THE VERTICAL RAILROAD
THE VERTICAL RAILROAD
The crème de la crème of lunar locales, & THE destination of a probable race to claim it for one nation!
. . Malapert Mountain is located 122 kilometers from Luna’s South Pole. The site is power-rich. A central peak 5KM high basks in sunlight over 90% of the time. 7% of the time, the peak experiences a full sunset. The entire disk of the Earth remains in constant view from the lunar peak, which means that continuous real-time operations between the Earth and Luna are possible. "From the peak, you could beam power & control to devices all throughout the south polar region."
. . They believe there’s a six-degree downslope to Malapert Mountain, to the west-northwest. That should make for easy access to surrounding points of interest. Nearby, permanently shadowed craters are just right for installing infrared telescopes that must work under super-cold conditions. They probably also shade water lodes.
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July 9, 09: An inflatable free standing tower could one day carry equipment and tourists 20km above Earth, and it could be completed much sooner than a cable-based space elevator, say researchers at York U in Toronto, Canada.
. . They envision a giant tower assembled with a series of modules made up of Kevlar-polyethylene composite tubes that would be made rigid by inflating them with a lightweight gas such as hydrogen or helium. This would actively stabilize the giant tower and allow for flexibility. The elevator would support a series of platforms or pods that would launch payloads into Earth orbit.
. . "You can visualize it as a system of nesting segments that roll out vertically and snap into position, much like a telescoping wand." The 20-kilometer version (15 km tower atop a 5 km mountain) would be made up of 100 modules, and would weigh 800,000 metric tons when pressurized. The full scale structure would also require gyroscopes and active stabilization systems in each module to help it stay upright and withstand winds.
. . The problems with a space tether include material strength constraints, the need for in-space construction, the fabrication of a cable at least 50,000 km in length, and the aging and meteorite-damage effects associated with a thin tether or cable in Low Earth Orbit. Not to mention the envisaged use of ribbons woven from super strong nanotubes, which is a material that is as yet non-existent. The York inflatable tower, on the other hand, would use materials that are already available.
June 2, 06: Scientists and science fiction fans alike have big plans for carbon nanotubes; it has been hoped that a cable made of carbon nanotubes would be strong enough to serve as a space elevator. However, recent calculations by Nicola Pugno of the Polytechnic of Turin, Italy, suggest that carbon nanotube cables will not work.
. . American engineers worked on the problem in the mid-1960's. What type of material would be required to build a space elevator? According to their calculations, the cable would need to be twice as strong as that of any existing material including graphite, quartz, and diamond.
. . In something of a "downer" for space elevator fans, Pugno has calculated that inevitable defects will greatly reduce the strength of any manufactured nanotubes. Laboratory tests have demonstrated that flawless individual nanotubes can withstand about 100 gigapascals of tension; however, if a nanotube is missing just one carbon atom, it can reduce its strength by as much as 30%. Bulk materials made of many connected nanotubes are even weaker, averaging less than 1 gigapascal in strength.
. . In order to function, a space elevator ribbon would need to withstand at least 62 gigapascals of tension. It therefore appears that the defects described above would eliminate carbon nanotubes as a usable material for a space elevator cable.
Nanotube cable, also known as a quantum wire, would theoretically conduct electricity up to 10 times better than traditional copper wire and weigh one-sixth as much. Scientists believe quantum wires could make spacecraft much lighter and more powerful, and may lead to faster computers and other commercial applications.
. . Discovered in 1991, carbon nanotubes are tiny, molecular cylinders formed purely of carbon atoms. They are created by shooting high-powered lasers at a carbon target. Each nanotube is just one nanometer in diameter, or 10,000 times smaller than the width of a human hair.
. . Currently only 2% of all nanotubes can be used as quantum wires, and sorting these --called "armchair nanotubes"-- from the rest is nearly impossible. Researchers at the lab believe they can get around this problem by growing the desired nanotubes like crystals.
. . Some engineers have also talked about building a 100,000-km-long tether made of nanotubes for a space elevator that would carry astronauts and cargo into orbit.
