Satellite messaging devices, such as satellite phones, one-way satellite messengers and two-way satellite messengers are a CRITICAL piece of equipment to have in your backpack should an accident occur in a remote area. You could be hours from a trailhead, but if you have the ability to communicate you may be able to organize a helicopter rescue to pick up the victim within 30 minutes depending on the location. If you don’t have a means of communicating, you will be forced to either begin transporting the victim towards medical help, or if just a party of two, leave the victim and go out to the trailhead to summon help.
Ten years ago, satellite communication devices were super expensive and cost prohibitive for amateur explorers. Not so much now. You can get a basic satellite messaging device for $200-400. The most common satellite devices used by backcountry travellers are two-way messengers. These allow you to send and receive messages. Popular two-way satellite messengers include the Garmin InReach Mini, the SPOT X, and the Somewear Global Hotspot.
There are also still several one-way satellite messengers on the market. These devices are less expensive, and will function as an emergency communication tool, but they do not let you receive messages. With a one-way messenger, like a personal locator beacon, you can’t confirm that a rescue has been initiated and help is on the way.