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NIST Laser-Based Method Cleans Up Grubby Nanotubes

Before: Dirty CNT's

After: Purified CNT's

Before and after electron microscope images of a pyroelectric detector coated with single-walled nanotubes (SWNTs) visually demonstrate the effect of the laser cleaning process. In addition, the SWNTs look visibly blacker after laser treatment, suggesting less graphitic material and increased porosity. (Image and Caption Source: NIST)
Before carbon nanotubes can fulfill their promise as ultrastrong fibers, electrical wires in molecular devices, or hydrogen storage components for fuel cells, better methods are needed for purifying raw nanotube materials. Researchers at the National Institute of Standards and Technology (NIST) and the National Renewable Energy Laboratory (NREL, Golden, Colo.), have taken a step toward this goal by demonstrating a simple method of cleaning nanotubes by zapping them with carefully calibrated laser pulses.

“Controlling and determining tube type is sort of the holy grail right now with carbon nanotubes. Purity is a key variable,” says NIST physicist John Lehman, who leads the research. “Over the last 15 years there’s been lots of promise, but when you buy some material you realize that a good percentage of it is not quite what you hoped.

"Anyone who thinks they’re going into business with nanotubes will realize that purification is an important—and expensive—step. There is a lot of work to be done.”

When carbon nanotubes—the cylindrical form of the fullerene family—are synthesized by any of several processes, a significant amount of contaminants such as soot, graphite and other impurities also is formed. Purifying the product is an important issue for commercial application of nanotubes. In a forthcoming issue of Chemical Physics Letters*, the NIST/NREL team describes how pulses from an excimer laser greatly reduce the amount of carbon impurities in a sample of bulk carbon single-walled nanotubes, without destroying tubes. Both visual examination and quantitative measurements of material structure and composition verify that the resulting sample is “cleaner.” The exact cleaning process may need to be slightly modified depending on how the nanotubes are made, the authors note. But the general approach is simpler and less costly than conventional “wet chemistry” processes, which can damage the tubes and also require removal of solvents afterwards.

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Space Weather Now at the Space Environment Center

Freelance journalists spend a lot time with their noses in their browsers building their space elevator blogs. I use Firefox (this site is optimised for Firefox which you may already know if you use IE) and I love Accuweather's ForecastFox extension which puts 3 days and nights of weather in my browser's status bar.

This would be really useful if I ever actually got up from the computer and went ouside but for now it at least serves to remind me there IS an outside.

A significant geomagnetic storm impacted the Earth beginning early Thursday afternoon around 1:00 p.m. Eastern time, 14 December, according to forecasters at the NOAA Space Environment Center in Boulder, Colo. Impacts from this event can cause problems with High Frequency communications, satellite operations and induce currents in power grids. (Source: ESA)
Knowing Earth weather wouldn't be quite so useful if I lived and/or worked in space though. Knowing the space weather forecast can mean the difference between hidely safely behind radiation shielding or becoming a tiny, glowing constellation affectionately known as the Crispy Critter.

Space Weather Now ... give[s] the non-technical user a 'plain language' look at space weather. The page refreshes automatically once a minute.

The various sections are:

Events and Announcements

Solar X-ray Imager (SXI) - a Solar X-ray Imagers (carried by the Geostationary Operational Environmental Satellites (GOES) 12 and 13 spacecraft) that monitor the Sun’s X-rays for solar flares, coronal mass ejections, and other phenomena that impact the geospace environment .

National Oceanic and Atmospheric Administration (NOAA) Scales - The scales describe the environmental disturbances for three event types: geomagnetic storms, solar radiation storms, and radio blackouts. The scales have numbered levels, analogous to hurricanes, tornadoes, and earthquakes that convey severity. They list possible effects at each level. They also show how often such events happen, and give a measure of the intensity of the physical causes.

Maximum in past 24-hours - These are the highest values over the last 24-hours for Geomagnetic Storms; planetary K-values for the last 8 3-hourly periods. Solar Radiation Storms; average 5-minute protons at >10 MeV from primary GOES satellite. Radio Blackouts; X-ray 1-minute values from primary GOES satellite.

Currently - Geomagnetic Storms (latest 3-hour K-value), Solar Radiation Storms (averaged 5-minute proton value), and Radio Blackouts (x-ray 1-minute value) current values.

Real-time Solar Wind pages - Solar wind values collected by the Advanced Composition Explorer (ACE). Data is averaged over the last 15-minutes for the values. The latest dial display can be linked to at : Explanation

Auroral Map - The plots on this page show the current extent and position of the auroral oval at each pole, extrapolated from measurements taken during the most recent polar pass of the NOAA POES satellite.

