October 06, 2006

Superthread 100 times stronger than steel

Pointed out by colony worlds Superthread fibers, developed by Los Alamos scientist Yuntian Zhu, are 100 times stronger than steel (pound for pound for the same weight), tougher than diamonds, and roughly one-ten-thousandth of a human hair in diameter. This would be about 50 GPA.

Currently, Laboratory scientists, including Zhu, also of MPA-STC, are developing arrays of ultralong, super-strong, lightweight, double-walled carbon nanotubes. These arrays allow the nanotubes to be spun into fibers. Given the impressive results obtained for early prototype fibers, the Laboratory and CNT Tech entered into an exclusive license agreement.

Within six months, CNT Tech plans to be making 1 kilogram per day of SuperThread yarn. Over the next fifteen months, CNT Tech will scale up production of the nanotubes in its new laboratory at the Los Alamos Research Park. It will begin spinning the ultrastrong carbon-nanotube fiber on a custom-designed, computer-controlled spinning machine developed by the world's foremost experts in the fields of textile manufacturing, and machine construction.

Colony worlds notes that Dr Bradley Edwards of Carbon Designs Inc thinks the date for the liftport roadmap to a space elevator is overly pessimistic. The roadmap does not take into account key developments like this that have already happened.

Getting significant bulk production of 50 GPA strength material would be a major development. Getting this stronger material into planes, space vehicles, cars, cridges, armor etc...

Theoretical article on using condensed multi-wall carbon nanotubes to get to 48.5GPA

Multiwalled carbon nanotubes have a strength of 63GPA one at a time The trouble has been getting that strength into bulk materials.

Imagined pictures of Project Orion use 1964-2000

October 05, 2006

Molecular motors, machines and valves

Thanks to Foresight nanodot for pointing out this Nature article about molecular motors, machines, and valves

The exquisite solutions nature has found to control molecular motion, evident in the fascinating biological linear and rotary motors, has served as a major source of inspiration for scientists to conceptualize, design and build — using a bottom-up approach — entirely synthetic molecular machines. The desire, ultimately, to construct and control molecular machines, fuels one of the great endeavours of contemporary science. The first primitive artificial molecular motors have been constructed and it has been demonstrated that energy consumption can be used to induce controlled and unidirectional motion. Linear and rotary molecular motors have been anchored to surfaces without loss of function — a significant step towards future nanomachines and devices. Furthermore, it has been demonstrated unequivocally that both linear and rotary motors can perform work and can move objects. However, although the first applications of molecular motors to the control of other functions have been realized, the whole field is still very much in its infancy and offers ample opportunity in the design of nanomechanical devices.

Major challenges in the development of useful nanomachines remain, such as the development of fast and repetitive movement over longer time frames, directional movement along specified trajectories, integration of fully functional molecular motors in nanomachines and devices, catalytic molecular motors, systems that can transport cargo and so on. As complexity increases in these dynamic nanosystems, mastery of structure, function and communication across the traditional scientific boundaries will prove essential and indeed will serve to stimulate many areas of the synthetic, analytical and physical sciences. In view of the wide range of functions that biological motors play in nature and the role that macroscopic motors and machines play in daily life, the current limitation to the development and application of synthetic molecular machines and motors is perhaps only the imagination of the nanomotorists themselves.

Before the full molecular nanotechnology Age

Accelerating futures discusses the leap in capabilities that will happen when we go from the first full desktop nanofactory to 200 million in 1 month

We will have lower performance version of full diamondoid molecular nanotechnology.

DNA nanotechnology and maturing near nanotech (I define near-nano as the growing matter control capabilities in the 2-20nanometer range).

It has started and it will be ramped up over the next few years. DNA has 1/50000 the material strength of diamond.

DNA nano will be mixed with polymers and other chemicals. The range of materials will grow and the degree of control will grow.

Regular production and rapid prototyping systems with faster and more flexible automation will also close somewhat the size of the leap in capability.

The nanomaterial revolution is starting to hit now before full desktop nanofactories.
We are getting materials like M5 fiber which is 2 to 4 times better than fibers like advanced kevlar.

Condensed multi-wall nanotubes is an example of steady progress to increase production, lower costs and accessing more of the full strength of carbon nanotubes. Improved bulk processes could give us fairly common and inexpensive access to carbon nanotube enhanced polymers and carbon nanotubes with up to 50GPa of strength.

We could get the taste of exponential manufacturing but with industrial scaled processes and using DNA and polymers. Plus mixing in other materials with near-nano precision. We also get the use of stronger of materials. Those will mainly be used initially in expensive systems and used in small quantities in parts of common systems. In 5-10 years, a lot of strong carbon nanotube material could be incorporated into a lot of products.

The full effect of nanofactories will not be felt until it is accompanied by acceleration of logistics and mining and processing of materials.

I also think the desktop nanofactory like the personal computer will be preceeded by the equivalent of mainframes. Big factories and labs with a lot of people using pre-cursor systems that could be less flexible but with products of comparable performance.

