Testing the iPhone Satellite Messenger: It’s Not Ready for Life or Death Situations in the Backcountry

I was surprised when I first read reports that Apple was teaming up with Globalstar to provide satellite messaging services on the iPhone 14 and newer models. I had last used a Globalstar-powered satellite messenger, an earlier version of the SPOT Gen4, a decade ago while hiking the Pacific Crest Trail. The idea was to send daily check-ins to my parents, to let them know I was OK. But what happened was that the device repeatedly failed to deliver check-ins, sometimes for several days in a row (this did not go over well with my mom). My next satellite messenger purchase was a Garmin InReach Mini, which uses the satellite network owned by Globalstar’s competitor, Iridium. 

My experience was not unique, which is why Iridium-based Garmin and Zoleo devices dominate in the backcountry today. But the temptation to dump a pricey subscription plan — most satellite messenger plans charge upwards of $100 a year — is huge given that, for now, Apple is not charging for its service. Backpackers and backcountry hunters carry satellite messengers primarily to contact the frontcountry in case of an emergency, so a dependable satellite network is essential. Would Apple’s satellite messenger service on the Globalstar network be reliable enough in the backcountry to warrant canceling my Garmin subscription? Would it be reliable enough to bet my safety on? We decided to test it.   

How We Tested the New iPhone Satellite Messenger

In July, prior to the release of satellite messaging on the iPhone, I ran a test of the best satellite messengers on the Outdoor Life annual backpacking gear testing trip. We tested two Garmin inReaches (Iridum), a Zoleo (Iridum), an ACR Bivy (Iridium), and two SPOT models (Globalstar) along the Pacific Crest Trail in Washington State’s Goat Rock Wilderness that included both forested and alpine stretches. For this test, I had members of the team press the check-in button for each satellite messenger at the same time, from the same location. This matters because your ability to connect to a satellite messenger is affected not only by your physical location — being under tree cover or inside a canyon reduces the odds of connecting to a satellite — but also the location of the satellites themselves. Unlike cellphone towers or even the higher orbit satellites that power television broadcasts, the satellites used for messengers are constantly moving, which helps ensure users are able to connect with one. 

Over five tests from five different locations, both the Zoleo and the Garmin devices successfully transmitted their messages, with the longest lag time being 14 minutes for the Zoleo device. (I was unable to confirm receipt of the ACR’s messages, unfortunately, as they were sent to my spam folder and subsequently deleted.) Both SPOT devices — the SPOT X and the SPOT Gen4 — failed to send one of the messages after successfully connecting to a satellite. 

At the time we were under heavy tree cover, which can pose a challenge to satellite messengers. Because the SPOT Gen4 is a one-way transmitter, it could only verify that it had connected to the satellite (which it did), not that the message was received on the other side. The SPOT X, on the other hand, indicated that it was unable to verify whether the message had been received (although not that it had failed to send). As a means to text from the backcountry, this is annoying. As a method for reassuring loved ones that you are OK, it’s frustrating. As a potentially life-saving piece of gear, it’s disqualifying. 

Globalstar owns SPOT, which made it difficult to ascertain what the real issue was: the hardware that backpackers were using on the ground, or the satellite network itself. But still, the results made us suspicious of the Globalstar network that Apple has now adopted.

In order to test the reliability of Apple’s new satellite messenger, OL executive editor Natalie Krebs headed to the Utah wilderness with a satellite-enabled iPhone 15 Pro, the SPOT Gen4, and the Garmin inReach Mini 2. Like with the original satellite messenger test, the idea was to send a message out from all three devices at the same time of day, from the same location. Would the satellite messaging on the iPhone 15 reliably send out messages, like the Iridium-enabled Garmin inReach Mini 2? Or would it drop messages like the Globalstar-owned SPOT? 

Test Results

Similar to the backpacking gear test, Krebs sent messages from a range of locations, including BLM, NPS, USFS, and national monument land. And like with the backpacking gear test, there was one missed message from the devices using the Globalstar network, and none from the Iridium network. In that instance, the iPhone got through 90 percent of the loading process before attempting to switch to an SMS message and providing a “Not Delivered” failed notification. Krebs reported that during the third test, when the Globalstar network appeared to falter, she was located inside of a shallow canyon. 

Krebs followed up this testing at the end of her hunting trip by sending a message from both a deeper canyon (Check-In 15), as well as a second stab at the shallow canyon (Check-In 16). The Garmin inReach Mini 2 successfully sent messages from both locations. Both messages from the SPOT Gen4 were delayed by 10 minutes. The iPhone satellite message took 70 minutes to deliver its message from the deep canyon, and 20 minutes to deliver its message from the shallow canyon (compared to the Garmin InReach). The timestamps and loading bars from Krebs’ iPhone gave no indication that there had been any kind of delay.

Here’s a full breakdown of the testing results with the iPhone satellite messenger.

