When NASA's first manned Artemis mission lifts off, the astronauts aboard will be equipped with individual second-generation GPS emergency beacons. Developed by the space agency's Search and Rescue (SAR) office for the international Cospas-Sarsat program, the beacons will provide the returning space travelers with a faster and more accurate emergency beacon, and the technology will be available to the public in a few years.
The development of the US GPS system and other forms of satellite navigation have not only revolutionized travel but have also had an massive impact on many other areas – in particular, in the development of small emergency beacons that can work almost anywhere in the world.
In 1979, the non-profit, intergovernmental Cospas-Sarsat program was established by the United States, Canada, France, and the former Soviet Union to develop a system of satellites and ground stations to detect emergency beacons and alert the relevant rescue services. Today, the program has expanded to 45 countries and organizations and is now undergoing a major upgrade with the help of NASA's SAR office at Goddard Space Flight Center in Greenbelt, Maryland.
To improve accuracy and response times, the American GPS and other Global Navigation Satellite Systems (GNSS) are being upgraded with new satellites equipped with search and rescue instruments that are set in higher medium-Earth orbits. Their higher perspective allows them to observe a greater area of Earth and detect beacons faster than constellations in lower orbits.
According to NASA, about 70 satellites will also have instruments that can support multilateration, which is a navigation technique that uses the time of arrival of a signal to multiple receivers to zero in on the transmitter with great accuracy very quickly, even if the signal is a single radio burst. This will bring down the search area from a radius of kilometers to just meters.
However, this greater accuracy means developing new beacons that can take advantage of the technology. The new, second-generation beacons from the SAR office are designed to front-load distress transmissions in the first minutes after being activated and then reducing these as the transmission continues They will also send not only the beacon's embedded identification information, but bespoke data from the user as well. NASA says that this saves battery life and sends rescue teams better data.
The beacons will be commercially available in a few years, firstly in the US where the necessary ground station upgrades have already been completed. But the first field application will be for the first Artemis astronauts returning from the Moon. With the help of NASA’s Johnson Space Center in Houston, the new technology will be used in the Advanced Next-Generation Emergency Locator (ANGEL) beacons that will be installed in the space crew's life vests.
"Under normal circumstances, the Orion capsule will be pulled onto the deck of a ship and astronauts will be removed by military and NASA personnel," says Johnson survival and rescue systems engineer Cody Kelly. "If the crew needs to egress into the water for whatever reason, they’re equipped with our life preservers, rafts and ANGEL beacons to ensure their quick recovery."
Beyond this, the SAR office and the University of Maryland, College Park will test a prototype device that will allow an unmanned drone to lock onto and home in on beacon signals to help search and rescue efforts, especially at sea.
The animation below describes the Cospas-Sarsat system.
Source: NASA
