NASA Uses Twin Processes to Develop New Tank Dome Technology

NASA has partnered with Lockheed Martin Space Systems in Denver, Colo., and MT Aerospace in Augsburg, Germany, to successfully manufacture the first full-scale friction stir welded and spun formed tank dome designed for use in large liquid propellant tanks.

The NASA and Lockheed Martin team traveled to Germany to witness the first successful aerospace application of two separate manufacturing processes: friction stir welding, a solid-state joining process, and spin forming, a metal working process used to form symmetric parts.

The twin processes were used by MT Aerospace to produce an 18-foot-diameter tank dome using high-strength 2195 aluminum-lithium. The diameter of this development dome matches the tank dimensions of the upper stage of the ARES I launch vehicle under development by NASA, as well as the central stage of the European Ariane V launcher.

"This new manufacturing technology allows us to use a thinner, high-strength alloy that will reduce the weight of future liquid propellant tanks by 25 percent, compared to current tank designs that use a lower-strength aluminum alloy that weighs more," said Louis Lollar, project lead for the Friction Stir Weld Spun Form Dome Project at NASA's Marshall Space Flight Center in Huntsville, Ala.

The concave net shape spin forming process, patented by MT Aerospace, drastically simplifies the manufacturing of large tank domes and reduces cost by eliminating manufacturing steps, such as machining and assembly welding, that are required when manufacturing traditional gore panel - a pie-shaped section of the tank dome --construction domes.

"The success of this project is proof positive that when innovation, partnership and expertise are brought together, we can deliver new capabilities at lower cost with greater reliability for NASA and the nation's space program," said Jeb Brewster, project manager of the Friction Stir Welded Spun Formed Dome project at Lockheed Martin Space Systems. "This team has pushed the envelope by using existing commercial materials combined with cutting edge technology. The results provide the potential for a significant improvement over the current processes and materials being used today."

The spherical tank dome was manufactured from a flat plate "blank" made of the 2195 alloy. The blank was constructed by friction stir welding together two commercial off-the-shelf plates in order to produce a large starting blank, reducing the cost of raw materials. The welded plate blank was then spun formed to create the single-piece tank dome.

This is the first time this combination of twin manufacturing processes has been successfully applied to produce a full-scale 2195 aluminum-lithium dome.

"This achievement also demonstrates that international cooperation between the United States and Europe can achieve very promising and concrete results with mutual benefits for future space programs," said Judith Watson, program manager at NASA's Langley Research Center in Hampton, Va. "Lockheed Martin and MT Aerospace have set up a very efficient and effective development team."

Two additional, full-scale development tank domes are scheduled for manufacture and testing in coming months as part of the joint, two-year technology demonstration program.

NASA has invested in the Friction Stir Weld Spun Form Dome Project since 2006, which is managed by the Exploration Technology Development Program for NASA's Exploration Systems Mission Directorate in Washington.

Inventors Answer Call for New Glove Designs

Two independent inventors answered NASA's call for innovative new designs for the next generation of astronaut gloves. Today's spacewalkers have to contend with bulky gloves that stiffen when pressurized, making it tough to grip and flex while completing tasks in the vacuum of space.

Peter Homer and Ted Southern put their prototypes to the test during NASA's 2009 Astronaut Glove Challenge, held Nov. 19 at the Astronaut Hall of Fame in Titusville, Fla., near NASA's Kennedy Space Center.

Homer, an engineer from Southwest Harbor, Maine, was awarded $250,000 after placing first. Southern, a sculpture major at New York's Pratt Institute, earned second place and $100,000.

The ultimate goal of the Astronaut Glove Challenge is to improve the current design, resulting in a stronger and more flexible glove that will reduce the hand fatigue experienced by astronauts working in space.

For the first Astronaut Glove Challenge held in 2007, competitors supplied only the inner pressure-restraining layer. The outer layer, which provides protection against extreme temperatures and micrometeoroids, was an added requirement this year. Representatives from NASA and the agency's spacesuit contractor, ILC Dover, observed and noted the gloves' performances in a series of three tests.

The competitor inserted his gloved arm and hand into a depressurized glove box for the dexterity and flexibility test, completing cycles of movements and tasks, such as gripping a handle, using tools, flexing the hand and wrist, and touching the tip of the thumb to the tip of each finger.

In the joint force test, test operators from ILC Dover sealed and pressurized each glove to 4.3 pounds per square inch (psi) of internal pressure, then tugged it through its full range of motion while measuring the amount of force each movement required.

