Context: An aerospace company, SpaceX, successfully launched its 13th Starlink mission after aborting the mission four times due to bad weather.

The Starlink mission carried 60 satellites that will join over 700 already in the orbit.

What is Starlink?

• Starlink is a network of satellites that provide internet.
• Each satellite is compactly designed, weighs about 260kg, and is equipped with four-phased array antennas, single solar array, ion propulsion system, navigation sensors, and debris tracking system.
• The satellite network operates at 550km above the Earth’s surface in low Earth orbit (LEO), unlike conventional internet satellites that are positioned much higher, at over 35,000km.
• SpaceX’s first Starlink mission was launched on May 24, 2019, which carried 60 satellites.
• The company has approval to launch 12,000 Starlink satellites, and it has requested the U.S. Federal Communications Commission (FCC) to approve launch of another 30,000 satellites.

How does it work?

• When an internet signal is sent from the Earth, one of the Starlink satellites receives it and then communicates with other satellites in the network.
• Once signal reaches the most ideally located satellite, it is relayed to a ground receiver.
• Starlink satellites communicate with each other using laser light, and at any given time, a Starlink satellite is connected to four other satellites in the mega-constellation.
• The phased array antennas allow satellites to transfer huge amount of data in a short period of time.
• The in-built navigation sensors provide altitude information to the satellites for precision internet data transfer.
• As the Starlink satellites orbit in LEO, they are much closer to the ground receivers, which significantly reduces latency during data transfer process.
• More number of satellites are required to have an extensive coverage, as they are positioned much closer to Earth, and can only cover a limited area.
• The ion thrusters, help the satellites move to orbit, manoeuvre in space, and de-orbit at the end of their life.
• And the inputs from the debris tracking system helps them perform manoeuvres to avoid collisions with space debris and other spacecraft.

How will it be useful?

• The network of LEO satellites will deliver high speed, low latency internet in remote areas where connectivity is limited or completely unavailable, including on aeroplanes and ships.
• People living in areas where traditional internet is inaccessible, will be able to benefit the most from Starlink internet service, depending on its availability.

Companies like Amazon, Telesat, and OneWeb are also considering to operate LEO-based internet service.

Amazon’s Project Kuiper has been approved by the FCC, with a constellation of 3,236 satellites in the LEO.

https://www.thehindu.com/sci-tech/technology/spacex-launches-its-13th-starlink-mission-what-does-the-company-plan-to-achieve/article32844230.ece?homepage=true

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