Tests will help in development of asset and inventory tracking systems

NASA's George C. Marshall Space Flight Center is partnering with Intermec on a research project that will test the performance of several types of automatic identification and tracking (AIT) technologies in space, including direct part marks and RFID tags.

As part of the technology development project, Intermec will evaluate markings that have been exposed to low earth orbit environments during the third and fourth Materials International Space Station Experiment (MISSE) missions. Intermec also will prepare additional marked samples and RFID tags to be included in MISSE 6, scheduled for July 2007. The MISSE 3 and 4 materials are still on the International Space Station, and are expected to be returned in a few months.

The project will determine how well the tracking technologies perform when exposed to the harsh conditions of space. During the July mission, astronauts will mount a small aluminum case containing sample materials on the exterior of the space shuttle. After being exposed to conditions in orbit, they will be tested to determine the effects of exposure to extreme levels of ultraviolet radiation, atomic oxygen, hard vacuum, and contamination. Afterward, they will be evaluated and certified for use on future space vehicles and added to NASA's part identification requirements.

"Special identification markings for use with spacecraft will play an increasingly important role as we prepare more complex vehicles and systems to support the implementation of the Vision for Space Exploration," says Fred Schramm, administrator, internal research and development program, NASA Marshall Space Flight Center. "We have to make use of markings that have been properly tested to the demanding environments of space travel and support a wide variety of tasks."

Variety of Technologies

For the MISSE 6 experiment, Intermec will provide direct-marked Data Matrix bar codes, as well as several types of RFID tags. These will include a ruggedized tag housed in plastic, as well as a tag with a flexible substrate. The Data Matrix codes will be applied to samples of aluminum-lithium alloys.

NASA will also test nanocodes (or chemical bar codes), which are mixtures of chemicals in known quantities that are read with x-ray fluorescent hand-held technology.

Intermec will evaluate the RFID tags and bar code marks for any readability issues. "We want to make sure the data hasn't been corrupted," says Larry Huseby, director of business development at Intermec.

NASA has long been a champion of using automatic identification technologies in its operations, particularly for direct marking of parts and equipment. Many of the technology development projects initiated at the Marshall Space Flight Center have later been commercialized.

"What NASA wants to do is basically the same thing that the Department of Defense wants to do and that the aerospace industry wants to do," says Huseby. "They want to be able to create permanent marks, so that parts can be individually tracked."

While NASA has typically turned to bar coding for this type of application, RFID holds promise for in-flight applications both because of the increased data capacity of the tags, and the ease of reading the tags for astronauts who are encumbered in bulky suits and gloves.

"It could allow the astronaut to work hands free without picking up a scanner," says Schramm. "We want to have something where if we send out a signal, we can find a specific package in a storage area. On these missions you have very limited space, so things are stacked up in containers all the way to the ceiling."

RFID also poses challenges, however. "The difficulty with RFID on space missions is, even if you have a very small tag, those tags add up in weight," says Huseby. "For NASA, weight is a critical issue. So they are looking for combinations of materials and marking technologies that when used together, will give them reliable performance in space."

Another obstacle that NASA anticipates is a difference in bar code reading conditions in space. "For the bar codes, what we're anticipating is that if you are outside, you will have a brightness/darkness issue that isn't as dramatic here on Earth," Schramm says. "On the reader side, you will have a heat and cold issue in terms of operability."

Read distance will also be a challenge, particularly for applications where an astronaut on a space walk wants to read a part mark some distance away. "Every time you move out there, you add risk to the astronaut," Schramm says. "We're working on an optical reader that will read at 20 to 60 feet. There are very few things on the market right now that will do that."

NASA is also testing RFID for an in-flight inventory tracking application. Aerospace engineering and technology services firm Barrios Technology has developed a system using hardware from RF SAW to help track hardware, spare parts, and personal items on the International Space Station. Beginning this fall, NASA will use the RFID tags and hand-held readers to track uniforms and toiletry items.