(Caption) The Seattle space needle pokes through the cloud tops (well, just fog really… it's only 184 meters high). Credit: Liem Bahneman, pixduas.com
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Arthur C Clarke allegedly said that the space elevator would be built fifty years after people stopped laughing. The first space tower though… well, that might need a hundred years. The idea of raising a structure from the ground up to 100 kilometers in height seems more than a bit implausible by today’s engineering standards, given that we are yet to build anything that is more than one kilometer in height. The idea that we could build something up to geosynchronous orbit at 36,000 kilometers in height is just plain LOL… isn’t it?
Space tower proponents point to a key problem with the space elevator design. It may only be after we have spent years inventing a method to manufacture 36,000 kilometers of flawless carbon or boron nanotube fiber – which is light enough not to break under its own weight, but still strong enough to lift an elevator cabin – that we suddenly realize that we still have to get power to the cabin’s lifting engine. And doesn’t that just mean adding 36,000 kilometers of conventional (and heavy) electrical cable to the construction?
Mind you, building a space tower brings its own challenges. It’s estimated that a steel tower, containing an elevator and cabling, of 100 kilometers height needs a cross-sectional base that is a 100 times greater than its apex and a mass that is 135 times greater than its payload (which might be a viewing platform for tourists).
A solid construction capable of holding up a launch platform at 36,000 kilometers altitude might need a tower with ten million times the mass of its payload – with a cross-sectional base covering the area of, say, Spain. And the only construction material likely to withstand the stresses involved would be industrial diamond.
A more economical approach, though no less ambitious or LOL-inducing, are centrifugal and kinetic towers. These are structures that can potentially exceed a height of 100 kilometers, support an appreciable mass at their apex and still maintain structural stability – by virtue of a rapidly rotating loop of cable which not only supports its own weight, but generates lift through centrifugal force. The rotation of the cable loop is driven by a ground-based engine, which can also drive a separate elevator cable to lift courageous tourists. Gaining altitudes of 36,000 kilometers is suggested to be achievable by staged constructions and lighter materials. But, it might be sensible to first see if this grand design on paper can translate to a proposed four kilometer test tower – and then take it from there.
There are also inflatable space towers, proposed to be capable of achieving heights of 3 kilometers with hot air, 30 kilometers with helium or even 100 kilometers with hydrogen (oh, the humanity). Allegedly, a 36,000 kilometer tower might be achievable if filled with electron gas. This is a curious substance argued to be capable of exerting different inflationary pressures depending on the charge applied to the thin-film membrane which contains it. This would allow a structure to withstand differential stresses – where, in a highly charged state, the highly excited electron gas mimics a molecular gas under high pressure, but with a reduced charge it exerts less pressure and the structure containing it becomes more flexible – although, in either case, the overall mass of the gas remains unchanged and suitably low. Hmmm…
An inflatable 100 kilometer high, 300 kilometer long space pier, built to launch spacecraft horizontally. Humans might survive the G forces required to achieve orbit - which they certainly wouldn't do if the same trajectory was attempted from sea-level. Credit: Josh Hall, autogeny.org/tower/tower.html
If this all seems a bit implausible, there’s always the proposed 100 kilometer high space pier that would enable horizontal space launch without rocketry – perhaps via a giant rail gun, or some other similarly theoretical device that works just fine on paper.
Further reading: Krinker, M. (2010) Review of new concepts, ideas and innovations in space towers. (Have to say this review reads like a cut and paste job from a number of not-very-well-translated-from-Russian articles – but the diagrams are, if not plausible, at least comprehensible).
Ars Electronica made its debut on September 18, 1979. This festival of art, technology and society spotlighted the emerging Digital Revolution. In his preface to what was going on then, Mayor Franz Hillinger wrote (with specific reference to music): “Ars Electronica is giving rise to a new tonal coloration in which state-of-the-art technology is dovetailing with the intellectual spirit of the age to open up undreamt-of expressive possibilities. […] I am absolutely convinced that this new melodic parlance will ultimately be widely understood. After all, with the help of electronic music, it can even be made visible, be implemented in color, contour, line and rhythm that can be followed onscreen.” He would be proven correct.
Within a few years, Ars Electronica developed into one of the world’s foremost media art festivals. And its growing success was paralleled by the expansion of its annual lineup of events. The 1979 festival proudly presented 20 artists and scientists; in 2008, no fewer than 484 speakers and artists from 25 countries were in attendance. Don’t miss this year’s Live Stream on September 6 at 14:00 UT!
