Tom DeLay is a Composites Engineer at Nasa’s Marshall Space Flight Center in Huntsville, AL. Mr. DeLay has been with NASA for 19 years, and currently is doing R&D work on composite materials for cryogenic applications.

NASA Tech Briefs: What are the goals of your group?
Tom DeLay: Our group, the non-metallic division, has a team of about 10 people who work in composite-material processing, and another 10 down the hall who are more involved in materials properties. The overriding goal of our work is to make better materials for pressure vessels, better ways to make the vessels lighter, and finding ways to make the tanks more damage tolerant and impact resistant.

The work is so cross-cutting -- you find composites in sporting goods as well as aerostructures. I have some co-workers who work in high-temperature areas, like ablatives and solid rocket nozzles. We’ve also done all-composite structures, like x-ray telescope tubes and optical benches for optics people to keep lenses aligned.

In fact, a highly intensive project now is designing an all-composite liquid hydrogen fuel tank for a future system that is to replace the Shuttle. The problem is, in cryogenic applications the composites that overwrap the tank liner microcracks all over the place. That's what I've been looking at for the last few years.

The main issue with composites is not only that it’s light, but that it’s so incredibly strong. So when you have a composite-wrapped metal vessel, say, you’ve got the best of both worlds. The liner -- the metal -- takes care of the permeability, and the composite takes care of the strength.

NTB: What does ”composite-wrapped” mean?
DeLay: A metallic pressure vessel is just a tank. To get a lighter, higher performing vessel, you can have a much thinner lining and wrap it with a carbon matrix, which is usually a carbon epoxy. Using carbon filament winding, you wrap the tank up kind of like spinning a cocoon. The liner goes in a machine that rotates it, and as it rotates layers of light carbon fiber laid on top of it. The tank goes in the oven, then is cured with an autoclave. So what you end up with is a reinforced thin structure.

We also work with hand-laid-filaments, and fiber-placed winding. Fiber placement is similar to filament winding, but instead of using a continuous thread, one strand is placed directly on the mandril. Some filaments are under 1/20th inch in diameter and less than three feet long, others are like thick bandages.

NTB: Where are all these pressure vessels used?
DeLay: All satellites and launch vehicles have pressure vessels -- like the Shuttle's external tanks, or tiny ones in deep-space satellites. But take something closer to home -- a fireman’s air tank. Those things are heavy. The biggest portion of the weight of the tank is the metal, which is, say, about 100 millimeters thick. On top of that, many firemen’s tanks already have some composite layers. The composite materials are about 6 millimeters thick.

I’m fairly sure that with the right application of composites the thickness of the metal part of the tank could be cut in half. Unfortunately, to do that today, you run into problems of economics, of applying this relatively new technology for hundreds of thousands of units.

NTB: Is your group at Marshall the lead composite R&D center at NASA?
DeLay: We are in some areas, certainly as far as large composite structure manufacturing. Other people have done hand-lay-up structures, but as far the automated equipment, the oven, the autoclaves, and composite processing, we're the only people with the large equipment to make the large articles themselves.

That’s probably one of the reasons that some of the big aerospace companies are attracted to working with us -- because they can build test hardware in our facilities.

Also, from what I understand, as far as handling liquid hydrogen our facility is unique. There are other people that handle liquid hydrogen, but at a smaller scale. We’ve got quite a setup just across the road -- this is the place where the Saturn V was developed, the Saturn S-IB, and the Shuttle main engines. We’ve got world-class expertise.

NTB: Tell us more about your relationships with the commercial sector.
DeLay: We're open for many possibilities -- our new Administrator is encouraging more industry partnering with NASA. It's such an obvious thing that we need to do.

This brings up something interesting. There certainly are private testing labs out there. But we can’t go head to head with them and address a standard process that is already in the commercial sector. We’re a government agency, and we’d be in trouble for competing against the commercial sector. But if the relationship is for something that goes against the norm, the thinking is that things are not very affordable for the typical company.

NTB: How would such a relationship be initiated?
DeLay: We have arrangements through which a company could talk to NASA and get a Space Act deal together to develop some new technology. For example, a small company has just licensed a patent of ours, and they've also had a contract with us through SBIR [Small Business Innovation Research Program].

The doors are wide open for NASA to do additional development and testing. Say someone wanted to build a tank of certain size, to hold certain materials, etc. NASA would cost out the materials and our brain time, so to speak, and assign us our tasks.

As far as our commercial outreach goes, the technology and patent disclosures are extraordinarily important. That’s what the tech disclosures are all about. I've submitted about nine or 10 tech disclosures, as well as a bunch of patents. Once the NASA tech transfer office checks if they're commercially viable, out they go, and show up in NASA Tech Briefs.

There’s a lot of brains out there in the commercial sector, and a good potential for joint ventures. The only thing you need is for the right people to get together who have a common goal and a passion for technology.

Tom DeLay can be reached at tom.delay@msfc.nasa.gov.