Oct 14, 03: Los Alamos National Laboratory researchers are proposing an elevator reaching 62,000 miles into the sky to launch payloads into space more cheaply than the shuttle can. "The first country that owns the space elevator will own space," said lab scientist Bryan Laubscher.
. . A 32 million-story-tall cable, would be carried into orbit on a conventional spacecraft, then gradually dropped down to Earth to be attached to a platform similar to an ocean oil-drilling rig.
. . Earth's magnetosphere, far above where the shuttle typically travels, could be a radiation hazard.
. . A payload on the shuttle costs about $15,000 per kilogram to launch into orbit. A payload on the first space elevator likely would cost about $1,000 per kilogram, which could drop to $50 to $100 in time.
. . Backers say the elevator would make it affordable to launch solar power satellites. Such satellites could collect as much energy as a nuclear power plant and beam it anyplace on Earth. "None of us can imagine how the space elevator will change the world," Morgan said. "I'd love to be here 15 years after the first one is built to see how the world changes. I think it will change everything."
Sept 17, 03: The 2nd Annual International Conference on the Space Elevator was held September 12-15. The event was co-sponsored by the Los Alamos National Laboratory of Los Alamos, New Mexico and the Institute for Scientific Research, Inc., based in Fairmont, West Virginia.
. . No longer merely theoretical, research and development dollars are actually being spent on fleshing out how best to build these sky high beasts of burden. Preliminary studies of the space elevator suggest that it would be capable of lifting 5-ton payloads every day to all Earth orbits, the Moon, Mars, Venus or the asteroids. Furthermore, it could be operational in 15 years. Now projected to be on the order of a $6 billion investment, the first space elevator could quickly reduce lift costs to $100 per pound. That far outstrips todays pricey launch costs of roughly $10,000 to $40,000 per pound.
. . 86-year-old Arthur C. Clarke recounted an earlier prediction about when the space elevator might be up and operating. "Itll be built 10 years after everybody stops laughing... and I think they have stopped laughing", he said.
. . Clarke also pointed to difficulties ahead. "I dont quite know how were going to solve the issue of space debris. Thats going to be a major problem in making the space elevator practical", he advised. Damage to the space elevator is a worry, Clarke said. He added that the heavenly elevator is sure to become a target for terrorism. "We need to remove economic and other grudges. But, of course, you could never cope with total lunatics that could do anything."
The magic substance that appears likely to literally hold the space elevator concept together is the carbon nanotube. A ribbon, 100,000 km long, made of carbon nanotubes, would be less than a meter wide and thinner than a newspaper page. But that ribbon would be hundreds of times sturdier than steel and one-fifth the weight.
. . ISRs Edwards points to new work in China that suggests carbon nanotubes can be fused together, without need of a matrix material. If perfected, he said, single-fiber carbon nanotubes might offer incredible strength --several times stronger than what is required to fabricate space elevator ribbon.
. . Some experts have begun assessing the feasibility of building large space structures out of carbon nanotube composites, Edwards said. Once the structure is made, then the carbon nanotube surface would be coated with a reflective metal -- perfect as a giant, but lightweight, space-rated mirror.
. . Next year may well be a turning point in the history of the space elevator. U.S. lawmakers have written into an appropriations bill $2.5 million in funds to foot-the-bill for further engineering reviews, develop data bases, and address critical issues related to the space elevator.
Sept, 02: A space elevator is essentially a long cable extending from our planet's surface into space with its center of mass at geostationary Earth orbit (GEO), 35,786 km in altitude. Electromagnetic vehicles traveling along the cable could serve as a mass transportation system for moving people, payloads, and power between Earth and space.
. . Current plans call for a base tower approximately 50 km tall --the cable would be tethered to the top. To keep the cable structure from tumbling to Earth, it would be attached to a large counterbalance mass beyond geostationary orbit, perhaps an asteroid moved into place for that purpose.
. . "The system requires the center of mass be in geostationary orbit," said Smitherman. "The cable is basically in orbit around the Earth."
. . Four to six "elevator tracks" would extend up the sides of the tower and cable structure going to platforms at different levels. These tracks would allow electromagnetic vehicles to travel at speeds reaching thousands of kph!
