Hall of fame inducts space tech stars
By Tariq Malik
(SPACE.com) -- The uses for new space technologies developed by NASA and industry professionals are not limited to Earth-orbiting spacecraft. Often such technologies can be spun off into commercial products that better the lives of humans firmly rooted to terra firma.
To recognize the value of these commercial spinoffs and the importance of space science in general, NASA and the Space Foundation created the Space Technology Hall of Fame, which has spent the last 16 years recognizing innovative products and inducting them into its ranks.
This year, the Hall of Fame honored four innovations during an April 1 ceremony at the 20th National Space Symposium held in Colorado Springs, Colorado. They include new medical devices and procedures used by thousands of consumers each year, as well as technologies that have had the broader impact of increasing air travel safety and telecommunications service.
The 2004 inductees include:MedStar Monitoring System from the Cybernet Medical CorporationLADARVision 4000 system for LASIK eye surgery from Alcon, Inc.Multi-junction solar cells from Spectrolab, Inc.Precision GPS Software System from NASA's Jet Propulsion Laboratory.
Keeping healthy with MedStar
The MedStar System is a small device designed to help people with chronic diseases not only keep tabs on their health from home, but keep their doctors informed as well.
MedStar monitoring device.
At MedStar's heart is a small gray box about the size of a desk stapler which connects to a variety of off-the-shelf health-monitoring equipment, such as a blood pressure sleeve, weight scale or blood glucose monitor. The system is useful for patients with chronic health problems, such as the elderly and diabetic, as well as those with asthma or congestive heart failure.
Once a patient uses one of the monitoring devices connected to MedStar, the system transmits the data through a standard telephone line to a collection server, where it is then sent to either the relevant hospital or physician. An Internet-based record management system allows for remote health monitoring by off-site caregivers such as personal physicians.
Developed by Ann Arbor, Michigan-based Cybernet Medical Systems, MedStar evolved from NASA-funded research that ultimately led to a wireless, miniature physiology-monitoring device used by astronauts aboard the International Space Station. But the NASA system went farther than just human health.
"What we had developed for NASA was a much larger, much more complete physiological system," said Eric Lichtenstein, CEO of Cybernet Medical Systems. "You could monitor mechanical hardware as well as electrical, basically anything with a physical data output."
For example, the original system could monitor the health of an astronaut inside a space suit while at the same time measuring the suit's performance, he added.
A better vision
The LADARVision 4000 system relies on laser radar technology originally developed to help NASA spacecraft rendezvous and dock with satellites during service calls.
The LADARVision 4000 system.
The tracking ability of the laser radar system lent itself to LASIK eye surgery, which uses an excimer laser to improve a patient's vision by physically reshaping the cornea. But the human eye is in constant motion during the surgical procedure, making small, involuntary movements at a rate of about 100 times per second. Eye tracking devices are used to constantly sample the eye position at any given time during the surgery.
In the 1980s, researchers at Autonomous Technologies Corp. -- now a part of Alcon, Inc. in Fort Worth, Texas -- developed the pointing and scanning laser beams that led to LADARVision 4000.
Today, the LASIK system uses two lasers to perform a surgery. The first, an infrared laser, consistently tracks the eye position about 4,000 times per second, about four times faster than the speed needed to keep up with involuntary eye movements for a surgery. The system's second laser then reshapes the cornea.
"The faster you go the more robust your system, which cuts down on all kinds of error," said Gary Gray, an associate technical director at Alcon, Inc.
Video-based eye-tracking systems can typically follow eye movements between 60 and 250 times per second, though the eye can move outside limits set by eye surgeons and require a halt in the entire procedure until the laser can be centered again.
"In LADARVision 4000, [the surgeon's] image of the eye doesn't move, it seems to be completely still," Gray said. Since the tracking laser keeps constant tabs on the eye movement, the eye appears stabilized to the actual operating laser, he added.
Alcon researchers hope to have an even newer system, the LADARVision 6000, ready by the end of the year.
Catching the sun
Multi-junction solar cells have become critical technology for the lives of spacecraft orbiting Earth and circling other worlds. More efficient than single-junction silicon or gallium arsenide cells, which absorb a fixed range of the light spectrum to generate solar power, multi-junction cells rely on multiple cell layers to capture wider variety of light wavelengths.
Spectrolab's multi-junction solar cells.
The double-junction (two layers) and triple-junction (three layers) cells developed by Boeing's Spectrolab, Inc. and the Air Force Research Laboratory have improved the power generation capabilities of today's telecommunications and other spacecraft.
Traditionally, single-junction solar cells convert about 19 percent of the light striking their surfaces into useable power. Spectrolab's dual-junction cells have pushed that up to about 24 percent and the triple-junction cells reach up to 28 percent efficiency.
Nasser Karam, vice president for advanced products at Spectrolab, said that the key to the multi-junction cells is the ability to not only to collect light at different wavelengths, but also to efficiently connect cells both optically and electrically.
Because the cells generate more power over the same surface area as their standard, single-junction counterparts, they are useful for satellite manufactures hoping to add capabilities to existing spacecraft buses. The use of multi-junction cells has led to higher-power satellites to provide various communications services such video streaming, direct broadcast capabilities, as well as global positioning services.
Spectrolab's triple-junction solar cells are the choice power source of NASA's robotic Mars explorers Spirit and Opportunity. Past Mars missions, such as 1997's Pathfinder, relied on standard gallium arsenide cells.
"The large increase in efficiency is what led us to use them," said Richard Ewell, power subsystem element manager for the current rover effort at NASA's JPL. "In this case, we get 40 percent more output within the same area than we would get with strictly gallium arsenide cells."
Karam said Spectrolab researchers are looking to build even more powerful cells, including five-junction and six-junction versions, in the future.
GPS: From satellites to air traffic control
Researchers at NASA's Jet Propulsion Laboratory developed the final innovation inducted into the 2004 Space Technology Hall of Fame, a precision GPS software system designed to track locations with an accuracy of just a few centimeters.
A Navstar GPS satellite.
JPL scientists have worked since 1985 to develop the GPS software, which uses a multitude of ground tracking stations and GPS satellites to determine locations anywhere on Earth. The system can also work in reverse, tracking satellite orbits equipped with positioning beacons with an accuracy of a few centimeters.
"This was a spinoff that was driven primarily by the science," said Stephen Lichten, manager for the tracking systems and applications section at JPL. The software was originally developed for geophysical studies, such as measuring continental plate motion over time, he said.
The JPL system has since been adopted by the Federal Aviation Administration , which incorporated it into the Wide Area Augmentation System used to track aircraft across the continental United States and Alaska to improve air travel safety. With an improved GPS system, pilots should be able to plot more direct routes without relying on ground assistance, saving on fuel and flight times, FAA officials said.
Lichten said one of the wide-ranging benefits of the software system is its ability to monitor natural hazards like volcanoes, which tend to give off pre-eruption signals that could alert officials to danger. The system can deliver real-time positioning information via the Internet as well, which could help farmers grow crops over large distances using remote-controlled tractors.
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