Satellites orbiting around the Earth
Do you wish that internet could be beamed down from space across the globe? SpaceX wants to make that dream come true with a huge constellation of 4,425 satellites iStock

Elon Musk is keen to set up a giant constellation of satellites orbiting the Earth to offer super-fast internet speeds across the globe. To this end, he has asked the US government for permission to launch a record 4,425 satellites into space.

In an application filed with the US Federal Communications Commission (FCC) on Tuesday (15 November), Musk's organisation SpaceX requested approval to launch a "non-geostationary orbit satellite system in the Fixed-Satellite Service" that will broadcast on the K<sub>u and K<sub>a frequency bands.

The K<sub>u band is primarily used for satellite communications for fixed and broadcast services, as well as by Nasa to send data between Earth, space shuttles and the International Space Station. The K<sub>a band is used for communication satellites that need higher bandwidth, as well as scientific experiments such as monitoring data from the James Webb Space Telescope and the Kepler Mission.

According to the Union of Concerned Scientists, there are already 1,419 satellites orbiting the Earth that are currently in operation, and on top of that, there are about 2,600 defunct satellites also floating around in space.

Musk's plan would see him launch more satellites in one go than the total number that has been launched into space since the Soviet Union's Sputnik I made history as the first artificial Earth satellite in 1957.

How the satellite internet network would work

Of course, the satellites won't all be launched at the same time – the first deployment would consist of 1,600 satellites, with a later deployment of 2,825 units. The satellites, each of which would weigh 386kg, would be launched in blocks of up to 50 at five different orbital heights ranging from 1,150km to 1,275km.

The satellites will vary by up to 175km in distance from each other, and eventually over time they will build up into an entire constellation of internet satellites. Each satellite would be able to offer internet coverage covering an ellipse about 2,120km wide, with a download capacity ranging from 17-23Gbps per user. The first deployment of 1,600 satellites will aim to aggregate a total capacity of 32Tbps.

"The system is designed to provide a wide range of broadband and communications services for residential, commercial, institutional, governmental and professional users worldwide," SpaceX writes in the application.

"With deployment of the first 800 satellites, SpaceX will be able to provide widespread US and international coverage for broadband services. Once fully optimised through the Final Deployment, the system will be able to provide high bandwidth (up to 1Gbps per user), low latency broadband services for consumers and businesses in the US and globally."

SpaceX argues that a space-based internet satellite network is needed as there are currently 4.2 billion people offline due to not having access to the internet or being able to afford to gain access to it.

Connecting the world, but not for free

Users will be able to access the internet service by installing a phased array antenna that can be mounted on roofs or walls. SpaceX has designed the system to be low-cost and environmentally friendly so the firm can offer attractive and affordable subscriptions to consumers.

Musk first mentioned the idea of a satellite-based internet network in January 2015, but he made it clear that most people would probably still continue to access the internet via broadband. The SpaceX service would only probably take about 10% of the business-to-consumer direct internet traffic, but more than 50% of long-distance internet traffic, which could offer a challenge to broadband providers if the service works.

It's also important to note that the idea of beaming internet from space is not new. In 2014, Chicago-based startup Outernet had the idea of offering free Wi-Fi broadcasting from thousands of tiny 10cm cube-shaped satellites orbiting the Earth.

The reason so many satellites would be needed is because each one only lasts between five to seven years before they start to decay, which renders them unusable within a year. Interestingly, SpaceX has designed the satellites to decommission themselves by going into a circular orbit at 1,075km in order to use up all remaining propellant.

The satellite then de-spins reaction wheels, draws batteries down to a safe level and powers down in order to make itself nonreactive (a process known as 'passivating'). Then, when it is powered down and safe, the satellite slowly re-enters the Earth's atmosphere , which degrades the satellite completely over several months, meaning there would be less debris left in our orbit.