Globalstar investigated the dropped messages and says the missing SPOT X message from our backpacking gear test actually sent successfully (even though we never received it). Whether this instance represents an anomaly or there’s something interfering with Globalstar’s ground stations and the final recipient is unclear. They did confirm that Krebs’ message from the SPOT Gen4 failed to transmit. Beyond that, Globalstar did not respond to questions for this story as of press time.

How Satellite Networks Work

The satellites maintained by Globalstar and Iridium are low earth orbit (LEO) satellites. These satellites are no higher up than 1500 kilometers (930 miles) above Earth’s surface, and typically closer to 500 miles. The advantage to having satellites this low is that it allows devices with smaller antennas, such as satellite messengers or smartphones, to reach them. The disadvantage is that there will be times when your satellite messenger doesn’t have a clear line of sight with the satellite — think canyons or mountainous regions. Tree cover also poses a challenge to satellite messengers.

Of course, mountains and canyons and forests are where Outdoor Life readers would most like their satellite messengers to work. To solve for this problem, Globalstar and Iridium both designed their satellites as a moving array. But that’s where their similarities end. 

How the Iridium Network Works

Iridium designed their network with 66 satellites in concentric orbits around the poles, traveling at speeds of 17,000 miles per hour. Because the satellites are always moving, it’s only a matter of time before they come into view on the other side of the mountain or overhead where you are trekking through a canyon. Once your device connects to the satellite, it can transmit a message.

But that’s just the first step in the process; the second is getting your message to a ground station where it can be routed to the correct recipient, whether that’s your spouse or emergency services. Just like sending a message up to a satellite, the satellite must have line of sight with a ground station to complete the message send. Iridium has four ground stations, in Tempe, Arizona; Fairbanks, Alaska; Svalbard, Norway; and Punta Arenas, Chile. Satellites that are too distant to quickly connect with a ground station will relay their messages to other satellites instead — sometimes hopscotching to as many as six different satellites before achieving line of sight with a ground station. 

How the Globalstar Network Works

Globalstar uses a different design entirely. Their array is set at a slant around the earth, so that their 24 satellites can still cover 80 percent of the globe. Unlike Iridium, these satellites can’t communicate with each other. Globalstar, however, has significantly more ground stations than Iridium — 28 in total — such that, according to Globalstar, there is essentially no delay in getting the messages back to the ground.

Something to keep in mind about these satellite arrays is that they are not easy to change. Chirag Patel, director of project management for Globalstar, told me that their satellites are designed to last a minimum of 10 years, with some that have been in orbit for as long as 18 years. Iridium shared that they have nine spares currently in orbit, so that if one of the satellites in their array breaks down, they can swap in a backup without the need to launch new satellites into orbit. 

Globalstar’s view is that by putting a greater emphasis on their ground stations the company can be more nimble in the face of technological changes. 

“If the technology changes tomorrow, you’re not going to be able to launch a new satellite tomorrow,” Patel says, explaining Globalstar’s choice to comparatively deemphasize the satellite portion of its satellite network. “So instead of me changing a satellite, I could change the infrastructure on the ground to incorporate the latest and greatest [technological advantages] … The satellite becomes more of a mirror that just sends and receives the information. It’s a dumb pipe, is another way of looking at it.” 

According to Globalstar, eliminating the need for a message to hop around to different satellites means that the message will get to its intended recipient faster. In our testing, Apple’s messages did typically land at their destination a minute or two before Garmin’s.

Global Coverage

For Iridium, the goal is complete coverage. 

“Most people don’t cover the poles because they don’t think there’s much business there to be had,” Tim Last, senior vice president for Iridium, tells me. “We do because of the nature of what we do and the types of customers we serve.” 

Iridium’s view that its network was more effective at global coverage was shared by Globalstar. 

“The only thing we don’t cover is the North Pole and the South Pole,” Patel says. “[Our network] covers more than 99 percent of the global population.” 

Apple, by contrast, states on its website that its “satellite connectivity might not work in places above 62-degree latitude, such as northern parts of Alaska.” 

Because of its network design, Iridium is able to provide better coverage to more remote parts of the world. 

“We’ve lost count of the number of partnerships and sponsorships and great stories we’ve had from the global exploration community. People rowing across the Atlantic, walking to the South Pole,” says Last. “This is the bread and butter of Iridium’s network.” 

The experienced hunters and adventurers we know in Alaska almost universally opt for messenger devices on the Iridium network, due to the difficulty in connecting to Globalstar’s satellites. 

Other Issues with the iPhone Satellite Messenger

Krebs noted during her testing that when she had even one bar of service, even if it wasn’t sufficient to send a normal text message, the satellite messenger option was not available. Switching to airplane mode in this instance did not help, as the satellite messenger does not work in airplane mode. Another quirk is that the iPhone directs you to orient the device in a particular direction toward the sky when in use, likely as a result of the smaller size of its internal antenna. (Apple sent me a press release in response to my request for an interview, but did not respond to follow-up questions. Globalstar also declined to discuss its partnership with Apple.)

