Stranded on a desert island; lost in the forest; stuck in the snow; injured and unable to get back to civilization. Human beings have used their ingenuity for millennia to try to signal for rescue. there’s been a progression of technological innovations: smoke signals, mirrors, a loud whistle, a portable radio, a mobile phone. With each invention, it’s been possible to venture a little farther from populated areas and still have peace of mind about being able to call for help.

But once you get past the range of a terrestrial radio tower, whether it’s into the wilderness or out at sea, it starts to get more complicated and expensive to be able to call for rescue. In the next year or so, it’s going to become a lot simpler and less expensive. Probably enough to become ubiquitous. Hardware infrastructure is already in place, and the relevant software and service support is rolling out now.

It’s been possible for decades for adventurers to keep in contact via satellite. The first commercial maritime satellite communications was launched in 1976. Globalstar and Iridium launched in the late 90s and drove down the device size and service cost of satellite phones. However, the service was a lot more expensive than cellular phone service, and not enough people were willing to pay for remote comms to be able to overcome the massive infrastructure costs, and both companies went bankrupt. Their investors lost their money, but the satellites still worked, so once the bankruptcies were hashed out they fulfilled their promise, as least technologically.

On a parallel track, in the late 1980s International Cospas-Sarsat Programme was set up to develop a system for satellite aided search and rescue system that detects and locates emergency beacons activated by aircraft, ships and people engaged in recreational activities in remote areas, and then sends these distress alerts to search-and-rescue (SAR) authorities. Many types of beacons are available, and nowadays they send exact GPS coordinates along with the call for rescue.

In the 2010s, the Satellite Emergency Notification Device or SEND device was brought to market. These are portable beacons that connect to the Globalstar and Iridium networks and allow people in remote areas not only to call for help in emergencies, but also to communicate via text messaging. Currently the two most popular SEND devices are the Garmin inReach Mini 2 and the Spot X. These devices cost $400 and $250 USD respectively, and require monthly service fees of $12-40. For someone undertaking a long and dangerous expedition into the backcountry, these are very reasonable costs, especially for someone who does it often. But for most people, it’s just not practical to pay for and carry a device like that “just in case.”

In 2022, the iPhone 14 included a feature that was the first step in taking satellite-based communication into the mainstream. It allows iPhone users to share their location via Find My feature with new radio hardware that connects to the Globalstar service. So if you’re out adventuring, your friends can keep track of where you are. And if there’s an emergency, you can make an emergency SOS. It’s not just a generic Mayday: you can text specific details about your emergency and it will be transmitted to the local authorities. You can also choose to notify your personal emergency contacts.

Last week, at WWDC, Apple announced the next stage: in iOS 18, iMessage users will be able to send text messages over satellite, using the same Globalstar network as its SOS features. Initially at least, this feature is expected to be free. With this expansion, iPhone users will have the basic functionality of a SPOT or inReach device, without special hardware or a monthly fee.

SpaceX’s Starlink, which first offered service in 2021, has much higher bandwidth and lower latency than the Globalstar and Iridium networks. Starlink’s current offering requires a dinner plate sized antenna and conventional networking hardware to enable high bandwidth mobile internet. It’s great for a vehicle, but impractical for a backpacker. However, SpaceX has announced 2nd generation satellites that can connect to 1900MHz spectrum mobile phone radios, and T-Mobile has announced that it will be enabling the service for its customers in late 2024, and Apple, Google, and Samsung devices are confirmed to be supported. Initially, like Apple’s service, this will be restricted to text messaging and other low-bandwidth applications. Phone calls and higher bandwidth internet connectivity are promised in 2025.

The other two big US carriers, AT&T and Verizon, have announced they will be partnering with a competing service, AST SpaceMobile, but it’s unlikely those plans will come to fruition very soon. Mobile phone users outside the US will also need to wait. Apple’s Message via satellite is only announced for US users, as is T-Mobile’s offering.

So if you’re in the US, and have an iPhone, or are a T-Mobile subscriber with an Apple, Samsung, or Google device, you’ll soon be able to point your phone at the sky, even in remote areas, to call for help, give your friends an update on your expedition, or just stay in touch. Pretty soon, Tom Hanks won’t have to make friends with a volleyball when he crash lands on a deserted island, at least not until his battery dies.