AEDC continues important role in America's space program

  • Published
  • By Shawn Jacobs
  • AEDC/PA
ARNOLD AIR FORCE BASE, Tenn. --  Next week's 2012 Tennessee Space Week (TSW) (Jan. 22-28) will provide students an opportunity to learn of Tennessee's contribution to space exploration and, more specifically, the impact of Arnold Engineering Development Center (AEDC) on the U.S. space program.

A proud legacy

AEDC provides essential testing for the nation's ongoing space programs just as it did in the early years of space exploration for programs such as projects Mercury, Gemini and Apollo. The successful final flight of the Space Shuttle last year was, in large part, a result of testing at AEDC, at shuttle speeds from liftoff to Mach 1.5 in the center's 16-foot Transonic Wind Tunnel (16T). AEDC played a key role in the "Return to Flight" after the breakup of Columbia on re-entry in February 2003. Foam impact testing - for the effects of foam hitting the solid rocket booster - was also conducted in the AEDC Ballistic Impact Range S-3.

"Over the history of the space program, we've pretty much touched anything that's gone to, through, from or in space in some manner or fashion, anywhere from propulsion systems and the rockets that put them up there," Jim Burns, AEDC's space test lead, said. "[That includes] the aerodynamics on the payload fairings, the separations of those systems to make sure that they can safely separate on orbit, the materials that are used in spacecraft, the on-board control systems [and] the sensor systems. If it's been in or around space, it's probably been through AEDC at some point in its life."

AEDC played a key role in keeping the Titan IV, America's only expendable, heavy-lift launch vehicle, from being grounded by performing qualification testing of a new Stage II engine. AEDC has also tested the RL-10 engine variants which power the Delta IV and Atlas V Evolved Expendable Launch Vehicles. Additionally, AEDC tested the ability of both Titan and Delta payload fairings to safely separate after passing through the atmosphere following launch.

The NASA/European Space Agency (ESA) Cassini mission to Saturn deployed a probe to Saturn's moon, Titan, to assess the moon's environment. The Huygens probe deployed a parachute for its descent. Drag data was acquired in 16T on a model of the Huygens probe.

In another NASA/ESA joint venture, an Infrared Sub-millimeter Telescope mirror was calibrated in the AEDC 10V sensor calibration chamber to support sky-mapping efforts.

AEDC also supported development of technologies on several NASA space probes and experiments. The protective nose tip material for the Galileo Space Probe that sampled Jupiter's atmosphere in 1995 was evaluated by launching scale models at 11,000 mph down the AEDC 1,000-foot-long G-Range.

The center began supporting the development of the International Space Station (ISS) in 1992 by testing a hatch for the station to help determine its ability to survive the extreme cold and hot temperatures of space. The 2-pound, 53-inch-square hatch underwent thermal/vacuum testing in AEDC's 12-foot vacuum chamber (12V). A year later, a viewing cupola for the ISS was brought to AEDC, where it was covered in blankets, fitted throughout with heaters and then placed in a space chamber, where it was subjected to temperatures as low as -300 degrees Fahrenheit.

Deployment of structures in space after launch presents another considerable design challenge. AEDC tested solar panels for the NASA Wilkinson Microwave Anisotropy Probe (WMAP) to determine if the panels would deploy properly in space. AEDC officials routinely discuss potential investigations supporting development of NASA missions.

A relevant present

AEDC has supported NASA in Tennessee and at its two remote operating locations ─ the Hypervelocity Wind Tunnel 9 Facility in Silver Spring, Md., and the National Full-Scale Aerodynamic Complex at Moffett Field, Calif., ─ making numerous contributions to space exploration. Recently, all three locations have supported the development of the Mars Science Laboratory (MSL) with materials, vehicle and parachute tests.

In May 2011, NASA formally announced that the Orion crew capsule is the spacecraft that will carry humans back into deep space. Before Orion is ready for crewed missions to an asteroid or Mars, aerothermal testing was recently conducted at Tunnel 9 on a 4 percent scale model of the Orion capsule. The test looked at the heat-transfer rate on the heat shield of the capsule. In 2006, Tunnel 9 made use of conventional and advanced measurement techniques during the aerothermal testing of NASA's scale model of the module.

Some of the most recent testing done by Burns' group involved a long-range program dealing with electric propulsion.

"That backed off, but it's coming back up again," Burns said. "As the cycle of things in space moves from near Earth to deep space probes, the technologies that they're pursuing changes, so now the electric propulsion world is starting to grow again and that's one of the areas we're working with.

"We're also trying to work with them [NASA] in materials and environmental efforts. The space environment is, of course, different than the terrestrial environment we're used to here on Earth, and systems have to operate in that. How do you test things for those more complex environments?"

A promising future

Even with transition in the space program and budget constraints, Burns said he believes AEDC partnership with NASA looks promising.

"Because AEDC is so diverse and space is so diverse, there are always parts that are being done at AEDC," he said. "[For example] in aerodynamics, you have to get through the atmosphere to get to space ... and then you have the work in space - that's going on as well. You have the whole gamut happening.

"Obviously, with the budgets we have today and looking at the future, none of us can go it alone. A partnership between us, NASA [and] the other space agencies within the U.S. - we've got to do it together because no one is going to have the whole budget for everything."

AEDC has laid the foundation for a new space test capability - the Space Threat Assessment Testbed (STAT). STAT will create a realistic space environment to perform developmental and early operational testing of space hardware for the Department of Defense (DOD) and other agencies against natural and man-made threats. It will allow the center to do integrated system testing, training, tactics, techniques and procedures development and represents a significant step toward the development of a new national test capability.

The center can operate other facilities that contribute to the nation's space program when needed. These include vacuum chambers used to test sensors and electric propulsion thrusters; the Mark I Space Chamber, with the capability to test the operations of an entire satellite for extended periods of time; ballistic ranges used to test high-speed, high-altitude flight; arc heater facilities used to test materials for the rigors of re-entry into Earth's atmosphere; and rocket engine test cells used to test upper-stage engines at replicated altitudes of up to 100,000 feet.

TSW is a statewide project designed to increase student interest and performance in science and mathematics through a focus on aerospace programs and accomplishments. Activities are co-sponsored by the Tennessee Education Association (TEA), the Tennessee Space Grant Consortium, Vanderbilt University and NASA.

Following the Space Shuttle Challenger tragedy, Jan. 28, 1986, TEA acted to honor the life and teaching of Christa McAuliffe, America's first teacher in space, who lost her life in the mishap. TSW is held the last full school week in January each year.