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

Memorial Day weekend 2024 started with a blue sky and a mild three- to four-foot chop in the water off the Gulf Coast of Mississippi — a perfect day for a fishing competition. A team of five was about 40 miles offshore checking their sonar, and 30 seconds later the boat was gone. They were in the water struggling to pull on life jackets and grab the coolers as they bobbed up. When a boat sinks, survivors can be virtually invisible amid the vast expanse of water.

When their fishing trip went wrong, Easton Barrett had the only mobile phone and no cell service. He recorded a brief farewell, planning to put his 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, which sent a distress signal to the Search and Rescue Satellite-Aided Tracking (SARSAT) technology carried by multiple satellites in Earth orbit. In the SARSAT system, developed partly by NASA, an emergency signal containing the transmitter’s location is directed 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 was a Florida Coast Guard boat.

“Ever since, I have tried to teach others about safety on the water and in the outdoors by using a PLB,” said Barrett. “If that will save one life, it’s worth the effort.”

A beacon like the one that saved his crew, a registered ResQLink PLB developed by ACR Electronics Inc. of Fort Lauderdale, Florida, also notifies the device owner’s emergency contact, indicating a distress call was activated. All emergency beacons must meet the same requirements to ensure they work when needed. Every rugged, buoyant, handheld devices have a five- to 10-year battery life.

SARSAT began operations in 1982, becoming 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. Now there are 62 satellites in the program and 45 nations contributing services, from operating ground stations to providing rescue crews. More than 63,000 lives have been saved.

SARSAT by the Numbers

The Search and Rescue Satellite-Aided Tracking system developed over several decades by NASA and other government agencies saves lives on land or at sea.

• 1982 — the start of U.S. operations
• 1985 — the start of international operations
• 62 operational satellites
• 45 nations contributing services
• 63,000+ lives saved

One rescue in 2024 demonstrates how it all comes together.

• 40 miles off the Mississippi Gulf Coast
• 5-person team participating in a fishing competition 
• 30 seconds for a boat to sink
• 200 pounds of bait dumped to make a cooler buoyant
• 3 close encounters with wildlife, likely sharks and eels
• 4 hours in the water
• 1 personal locator beacon
• 1 Coast Guard rescue boat
• 5 lives saved

Source: NASA