SpaceX rocket which Boost your Internet Speed 100 times !
On the 24th of May, SpaceX launched a Falcon 9
rocket filled with 60 satellites into space. This marked the beginning of their
ambitious new project called “Starlink”. Which aims to provide high
quality broadband internet to the most isolated parts of the planet, while also
providing low latency connectivity to already well-connected cities. SpaceX aim
to make their broadband as accessible as possible, claiming that anyone will be
able to connect to their network if they buy the pizza box-sized antenna which SpaceX
is developing themselves. This launch of 60 satellites, was just the first of
many. SpaceX has 12,000 satellites planned for launch over the next decade,
dramatically increasing the total amount of spacecraft around Earth’s orbit. This
will cost SpaceX billions of dollars, so they must have a good reason for doing
so. Let’s see how this network will work, and how it will compete with existing
internet providers. Back in 2015, Elon announced that SpaceX had began working
on a communication satellite network, stating that there is a significant unmet
demand for low-cost global broadband capabilities. Around that time, SpaceX
opened a new facility in Redmond, Washington to develop and manufacture these
new communication satellites.
The initial plan was to launch two prototype satellites into orbit by
2016 and have the initial satellite constellation up and running by 2020. But
the company struggled to develop a receiver that could be easily installed by
the user for a low cost, this delayed the program and the initial prototype
satellites weren’t launched until 2018. After a successful launch of the two
prototypes, Tintin-A and B, which allowed SpaceX to test and refine
their satellite design, SpaceX kept pretty quiet about what was next for the Starlink
project, until November 2018 when SpaceX received the approval from the FCC to
deploy 7,500 satellites into orbit, on top of the 4,400 that were already
approved. On May 24th, the first batch of production satellites were launched
into orbit and people around the world quickly started to spot the train of
satellites moving across the night sky.
This launch is a sign of things to come, while this initial group of satellites are not fully functional, they will be used to test things like the earth communications systems and the krypton thrusters. Which will be used to autonomously avoid debris and de-orbit the spacecraft once it has reached the end of its lifecycle. Let’s look at these functionalities first. Essentially SpaceX use electric potential to fire ions out of the spacecraft to provide propulsion. Xenon is ideally used, because it has a high atomic mass allowing it to provide more kick per atom, while being inert and having a high storage density lending itself to long term storage on a spacecraft. However, SpaceX opted for krypton, as xenon’s rarity makes it a far more expensive propellant. This ion thruster will initially be used to raise the Starlink satellites from their release orbits at 440 km to their final orbital height of 550 km. They will also be used in conjunction with on board control momentum gyroscopes located here, and the US Governments’ space debris collision prediction system to allow the satellites to adjust their orbits to dodge collisions.
Watch Falcon 9 launch 60 Starlink satellites → https://t.co/bJFjLCzWdK https://t.co/zXwBMcXUDJ
— SpaceX (@SpaceX) May 4, 2021
When the satellites have reached the end of their service life, they can
then use the same attitude controls and thrusters to de-orbit the satellite. Space
X have included all the necessary hardware to minimise space debris risk. In
their Federal Communications Commission approval application, they claim
that 95% of the satellite will burn up on re-entry. With only the ion thruster
internal structure and silicon carbide components, standing a chance of
survival. Those silicon carbide components are likely to survive, as they are
essential materials for the operation of lasers and thus have an extremely high
melting point of 2,750°C. Which brings us to our communications abilities, the
primary function of the satellite. SpaceX have been tight lipped on many of the
details of the satellite, but thanks to that FCC filing.
We know that the satellites will contain 5 1.5 kilogram silicon carbide components, which indicates that each satellite will contain 5 individual lasers. These lasers, like our fibre optic cables here on earth, will use light pulses to transmit information between satellites. Transmitting with light in space offers one massive advantage over transmitting with light here on earth. However, the speed of light is not constant in every material, in fact, light travels 47% slower in glass than in a vacuum. This offers Starlink one huge advantage that will likely be its primary money maker. It provides the potential of lower latency information over long distance, in simpler terms let’s imagine this as a race between data packets. A user in London wants the new adjusted price of a stock on the NASDAQ from the New York stock exchange. If this information were use a typical route, let’s say through the AC-2 cable [RI-3], which has a return journey of about 12,800 kilometres to make through our glass fibre optic cable. In a vacuum light travels at a speed of 299,792,458 meters per second. The speed of travel in glass depends on the refractive index and the refractive index depends on wavelength, but we will take the reduction as 1.47 times slower than the speed of light in a vacuum [203940448 m/s]. This means the data packet will take roughly 0.063 seconds to make the round trip, and thus has a latency of 0.063 seconds, or 62.7 milliseconds. With the additional steps that add to this latency like the conversion of light signals to electrical signals on either end of the optical cable, traffic queues, and the transfer to our final computer terminal, this total time comes out at about 76 milliseconds.
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