaced the steam engine's chimney. No steam would be lost, instead the steam would make its way through the panels, cool down by radiating their heat into space, and work its way back into to water tanks as a stream of water as steadily as the engine could puff it out.

Another set of radiator panels, 90 degrees offset from the others, carried a different fluid: ammonia-water mix. Any excess heat generated by the ship: the body heat of the crew, mechanical stress from mechanisms, heated air from the furnace, all would be taken by this mixture and radiated off into space as well. The cooler fluid would cycle back through the ship cooler and ready to absorb heat.

These radiator panels were probably the most important single system on the ship, for without it the crew would be cooked. While the ship could run its steam engine without the radiators as long as the waste steam is ejected, but the ship systems radiator must remain intact or the ship would just keep getting hotter as its machines and devices clanked along.