Immersed in Saltwater For Days, SanDisk Flash Memory Cards Survive To Tell a Tale
- And Bring Honors For UC-Santa Cruz Engineering Students
All Photographs Courtesy of UC-Santa Cruz
SUNNYVALE, CA, JULY 7, 2005 - Engineers at SanDisk® Corporation (NASDAQ: SNDK) have salvaged valuable data from a high-flying atmospheric research balloon that plunged into the Pacific Ocean after it was launched by a team of university students off the central California coast. As a result, astronomical observatories that benefit from the project now have information that will help them focus more clearly on objects in outer space, and the students have been awarded special honors for their effort.
Monterey Bay coast shot from research
balloon at 25,000 feet
This remarkable chain of events began when the students, all engineering seniors at the University of California-Santa Cruz, released a helium-filled balloon with instruments that included atmosphere probes, a transmitter, a digital camera and a custom-built data recorder. Both the camera and the recorder used SanDisk SD™ flash memory cards to capture images and continuous telemetry readings.
Calling themselves Team BAT (for Balloon Atmospheric Telemetry), the students launched their balloon in early March from a softball field in Watsonville, a coastal agricultural community south of Santa Cruz. Their intent was for it to rise 75,000 feet and continually record information on turbulence including wind velocity, temperature, humidity, pressure, altitude, longitude and latitude. These are parameters that help astronomers to measure light distortion in the atmosphere and adjust their telescopes for the clearest image.
With a GPS device giving the balloons position, the students were able to track its flight path for about two hours. They were expecting it to reach maximum elevation before deploying a parachute and settling gently back to earth. But things suddenly went haywire. A sudden shift in the wind pushed the balloon and its payload of electronics over the ocean, where it ultimately ruptured and splashed into the waves about two miles offshore from Pajaro Dunes, presumably never to be seen again. Team BAT was ready to scratch the mission as a failure after gleaning only erratic bits of data from the transmitter.
But fortune prevailed. Five days after the balloon disappeared, a beachgoer found the apparatus washed ashore about 20 miles north of where it had dropped into the ocean, and called the university. When the students arrived, they saw that the small padded lunch bag containing the circuit board for the telemetry equipment - and a SanDisk 1-gigabyte (GB) standard SD memory card - were thoroughly soaked by saltwater. Nearby were the shattered remains of the digital camera, which had been separated from the bag. Amazingly, the memory card, a SanDisk 128-megabyte (MB) standard SD card, was among the rubble.
Prof. John Vesecky, left,
and Team BAT
Back at the UC-Santa Cruz lab, the excited students dried out the card from the camera, slipped it into a card reader on a PC, and observed a string of breathtaking, high-elevation photos, the last one shot at 40,000 feet. Not a single image was lost. But the SanDisk SD card from the data recording device was completely unreadable. So Dave Van Unen, engineering lab staff for the universitys Jack Baskin School of Engineering, sent the card to SanDisk as a last resort.
After a week of repeatedly scanning the card with a special reading device and getting intermittent errors, Ysabel Tran, a technician in SanDisks engineering lab, was finally able to extract all of the data on the card. She transferred it to another SD card, which was immediately relayed to Team BAT.
UCSC engineering student Roberto Menchaca said that although his group estimated a peak altitude of 60,000 feet for the balloon, in fact the card data recovered by SanDisk showed a maximum of 81,863 feet -- far above the original objective. And while the balloon transmitter radioed just 1,028 samples of data, the card yielded a whopping 53,406 samples. "This gave us more accurate data and, just as important, it was continuous, whereas the data we received by radio was full of gaps," he said.
Elated at their now successful project, the students presented their report to their research sponsors. And when graduation ceremonies were held in early June, the university gave them both the Dean's Award and the Chancellors Award - a rare double honor. Members of the team, apart from Menchaca, consisted of project leader Skye Vendt-Pearce, Bartolo Alvarado, Amanuel Mengistu and Kathy Phan.
"Were delighted that we were able to assist these aspiring engineers and thus contribute to the space program," said Nelson Chan, SanDisks executive vice president and general manager for consumer and handset business. "This amazing series of events once again demonstrates the durability of SanDisks flash memory cards."
Bartolo Alvarado with
Dr. John Vesecky, professor of electrical engineering at UC-Santa Cruz and the faculty "mentor" of the student team (along with Prof. Don Wiberg, Cyrus Bazeghi and Stephen Petersen), said the overall project was supported by astronomers from the Palomar and Lick observatories in California and funded by Cal Space, a state grant program that promotes space-related education within the university system, and the Center for Adaptive Optics at UC-Santa Cruz.
"The students were measuring variations in atmospheric turbulence as indicated by wind shear and temperature changes," said Vesecky. "These are little fluctuations in air temperature that occur in sizes of from 10 centimeters to a few hundred meters. They are like eddies in the atmosphere and they create distortion - the'twinkling in the stars that people see from earth - and generate fuzzy images for space telescopes. It's like looking at lights through a swimming pool ."
By using the student balloon data, land-based astronomers can begin to profile the layers of turbulence and compensate for them, he added. This process is called "adaptive optics," and the UC-Santa Cruz program in this field is nationally recognized. Another student balloon called the HASTE project was launched in June and a third may be released this fall, said Vesecky.
SanDisk is the original inventor of flash storage cards and is the worlds largest supplier of flash data storage card products, using its patented, high-density flash memory and controller technology. SanDisk is headquartered in Sunnyvale, CA and has operations worldwide, with more than half of its sales outside the U.S.
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