Saturday, August 22, 2009

Mars shelters

Mars shelters would need the reliability of self-sensing materials, the durability of self-healing materials, and the weight savings of multi-functional materials. In other words, a house on Mars and a good spacecraft need many of the same things. All of these are being considered by researchers, Thibeault says.
Mind-boggling advanced materials will come in handy on Earth, too.
"NASA's research is certainly focused on aerospace vehicles," notes Anna McGowan, manager of NASA's Morphing Project (an advanced materials research effort at the Langley Research Centre). "However, the basic science could be used in many other areas. There could be millions of spin-offs."
But not yet. Most advanced materials lack the engineering refinement needed for a polished, robust product. They're not ready for primetime. Even so, say researchers, it's only a matter of time: Eventually that car salesman will stop laughing ... and start selling your space-age dream machine.


Scientists are still searching for a good solution. The trick is to provide adequate shielding without adding lots of extra weight to the spacecraft. Some lightweight radiation-shielding materials are currently being tested in an experiment called MISSE onboard the International Space Station. But these alone won't be enough.
The real bad guy is Galactic Cosmic Radiation (GCR) produced in distant supernova explosions. It consists, in part, of very heavy positive ions - such as iron nuclei - zipping along at great speed. The combination of high mass and high speed makes these little atomic "cannon balls" very destructive. When they pierce through the cells in people's bodies, they can smash apart DNA, leading to illness and even cancer."It turns out that the worst materials you can use for shielding against GCR are metals," Bushnell notes. When a galactic comic ray hits a metallic atom, it can shatter the atom's nucleus - a process akin to the fission that occurs in nuclear power plants. The secondary radiation produced by these collisions can be worse than the GCR that the metal was meant to shield.

Revolutions in technology

Revolutions in technology - like the Industrial Revolution that replaced horses with cars - can make what seems impossible today commonplace tomorrow.Such a revolution is happening right now. Three of the fastest-growing sciences of our day - biotech, nanotech, and information technology - are converging to give scientists unprecedented control of matter on the molecular scale. Emerging from this intellectual gold-rush is a new class of materials with astounding properties that sound more at home in a science fiction novel than on the laboratory workbench.Imagine, for example, a substance with 100 times the strength of steel, yet only 1/6 the weight; materials that instantly heal themselves when punctured; surfaces that can "feel" the forces pressing on them; wires and electronics as tiny as molecules; structural materials that also generate and store electricity; and liquids that can instantly switch to solid and back again at will. All of these materials exist today ... and more are on the way

Super Spaceships

Tomorrow's spacecraft will be built using advanced materials with mind-boggling properties.
"What I'm really looking for," you say to the salesman, "is a car that goes at least 10,000 miles between fill-ups, repairs itself automatically, cruises at 500 mph, and weighs only a few hundred pounds."
As he stands there wide-eyed, you add, "Oh yeah, and I can only spend about a quarter of what these other cars cost."
A request like this is sure to get you laughed off the new-car lot. But in many ways, this dream car is a metaphor for the space vehicles we'll need to expand our exploration of the solar system in the decades to come. These new spacecraft will need to be faster, lighter, cheaper, more reliable, more durable, and more versatile, all at the same time.Impossible? Before you answer, consider how a rancher from 200 years ago might have reacted if a man had asked to buy a horse that could run 100 mph for hours on end, carry his entire family and all their luggage, and sing his favourite songs to him all the while! Today we call them minivans.