. . An equatorial location is ideal for a tower of such enormous height because the area is practically devoid of hurricanes and tornadoes and it aligns properly with geostationary orbits.
. . The workshop's findings determined the energy required to move a payload by space elevator from the ground to geostationary orbit could remain relatively low. Using today's energy costs, researchers figured a 12,000-kg Space Shuttle payload would cost no more than $17,700 for an elevator trip to GEO. A passenger with baggage at 150 kg might cost only $222! "Compare that to today's cost of around $10,000 per pound ($22,000 per kg)," said Smitherman. "Potentially, we're talking about just a few dollars per kg with the elevator."
. . Researchers noted that "maximum stress [on the cable] is at geosynchronous altitude so the cable must be thickest there and taper exponentially as it approaches Earth. Any potential material may be characterized by the taper factor --the ratio between the cable's radius at geosynchronous altitude and at the Earth's surface. For steel the taper factor is tens of thousands --clearly impossible. For diamond, the taper factor is 21.9, including a safety factor. Diamond is, however, brittle. Carbon nanotubes have a strength in tension similar to diamond, but bundles of these nanometer-scale radius tubes shouldn't propagate cracks nearly as well as the diamond tetrahedral lattice."
. . Carbon nanotube (CNT) is a new form of carbon, equivalent to a flat graphene sheet rolled into a tube. CNT exhibits extraordinary mechanical properties: the Young's modulus is over 1 Tera-Pascal and the estimated tensile strength is 200 Giga-Pascals. The desired strength for the space elevator is about 62 GPa.
. . The elevators would float "above" the track, propelled by magnets, using no moving parts. This feature would allow the space elevator to attain high vehicle speeds without the wear and tear that wheeled vehicles would put on the structure.
Feb 24, 02: Deploying the ProSEDS tether is good first practice for unleashing a 100,000-kilometer long ribbon as part of the researcher's elevator to space project. What ProSEDS hopes to demonstrate is electrodynamic tether propulsion.
. . Similar to the principle of an electric motor in many household appliances, as well as automobile generators, when a wire moves through a magnetic field, an electrical current results. As this current flows through the wire, it experiences a push from any external magnetic field. For a space tether, that magnetic field is found naturally around the Earth. The force exerted on the tether by the magnetic field can be used to raise or lower a satellite's orbit, depending on the direction of the current's flow.
. . Once in space, ProSEDS will deploy from the Delta 2's second stage the lengthy two-part tether: a 3.1-mile-long (5 kilometers), ultra-thin bare-wire tether connected with a 6.2-mile-long (10 kilometers) non-conducting tether. Thanks to touchy-feely physics, the tether will produce thrust, forceful enough to lower the altitude of the spent Delta 2 upper stage.
Aug 19, 02: The world's space programs are vertically challenged. The first space elevator could possibly be constructed at a price tag of between $7 billion to $10 billion. "This is a vertical railroad." It could be literally up and operating about 2019.
. . The space elevator is a ribbon that stretches some 100,000 kilometers from Earth to space. This high-wire act would be anchored to an offshore sea platform floating near the equatorial line in the Pacific Ocean. At the other end, high above Earth, the elevator is tipped by a counter weight. Electrically powered "climbers", energized by laser beam, would make their way up and down the ribbon. It takes 7.5 days to get to geosynchronous orbit and the same amount of time to get back down. These automated devices are built for the long haul; they ride the length of the ribbon topped by spacecraft, construction materials, and eventually passenger-carrying pods.
. . Carbon nanotubes possess incredible properties. One of those is having a tensile strength 100 times stronger than steel, or one-fifth the weight. Weight is the enemy --its own weight, not the elevator-- remember, it's 100,000 K long!
. . Lightning, wind, the degrading effects of atomic oxygen on the cable, radiation, wearing down of the ribbon by sulfuric acid droplets drifting in the upper atmosphere --all these and other uncertainties are being dealt with. Then there's the worry of meteoroid hits, pings from the shooting gallery of space junk, and collisions with satellites. Even the threat of a terrorist attack on a space elevator is being assessed. So too are public health risks of using tiny carbon nanotubes, so ultra-small in size that the effects of ingesting the substance into the lung calls for detailed study. No killer problems have been identified to date.
