Starlink satellites will form a chain of lights in the sky (SpaceX)

This week the UK has been treated to a view of SpaceXs Starlink satellites passing overhead each evening.

The satellites appear as bright dots moving across the night sky in a perfect line as they orbit the Earth.

There are currently 420 Starlink satellites in orbit and SpaceX plans to put 12,000 up there eventually. The company, founded by billionaire Elon Musk, says these satellites will create a global internet network accessible from any place on Earth.

With performance that far surpasses that of traditional satellite internet, and a global network unbounded by ground infrastructure limitations, Starlink will deliver high speed broadband internet to locations where access has been unreliable, expensive, or completely unavailable, SpaceX writes on its website.

At present Starlink is a part of SpaceX but there have been rumours it may be spun-off into a separate company. The eventual aim could be to capture a big piece of the $1 trillion worldwide internet connectivity market. Revenue from that could help fund SpaceXs greater ambitions to colonise Mars.

Each Starlink satellite is equipped with four powerful phased array antennas that are capable of an enormous amount of throughput when it comes to radio waves. Therefore, internet signal can be communicated up to a satellite and spread out through the network before being fired back down again to any location on Earth.

Delivering internet via satellite is much more efficient because the signal travels 47% faster as a wave through the vacuum of space than it does being channelled along a fibre optic cable buried in the ground.

From an infrastructure perspective, it also means theres no need to lay vast amounts of cabling across parts of the world.

Current satellites sending internet signals are around 22,236 miles (35,786 km) above the Earth. This results in a time delay in sending and receiving data. Starlink satellites are smaller and orbit closer, meaning they can carry and triangulate data much faster.

Elon Musk has said the Starlink network would be able to provide minor internet coverage after 400 spacecraft were up and in orbit and moderate coverage after about 800 satellites became operational.

On board each satellite is a powerful Ion propulsion system and a custom-built in-house navigation sensor.

Together the two are able to automatically steer the satellites out of the way of space junk. It also helps guide the satellites to the optimum position for delivering data transfer.

After the first Starlink batch of 60 was launched in May 2018 and the second in November, astronomers complained how the bright satellite chain was hampering their observations.

In response, SpaceX came up with a darkening treatment to lessen reflectivity its a type of coating that is now added to all the satellites.

At the time, Jeff Hall, director of the Lowell Observatory in Flagstaff, Arizona, said the Starlink satellites have been just an occasional problem so far but noted the risk to stargazing will grow as the constellation expands and other companies launch their own fleets.

He heads the American Astronomical Societys committee on light pollution, space debris, and radio interference, and is working with SpaceX on the issue.

Alan Duffy, an astronomer at Swinburne University in Melbourne and the lead scientist of the Royal Institution of Australia said: A full constellation of Starlink satellites will likely mean the end of Earth-based microwave-radio telescopes able to scan the heavens for faint radio objects.

The enormous benefits of global internet coverage will outweigh the cost to astronomers, but the loss of the radio sky is a cost to humanity as we lose our collective birthright to see the afterglow of the Big Bang or the glow of forming stars from Earth, he toldScienceAlertlast year.

As well as adding the reflective coating, SpaceX will gradually move the satellites further away as the constellation grows. This will reduce their visibility from Earth but may interfere with more powerful deep-space observations.

The South African-born billionaire founded web software company Zip2 in 1995, along with his brother Kimbal which was sold to Compaq in 1999, with Musk receiving $22m (17m) for his share of the sales.

He used part of that money to found the online financial services company X.com which later became PayPal following a merger in 2000 and when that sold to eBay two years later he earned $165m (133.5m).

He is also one of the co-founders, CEO and product architect of Tesla Inc, having taken on the CEO role in 2008 which he still holds to this day.

Musk founded SpaceX or Space Exploration Technologies in May 2002, with $100m (81m) of his fortune.

The companys aim is to develop and manufacture space vehicles with a focus on advancing rocket technology.

As of April 2020 he is said to be worth around $38bn (25bn) making him the 23rd richest person in the world.

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What are Elon Musk's Starlink satellites and how do they work? - Metro.co.uk