PHYS.org 1/24/2020
For three decades the Cospas–Sarsat system has used relays on satellites such as Europe’s MSG and moreAs well as providing global navigation services, Europe's Galileo satellite constellation is contributing to saving more than 2000 lives annually by relaying SOS messages to first responders. And from now on the satellites will reply to these messages, assuring people in danger that help is on the way.
This ESA-design "return link" system, unique to Galileo, was declared operational this week, during the 12th European Space Conference in Belgium. The delivery time for the return link acknowledgment messages from initial emergency beacon activation is expected to be a couple of minutes in the majority of cases, up to 30 minutes maximum, depending primarily on the time it takes to detect and locate the alert.
"Anyone in trouble will now receive solid confirmation, through an indication on their activated beacon, informing them that search and rescue services have been informed of their alert and location," explains ESA's Galileo principal search and rescue engineer Igor Stojkovic. "For anyone in a tough situation, such knowledge could make a big difference."
More:
https://phys.org/news/2020-01-galileo-sos-messages-worldwide.html