More on the materials revolution:
Los Alamos appears to have created 50 GPA superthread material in bulk quantities. They expect to making kilograms quantities early in 2007 and then scaling up to industrial quantities after that They look to continue to refine the processes to make stronger stuff.

Theoretical article on using condensed multi-wall carbon nanotubes to get to 48.5GPA

October 04, 2006

Space elevator roadmap beta is out, Optimistically 2031

The road map to space elevator (SE) development outlines what tests and demonstrations need to be done before we can build the first SE. Determination was made of activities that absolutely had to be done. They estimated the time it would take with feedback from a couple of independent people with space experience. The short summary is that there are 8 major system tests, and even with optimistic assumptions, the earliest practical date we see for commercial operation of the SE is 2031.

The announcement with links to the roadmap pdf is here

Online copy of a 1970 Nuclear Pulsed propulsion system

Another useful pdf that discusses various issues for Orion style systems in detail

Here is a paper from 1964

Thanks to from the writer Mauk2 on the nasaspaceflight forums The forum has a lengthy discussion on all things nuclear pulsed propulsion.

Mauk2 has an interesting speculation about using the planned Ares V and some SRBs to loft 600 tons of a pulsed propulsion vehicle about the turbopause

From the first pdf, Table 1 on page 16 has a column labeled "W, m/sec." W is the parameter assigned to the specific strength of the pusher plate material.

The W parameter is very, very important in the performance of an EPP using plasma drive. In 1970 they assigned W a value of 300 meters/second, which was the performance achieveable with steel at a density of 8 grams per cubic centimeter and a yield strength of 100,000 pounds per square inch.

Using modern steel (strength of 500,000 psi), the W parameter goes from 300 to 600 or better. This one simple improvement would result in an Isp of 10,279 seconds in vacuum. Hold all other parameters constant, and merely scale them by a factor of six to cover the larger mass of this design versus the reference 100 ton design. Instead of 20 kilograms, the pulse units mass 120 kilograms. If the total launch mass is 600 tons, 108 tons in propellants and 192 tons in structure, payload would be 300 tons. It would be one stage to Mars.

Making the pusher plate out of stronger and lighter materials would further improve system performance.

Nice mundane progress

Another step to commercially viable carbon nanotubes

A new method developed at Northwestern University in Evanston, Ill., for sorting single-walled carbon nanotubes promises to overcome the problem of sorting carbon nanotubes by size and type. The method works by exploiting subtle differences in the buoyant densities of carbon nanotubes as a function of their size and electronic behavior. Current methods for synthesizing carbon nanotubes produce mixtures of tubes that differ in their diameter and twist. Variations in electronic properties arise from such structural differences, resulting in carbon nanotubes that are unsuitable for most proposed applications.

Single-walled carbon nanotubes are coated in soap-like molecules called surfactants, then spun at tens of thousands of rotations per minute in an ultracentrifuge. The resulting density gradient sorts the nanotubes according to diameter, twist and electronic structure. Credit: Zina Deretsky (adapted from Arnold et al.), NSF

$10 million genome X-prize

Quantum communication advance

From CNET, physicists in Denmark have teleported information from light to matter, bringing quantum communication and computing closer to reality. The experiment involved, for the first time, a macroscopic atomic object containing thousands of billions of atoms. They also teleported the information a distance of half a meter, but believe it can be extended further.

"Creating entanglement is a very important step but there are two more steps at least to perform teleportation. We have succeeded in making all three steps--that is entanglement, quantum measurement and quantum feedback," Professor Eugene Polzik added. He and his team at the Niels Bohr Institute at the University of Copenhagen in Denmark made the advance. "Quantum information is different from classical information in the sense that it cannot be measured. It has much higher information capacity and it cannot be eavesdropped on. The transmission of quantum information can be made unconditionally secure."

Picometer resolution from different methods

$4,000,000 in Prize Money for breakthroughs in Space Technology

The Spaceward Foundation has announced $4 million in prizes for space technology over the next 5 years. This is 10 times the purse to this point.

The 2006 prize purse will remain $200,000 per each of their two competitions, increasing to $300,000 in 2007, and so on, until they reach $600,000 in 2010. Any unwon prizes will automatically roll over to the following year NASA provides the prize money, but not with operating funds. Commercial sponsorship is needed for operating funds.

they have prizes for developments towards Space elevators and Mars Robots

How efficient would Project Orion nuclear vehicles be?

This from the spacebombardment blog

Payload Fraction
Advanced Interplanetary Orion 10,000 tons
one) 61% 6100 tons to orbit
two) 57% 5700 tons to Lunar landing
three) 53% 5300 tons to lunar surface and back
four) 53% 5300 tons to mars orbit and back
five) 45% 4500 tons to Venus orbit then Mars orbit then Earth orbit.
six) 13% 1300 tons to Enceladus and back
Shuttle - Cargo 1.6% (LEO) to 0.8% (ISS)

ISP Hours ISP seconds

AM-Beam MAX 2,834 10 million
H->Fe Fusion MAX 1,417 5.1 million
H->He Fusion MAX 850 3.1 million
IC-Fusion MAX 283 1 million
ORION MAX 278 1 million
NSWR 90% UTB MAX 133 479,000
AIM 17 61200
mag Orion 8.2 30000
VASIMR (high gear) 8 28800
Mini-Mag Orion 6 21600
ORION Low Altitude 4 14400

Space Shuttle x3 SSME 0 455

October 03, 2006

New Semiconducting material: Solar cells with 45% efficiency

Semiconductor material with three energy bands could be used to make solar cells with efficiencies of around 45 percent, compared with 25 percent for conventional cells that use a single semiconductor and 39 percent for cells with layers of mixed semiconductors.