For more than three decades now, this world-renowned event has provided an annual setting for artistic and scientific encounters with social and cultural phenomena that are the upshot of technological change. Symposia, exhibitions, performances and interventions carry these inquiries beyond the confines of conventional conference spaces and cultural venues and take them out into the public sphere and throughout the cityscape. In this process of pervading public spaces and staging festival activities in interesting and appropriate physical settings, Ars Electronica has consistently displayed extraordinary imaginativeness. From the harbor to the mines, from factories to outlying monasteries, unusual locations have repeatedly served as sites of performances and interventions, and have, in turn, been reinterpreted by them.
But the attractiveness of Ars Electronica isn’t attributable solely to participation by renowned scientists and artists from all over the world. Or to remarkable venues. Above all, it’s the international audience that makes the biggest contribution to the festival spirit: the colorful mix of old friends and new faces who conjure up extraordinary circumstances – a “fruitful state of emergency” – every September in Linz.
Be sure to tune in on Monday, September 6th when the Ars Electronica Festival will be featuring Repair dealing with the issues of light pollution!
Another new iPhone app for astronomy, and this one, called SpaceWalking combines a 3D scale model of the Solar System with location-based data from GPS satellites to place a virtual scale model of the Solar System in your neighborhood to explore. For more info, check out the Spacewalking website. If you’re quick, follow the @SpaceWalkingApp on Twitter for a special deal.
Also, I have two of these apps to give away. First two commentors who can answer this question correctly win: How far is Jupiter from the Sun?
Screenshot of a new exoplanet app for iPhone and iPad.
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Just in time for the announcement yesterday of the multi-planet solar system discovery, and an upcoming exoplanet announcement by the Kepler team comes a new version of a free exoplanet app for iPhone and iPad. We got a note from Hanno Rein, who developed “Exoplanet,” and who just finished his PhD in astrophysics at the University of Cambridge. “It lists all discovered extrasolar planets with a lot of background information, many visualizations and animations,” he said. Other highlights include an easy search and filter for the database, real telescope images of the host star, visualizations of the orbits and the habitable zone, interactive 3D size comparison to our own solar system and much more.
With all the exoplanet news lately, “Exoplanet” is updated daily and push notifications are sent out whenever a new planet is discovered (although they can be turned off if you don’t want to get notifications). Pretty much everything known about any exoplanet is included, such as physical parameters, along with various visualizations and background information, which make this exciting subject accessible for a wider audience.
New for version 3.9 are direct links to planets and planetary systems, links to other planets of the same multi-planetary system have been added, and you can now link from any e-mail or website directly to this application by using a URL form of the exoplanet, for example, ://Fomalhaut
Rein developed this app while a student, and wanted to keep it free (knowing how hard it is to be a poor student!) so there are ads on the app. But a non-ad version is available for only $.99 USD.
I don’t have an iPhone or iPad (yet!) but Fraser does, and he said the Exoplanet app is very cool!
More than 3,300 solar panels have been erected on a vacant five acres at NASA's Kennedy Space Center. Credit: NASA/Jim Grossman
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Today, the total oil and natural gas production provides about 60 percent of global energy consumption. This percentage is expected to peak about 10 to 30 years from now, and then be followed by a rapid decline, due to declining oil reserves and, hopefully, sources of renewable energy that technologies that will become more economically viable. But will there be the technology breakthroughs needed to make clean and exhaustible energy cost effective?
Nobel prize winner Walter Kohn, Ph.D., from the University of California Santa Barbara said that the continuous research and development of alternate energy could soon lead to a new era in human history in which two renewable sources — solar and wind — will become Earth’s dominant contributor of energy.
“These trends have created two unprecedented global challenges”, Kohn said, speaking at the American Chemical Society’s national meeting. “One is the threatened global shortage of acceptable energy. The other is the unacceptable, imminent danger of global warming and its consequences.”
The nations of the world need a concerted commitment to a changeover from the current era, dominated by oil plus natural gas, to a future era dominated by solar, wind, and alternative energy sources, Kohn said, and he sees that beginning to happen.
The global photovoltaic energy production increased by a factor of about 90 and wind energy by a factor of about 10 over the last decade. Kohn expects vigorous growth of these two energies to continue during the next decade and beyond, thereby leading to a new era, what he calls the SOL/WIND era, in human history, in which solar and wind energy have become the earth’s dominant alternative energies.
Kohn noted that this challenge require a variety of responses. “The most obvious is continuing scientific and technical progress providing abundant and affordable alternative energies, safe, clean and carbon-free,” he said.
One of the biggest challenges might be leveling off global population, as well as energy consumption levels.
