Satellite phone facts for kids
A satellite phone is like a special mobile phone that connects to satellites orbiting Earth instead of regular cell towers. This means you can use it in many places where normal cell phones don't work, as long as you have a clear view of the sky.
Satellite phones are super useful for people on adventures in faraway places, like hiking, fishing, or boating trips, where there's no cell service. They're also important for businesses in remote areas, like mining. Because they rely on satellites, they usually keep working even during natural disasters or conflicts, making them great for emergencies when other communication systems are down.
The phones themselves can look different. Older ones were big, like early mobile phones, often with a large antenna. Newer ones are much smaller, similar to regular smartphones. Some even look exactly like a smartphone! For places like ships, the equipment can be larger, with a special antenna that automatically follows the satellites.
Recently, some regular smartphones have started adding satellite features. This means you can send emergency messages or texts from your normal phone even when you're out of cell service.
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How Satellite Phones Started
The idea of using satellites for phone calls began very early in the space age. The first phone calls using satellites were made in 1958, not long after the first satellite, Sputnik I, was launched.
The first satellite made specifically for mobile communication was called MARISAT. Later, a company called INMARSAT took over its operations in 1979, becoming one of the first private companies to offer satellite communication.
How Satellite Networks Work
Satellite phone systems use two main types of satellites: those in a high orbit called geostationary orbit (GSO) and those in a lower orbit called low Earth orbit (LEO).
Geostationary Satellites
Geostationary satellites orbit very high above Earth, about 35,786 kilometers (22,236 miles) up. From Earth, they seem to stay in the same spot in the sky. This is good because you only need a few satellites (three or four) to cover most of the Earth, which saves on launch costs.
However, because they are so far away, there's a small delay when you make a call or use the internet. Also, these satellites are very big and expensive. They offer good internet speeds, from 60 to 512 kilobits per second (kbps).
A downside is that these phones work best closer to the equator, usually between 70 degrees north and 70 degrees south. If you're too far north or south, the satellite appears very low in the sky, and signals can get blocked by hills or trees. If your signal is blocked, your call might drop, and you'll need to move to a clearer spot.
Here are some companies that use geostationary satellites:
- Inmarsat: This is one of the oldest satellite phone companies, started in 1979. They cover most of Earth, but not the very cold polar regions.
- Thuraya: Based in the United Arab Emirates, Thuraya covers Europe, Africa, the Middle East, Asia, and Australia.
- Tiantong: This is a Chinese satellite phone system that plans to cover China, nearby areas, the Middle East, Africa, and parts of the Pacific and Indian Oceans.
Low Earth Orbit Satellites
Low Earth Orbit (LEO) satellites fly much closer to Earth, between 640 and 1120 kilometers (400 to 700 miles) high. They move very fast, circling the Earth in about 70 to 100 minutes. Because they are always moving, your phone needs to "hand off" your call to another satellite as one moves out of view.
A single LEO satellite is only visible to your phone for about 4 to 15 minutes. To make sure you always have coverage, a whole group of satellites (often 40 to 70) works together. The big advantage of LEO systems is that they can provide coverage everywhere on Earth, even at the poles!
Here are some companies that use low Earth orbit satellites:
- Globalstar: This network covers most of the world's land. They use 48 active satellites.
- Iridium: This network uses 66 satellites in a special orbit that covers the entire Earth. Their satellites can even talk to each other to send data to the closest ground station.
Both Globalstar and Iridium started in the late 1990s. They faced some financial challenges at first but are now working well and even launching newer satellites for faster internet. Current speeds for these phones are between 2200 and 9600 bits per second.
In recent years, companies like T-Mobile and SpaceX are working together to use Starlink satellites to provide cell service directly to regular phones, even in areas without cell towers. This will start with text messages and later include voice calls and limited internet.
Finding Your Location
LEO satellite systems can sometimes figure out your phone's location, but it might not be super accurate, sometimes off by tens of kilometers. Some satellite phones can show your location on their screen.
Special Phone Numbers
Satellite phones usually have special phone numbers, like their own "country codes."
For example, Inmarsat satellite phones often start with +870. Other systems, like Iridium, use codes like +881 6 and +881 7. This helps identify them as satellite phones.
How Much Do Satellite Phones Cost?