The researchers found that introducing a few atoms of oxygen into a zinc-manganese-tellurium (ZnMnTe) alloy splits the compound semiconductor's conduction band into two parts. Similarly, adding nitrogen to a semiconductor such as gallium arsenide phosphide will also give a multi-band semiconductor.

LBNL has licensed the technology to RoseStreet Labs, a startup in Phoenix, AZ, which plans to commercialize solar cells made from these multi-band semiconductors. Because it's an entirely new technology, though, it's hard to say when such a solar cell will be available, Walukiewicz says.

October 02, 2006

Minimag Orion and follow on ideas

The objective of the (First page of the minimag pdf) minimag orion proposal was to eliminate the pusher plate from the original Orion concept and replace it with a very large superconducting coil perhaps a kilometer away from the blast center.
Here is a powerpoint presentation on the orion project, mag orion (1999) and minimag orion from Andrews Space

The original concept from the 1960s was to toss nuclear bombs out the bottom of a space ship and then explode them and have the blast hit a large metal pusher plate. Tests with a metal sphere showed that the basic concept would work and there were many designs. Super Orion was a large version that could move millions of tons and used fusion bombs. (A large planned container ship would have 14,000 containers (TEUs) which average 14 tons loaded. A million tons would be 5 of those large ships loaded.) The case for Orion is described here. I agree with the case for Orion.

Mag Orion would have detonated 100 kiloton bombs 2 kilometers behind the space craft and had a superconducting magnetic sail interact with the blast to generate 1,000,000 newtons at 30,000 ISP.

Mini-mag Orion would use sub-critical explosions with Z pinch technology. 5 tons of explosive power with a 5 meter magnetic bottle. Specific Impulse of 21,500 sec and thrust 625,000 Newtons.

There has been follow up work on updating the Orion concepts:
Pdf from 2002. Project Orion and Future Prospects for Nuclear Pulse Propulsion, G. R. Schmidt; J. A. Bonometti; C. A. Irvine Journal of Propulsion and Power 2002

Here is a summary of the minimag Orion plan. Pulsed nuclear fission propulsion achieves the combination of high thrust values and specific impulse necessary for crewed exploration mission to both the inner and outer planets of the solar system. This mission capability would be sufficient for a 100 metric ton payload to reach Mars in 60-90 days.

There is a proposed follow on to the minimag orion work.
They have plans to increase the yield fraction (estimated at 10% of the fissionable material from MCNP results). It could be increased with a deuterium-tritium fusion boost. This will allow for a smaller package and allow for a greater amount of thrust for a given quantity of fissionable material. They would investigate how the magnetic bottle will change under these conditions as well.

Other reading:
This site explains how the space shuttle works. The solid rocket boosters have about 11 million newtons of thrust each. All three engines have about 30 milion newtons

National Post: 50% of baby boomers may live over 100 years

Canada's National Post newspaper examines life extension A growing anti-ageing movement believes the Baby-Boom generation will live longer than any generation before it. Ronald Klatz, co-founder of the American Academy of Anti-Aging Medicine, predicts fifty percent of Baby Boomers can live up to 100 and beyond. He predicts genetic research on stem cells and cloning "will take us to 120 and beyond. Soon, we will be the Ageless Society."

Currently, the Gerontology Research Group estimates 450 people in the world are 110 or older (those who live longer to 110 years or more are calledsupercentenarian), 60 to 75 of them in the U.S. Currently, only one in one thousand centenarians live to be 110 and one in 44 live another 5 years to 115.

Canada has 4,000 centenarians, 3,400 of whom are women, according to the government of Canada's chief actuary, Jean-Claude Menard

More on DNA building blocks

From Soft machines, discussion about a paper on DNA structures. Rapid Chiral Assembly of Rigid DNA Building Blocks for Molecular Nanofabrication Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on a side, that can self-assemble in seconds with near-quantitative yield of one diastereomer. They can be connected by programmable DNA linkers. Their triangulated architecture confers structural stability; by compressing a DNA tetrahedron with an atomic force microscope, we have measured the axial compressibility of DNA and observed the buckling of the double helix under high loads.

The European writers devised a method of making rigid DNA tetrahedra, with edges less than 10 nm in size, at high (95%) yield. They also measured the stiffness of the DNA tetrahedra. DNA tetrahedra stiffness is about 20 MPa. This is 50,000 times less stiff as diamond. It is about as stiff as hard rubber.

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