In one disturbing instance that was not a part of our official testing protocol, Krebs tried to resend two messages through her iPhone satellite messenger that a contact hadn’t responded to. After copying and pasting the first one, she went back to her message history and found that both of the original messages had vanished. 

When Krebs initially set up satellite messaging on her iPhone, we were both surprised to discover that while she could send a message to my phone — a Google Pixel — I would not be able to reply to her. This is in contrast to current two-way satellite messengers, including all Garmin devices and the SPOT X, where a frontcountry recipient can respond via text or email from any device. This may be in part because Apple has decided not to opt for a standards-based technology. 

While in the past, satellite messaging was enabled by different and proprietary satellite technology, Last, the Iridium executive, says that recently satellite and cellular companies have agreed on a standard that allows their tech to be compatible. Last says that after a deal with Qualcomm for a proprietary service failed to gain traction, Iridium moved toward a standards-based approach that would enable its satellites to connect to a variety of devices. 

“What Apple is doing with Globalstar is actually proprietary,” Last says. “The reason they partnered with Globalstar, frankly, is that Globalstar was a company that was desperate to make a deal with Apple.” 

While Globalstar is Iridium’s only real competitor in LEO satellites, Last was dismissive of their partnership with Apple. 

“[Globalstar] would agree to bend their satellite network to anything that Apple wanted,” Last says. “It’s not because [Globalstar was] the most reliable network. It’s not because they’re the market leader. It’s because [Apple] saw an opportunity to trial and test this technology and to do so with somebody that had the right kind of spectrums, an L-band and S-band spectrum, and had some satellites up there.” 

Globalstar recently received approval from the FCC to launch an updated satellite array into space (this despite an attempt on SpaceX’s part to delay it). This will add additional capabilities to Globalstar’s network, and also expand the network to 32 satellites. Apple is lending Globalstar $252 million to assist in making this happen, but that doesn’t mean Globalstar is abandoning the SPOT devices. 

“Our last set of satellites were launched in 2010,” Patel told me. “Timing-wise, it kind of worked out. We’re about to launch our next generation of satellites here soon. We have our spectrum, it’s a great spectrum, and at the same time we have our existing customers … so we have to maintain backwards compatibility.” (Patel told me he couldn’t talk about who Globalstar’s other partnerships were with.)

We’ll be watching to see how Globalstar’s satellite refresh, or other updates from Apple in the future, help to bring Globalstar-powered satellite messengers, including the iPhone, up to the same standard of reliability as the Iridium-based ones. Last, however, was not concerned about the competition posed by the iPhone for Iridium-enabled satellite messengers. 

“Today they’re offering the service basically free of charge. Whether anybody will ever pay for that sort of capability on Apple is anyone’s guess. We’re interested in customers that actually pay us for the service, whether they be on Android, iPhone, or anywhere else for that matter.”

Final Thoughts

Based on our testing and research, outdoorsmen and women who are headed into the backcountry should not cancel their inReach or Zoleo subscriptions. If you get lost or injured beyond cell service, a satellite messenger on the Iridium network is what you want. It could save your life, or one of your buddy’s lives. However, Apple’s iPhone satellite messenger is better than nothing and it’s worth installing as a backup or for casual outings when you unexpectedly find yourself without cell service. 

I wouldn’t be surprised if some of the issues with Apple iPhone’s satellite messenger, such as its failure to activate unless you are in a complete dead zone, are resolved in future iOS updates or newer models of the iPhone. Globalstar’s network is another issue. The primary purpose of a satellite messenger is to send your GPS location in the event you need rescuing. All of the rest of it — weather forecasts or sending voice memos or facilitating group chats — is window dressing. 

That being said, as a non-lifesaving piece of gear, Krebs did appreciate having satellite messenger capabilities on her iPhone. “Overall, I was impressed with the iPhone sat messaging,” she told me. “It gave me a lot of feedback about how to use it and worked as expected most of the time.” (Krebs did note that, because she was also using her iPhone for onX tracking, topo maps, and photos, the battery depleted much more quickly than her inReach Mini 2, which stayed above 50 percent for the entire week.) If you have an iPhone 14 or a newer model, you should absolutely try this tech out. 

And if you don’t, there will be plenty of competition to Apple’s satellite messaging capabilities in the near future.

“There are going to be a number of new generation satellite programs over the next ten years,” says Last. “You’re going to see standards-based phones, tracking devices all be able to use satellites.”

Garmin is already offering Iridum-powered SOS services on Google’s latest Pixel phone. Starlink is slated to provide T-Mobile customers with satellite messaging access in the very near future. AT&T is partnering with AST SpaceMobile to build out their own space-based broadband network. Even Iridium itself is developing a product for this space, which it expects to be available by the end of next year. Whatever the current issues with the iPhone’s satellite messaging capabilities, “off-grid” is well on its way to becoming an anachronism.