Wednesday, April 5, 2017

Renderings of Handwavium pt. 3

So we have lifters that can go into orbit. This is a classic trope of Traveller. In fact the idea of personal orbital transport is way older than that. A character with a flying car capable of reaching low orbit appears in Waldo (Robert A. Heinlein, 1942). So an air/raft or hopper or flitter going to orbit is something we've lived with in literature for a long time.

Classic Traveller had the open-topped air/raft and going to orbit required the passengers to ear spacesuits (the living, organic ones anyway). For my part, I think an orbital hop with no preventative measures is a little dicey for the following reasons:

1) Armor - we always hear about the relatively thick hulls of starships in Traveller and other classic games. One reason for those thick hulls is micro-meteors. A tiny chip of Godknowswhut recently gouged a window on the International Space Station. Most source material doesn't give a flying car anywhere near the armor to stop, say a rifle shot and such debris is traveling much faster than a bullet.

2) Thermal management - areas of spacecraft that are in sunlight get very hot very fast. Areas in shadow get very cold very fast. This stresses the areas in between and can cause expansion, contraction, and mechanical failure. Again an aircraft is not designed like a spacecraft and is liable to malfunction, anything from doors jammed shut to coolant or fuel pumps freezing and failing.

3) Waste heat - dumping heat in space requires large expensive radiators. An aircraft can be (surprise) air cooled. A reaction engine will carry some heat from its operation away. A reactionless drive will just heat up.

4) UV - an aircraft flying to orbit (especially an open topped one) will have its interior discolored or faded by ultraviolet. Plastic (or those new leather seats) can degrade.with enough exposure. Canopies can prevent this especially polarizing or one way mirror versions. Canopies can also protect the passengers from potentially fatal micro-meteors see above.

Lifters do not have all these features for reasons of cost and weight. An occasional trip to orbit ought to go smoothly enough. A lifter used regularly on a vacuum world or to make orbital hops needs modifications or something is going to go very wrong. Using Skippy from me previous posts if came up with the following modified version:

Skippy gets a white thermal blanket that insulates from extreme temperatures as well as affords some protection against micro-meteors. It also looks a little puffy. The hopper now has a canopy attached that protects the passengers from harmful sunlight as well as meteors. It also lets them take their helmets off briefly and scratch their noses. Finally the propulsion foils have small heat sinks attached to allow Skippy to dump waste heat.

But seriously, use a shuttle if you can.