From: CS Renegade <njg@c...>
Date: Fri, 3 May 2002 23:25:24 +0100
Subject: RE: [DSII] When gravity fails
From: ~ On Behalf Of Christopher Downes-Ward Sent: 01 May 2002 11:54 Subject: [DSII]When gravity fails > Thinking specifically about movement of wheeled vehicles The very low-G / zero-atmosphere has been covered by earlier posters and also in past threads. I'd like to bring in near-G / thin atmosphere environments. First of all, is it right to associate thin atmospheres with low surface gravity? As a simple rule of thumb it will do, but at some point the average density of the planet will become a factor. The problem is, I don't know how "trivial" a change in, for example, the Earth's density would be needed to give us a radically thicker or thinner atmosphere. There is also the possibility that your planet has not been formed with the same cocktail of gasses as as the Earth. Combine this with the density and you may have an atmospheric pressure that falls off much more quickly or slowly than we are accustomed to. I know there are r.a.sf.s lurkers on this list. (Too many threads have been too similar for them all to be coincidences.) You are hereby invited to prove your scientific prowess, or at least recommend a decent book on planetbuilding that is still in print. If your vehicle engines require oxygen then the proportion of O2 to other gasses in the atmosphere will affect CFEs. Do MHTs require external oxygen? The FGPs will of course be unaffected, although "air" density will have a big impact on GEVs and aircraft. If the atmosphere is thin but the ratio of oxygen to other gasses is normal then the classic supercharger will help. If oxygen is simply scarce, troops will need bottled oxygen and vehicles will be battery-powered if no better powerplant is available. > How does lower gravity affect wheeled vehicles? If engine power is maintained, you also have a higher power/weight ratio. However, I would think that it's still mass that counts, not weight, so a vehicle will be no faster. Is weight or mass the main limiting factor on the durability of suspensions?* Yes, traction will be lower, but is wheelspin really a problem for many AFVs? Ground pressure will be lower, so there should be less chance of becoming bogged down. All real-world information on the care & feeding of AFVs welcome here. * painting here with a very broad brush to include everything from transmission through to the actual wheels / tracks / gubbins...