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NASA Tests All-Composite Prototype Crew Module
coondoggie writes "With an eye toward building safer, lighter and tougher spacecraft, NASA said today its prototype space crew module made up of composite materials handled tests simulating structural stresses of launch and atmospheric reentry. The idea behind NASA's Composite Crew Module project is to test new structural materials for possible future NASA spacecraft. According to NASA, composite materials are being looked at because they are stiff and lightweight and can be formed into complex shapes that may be more structurally efficient. In space travel, where every additional pound of weight drives costs higher, any weight savings provides increased payload capacity and potentially reduces mission expense."
I am (or was before I got lazy) and avid Cyclist. And well the materials used in the bicycle industry are basically the high tech materials that are starting to be put into the aerospace industyr (due to safety and devolpment periods bikes tend to put out new materials first).
When Carbon Fibre started to become omnipresent in road cycling it was only sparing used in mountain biking. This was due to precieved, and real, issues dealing with durability. Rocks and branches hitting Carbon Fibre frames and causing small failures that normal use would increase and cause catastropic failure. But now carbon is everywhere because design and testing have overcome these problems, and the aerospace industry, with actual and good engineers will be able to do the same.
Granted not everything will be composite. There are lots of things that are done better by Aluminum, or steel, or titanium. But for large, odd shaped structural pieced carbon fibre can't be beat. This is a good thing, so long as NASA doesn't go Carbon Crazy like the bike industry. You can almost buy a 100% Carbon Fibre bike, gears, cables, everything.
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What you describe are properties of ceramics. There's a reason composites are used and that is to overcome inherent weaknesses that a material alone would have. The brittleness in ceramics are the reason they are coupled with polymer/metals to improve ductility and fracture toughness, but ceramics have a higher strength/weight than metals and polymers depending on the application.
Just FYI, wood is a very good composite material. It comes in strength, lower ductility versions (something like oak/maple) as well as higher ductility, but lower strength (balsa comes to mind) as well. The idea is to know what you need, and find the combination to fill the niche.
Since NASA has been flying honeycomb as structural material since the 60's, I'm pretty sure they do. Among other things, the skin of the SLA (the Saturn Launch Adapter, the conical 'garage' between a Saturn Ib or V booster and the Apollo CSM) was structural honeycomb.
Contrary to what you might think, hydrocarbons actually provide better shielding against cosmic rays than aluminum, which produces secondary radiation even more dangerous than cosmic rays. Here is an article from NASA that explains this in more detail.
I don't know about everyone else, but the image that shows up in the Layer 8 blog has the crew module squashed down so that it appears shorter than it is wide. This is the result of image distortion. The actual NASA press release has the original image with its correct aspect ratio, along with a short video about the testing that shows some of the static rig and test equipment.