Satellite phones can be quite expensive, especially the newest models. While you might find older used ones for around $200, new ones can cost over $1,000. Each satellite phone is made to work with only one specific network, so you can't switch it to another.
The most expensive satellite phones are BGAN terminals, which can cost thousands of dollars. These offer faster internet and voice calls. Sometimes, providers offer discounts if you sign up for a long-term plan.
Calling Costs
Making calls from a satellite phone usually costs between $0.15 and $2 per minute. However, calling a satellite phone from a regular landline or mobile phone can be much more expensive, sometimes $3 to $14 per minute. The person receiving the call doesn't pay anything unless they use a special reverse-charge service.
Calls between different satellite phone networks can also be very expensive, sometimes up to $15 per minute. Calls from a satellite phone to a regular phone are usually around $0.80 to $1.50 per minute.
Most satellite phone networks offer pre-paid plans, where you buy credit vouchers ranging from $100 to $5,000.
One-Way Services
Some satellite phone networks have a special one-way "paging" feature. This can alert you to an incoming call even if you're in a place with poor signal, like indoors. When you get the alert, you need to move to an area with better coverage to answer the call.
Globalstar also offers a one-way data service, often used for tracking things like vehicles or equipment.
Rules and Restrictions
In some countries, owning a satellite phone is against the law. This is often because their signals can bypass local phone systems, making it harder for governments to control or listen in on communications. Some governments worry that satellite phones could be used for illegal activities.
Here are some examples of countries with restrictions:
- China: Inmarsat was the first company allowed to sell satellite phones here in 2016.
- India: Only Inmarsat satellite services are allowed. Bringing in or using other satellite phones like Thuraya or Iridium is illegal.
- Russia: New rules in 2012 allow non-Russian visitors to use satellite phones for up to six months, but the government can intercept calls.
Keeping Your Calls Private
All modern satellite phone networks use special codes (encryption) to keep your voice calls private and prevent others from listening in. However, in 2012, some security experts found ways to break these codes. This means that if you need very high security for your calls, you might need extra encryption.
Phones That Connect to Both Satellites and Cell Towers
In the early 2020s, some phone makers started putting satellite features directly into regular smartphones. At first, these features were mainly for sending emergency text messages because regular phone antennas aren't as strong.
- In 2018, Thuraya launched the X5 Touch, which they said was the first smartphone that could connect to both regular cell networks and satellites.
- In 2021, Thuraya released another phone like this, the XT Lite.
- In 2022, Apple's iPhone 14 started offering an "Emergency SOS via satellite" feature, letting users send emergency texts when out of cell service. Apple later invested in Globalstar, one of the satellite companies.
- In 2023, the iPhone 15 added satellite communication for roadside assistance.
- In 2024, Thuraya launched the Skyphone, another Android-based phone that combines 2G/3G/4G and satellite connections.
Recent Changes in Satellite Phones
More recently, smartphone companies are adding satellite communication features directly into their devices. For example, Apple's Emergency SOS via satellite on the iPhone 14 lets you send emergency messages when you're away from cell service. This makes satellite communication easier for everyday users without needing a separate satellite phone.
The need for reliable communication in remote areas is growing, especially with more people working remotely and during natural disasters. Companies like SpaceX (with Starlink) and AST SpaceMobile are building new satellite networks. These networks aim to offer wider coverage and faster connections, potentially making satellite communication more affordable and practical for everyone.
Notable Phones with Both Cellular and Satellite Connections
- 2018: Thuraya X5 Touch
- 2021: Thuraya XT Lite
- 2022: Apple iPhone 14
- 2024: Thuraya Skyphone
Cell Service from Space
Companies are also working on bringing regular cell service directly from satellites to your existing smartphone.
- In 2022, T-Mobile partnered with Starlink to use their satellites for cell service, expected to start in late 2024.
- Also in 2022, AST SpaceMobile began building a satellite network designed to let regular, unmodified smartphones connect to satellites in areas without cell towers.
- In 2023, Qualcomm announced "Snapdragon Satellite," a service that will allow phones with their special chip to send and receive texts via satellites.
- In 2024, Iridium introduced "Project Stardust," a service planned for 2026 that will provide messaging, emergency calls, and internet for things like cars and smartphones using their existing satellites.
Images for kids
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Satellite phones on display
See also
- Broadband Global Area Network (BGAN)
- Mobile-satellite service
- Satellite internet
- Telecommunications