Finally, the gloves' strength capabilities were measured in the burst test. The room quieted as test operators sealed the glove and filled it with water, slowly increasing the pressure. Competitors, judges and other spectators leaned forward, watching the glove for signs of weakness or rupture.

The event was sponsored by Secor Strategies LLC of Titusville, Fla., and non-profit Volanz Aerospace of Owings, Md., managed the event for NASA.

"Both of you did better than the (current) Phase VI glove, and you both get a round of applause for that," said Alan Hayes, Volanz Aerospace chairman. "The test results were incredibly close."

Both Homer and Southern began working on the project in spring 2006 and competed in the first Astronaut Glove Challenge. Homer took home $200,000 after winning that event. After the 2007 challenge, Southern teamed up with former competitor Nikolay Moiseev.

Prior to the challenge, competitors were in the dark about who else would participate or what their designs might be.

"You're sort of developing in the vacuum of your own little world," Homer said. "You're hoping that you're going far enough with your design. And then there's the aspect of, 'Who am I going to be going up against?' I didn't know Ted was competing until we walked in and saw each other."

The Astronaut Glove Challenge is one of six Centennial Challenges prize competitions managed by NASA's Innovative Partnerships Program.

Astronaut Dr. Schmitt Visits Glenn

Dr. Harrison Schmitt, an astronaut on Apollo 17 and the last man to set foot on the moon, visited NASA's Glenn Research Center on October 27, 2009. After delivering a speech to Glenn employees, Dr. Schmitt toured some of the Glenn facilities, including the Low Impact Docking System (LIDS) Seal Lab in Building 63. In this lab, Dr. Schmitt met Dr. Bruce M. Steinetz, Senior Technologist and Seal Team Leader. They discussed the new LIDS that NASA is developing that will dock Constellation spacecraft to one another and to the International Space Station. Glenn is procuring, developing and testing the seal technology for LIDS.

Test Stand A-2 Peering Out from the Fog

At Stennis Space Center, three large engine test stands were built the early 1960s to test the first and second stages of the Apollo Saturn V rocket that carried Americans to the moon. Since 1975, the test stands have supported testing of the Space Shuttle main engines. The last planned test was conducted in July of 2009.

In this photo, the A-2 Test Stand peered out from a thick blanket of fog during the early morning hours of Oct. 28, 2009. This photo was taken from the top of the B Test Stand.

The A-1 and A-2 test stands are transitioning to support J-2X engine testing for the Constellation Program, while the B-1/B-2 test stand will support stage testing. For the first time since the 1960s, a new test stand, called A-3, is under construction with a scheduled completion date of 2011. The A-3 test stand will be 300 feet tall and will enable engineers to conduct simulated high-altitude testing up to 100,000 feet.

NASA's Fermi Telescope Celebrates First Year of Gamma-Ray Science

NASA will hold a news teleconference at 2 p.m. EDT on Wednesday, Oct. 28, to discuss the first-year science results from the Fermi Gamma-ray Space Telescope. This event replaces the originally scheduled Oct. 29 media conference at NASA Headquarters in Washington.

Fermi studies gamma rays, the highest-energy form of light. Findings discussed will include measurements relevant to the search for new theories of gravity.

The panelists are:
- Jon Morse, director, Astrophysics Division, NASA Headquarters
- Julie McEnery, Fermi project scientist, NASA's Goddard Space Flight Center in Greenbelt, Md.
- Peter Michelson, Fermi Large Area Telescope principal investigator, Stanford University in Palo Alto, Calif.
- Robert Kirshner, professor of astronomy, Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
- Mario Livio, astrophysicist, Space Telescope Science Institute in Baltimore

NASA's Fermi Telescope Celebrates First Year of Gamma-Ray Science

NASA will hold a news briefing at 2 p.m. EDT on Thursday, Oct. 29, to discuss the first-year science results from the Fermi Gamma-ray Space Telescope. The briefing will be held in the James E. Webb Memorial Auditorium at NASA Headquarters, 300 E St. S.W., in Washington. It will be carried live on NASA Television and streamed on the agency's Web site.

Fermi studies gamma rays, the highest-energy form of light. Findings discussed will include measurements relevant to the search for new theories of gravity.