The new laser adaptive optics system in action. At Mount Hopkins in Arizona, a bundle of five lasers is shot into the atmosphere to improve the imaging of the 6.3-meter MMT telescope. Image Credit: Thomas Stalcup
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While it’s handy for us humans (and all of the other life on our planet for that matter), the atmosphere is almost universally cursed among astronomers. It’s great for breathing, but when it comes to astronomical observations of faint objects, all the atmosphere tends to do is muck up the view. In the past 20 years, development of adaptive optics – essentially telescopes that change the shape of their mirrors to improve their imaging capability – has dramatically improved what we can see in space from the Earth.
With a new technique involving lasers (Yes! Lasers!), the images capable with an adaptive optics telescope could be nearly as crisp as those from the Hubble Space Telescope over a wide field of view. A team of University of Arizona astronomers led by Michael Hart has developed a technique that helps calibrate the surface of the telescope very precisely, which leads to very, very clear images of objects that would normally be very blurry.
Laser adaptive optics in telescopes are a relatively new development in getting better image quality out of ground-based telescopes. While it’s nice to be able to use space-based telescopes like the Hubble and the forthcoming James Webb Space Telescope, they are certainly expensive to launch and maintain. On top of that, there are a lot of astronomers competing for very little time on these telescopes. Telescopes like the Very Large Telescope in Chile, and the Keck Telescope in Hawaii both already use laser adaptive optics to improve imaging.
Initially, adaptive optics focused in on a brighter star near the area of the sky that the telescope was observing, and actuators in the back of the mirror were moved very rapidly by a computer to cancel out atmospheric distortions. This system is limited, however, to areas of the sky that contain such an object.
Laser adaptive optics are more flexible in their usability – the technique involves using a single laser to excite molecules in the atmosphere to glow, and then using this as a “guide star” to calibrate the mirror to correct for distortions caused by turbulence in the atmosphere. A computer analyzes the incoming light from the artificial guide star, and can determine just how the atmosphere is behaving, changing the surface of the mirror to compensate.
In using a single laser, the adaptive optics can only compensate for turbulence in a very limited field of view. The new technique, pioneered at the 6.5-m MMT telescope in Arizona, uses not just one laser but five green lasers to produce five separate guide stars over a wider field of view, 2 arc minutes. The angular resolution is less than that of the single laser variety – for comparison, the Keck or VLT can produce images with a 30-60 milli-arcsecond resolution, but being able to see better over a wider field of view has many advantages.
In the image on the left, the cluster M3 appears blurry with the laser adaptive optics system turned off. Things are much clearer using the system, and individual stars in the cluster become visible, as can be seen in the image on the right. Image Credit: Michael Hart
The ability to take the spectra of older galaxies, which are very faint, is possible using this technique. By taking their spectra, scientists are better able to understand the composition and structure of objects in space. Using the new technique, taking the spectra of galaxies that are 10 billion years old – and thus have a very high red shift – should be possible from the ground.
Supermassive clusters of stars would also be more easily scrutinized using the technique, as images taken in a single pointing of the telescope on different nights would allow astronomers to understand just which stars are part of the cluster and which are not gravitationally bound.
The results of the team’s efforts was published in the Astrophysical Journal in 2009, and the original paper is available here on Arxiv.
Artists concept of a space elevator. Credit: Caltech
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After our recent article featuring the concept of a lunar elevator, many of you posted questions about both lunar elevators and space elevators in general. Liftport’s Michael Laine has graciously agreed to provide answers for these questions, and if anyone has additional questions, leave them in the comment section here. We’ll post Michael’s answers in a subsequent post.
For those of you who have really big questions, you may want to attend the first lunar elevator workshop in Seattle, Washington this coming weekend, July 29-August 1 in Seattle Washington. See this link for more information.
And there’s also a space elevator conference August 13-15 at the Microsoft Conference Center in Redmond, Washington. Find more details at this link.
Concept for a lunar elevator. Credit: Liftport, courtesy Michael Laine
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The idea of a space elevator has been around since the late 1800’s, but despite big dreams and years of research, the low-cost, easy access to orbit that a space elevator promises is likely still decades away. The biggest problem rests on the fact that no one has been able to successfully manufacture long ribbons made of ultra-light, ultra-strong carbon nanotubes, the only known material that is strong enough for a space elevator. But entrepreneur Michael Laine believes a lunar elevator – a space elevator from the surface of the Moon – could be created with materials that are available now. With more research and the right amount of capital, Laine says a lunar elevator could be built within a decade.
