Memory cards survive plummet into ocean

A high-flying, student-assembled research balloon that appeared doomed after crashing into the Pacific Ocean has ended up yielding valuable astronomical data, thanks to hardy memory cards that survived the plunge.

As a result, astronomers now have information that will help them focus more clearly on galaxies, planets, stars, comets and other objects in space. And the California engineering students who first set the balloon afloat have been awarded special university honours for their efforts -- and seen how a seemingly sunken venture can end up an unexpected treasure trove.

The balloon, set aloft by students at the University of California at Santa Cruz to measure atmospheric turbulence, plunged into the ocean and was assumed lost after it broke apart in flight.

"It was a sad feeling, thinking that we weren't going to see the balloon again," said Skye Vendt-Pearce, the 23-year-old leader of the student team. "It was, 'Oh, we have nothing to show for our four or five months of work.' It was like saying goodbye to a friend."

Two inexpensive shop-bought SanDisk memory cards survived the crash and a soaking in the ocean, raising intriguing possibilities for other uses of the sturdy consumer electronics storage devices, which are small and light, and don't have many moving parts.

"It doesn't happen often that this stuff gets destroyed or falls out of the sky, but when it does, it's quite often we're able to recover the data," says Norm Frentz, marketing manager for the mobile handset group at SanDisk.

Memory cards, which typically include several NAND flash memory chips, are one of the great supporting actors in the tech world. Increasing densities of flash cards have allowed digital-camera makers to produce cameras that can hold far more pictures than standard film cameras. (Mobile phones and most MP3 players rely on flash memory as well, but it's typically embedded and doesn't come on removable cards.)

In the rough
The University of Santa Cruz students know firsthand how tough flash cards can be.

The journey started in March, when students at the university's Jack Baskin School of Engineering released a helium-filled balloon containing atmosphere probes, a transmitter, a digital camera and custom-built data recorder. The camera and the recorder each contained SanDisk SD flash memory cards to capture images and continuous telemetry readings.

The balloon was supposed to rise 23,000m and record information on atmospheric turbulence as indicated by wind shear and temperature changes. These parameters help astronomers measure light distortion in the atmosphere and adjust their telescopes to get the clearest image, according to John Vesecky, a professor of electrical engineering at UC Santa Cruz and the faculty mentor of the student team.

"These are little fluctuations in air temperature that occur in sizes from 10 centimetres to a few hundred metres," Vesecky said. "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."

With a GPS, or Global Positioning System, device indicating the balloon's position, the students were able to track its flight path for about two hours. They expected it to reach maximum elevation before deploying a parachute and returning to Earth. But things went awry when a shift in the wind pushed the balloon over the ocean, where it ruptured and splashed into the waves about two miles offshore. Team BAT (Balloon Atmospheric Telemetry) was ready to ditch the mission as a failure after gleaning only erratic bits of precrash numerical data from the transmitter via amateur radios placed aboard the craft.

The five-person team -- which spent months on the project and made two unsuccessful attempts to send the balloon skyward before it finally took flight -- was, to say the least, disappointed at the loss of the equipment.

But 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 a small padded lunch bag containing the circuit board for the telemetry equipment and a SanDisk 1GB standard SD memory card had been thoroughly soaked by saltwater. Nearby were the shattered remains of the Aiptek PenCam SD digital camera, which had been separated from the bag. The memory card, a SanDisk 128MB standard SD card that generally sells for about $20, was among the rubble.