The panelists are:
- Jon Morse, director, Astrophysics Division, NASA Headquarters
- Julie McEnery, Fermi project scientist, NASA's Goddard Space Flight Center in Greenbelt, Md.
- Peter Michelson, Fermi Large Area Telescope principal investigator, Stanford University in Palo Alto, Calif.
- Robert Kirshner, professor of astronomy, Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
- Mario Livio, astrophysicist, Space Telescope Science Institute in Baltimore

Friction Stir Weld

This close-up view of the friction stir weld tack tool used to manufacture of space shuttle external tanks shows the process of tack welding barrel panels together. Barrels were previously fabricated using traditional fusion welding, but friction stir welding is different in that the materials are not melted. A rotating tool pin uses friction and applied pressure to join the 20-foot longitudinal panels together.

Friction stir welding is the most recent upgrade to the space shuttle's external tank, the largest element of the shuttle and the only element that is not reusable. The new welding technique utilizes frictional heating combined with forging pressure to produce high-strength bonds virtually free of defects. Friction stir welding transforms the metals from a solid state into a "plastic-like" state, and then mechanically stirs the materials together under pressure to form a welded joint. Invented and patented by The Welding Institute, a British research and technology organization, the process is applicable to aerospace, shipbuilding, aircraft and automotive industries. One of the key benefits of this new technology is that it allows welds to be made on aluminum alloys that cannot be readily fusion arc welded, the traditional method of welding.

JPL Develops High-Speed Test to Improve Pathogen Decontamination

A chemist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has developed a technology intended to rapidly assess any presence of microbial life on spacecraft. This new method may also help the military test for disease-causing bacteria, such as a causative agent for anthrax, and may also be useful in the medical, pharmaceutical and other fields.

Adrian Ponce, the deputy manager for JPL's planetary science section, devised the new microscope-based method, which has the potential to quickly validate -- from days to minutes -- a spacecraft's cleanliness.

NASA adheres to international protocols by striving to ensure that spacecraft don't harbor life from Earth that could contaminate other planets or moons and skew science research. Microbes known as bacterial endospores can withstand extreme temperatures, ultraviolet rays and chemical treatments, and have been known to survive in space for six years. This resilience makes them important indicators for cleanliness and biodefense, Ponce said.

"Bacterial endospores are the toughest form of life on Earth," Ponce explained. "Therefore, if one can show that all spores are killed, then less-resistant, disease-causing organisms will also be dead."

The new technology works by looking for dipicolinic acid -- a major component of endospores and evidence of endospore growth -- by first applying terbium to a dime-sized area. Terbium is a chemical element used to generate the color green on television screens. That area is then illuminated under an ultraviolet lamp. Within minutes, one can see through a microscope aided by a digital camera whether live endospores are present. That's because they will literally glow: The terbium will show the endospores as bright green spots.

Ponce co-authored a paper on the new technology, called Germinable Endospore Biodosimetry, along with Pun To Young, a post-doctoral student at the California Institute of Technology in Pasadena, in the journal Applied and Environmental Microbiology. The research was also highlighted in Microbe, a magazine of the American Society for Microbiology.

The technology has piqued the interest of the U.S. Department of Homeland Security. The federal agency is funding development of a portable instrument based on Ponce's research that could quickly check for decontamination of pathogens after a biological attack. Ponce is working with the Department of Homeland Security and Advance Space Monitor, a company based in Falls River, Mass., to develop the instrument, which they plan to have ready for use by 2011. JPL and Caltech licensed the technology to Advance Space Monitor.

"As part of the Department of Homeland Security Science and Technology Directorate's near-term bioassays effort, the technology could enable the rapid assessment of facility sterilization. This could significantly reduce the time and cost of building restoration following a bio-contamination event," said James Anthony, chemical and biological research and development program manager at the Dept. of Homeland Security. A bioassay is an assessment of whether certain biological material is present on a surface being tested.

Anthony added that the technology could also be used in bio-containment facilities that have regularly scheduled decontamination requirements and rapidly reactivate important bio-defense research facilities.

Besides outer space and defense purposes, this new technology might also be applied in hospitals, child-care centers, dentists' offices and nursing homes.

"Given all the problems with hospital-acquired infections, assessing the sterility and hygiene of medical equipment and surfaces is becoming increasingly important," said Ponce.

Funding for Ponce's project was provided by NASA's Astrobiology Science and Instrument Development Program and Mars Technology Program, and the U.S. Department of Homeland Security's Chemical and Biological Research and Development division.