While Laine said he is still “emotionally very invested” in the concept of a space elevator based on Earth, for now he has shifted his focus to the lunar elevator. “There was a question of where was I going to put my time,” he told Universe Today, “and being able to do this soon – perhaps within 5-7 years and not some mythic 15-25 years in the future is enticing.”
Since the Moon’s gravity is only one sixth that of Earth, it drastically reduces the requirements of the ribbon. A material that is available now, a synthetic polymer material called Zylon (poly(p-phenylene-2,6-benzobisoxazole) which has high strength and excellent thermal stability, could be used.
Additionally, the components to build the elevator that would be sent to the Moon would be relatively lightweight, so a smaller rocket would do the job. “The physical requirements of the system look like you could use a standard Atlas or Delta rocket to launch the components.” Laine said. “That’s a big deal that you don’t need to build something like a Saturn V.”
While Laine said he believes a lunar elevator in 5-7 years is feasible, he didn’t want to go on record as saying it could be built in such a short time frame without adding some major caveats.
The biggest hurdle could be getting access to the 6 cubic meters of the Zylon material. “That actually could be the biggest challenge,” Laine said.
Additionally, there are still an untold amount of unknowns about building such a system. “I used to say for the space elevator that we still didn’t know all the questions, let alone the answers,” Laine said, “and that is even more true for the lunar elevator.”
The other hurdle is money. But a lunar elevator might actually be cheaper to build, initially, than a space elevator from Earth. Artists concept of a space elevator. Credit: Caltech
An Earth-based elevator is essentially a long cable – perhaps 100,000km (62,000 miles) long — that is anchored on Earth at one end with a counterweight at the other end (a large satellite, for example) in (beyond) geosynchronous orbit. Gravity and centripetal acceleration keeps the cable, or ribbon rigid and a small elevator, or “Lifter,” can move up the elevator at a fraction of the energy and financial expenditure of launching an object into orbit. Once the elevator is built, using the elevator to put things in orbit could cost hundreds of dollars per pound, versus the $7,000 per pound it takes to launch satellites with the space shuttle.
A lunar elevator would use a ribbon at least 50,000 kilometers (31,000 miles) long extending through the Earth-Moon L1 LaGrange point from an anchor point near the center of the visible part of Earth’s moon. A smaller Atlas or Delta rocket could send the components the L1 point, and the Zylong ribbon would be spooled from that point towards the Moon and the Earth.
“You would use the Atlas hardware as part of your counter weight,” said Laine. “But that’s a very small counterweight, which means that your cargo that you are taking up and down from the Moon is going to be small. This is not like the Earth elevator where you were going to be putting 100 tons a week into space. This is a very small system, capable of transporting 200-250 kilos.” One concept of a lunar space elevator. Credit: Star Technology and Research, Inc./Jerome Pearson
But to put that in perspective, Laine said, the entire sample return system for the Japanese Hayabusa probe that recently returned from an asteroid was only about 20 kilos.
And that’s what Laine has in mind for the first lunar elevator: a sample return mission. “It would be a lunar sample return mission within the next 5-7 years, for what we think is a pretty reasonable price,” he said.
Once the initial ribbon is up and running, Laine said you could send up more ribbon to strengthen it, using same concepts for the Earth elevator, such as multiple stages of construction and ribbons that are added to it.
Of course, none of this – including the money – is trivial. Although the first string might be less expensive than an Earth elevator, additional construction of the lunar elevator would be fairly expensive, and take more time compared to the Earth elevator. “Once the first string on the Earth elevator is built, you work from the bottom and go up, whereas on the lunar elevator you’ll have to send it from Earth. So that part starts adding up in a hurry,” Laine said. “We don’t have a complete estimate on price yet but an Atlas or Delta, that is a known and reasonable price tag. We’re not talking about billions and billions of dollars here — maybe hundreds of millions — but not billions.”
Still, he has a vision and a plan.
“It is not a flag and footprints vision of going to the Moon,” Laine said, “but it goes to the heart of the new NASA budget and focus of developing technologies and infrastructure so that things can happen. And that’s what we hope we can do by developing this ribbon. And then we jumpstart the process of creating an outpost or a research lab. We’ve played with the idea of using the counterweight at the end and using a habitat, something like a Bigelow (Laine stressed he hasn’t talked with the Bigelow people yet about this) and if we could tie a couple of modules together they would make a great counterweight and that puts you in an interesting position. Some people don’t think going to the Moon is worthwhile if you are going to Mars, but a lot of people think a fuel depot makes sense. We could be a great fuel depot for some of those long duration missions because we want that extra mass. In the Earth elevator, the counterweight is basically dead mass. For the lunar elevator, it becomes a working environment. So some people go to the modules, some people go to the Moon, some people go to Mars using this as a refueling and construction station. Once it is up and running you have safe reliable access to the moon, for the price of a Delta or an Atlas. That’s huge.”
