A climb up the world's highest mountain is no afternoon stroll, and the technology supporting the 1998 American Everest Expedition was not your average office equipment
Armed with equipment specially designed by the Media Lab at MIT, the expedition's professional mountaineering team was seeking data about Everest's climate and geology. They also served as human guinea pigs for a study of human physiological response to a place at the limits of human ability to survive.
"Instead of guiding up other people, they are climbing for science," said Michael Hawley, the MIT professor who headed up the Media Lab's '98 technology effort. "This year, there's going to be a tremendous gush of data coming off the mountain."
That "gush of data" became part of the technological challenge during the preparation for that climb to the 29,028-foot summit of Everest. The scientists behind the expedition had to wrestle with the design and operation of the computer equipment that the climbers carried with them, tackling issues from power conservation and its corollary, battery life, to real-time monitoring of remote systems.
Technology bound for Everest cannot be complex to operate, because its climber users will likely be physically clumsy and mentally dulled from oxygen deprivation and fatigue. Nor can it be finicky, because the climate stresses the technology just as surely as it squeezes the humans. Above 26,000 feet, there is one-third the oxygen present at sea level, and temperatures on the mountain can fluctuate wildly, from well below zero Fahrenheit to uncomfortably hot on cloudless days when the sun reflects off the snow.
"The problem is you've got to build something that's absolutely bombproof," Hawley said, if it is to withstand the climatic conditions, and "idiot-proof" to withstand rough handling by the climbers. Media Lab scientists and students designed special extreme-climate weather sensors and vital-sign monitors so that researchers at the Yale School of Medicine and Boston's Museum of Science could conduct their experiments on Everest, whose summit literally pokes into the jet stream. The experiments took place during the short window when conditions relent enough to make climbing big mountains such as Everest possible.
Even at base camp, more than 10,000 feet below the summit, the technology must be rugged. The computers that will process the data coming off the mountain must be able to function in a tent at 17,500 feet - higher, that is, than the Alps or the Rockies, and a far cry from the climate-controlled office most computers call home.
Still, things are tougher for the climbers themselves. Those who miscalculate and are high on Everest when the weather turns bad usually don't make it back down. In 1996, the most lethal year on the mountain, one person died for every six-and-a-half who reached the summit. Even in the least deadly year, 1993, the perils of exposure, avalanches and falls are such that one person died for every 16 who made it to the top.
To monitor those perilous weather conditions, which have been only spottily recorded, researchers want to install a sensor at the summit. Hawley and his team created a probe designed to measure the harsh climate without succumbing to it.
"Turns out that no one has measured the wind speed at the summit," and only a few measurements of barometric pressure or temperature have been taken, Hawley said. "Moreover, measurements taken by previous climbers have recorded conditions that were by definition atypical, because climbers make a summit attempt only on 'good" days."
To help researchers gather weather data, the Media Lab team built a 5-pound cylinder that was bolted onto an existing pole steps from the summit. The cylinder, roughly the size of a human thigh, was mostly batteries, with a coin-size sensor to measure wind speed, temperature, barometric pressure, light and humidity. It was designed to record and transmit data back to the Media Lab by tossing bits up to a passing satellite 36 times a day for one year.
Researchers from the Media Lab hoped to obtain precise measurements of the summit using geo-positioning satellites. Even though ice, rocks and snow routinely slough off the mountain, Everest is getting higher, thrust upward from the same collision of the Indian plate with the Eurasian plate that created the Himalayas some 50 million years ago.
As the climbers made their way to the summit, they wore backpacks designed at the Media Lab for Yale researchers conducting experiments on human functioning under extreme conditions. Yale was pursuing its 'extreme' research in partnership with the National Aeronautics and Space Administration, with an eye toward the coming human exploration of "the hostile and remote environment of space," said Ronald Merrell, chairman of the Yale medical school's department of surgery.
Everest is certainly hostile and remote, and given the extreme conditions, Yale researchers want to track climbers' skin temperature, heart rate, blood oxygen level and body-core temperature. In response, the Media Lab team devised a sensor system that was lightweight, because the gear and oxygen most climbers carry are already a heavy burden.
The sensors also had to function for prolonged periods without requiring fussy maintenance such as battery changes. Media Lab graduate student Robert Poor had previously created vital-sign monitors for marathon runners, but a summit attempt on Everest can take up to a week, far longer than the several hours it takes runners to complete a marathon.
The Media Lab team designed packs to lie snug against the male climbers' chests for the duration of the summit attempt. The packs weigh around 2 pounds apiece, and each uses three commercially available 9V lithium batteries.
Obtaining power without bulk was probably the biggest obstacle. The pack batteries had to be long-lasting without being too heavy or numerous, Poor said, "so that people wearing these things aren't just carrying around a battery pack with a little technology on the side."
The Media Lab solved the power problem by creating sensors that use energy intermittently. The batteries are in "sleep" mode for five minutes at a stretch, drawing minimal power, and awaken every sixth minute to provide the power that the sensors need to take their readings, fire up their radio transmitter and send the data back to base camp.
Disk drives, too, needed special attention for the conditions at base camp, because they operate using a bubble of air and air density fluctuates, depending on altitude. Drives are manufactured according to specifications for different altitudes, but so far there has not been much demand for machines that can function well at 17,500 feet, according to Ted Selker, IBM fellow at the Alamaden Research Center in San Jose, Calif.
Selker accepted the design challenge by making a 4-pound ThinkPad 560 work at high altitude and low temperatures. Testing showed that their drives appear to function as requested, with the bonus finding that they are now rated to function at 20,000 feet.
With the equipment ready to go, the main task during the expedition was the monitoring of the systems. At the request of the Yale researchers, the Media Lab designed the systems so that their sleep cycle can be overridden in the event of suspicious-looking data. Reaction must be immediate if a sensor detects a drop in core temperature. "Somebody needs to tell the climber, 'your core temperature is down, you're in trouble'," Merrell said.
Although Yale scientists can radio the climbers with the results, both groups need to appreciate that some of the technology naturally will fail during these field tests, Poor said. "We wanted to make sure they understand that this is an experimental system," he said. "We're not assuming that this is data that the climbers will use to make mission-critical decisions."
Nonetheless, medical ethics require that scientists at base camp let climbers know if readings look dangerous, according to Merrell. "It really was not reasonable to test out these things passively," he said. "If you're field-testing something that says your subject is in grave physical danger … you must tell the subject."
The Yale researchers at base camp established a tele-medicine link to medical databases for information they can relay to the climbers in an emergency. However, rescue still would have been unlikely from a place where the thin air that robs mountaineers of strength and judgment also prevents helicopters from flying in for evacuation. The improbability of rescue is a harsh fact known to all who climb big mountains, monitoring climbers' vital signs from base camp won't much change the outcome of any emergency.
