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Space Elevator Company Fission
Dag Maggot writes "Highlift Systems seems to be going through some turbulent times with cofounder Michael Laine leaving to form his own space elevator company LiftPort. Interestingly, Liftport pledges to be a "transparent" company, and as such have provided the full text of the original space elevator proposal which was made to NASA NIAC." We mentioned Liftport before, but the proposal is new and quite interesting.
The space elevator seems to be the most promising alternative to the Shuttle program. The biggest problem are the carbon-nanotubes, it is not clear yet, how they are to be produced and a BIG quantity of them will be necessary for the project.
... or the poor connection of the server ... I hope for the first.
The site seems to be slashdotted already - 3 minutes, this should be a Slashdot record. On the other side it indicates the interest to the subject
I've spoken with Mr Laine concerning Lift Port systems. From what he told me, he is not leaving High Lift. Lift port was simply created for some sort of capital creation reason.
So, as far as I know, Michael Laine has not left the Highlift...
There are some crazy design specs that people don't usually consider besides the nanotubes and the lack thereof.
1) due to the weight of the cable, it needs to be thicker at the middle and taper off at the ends - this makes the attachment of a vehicle to traverse the cable considerably more difficult
2) the growing - you can't "lower" a cable from a space station. the center of gravity must remain at the geosync point if you want to stay afloat
3) the keeping cable tensioned - this involves capturing a sizable asteroid into an orbit dangerously close to the earth (as in, genocidal proportions if shit goes wrong) - and after you anchor the cable, push it back out so it will keep tension (geosync don't work here). A fly-by capture is out of the question, and actually dragging a asteroid to our doorsteps is impossible by today's figures.
Space elevator, while cool, has a loooong road ahead of it - I am not betting my money on it (within my lifetime, anyhow). Granted I probably seem like a pesky naysayer that's keeping technology from going places - but just imagine stuff we developed WITHOUT first thinking it through; I think the nuclear stockpile on US and Russian sides definitly proves my point.
I'm all for it if they can bring the damn asteroid here SAFELY, though. (Shuttles so far has a roughly 2% failure rate - and that's two completely fatal ones - I don't want the fate of the world depending on that kind of odds)
My life in the land of the rising sun.
A nice article on space elevators without the fancy scientific buzzwords can be found here
You can also construct the cable in a satellite that's on geosynchronous orbit. Molecular construction both ways, so that one end lowers itself to earth, while another grows into space and towards the space station acting as the elevator end point.
As for space elevators in general, not only does the construction pose significant obstacles, but the reality of having a tensile cable stretched from earth to the sky (literally) introduces interesting variables. Back-up plans in case a plane flies smack into the cable? Effects of wind, lightning, hurricanes? What happens if the cable snaps below geosynchronous orbit? Anyway, sure, problems abound, but there's something very exciting about the idea of building something as massive as a space elevator will be.
Also, there won't be a great deal of taper if they get the material strength they expect - about a 2:1 ratio iirc.
You may have noticed this term being spun about in the thread; the answer is nanotubes.
A nanotube is like a bucky-ball (buckminster fullerine) but elongated into a cylinder. To the uninitiated a bucky-ball is a small macromolecule composed of 60 carbons. It looks like a football (european) and hence its name. So nanotubes are cylinders of hexagonallybonded carbon.
Potentially you could have "threads" of nanotubes that are bonded completely with strong chemical bonds, in comparison most materials we use in construction today consist of mostly much weaker interactions based on small charge dipoles and momentary charge variation (van-der-vaals force). IIRC correctly a van-der-vaals bond is about a thousand times weaker than a covalent (chemical) bond, and it is forces like these that hold the materials like kevlar together. The way the carbons bond in nanotubes should be compared to that of diamond, so in layman's terms a nanotube is a very long and very narrow cylindrical diamond.
A rope or sheet of woven nanotubes (of good length) would have a surely unbelievable tensile strength and hence people want to use them in applications like these (as well as in many other areas).
However AFAIK nobody has managed to develop nanotubes efficiently with significant length yet. However I keep seeing journals with articles on nanotubes and their practical applications so money's going into this field and it can only be a matter of time before a method of cheap production is found. The only method I know to date is vaporisation of gaphite with a laser - the resulting dust contains a variety of carbon species including bucky balls and nanotubes.
Nanotubes also conduct electricity and heat efficiently and seem to act as excellent lubricant.
The revised, second-phase report, much advanced over the first, should appear Any Day Now. Just waiting for NASA approval. There's also a book that expands on the idea.
The web server was having troubles late last night, so slashdotting only provided the final straw. We'll be back.