NASA’s Life-Saving Technology Where Cell Signals Can’t Go

Memorial Day weekend 2024 began with blue skies and a mild three- to four-foot chop off the Mississippi Gulf Coast, ideal conditions for a fishing competition. A five-person team was about 40 miles offshore checking its sonar when, 30 seconds later, the boat was gone. The crew was in the water struggling to pull on life jackets and grab coolers as they bobbed up, and survivors in such cases can be virtually invisible in the vast ocean. Easton Barrett had the only mobile phone and no cell service; he recorded a brief farewell and planned to put the phone in a cooler in hopes someone would find it. Another team member activated a personal locator beacon (PLB) that had been stowed at the last minute, sending a distress signal to the Search and Rescue Satellite-Aided Tracking (SARSAT) technology carried by multiple satellites in Earth orbit. The ordeal included 200 pounds of bait dumped to make a cooler buoyant, three close encounters with wildlife likely sharks and eels, and four hours in the water before one Coast Guard rescue boat arrived, saving all five lives.

SARSAT works by directing an emergency signal containing the transmitter's location to the nearest available ground station. A mission control center then alerts rescue coordination centers to mobilize search and rescue crews; for Barrett and his crew, that meant a Florida Coast Guard boat. Barrett later said he has tried to teach others about safety on the water and in the outdoors by using a PLB, adding, "If that will save one life, it's worth the effort." The beacon that saved his crew was a registered ResQLink PLB developed by ACR Electronics Inc. of Fort Lauderdale, Florida; Barrett is identified as an ACR customer. The device also notifies the owner's emergency contact that a distress call was activated. All emergency beacons must meet the same requirements to ensure they work when needed: rugged, buoyant, handheld devices with a five- to 10-year battery life.

SARSAT began operations in 1982 and became an international collaboration in 1985. The flight and ground technologies used globally were originally developed at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Today the program has 62 satellites and 45 nations contributing services ranging from operating ground stations to providing rescue crews, and more than 63,000 lives have been saved. The system, developed over several decades by NASA and other government agencies, saves lives on land or at sea.