NASA Goddard

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Nobody flies without manufacturing – how the Advanced Manufacturing Branch at NASA’s Goddard Space Flight Center is helping to push the limits of space technology. When it comes to advancing space exploration, the sky’s the limit at NASA’s Goddard Space Flight Center (GSFC), a place where studying black holes, conducting gravitational mapping of the moon, exploring Mars and Jupiter, and visiting the International Space Station propel science beyond what was ever thought possible. Located in Greenbelt, Md., the GSFC designs, builds, and operates satellites and scientific equipment such as the Hubble Space Telescope, GOES weather satellites, LandSat earth imaging systems, the SOHO solar observatory, and many others. A big part of the GSFC’s capabilities comes from its on-site Advanced Manufacturing Branch, which provides broad machining, fabrication, and assembly services via punches and press brakes, gauging systems, turning machines, and GF AgieCharmilles multi-axis high-speed machining centers. And with in-house metal finishing, composite layup and curing, rapid prototyping, precision assembly, and more, there’s not much the branch can’t handle. Matt Showalter, associate branch head for the Advanced Manufacturing Branch, code 547, often thinks of the facility as Goddard’s “temple of science and engineering.” He said, “It’s a place for ideas to become reality. The branch’s motto, based on an old advertising logo, is “we bring concepts to flight.” For nearly a decade, Showalter has been part of a team devoted to continuous improvement of Goddard’s manufacturing abilities. Showalter explained, “Our purpose here is to ensure that we have the capability and capacity to do anything that comes through the door. Prior to our initiative to modernize the shop, we were totally dependent on older systems and there were some things we just couldn’t do. You can limit yourself from a science and engineering perspective if you don’t put new technologies into your manufacturing.” Before the modernization initiative was begun at Goddard nine years ago, one missing piece of the manufacturing puzzle was multi-axis high-speed machining. To that end, the Advanced Manufacturing Branch team has invested in Mikron multiaxis machining centers from GF AgieCharmilles. Starting with one Mikron HSM 600U machine seven years ago, the facility now has an impressive 4-machine high-speed machining cell containing the original HSM 600U together with a Mikron HSM 400U, Mikron HPM 800U and Mikron HPM 1350U. Showalter explained that bringing in new machine tool technology is a collaborative effort, controlled by strict federal procurement regulations, where potential vendors are invited in to show off their wares. Beginning with discussions about future needs of the engineers and scientists, and technical assessments by technicians from the shop floor, everyone contributes in developing the statement of work that defines the specifications for the necessary machine technology to meet the current and future requirements of the organization.
It’s not just a piece of equipment, but a complete package of support, tooling, and training. “When it hits the floor, we want it running and not waiting three years to tool it up.” Today’s satellites and associated instruments are getting lighter and smaller, with modern satellites coming in at onefourth the size of their older cousins. “We have to minimize weight, because it’s expensive to launch. As part features get smaller, our tolerances get smaller as well. And the high speed machining centers are critical to this work.” With the capability of Mikron High Speed Machining (HSM) and High Performance Machining (HPM), the Advanced Manufacturing Branch is able to handle a variety of work. “We machine anything from aluminum, titanium, Inconel, Invar, stainless steel, and high-nickel alloys…you name it.” From these materials, the Advanced Manufacturing Branch employees use the Mikrons to machine an expansive range of workpiece types, from components measuring .030” across with features as small as a human hair, all the way up to workpieces that would fill a one-meter cube. Designed to accommodate workpieces up to 9.05” x 13.77”, the Mikron HSM 400U portal design provides simultaneous 5-axis machining in a compact footprint. Because of its reliability, traceability and accuracy, the Mikron HSM 400U is an ideal solution for the Advanced Manufacturing Branch’s prototype work and mold construction. Additionally, the machine provides excellent surface finishes and precision part details, while significantly reducing machining time for semi-finishing and finishing operations. The Mikron HSM 600U and Mikron HPM 800U are also based on a portal-type gantry design. These 5-axis machines are built for high-performance machining applications, and for 100 percent full 5-axis simultaneous machining operations, the two machines feature direct drives in their circular and swiveling axes, which securely clamp in place for precision part positioning. Thanks to their unique designs and modularity, these machines provide the Advanced Manufacturing Branch with high-accuracy machining for both its single part production and rational series production. GF AgieCharmilles’ Mikron HPM 1350U, on the other hand, is based on a cross-bed-type design. The machine’s frameshaped traveling column moves the spindle in the Y- and Z-axis travels, while the X-axis is in the table. This special design allows the Advanced Manufacturing Branch to eliminate problems associated with any superimposed machine movements. But there’s more to the story than high-performance and high-speed machining. The multi-axis capabilities of the Mikrons can allow Goddard engineers to design better parts. Said Showalter, “With the 5-axis system, we have the ability to take a multiple-component bracket or assembly configuration and make it into one part. We can go from plane normal to a reverse angle plane or compound angle plane and do everything in one workpiece and a single operation. So instead of stacked tolerances (as in a multiple-part assembly), our accuracies are controlled by a single reference coordinate system.” One of the people using the Advanced Manufacturing Branch’s services is Adam Matuszeski, electromechanical engineer at NASA. Matuszeski was part of the group responsible for building the Lunar Reconnaissance Orbiter, or LRO, which was placed into orbit around the Earth’s moon in 2009. Designed to map out potential landing sites and gather information about the moon’s surface and geography, the LRO mission, slated to last only 14 months, is still successfully streaming data back to Goddard. Circling the moon at an altitude of 30 miles, the LRO satellite carries seven high-tech devices designed to image the moon’s surface, measure radiation levels, and look for areas of frost and water ice, especially near the poles. Critical to the LRO’s success is always knowing the precise location of the spacecraft. To accomplish this feat, scientists mounted a small telescope on the orbiter’s antenna dish. Said Matuszeski, “The telescope looked through a hole in the dish, and was connected via fiber optics from the back of the telescope to a detector on the laser altimeter. Because it was going to the moon and taking very precise instrument data, it needed to have a way of knowing exactly where in space it was.” The solution was a tiny telescope hidden behind the antenna dish and designed to give a laser-referenced measurement from earth. It picks up a pulse of green laser light shot from a station at Greenbelt and measures the amount of time it takes to get from the earth to the LRO, indicating how far away the spacecraft is from earth.” “For this project, we had to run seven 0.25 mm diameter fiber optics across the spacecraft. The trickiest part of that was machining the tip of the connector, which is called the ferrule. It’s a 2.5 mm cylinder that’s hollow on one side, like a long thin cup about 17 mm long. We milled a flower-shaped pattern in the end of the cup using a .006”end mill on our Mikron machine, which allowed us to locate those seven fibers, six on the outside and one in the middle, then affix them there with an epoxy and polish them flat,” explained Matuszeski. With the LRO, NASA has already collected the same amount of data as all previous planetary missions combined. Another of the seven devices riding aboard the LRO is LOLA, short for the Lunar Orbiter Laser Altimeter. LOLA is a complex little device, but in simple terms, her job is to generate a high-resolution 3D map of the moon, which will help scientists find the best place to land future spacecraft, or possible sites for solar power stations. “LOLA uses what’s called a LIDAR. It’s like a radar, but it uses a laser for detection and ranging to measure distance,” said Matuszeski. “However, the art of creating a laser that can fly in space is kind of a black art, and it’s one of the things that our center at Goddard prides itself on. We’ve probably done five or six of them successfully over the last 15 to 20 years, and all of them were challenging.” Matuszeski went on to say that it’s quite difficult to build a laser that will last years in space, not only because of the
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NASA Goddard

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