> On Sat, 6 Sep 2003, LARRY KLAES wrote: > > > Would a Space Elevator pay for itself in the end? > > > > http://www.highliftsystems.com/ > > This remains to be determined. It might be a great way to get > humans into space but still might not solve the heavy lift problem. > I don't know what mass the proposed elevator designs are capable > of handling. While we do now have what can be called bucky-fibers > they are still expensive to manufacture and aren't continuous > molecular structures thousands of km in length -- so I don't know > how this would impact the capacity of a space elevator. There is > also the significant problem of where to put one, what happens to > the bottom levels during a tropical storm and the problem that all > hell breaks loose if the cable snaps at any point.
It is claimed here that all of these problems are manageable: http://www.eurekasci.com/SPACE_ELEVATOR/Phase1_Report/chapter1.html By the way, "continuous molecular structures thousands of km in length" is not a requirement. I'm wearing a very durable shirt nearly two meters from cuff to cuff, composed of individual fibers only tens of centimeters long. Carbon nanotube fibers might never exceed their current record lengths (someone held his thumb and finger apart at a conference recently to illustrate; how's that for a citation?) and still be woven into the required ribbons. How? On-chip MEMS technology has already delivered the DMD -- digital micromirror devices, now used in optical projection technology and elsewhere. I worked in the IC CAD industry for several years, and learned to yawn through the revolutions, but it still beats the living crap out of me how we can already have chips in commercial use using invisibly small devices incorporating *hinges*. I helped translate a patent from Japanese a few months ago, purporting to tell the world how DMDs might be used in microelectronic fabrication optics to improve the yield of ICs, and by the same token, DMDs themselves -- and by extension, virtually any MEMS-based device. I didn't see anything implausible, and it may be in production use already for all I know -- the Japanese are pretty secretive about these things. So, in a way, nanotech is already improving nanotech, or is about to. The day may come (sooner, perhaps, than even a jaded techie like me can handle it) when you can pour a bunch of buckytubes in one end of a nanoscale textile mill, and get a continuous ribbon out the other end, at an acceptable rate of production, and at an acceptable cost. For the terrestrial applicatons alone, people will do it if they can. Heavy lift is a non-problem if light lift costs crash through the currently-impermeable floor. If you had to build a car only by poking equipment and materials through a keyhole, engineers could figure out how to do that. A pain? Yeah, maybe, but some people build model ships in bottles, for the challenge. One space cadet's poison is another cadet's red, sizzling steak. If it costs a million bucks to open the door, but only pennies for each keyhole poke, someone will figure out ways to build that car on the other side of the door for well under a megabuck. The real problem (given a penny-a-poke keyhole) is creating demand for the car -- for many cars, really. A space elevator that "pays for itself" only in some accounting based on current launch costs alone doesn't really pay for anything. It just reduces costs for a service with limited demand in the first place. Without sufficient demand, it could never pay back -- and hence, never get funded. Unless, perhaps, some government forks out what's needed for a Mars mission, and the elevator is seen as mission-critical. (Or maybe my crystal ball has been infected by a Bulgarian computer virus. Who knows what the next 20 years will bring?) -michael turner [EMAIL PROTECTED] == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
