Dear all: Happy New Year. This is the first time I post message, though I have been on this list for quite a while. I have strong research backgroud and...
8515
Herbert Murray
hcm1955
Jan 6, 2009 3:04 pm
A novel to power a climber: http://news.bbc.co.uk/2/hi/science/nature/7792297.stm http://news.bbc.co.uk/2/hi/technology/7796325.stm...
8516
karikarhi
Jan 7, 2009 1:17 pm
... Very interesting. Would the elevator speed depend on the vibration frequency? What kind of frequencies would be needed for, say, 200 km/h speeds? Would...
8517
Andrew Swallow
am4987
Jan 7, 2009 4:12 pm
... The brush bristles can be replaced by ratchets. The ribbon would have to be made from at least 3 interwoven threads to give the ratchet something to grip....
8518
Scott Orshan
sdorshan
Jan 7, 2009 4:37 pm
Cute proposal, but I just don't see it working. Would vibrations on the ground get any higher than a few hundred meters? Wouldn't they be dampened by the...
8519
Tony Rusi
marsbeyond
Jan 7, 2009 4:53 pm
I remember reading an article in the Journal of British Inter-planetary Science (JBIS) that discussed several different methods on how to stop a space tether...
8520
Tony Rusi
marsbeyond
Jan 7, 2009 4:55 pm
A much more practical design is a Hoyt tether with multiple strands at great separation distances. ... From: Andrew Swallow <am.swallow@...> ...
8521
Andrew Swallow
am4987
Jan 8, 2009 5:44 pm
... [snip]> ... To go downwards just turn the racket upside down. You will also need a brake to slow down. ... the ... You would need two ribbons - one to go...
8522
Andreas
awnd329
Jan 9, 2009 11:25 pm
I agree, high frequency vibrations would dissipate way too fast. Also, the standing wave nodes would be a problem. The one way out is to use the lowest mode....
8523
Tony Rusi
marsbeyond
Jan 10, 2009 6:25 am
I have been looking at the toy helicopter the wright brothers played with as kids. I am suprised that no one has thought of using aerodynamic lift to aid the...
8524
Andrew Swallow
am4987
Jan 10, 2009 6:57 pm
... with as kids. I am suprised that no one has thought of using aerodynamic lift to aid the climber until it is out of the atmosphere. One example being...
8525
Andreas
awnd329
Jan 12, 2009 6:36 pm
All proposals of lift inside the atmosphere suffer the same problem: The benefit is minuscule. Even granting the first miles are the hardest, there are plenty...
8526
Herbert Murray
hcm1955
Feb 18, 2009 12:38 am
I am not sur if this is a real break thru but this article has been floating around the SE groups for a while From...
8527
Herbert Murray
hcm1955
Mar 1, 2009 2:24 pm
The main show stopper with an orbiting cable based space elevator is the very large expense of transporting the materiel into orbit. The first "starter" cable...
8528
Herbert Murray
hcm1955
Mar 1, 2009 3:10 pm
Distance around low earth orbit is 1.6 billion inches. There is about 5000 tons of space junk. At 0.1 pound per cubic inch that would be 100 million cubic...
8529
Ian Woollard
wolfekeeper
Mar 1, 2009 5:27 pm
... I like it! Let's do it! ;-) ... -- -Ian Woollard We live in an imperfectly imperfect world. Life in a perfectly imperfect world would be *much* better....
8530
Jerry Irvine
01rocket@...
Mar 1, 2009 6:55 pm
... The cost of collecting that much debris in that many orbits then fabricating it in orbit would exceed the cost of just launching it in sections with...
8531
Herbert Murray
hcm1955
Mar 1, 2009 7:50 pm
... 01rocket@...> ... 5000 tons of stuff shot into orbit at 10,000 dollars a pound cost 100 billion dollars. Gathering and changing orbits using a solar...
8532
Ian Woollard
wolfekeeper
Mar 1, 2009 9:02 pm
... Unfortunately, yes it is a lot more expensive, even with ion drives. The delta-v needed to change orbital planes significantly is extremely large, and in...
8533
Herbert Murray
hcm1955
Mar 1, 2009 10:57 pm
You can do any plane change with about 0.8 times the delta-V needed to reach the orbit in the first place. ISP for ion is about 2000 seconds, where for...
8534
Ian Woollard
wolfekeeper
Mar 1, 2009 11:29 pm
... No, actually the worst case is ~16 km/s delta-v- for example with a west-east orbit you may want to access the east-west orbit. There might be tricks you...
8535
Jo Jaquinta
jim_plummer
Mar 2, 2009 12:08 am
... Totally. Most of the "space junk" is quite small. If you really want a tug to zoom around moving it all you also have to factor in the weight of the tug....
8536
Jerry Irvine
01rocket@...
Mar 2, 2009 12:39 am
... There is one practical way. Use a laser to heat one edge of the junk to thrust it to an orbital change. If you had a laser tug with about a 200 mile...
8537
Tony Rusi
marsbeyond
Mar 2, 2009 3:22 am
some of the junk in LEO could be used for a counterweight ... From: Jerry Irvine <01rocket@...> Subject: Re: [space-elevator] Re: Orbiting Cable Based...
8538
Jerry Irvine
01rocket@...
Mar 2, 2009 3:56 am
... Given its density (nuclear shielding, solid propellant, dense steels), that is a far better use than "refining it in orbit for some rope or something". ...
8539
Craig Holm
craig_holm
Mar 11, 2009 1:51 am
When you say "heat" I presume you mean vaporize. If we're talking about a regularly shapped item, this might work. I have reservations about continuing...
8540
Craig Holm
craig_holm
Mar 11, 2009 1:55 am
Ian- I often enjoy reading your posts, but I have an issue with your signature line. In actual fact, we live in a perfect world, we're just too simple to...
8541
Craig Holm
craig_holm
Mar 11, 2009 2:00 am
Let's not forget the EMP produced by nuclear explosions. We might clear the skies, and we might wind turning off the lights as well. ... at least we may...
8542
Ian Woollard
wolfekeeper
Mar 11, 2009 3:16 am
... You my friend, are a pessimist; and are thus utterly unsuitable to post on this list. ;-) ... -- -Ian Woollard We live in an imperfectly imperfect world....
8543
Andreas
awnd329
Mar 12, 2009 5:29 pm
Regarding collection of space debris, I rather like the idea of a "debris-hopper". This would be a device that would use mechanical energy transfer...
