Posted on 08/04/2014 12:12:44 AM PDT by 2ndDivisionVet
Could rocket scientists be an endangered species?
You're probably betting "no," given the contemporary efforts to hurl hardware to the moon, to Mars, and to a passel of other unearthly locales. The rocket biz is busy, and it's diversifying. An enthusiastic troupe of private companies is also getting into the act, hoping to cash in by lifting off.
It seems that "rocket scientist" is a job category that's here for the long haul, like "mortician." But all this activity masks an important point: rockets are not a terribly efficient way to lift things into space. For every pound of payload, there are typically 25 pounds of rocket and fuel, and in some cases the vehicle is just thrown away after use. Rockets also suffer from a heavy foot on the accelerator, subjecting payloads and passengers to G-forces that warp faces into Botox ads. In addition, and despite nearly a hundred years of building these flame-belching devices, they're still vulnerable to colorful self-destruction. This is probably not a list of features you would accept in your next family car.
However, there's an intriguing alternative to traditional reaction technology that could beat rockets at their own game. It's called the space elevator.
What's a space elevator? Simply described, it's a thin ribbon, about 3 feet wide and 60 thousand miles long, stretching upwards from the surface of the Earth. The lower end is bolted to a heavy anchor (think of an oil drilling platform), and the top is capped with a counterweight. It's all arranged so that the center of mass falls at the geosynchronous orbital point, about 22,000 miles up. Like a rock on a string swung 'round your head, the ribbon is under tension, stays straight, and rotates with the Earth....
(Excerpt) Read more at huffingtonpost.com ...
I thought there were possibilities using lasers or microwave.
I think I first read about space elevators when I was a teen more than thirty years ago.
I don’t think they are any closer to reality now.
Anybody remember the space tether experiment failure of STS-75.
A space elevator would generate a considerable amount of current traveling down the shaft.
Great for cargo, but people will still need rockets to go to space, both to LEO and beyond GEO from the space elevator terminus.
HAH! I thought this was possible using a geosynchronous orbit. I had imagined it would need to be much bigger and sturdier. But would the atmosphere of the Earth somehow disrupt the orbit? I am thinking that the ribbon would have to be slack....because if strong enough winds push it, it could slow down or speed up the anchor at the space end just enough that the orbit could deteriorate.
It will take a super-material to support the weight.
Supposedly the economics of Spacex’s fully reusable launch vehicles are better than a space tether. I doubt this will be used, as a catastrophic accident would cause 10,000 miles or so of cable to come down anywhere around the equator, and there are populated areas on the equator.
I don’t think we will see a space elevator any time soon
A space elevator would generate a considerable amount of current traveling down the shaft.
Maybe that’s the answer to our energy problems.
A space elevator would be exposed to all kinds of weather extremes including space weather.
Even minor solar mass ejections can produce high currents in surface electric transmission lines. Consider the potential currents that a space elevator mighty be subjected to.
I think that there may be all kinds of engineering hurdles yet to be thought of for a space elevator.
I recall in the 70's, visiting a oil rig support supplier. They had sensors to drop into oil wells to determine the exact position of the well point. The sensors could be dropped as much as one mile. The sensor weighed 1-2 pounds. The electrical cable to connect it weighed hundreds of pounds, and could only support its own weight plus the sensor for several hundred feet. Steel cable was used to support it beyond this.
But, of course, the steel cable must also support its own weight. There were huge (8 foot diameter)coils of high strength one inch diameter steel cables to simply drop this little sensor into an oil well. All this was for a ONE MILE elevator, to drop a 2 pound sensor into an oil well.
A 60,000 mile elevator is much much more complicated than just 60,000 times worse.
Even if we had the material technology to build such a ribbon, how would we deploy it? A spool big enough to hold 60,000 miles of ribbon would be pretty big!
Arthur C Clarke came up with the idea.
This is a really dumb idea.
Arthur C Clarke came up with the idea.
While Mr Clarke is given the major credit for popularization of the concept and value of geosynchronous / geostationary satellites he is much less so for the idea of the "space elevator" although his novel on it, "Fountains of Paradise" (1979) was quite enjoyable and informative. However, the concept of space elevators date back to a thought experiment by the great Russian space theorist, Konstantin Tsiolkovsky, in 1895. Since then there have been multiple iterations, studies and story lines about it. Funny enough, almost simultaneous with Clarke's novel came fellow Brit-born author, Charles Sheffield's "Web Between Worlds" which I think did a better stab at the required engineering, but that is my opinion!
“It traverses the van Allen radiation belts too slowly, causing excessive radiation exposure to human passengers.”
That depends on the allowable size and weight of the compartment. A larger elevator could have shielding.
The bigger problem with the concept is what happens when a meteor, space junk or human action severs it...
Why build a space elevator when I’ve got some magic beans I’m willing to sell and they will do the exact same thing at half the price.
The electrical potential (Voltage) between the ground and the atmosphere above: "...ground‐level electric fields ranged from 3.2 to 7.6 kV per meter."
For all the gory details go here:>>
http://onlinelibrary.wiley.com/doi/10.1029/2011JD015710/pdf
For the uninformed that amounts to 7,600,000 Volts per kilometer of elevator height.
I love it when liberals become "scientists" 'cause they believe in magical thinking - whatever hair-brained scheme they can think up, can happen just because they thought of it.
Lurking'
How long would it take an elevator to go 60,000 miles.
And the thing would be a terrorist magnet.
Is it like the Maxwell House Elevator? Good to the last drop.
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