. . Arthur Clarke, asked when it would become real, responded: "The space elevator will be built about 50 years after everyone stops laughing."
Constructing a vertical railroad stretching into space is no longer wistful fantasy carried in science fiction novels. Just ask the folks at HighLift Systems in Seattle, Washington. For the last few months, officials at HighLift Systems have been talking it up with an alphabet soup of government agencies, like NASA, the Defense Advanced Research Projects Agency (DARPA), the Federal Aviation Administration (FAA), as well as the National Reconnaissance Office (NRO).
. . Meanwhile, testing of prototype space elevator equipment is near at hand.
Detailed design work on the space elevator concept has been made possible through NASA's Institute for Advanced Concepts (NIAC).
. . The challenge has now moved into the funding area. Funds needed for space elevator engineering are more difficult to come by because of the timescale for financial return.
. . There is success to report in making carbon nanotubes into more than a laboratory curiosity. But extra work is needed to push carbon nanotubes from vials to miles. "The composite development is moving more quickly than expected and we believe we will have impressive materials in the very near-term."
. . If a robotic climber slowly tools up to the far end of the cable, then releases from the line, it would have sufficient energy to escape from Earth's gravity-well and zoom onward to the Moon, Mars, Venus, or planetisimals.
. . For a space elevator to function, a cable with one end attached to the Earth's surface stretches upwards, reaching beyond geosynchronous orbit --which is 35,000 km (usta be 21,700 miles).
. . The competing forces of gravity at the lower end and outward centrifical force at the farther end, keep the cable under tension. The cable remains stationary over a single position on Earth. This cable, once in position, can be scaled from Earth by mechanical means, right into Earth orbit. An object released at the cable's far end would have sufficient energy to escape from the gravity tug of our home planet and travel to Luna or to farther targets.
. . Each equatorial base site that anchors space elevator operations would feature a huge tower that is a true skyscraper at 50 km (31 miles) tall.
. . The whole thing is made possible by carbon-nanotube-composite ribbon.
. . "I'm convinced that the space elevator is practical and doable. In 12 years, we could launch tons of payload every three days, at [about a hundred dollars a Kg]. In 15 years, we could have a dozen cables running full steam putting 50 tons in space every day... for even less, including upper middle class individuals wanting a joyride into space. Now I just need the $5 billion", Edwards added. A space elevator could be up within a decade. "There's no real serious stumbling block to this."
. . The project would use only two shuttle flights. Then, twenty tons of cable and reel would be kicked up to geosynchronous altitude by an upper stage motor. The cable is then snaked down to Earth and attached to an ocean-based anchor station, situated in the equatorial Pacific.
. . Once secure, a platform-based free-electron laser system is used to beam energy to photocell-laden "climbers". These are automated devices that ride the initial ribbon skyward. Each climber adds more and more ribbon to the first, thereby increasing the cable's overall strength. Some two-and-a-half years later, and using nearly 300 climbers, a first space elevator capable of supporting over 20 metric tons is ready for service.
. . "If budget estimates are correct, we could do it for under $10 billion. The first cable could launch multi-ton payloads every 3 days. Cargo hoisted by laser-powered climbers, be it fragile payloads such as radio dishes, complex planetary probes, solar power satellites, or human-carrying modules, could be dropped off in geosynchronous orbit in a week's travel time", Edwards said.
He is looking into the environmental impacts stemming from elevator operations. Being studied too is impact of lightning, wind and clouds on an Earth-to-space cable system. Space elevators for use on other worlds, like Mars and Luna are receiving attention as well.
Robert Hoyt, president of Tethers Unlimited, wants to toss ships moonward with a 100 km lariat. Rotating around a low Earth orbiting platform, a 9-ton tether --likely made of Zylon, an ultratough polymer-- would hook a spacecraft and fling it to the moon. A second tether orbiting the moon would catch the ship and pull it to the lunar surface, then scoop up useful minerals and cast the load back to Earth orbit.
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