Today’s Space Weather - A look at space weather for the more technical user. This page has the latest full-disk image, the 3-day Solar-Geophysical Forecast, Solar X-ray Flux plot, Satellite Environment Plot, and more information.

D-region Absorption - Long range communications using high frequency (HF) radio waves (3-30 MHz) depend on reflection of the signals in the ionosphere.

Solar Image References - Link to additional descriptions and sources of solar images

Latest Alert - Updated hourly and as Alerts, Warnings, or Watches are issued.

Last Advisory Bulletin - Updated as a Space Weather Bulletin is issued. The file contains back bulletins for the last 8 months.

Solar Cycle 23 Progression - A plot indicating the progression of the current solar cycle. These are updated at the first of each month.

Today’s Theme - A variety of short subject themes about space weather, products, services, or projects. They change each day and rotate through the provided list of themes.

USER Groups - Links to specific pages of importance to the various user categories served by SEC.


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Discovery Astronaut's Hand-eye Skills Tested by Canadians

(And no, we didn't shoot hockey pucks at them!)

A Canadian Space Agency sponsored experiment aboard Space Shuttle Discovery (STS-116) conducted on December 12th, 2006 tested for the causes of reduced hand-eye coordination capacity in microgravity. Research that could have a direct bearing on all activities in microgravity from running a space elevator to manufacturing tasks to serving drinks in a space hotel without spilling them on the customer.

Astronaut Sunita Williams performing the PMDIS experiment on NASA's shuttle flight STS-116. (Source: NASA)
According to the CSA press release linked in the title above "experience and science experiments have shown that, while in microgravity, astronauts have a harder time reaching and pointing to objects than when they are on Earth. This could be critical in emergency situations."

York University's Dr. Barry Fowler designed an experiment that resembles a simple computer game to research the causes of Perceptual-Motor Deficits in Space (PMDIS).

Astronaut Sunita Williams, led by Dr. Fowler, used a joystick to click on various-sized targets appearing on a computer screen and tap with a pointer directly on a purpose-built touch screen. The experiment simulated multi-tasking by requiring Astronaut Williams to push a button in response to a tone while simultaneously hitting targets.

"Once the 'why' of perceptual-motor deficits in space is known ", said Dr. Fowler, "we can start looking at how to remedy this problem. This research in space could also lead to new medical knowledge on how the brain adapts or not to disease or injury that can confound hand-eye coordination".


Space Diving

While most 'spacers' are currently occupied with how to get to space I'm actually more interested in the whys. One of which is space tourism.

Enjoying the view from a space hotel while learning to eat in reduced gravity might be a suitable challenge for those who think merely going to space is risky enough. Others will need more. Returning to Earth equipped with a parachute and pressure suit - spacediving - might be one of those.

Building on feats by the likes of Captain Joe Kittinger in 1960*, Canadian Arrow is proposing a new type of extreme sport [they] call "spacediving".

Canadian Arrow concieves of a future where "spacedivers may routinely take 60-second rocket fights to the edge of space, proceed to jump out, and while wearing a counter pressure suit, will free fall to earth from 40 miles or more. Even today, reaching 120,000 ft to make a high altitude jump requires a balloon ride of many hours. By contrast, a sub-orbital rocket could take skydivers from the ground to this altitude in just minutes!"

There are practical benefits as well. Canadian Arrow posits "this type of extreme sport could bring about a revolution in spacesuit design ... a self contained ballistic recovery system could be designed to bring a spacediver safely to the ground."

It makes me wonder if this might also be effective for anyone stranded on a space elevator or for emergency evacuation of low-orbit industrial or tourist facilities.

Canadian Arrow plans continue to explore spacediving while in the construction phase of building their sub-orbital rockets.


* William Thomas' Convergence Weekly has an excellent description of Kittinger's exploits in his SpaceDivers article.

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The 4th (and final) in a series of excerpts of my article in;

Liftport: The Space Elevator: Opening Space To Everyone
edited by Michael J Laine, Tom Nugent, Bill Fawcett
Published 2006 - 308 pages

Limited preview
- Table of Contents - About this book

[Links to previous/following excerpts are at the bottom of this post]

Solar power isn’t the only industry that would be transformed by inexpensive space platforms hoisted into orbit on the SE.

Delbert E. Day, the Curators' Professor of Ceramic Engineering and Senior Research Investigator at the Graduate Center for Materials Research, University of Missouri-Rolla knows who will be happiest when the SE comes on line.

