The Pegasus XL rocket's aft skirt fins are constructed from a single-piece, solid, foam core and wet-laid carbon composite construction around a central titanium shaft. Its wing panels consist of a carbon-faced foam sandwich. The rocket wing's channel section spars that carry the primary bending loads and half-ribs are also made of carbon.
ATK provided the solar array that will power the NuSTAR satellite itself, as well as powering its onboard sensors for NASA's planned multiyear experiments. The company built the NuSTAR observatory's instrument structure, which includes an integrated focal plane bench and optical bench, both made of high-strength composites.
The two halves of the the Pegasus XL payload fairing's composite shell are shown here being cleaned and inspected at Vandenberg Air Force Base before the spacecraft is encapsulated. (Source: NASA/Randy Beaudoin, Vandenberg Air Force Base)
The focal plane bench serves as a stable, multi-functional platform for NuSTAR's instruments. It also functions as the primary interface to the satellite bus structure. During launch, this bench supports the stowed mast/canister and the optical bench with its integrated X-ray optics. The focal plane assembly's instrument electronics and metrology detectors are also mounted on this bench. These perform instrument alignment, focus, and data collection, which are all mission-critical operations.
The optical bench is a precision-engineered, highly stable structure responsible for supporting the X-ray optics modules, metrology lasers, adjustment mechanism, and star tracker. Held stable within the optical bench, the X-ray optics modules will acquire images as the NuSTAR satellite maps supernova explosions and searches for black holes.
Ann, while the application of composites for the booster is new stuff, their use in the spacecraft itself is old hat. I worked at one spacecraft plant where we made our own composites from raw materials. One of our direct competitors, with whom we were merged later on, got their composites from a company whose main business was railcars. It was an interesting revelation when we found out.
I actually worked on the testing of the UARS satelite structure. It was the first large composite structure. If you recall, UARS recently fell back to earth. It was one of the largest satellites to do so. It was the size of a school bus and filled the Shuttle cargo bay. In testing we found some interesting things out about how the composites reacted structurally. Now, this was in the 1980s. It would have been nice to have some of the more robust CAE tools available today.
I will be the first to say that I am scared to death of flight composites (see Airbus failures, give me a DC-9 (shut up old man :-)), but I am also aware that these are amazing pieces of hardware. Congrats on the phenominal achievement of space-rated composites!
notarboca, if you're referring to the Airbus wing failures http://www.designnews.com/author.asp?section_id=1392&doc_id=245829 those were not caused by a composite problem, but by a problem with an apparently mis-spec'ed aluminum alloy and the misunderstanding on the part of design engineers about how to interface that alloy with composites. Also, it took 10 years for that problem to show up, and so far there have been no accidents caused by it. Personally, I'm more concerned with the airlines' lowered maintenance standards for commercial aircraft.
Good article Ann—one thing interesting to me is how composites will hold up relative to their environment. I suspect the ability to judge the aging process of the composites used for the satellite, while in space, is basically a guessing-game. I'm talking specifically about UV and radiation received by the structure as years progress. Another factor, strikes by debris and very small projectiles (meteorites) flying by. Ann, do you know if there are sensors to indicate "hits" taken by the satellite while in use? Also, are there mechanisms that will gage degradation and aging?
Bobjebgr, I think you're right about figuring out how composites will age in space: this is all pretty new and the NuSTAR satellite (as well as the Juno satellite) is an experiment in that direction. Composites have been used in aircraft for several decades, so there's already a lot of industry knowledge about wear due to UV and strikes. Regarding NuSTAR details, you may find answers at the link to the NASA site we gave in the article. There's also some discussion in the comments to the Juno spacecraft article: http://www.designnews.com/author.asp?section_id=1392&doc_id=244386
Although plastics make up only about 11% of all US municipal solid waste, many are actually more energy-dense than coal. Converting these non-recycled plastics into energy with existing technologies could reduce US coal consumption, as well as boost domestic energy reserves, says a new study.
This year's Dupont-sponsored WardsAuto survey of automotive designers and other engineers shows lightweighting dominates the discussion. But which materials will help them meet the 2025 CAFE standards are not entirely clear.
Artificially created metamaterials are already appearing in niche applications like electronics, communications, and defense, says a new report from Lux Research. How quickly they become mainstream depends on cost-effective manufacturing methods, which will include additive manufacturing.
SpaceX has 3D printed and successfully hot-fired a SuperDraco engine chamber made of Inconel, a high-performance superalloy, using direct metal laser sintering (DMLS). The company's first 3D-printed rocket engine part, a main oxidizer valve body for the Falcon 9 rocket, launched in January and is now qualified on all Falcon 9 flights.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.