But Laine said he doesn’t want to give anyone the impression that he and others interested in this concept have everything figured out. “We’ve studied this enough to know that it is feasible and interesting and likely to happen sooner rather than later, which is why we’re tackling it.”
So, Laine and a core group of space elevator enthusiasts are starting a series of workshops to discuss this concept and tackle some of the significant questions with anyone who is interested and who might have the brainpower and spirit to understand and undertake such a project.
The first workshop is July 29-August 1 in Seattle Washington. See this link for more information
“I’m a big believer in connecting with community, so if artists and musicians, want to come, that’s great,” Laine said. “Engineers, science guys, rocket guys would be helpful. But politicians and marketing people are equally important to answer the big questions of where we should focus our time and efforts.”
There is also a space elevator conference August 13-15 at the Microsoft Conference Center in Redmond, Washington. Find more details at this link.
Laine started a space elevator company in 2003, LiftPort, which fell to financial problems in 2007. He sees the lunar elevator as a possible rebirth for the company, which once had 14 full-time employees. “This is a renaissance project, a rising again,” he said. “I’m applying a lot of what I learned on the Earth elevator to this new vision. While tackling the Earth elevator, all my money came from real estate, and I had plenty of money for my needs. But this time is different. For us to build this thing we are going to have to earn our way.”
“But I think it could be phenomenally lucrative, too,” Laine continued. “We are going to make discoveries along the way that will lead to products and services that are not related to going to the Moon. We think there is a solid value proposition as part of this.”
NASA’s Robonaut 2 will be the first human-like robot to go to space, and teams from Johnson Space Center have been putting “R2” through a battery of tests to make sure this futuristic robot is ready for its first mission. R2 will become a permanent resident of the International Space Station, and will launch on space shuttle Discovery as part of the STS-133 mission, currently planned for November 1, 2010.
The 136 kg (300-pound) R2 consists of a head and a torso with two arms and two hands. R2 Once aboard the station, engineers will monitor how the robot operates in weightlessness. R2 is undergoing extensive testing in preparation for its flight, including vibration, vacuum and radiation testing. Watch the video for more information on how R2 operates. Continue reading “Robonaut Getting Ready for ISS Mission”
Solar Impulse's Chief Executive Officer and pilot Andre Borschberg flyes in the solar-powered HB-SIA prototype airplane for its first night flight attempt near Payerne airport July 7, 2010. Credit: KEYSTONE/Dominic Favre/POOL/SOLAR IMPULSE
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After flying for over 26 straight hours, pilot André Borschberg landed the solar-powered Solar Impulse HB-SIA airplane to cheers and applause at the Payerne airbase in Switzerland, successfully completing the goal of flying the aircraft through the night. According to Bertrand Piccard, president of Solar Impulse, there was power to spare, with over three hours of energy remaining in the sun-gathering lithium batteries. “This is a highly symbolic moment: flying by night using solely solar power is a stunning manifestation of the potential that clean technologies offer today to reduce the dependency of our society on fossil fuels!” Piccard said. “We are on the verge of the perpetual flight.”
With an official flight time of 26 hours and 9 minutes, the lightweight carbon fiber plane reached a a maximum altitude of 8,700 m (28,543 ft), a top speed of 68 knots (ground speed), an average speed of 23 knots. The HB-SIA flew solely on solar power, gathering and storing it during the daylight hours, and using the energy to fly through the night. Solar Impulse flies towards the night. Credit: KEYSTONE/POOL/Dominic Favre/Solar Impulse
“During the whole of the flight, I just sat there and watched the battery charge level rise and rise! Sitting in a plane producing more energy than it consumes is a fantastic feeling”, said Borschberg, CEO and co-founder of the Solar Impulse project.
The Solar Impulse HB-SIA has 12,000 solar cells built into its 64.3-meter (193-foot) wings, and is a prototype for an aircraft that the Solar Impulse team hope to fly around the world in a continuous flight in 2012.
Solar impulse weights 1,600 kg (3,500 lb), and is powered by four electric motors.
“Nothing can prevent us from another day and night, and the myth of perpetual flight,” a jubilant Piccard said at a press conference following the flight.
Update: Here’s a video from Solar Impulse, as the team waited for the sunrise:
