Last July, two hikers were on a backpacking trip in California’s Shasta-Trinity National Forest. Just northeast of Granite Lake – a small body of water surrounded by landslides and a rocky mountainside – one of them fell and was too badly injured to continue.
From their supplies, they pulled out a personal location guy. They extended the device’s antenna and pressed the button below. Immediately, a radio signal began to radiate at 406 megahertz and eventually hit detectors on satellites in orbit. These instruments, part of the National Oceanic and Atmospheric Administration’s Search and Rescue Satellite-Aided Tracking Program (Sarsat), picked up the signal and immediately pinged alarms to Earth.
Someone is in trouble near Covington Mill, California, the warnings told the Air Force Rescue Coordination Center, along with details of who owned the device and how to get in touch with them. Soon a helicopter was on its way to the latitude and longitude of the distressed hikers. After hoisting both hikers, the plane flew them to the hospital.
As for the desert’s distress call, it was not only a happy ending, but an easy one. (This incident, along with thousands of others, lives on in the Sarsat program Event History Database.) Locating hikers required no scrubbing of the track head registration sheet or deciphering notes wallpaper for cars left at the starting point. It’s by design: Sarsat’s slogan is “to take the ‘search’ out of search and rescue“Sarsat is a little-known American program aimed at rescuing lost or injured hikers and climbers, overturned ATV and snowmobile drivers, sailors aboard sinking ships and passengers in crashed planes. It is part of an international partnership called Cospas. -Sarsat, which involves 45 countries and two independent organizations.The system relies on simple devices that have one task – send a location-revealing emergency signal, anywhere, in any weather – and a system of satellites that listen for these calls. “If you really need your life saved, in my opinion this will be the one for you,” says Sarsat Earth Systems Engineer Jesse Reich.
As of 2022, NOAA’s database has more than 723,000 registered rescue units, mostly owned by those hoping they will never have to use them. However, more than 50,000 people worldwide have been rescued because they activated their 406 beacons, sending an SOS signal to space.
SARSAT started after an incident that could have benefited from its technology: In 1972, two members of Congress, Hale Boggs and Nick Begich, flew in a two-engine Cessna 310 across Alaska. Their plane disappeared in a remote area in bad weather. A 325,000-square-mile search that took 39 days and 90 planes found nothing. The search was interrupted and the politicians and their planes are still missing to this day.
Afterwards, Congress declared that planes had to carry emergency beacons that would be automatically dispatched in the event of a crash. But the plan had a technological limitation: Another planes would have to fly nearby to answer the call. NASA, perhaps not surprisingly, realized that satellites would have a much wider view and could also survey the large parts of the planet that are in fact the ocean. A group of space agency scientists studied what was possible, and by 1979, the United States, Canada, France, and the former Soviet Union had signed papers in Leningrad. The international cooperation, which was later to be made more official as Cospas-Sarsatlaunched its first satellite in June 1982.