How does Emergency SOS via satellite work?

Does Emergency SOS via satellite use cellular networks? How can my iPhone contact a satellite?

Emergency SOS via satellite how it works

Emergency SOS via satellite differs from previous safety features offered on Apple's devices. Emergency SOS via satellite provides a way to connect with emergency services when Wi-Fi or cellular network coverage is unavailable.

Instead of using ground-based cellular towers, Emergency SOS via satellite software and a special antenna makes it possible to track and connect with a satellite in space. Apple has partnered with Globalstar, which operates a constellation of 48 low-orbit communications satellites. Messages received by a satellite are relayed to a ground station then onward to the appropriate emergency services dispatch.

Sending a text to get help can take up to 15 seconds under a clear sky. With a less than ideal connection to the satellite or under tree foliage, delivering a text can take a minute or more. In the meantime, the iPhone provides guidance on which direction to point the device to optimize its satellite connection.