Ok, it's fun idea but it could work in theory (only). ;-) Take a small thin clindrical tank full of H2O2. Freeze it. Take it out and stuff it in a big, tall freezer. Freeze another load. Slot it together ontop of the previous one. Freeze another load. Slot it ontop of the previous one somehow. (Some sort of lubricant is required, and they dovetail in some cunning way, you'll see why in a minute.) Keep doing this till it's a few meters tall.
After a while you have the worlds tallest H2O2 'ice' lolly with no stick up the middle but no, you really wouldn't want to lick it. Anyway. Take it out of the freezer and stuff a peroxide rocket motor at the bottom. Ok, here's the clever bit. You don't actually need a tank ;-) As the rocket takes off the rocket 'somehow' takes a thin layer of H2O2 ice off the bottom and melts it very quickly from two or more sides (that's why it's thin ;-), and then pipes it to the engine. It ratchets down the next layer slightly, so the rocket shortens. It then takes the next layer and does the same, ratchetting down all the time. So the rocket gets shorter over time. (How the rocket takes the layer and melts it whilst holding on to the bit above and sealing well enough 'is left as an exercise for the reader'.) Because ice can take a few g's you don't need any tankage. Any thermal heating from the atmosphere just melts off some of the ice from the outside, but heat conductivity of ice isn't all that amazing- so how much would we lose? And besides, you'd probably lose more early on, when the rocket equation is less sensitive to the losses anyway, and less after you leave the atmosphere. Also, the peroxide will tend to sublime/melt in a vacuum, but again- it's only 6 minutes to orbit- so who cares? But the really nice thing is towards the end of the burn- you don't have any tankage left. Dry mass would be really small- you're just left with the engines and any payload. What's the thrust to mass ratio of a peroxide engine? Can you get 100+:1? Probably more I would think. Actually, you'd still want some hydrocarbons, otherwise you'd never really make orbit, the extra ISP you get from having the hydrocarbons makes it worthwhile. Again in theory you could freeze your hydrocarbons, and stack them with the peroxide. No melt, no boom... Let's see, assume a 50:1 'dry/dry mass' ratio (yes ice is dry ;-) ) and an ISP of 300. That gives a total delta-v of ~11.5km/s. That's ignoring losses due to atmospherics, but if the rocket is big enough, that's negligable anyway. So it makes orbit, and in theory, escape velocity in a single stage! ;-) One more advantage of this scheme, guidance is easy- and you certainly don't need to worry about fuel slosh ;-) I'm not so sure that Mojave is a good place to test this though. Too hot. Canada is cold and nobody lives there anyway, so it could be ideal. (Statistically speaking it's a big country but not many people; no insult is to be inferred ;-) ) Comments? ;-) _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