“In the ceramics field it would be those people who are making objects that are difficult to nearly impossible to make on earth,” says Professor Day. “In other words, people in the electronics and optical communications fields who know that there are materials out there, which, if they could be made, would find some immediate application.”

Ceramics and glasses are made by high-temperature melting of raw materials taken directly from the earth (clay, sand, etc.) and processed materials into inorganic, nonmetallic solids. They are made into everything from spark plugs, glass, electronic components and nuclear materials to abrasives, rocket components, and tableware.

Making any kind of glass means cooling the melted raw material with minimal crystal formation.

“There’s been lots and lots of research that hasn’t gone anywhere because many of the compositions that have desirable properties tend to crystallize,” says Professor Day.

“There are fluoride glasses people know have very good optical transmission qualities which are very difficult, in fact almost impossible, to make here on earth.”

An optical fiber made from fluoride glass transmits light over far greater distances than convention optical fiber without the degradation of the light signal found in silicon-based optical fibers. This could have the practical effect of reducing or even eliminating the installation and maintenance of expensive networking hardware enroute.

“One of the advantages of space is, at least from the very limited experiments we‘ve done, everybody’s reported that the crystallization tendencies of a melt are lower,” says Professor Day. “[If it did’t crystallize] that would be a major stride forward.

“Part of the problem is that we have done so few experiments because of the high cost [of going into space] and limited time available [once there]. I’m confident that if the SE was operational and [transport] cost a hundred dollars per pound, people would do experiments and we would find things we can’t even dream of [today].”

Permanently extending Earth’s economy into space in an economically and environmentally sustainable way is inspired by dreams but it will have to be achieved by political, business and technical realities that are harsher, colder and as unforgiving as space itself.

The ROI is out there if we can master and marshal our own mental and emotional universes so as to find the courage to change our ways and not simply repeat the mistakes of the past that have cost so much to learn.


Space Elevator (Excerpt I)

Space Elevator (Excerpt II)

Space Elevator (Excerpt III)

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Space Elevator ROI (Excerpt III) Updated

The 3rd in a series of excerpts of my article in;

Liftport: The Space Elevator: Opening Space To Everyone
edited by Michael J Laine, Tom Nugent, Bill Fawcett
Published 2006 - 308 pages

Limited preview
- Table of Contents - About this book

[Links to previous/following excerpts are at the bottom of this post]

Solar Power Satellites (SPS’s) concentrate the Sun’s energy and beam it to Earth using microwaves or lasers. Unlike terrestrial solar power, SPS’s generate electricity 24 hours a day from sunlight unfiltered by Earth’s atmosphere.

According to Larry Kazmerski, technology manager for solar energy technologies at the National Renewable Energy Laboratory in Colorado, rocket launch costs are birth control for an SPS industry that has would-be participants already lined up in the waiting room.

“2004 is the fiftieth anniversary of the Bell invention of the solar cell. One solar cell we had back then was five milliwatts of power,” says Kazmerski. “Last year the industry shipped out something like three-quarters of a gigawatt, something like nine billion cells. Most of that progress has been in the last 10 – 15 years. So, if you look 10 – 15 years ahead, technological progress tends to compress in time.

“Some people think even one SPS up there would be a business", he adds with a laugh.

“I actually served for three years on a NASA panel that looked at the future of space power. They have experts looking at SPS’s for Earth still because they said ‘eventually we’re going to have this.’

“Probably the primary thing right now is delivering those things up to space. The SE does attack a critical showstopper,” states Kazmerski. “If you can get this stuff up there cheap, all of a sudden space solar power becomes feasible.

“I actually served for three years on a NASA panel that looked at the future of space power. They have experts looking at SPS’s for Earth still because they said ‘eventually we’re going to have this.’

“Probably the primary thing right now is delivering those things up to space. The SE does attack a critical showstopper,” states Kazmerski. “If you can get this stuff up there cheap, all of a sudden space solar power becomes feasible.

“If you go up [in space] now every near-earth satellite uses dual or triple-junction solar power devices that are on the order of 28% efficient [in zero air mass]. They are not at their limits yet. They could still probably be optimized by adding a 4th junction to bring them up to 40 or 50% efficiency.

“I think right now, if the delivery system were sufficient, [current solar power technologies] would be good enough to start us. [But], right now, it would be difficult to deliver a square mile of photovoltaics up into space.”


Space Elevator (Excerpt I)

Space Elevator (Excerpt II)


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