We will look at the highlights of two featured articles and then list the other articles in the survey of the week in space news.
Featured – SpaceX Starlink Satellite Network – Pushing Technology for Low Latency
Universe Today – SpaceX Gives More Details on how their Starlink Internet Service Will Work. Less Satellites, Lower Orbit, Shorter Transmission times, Shorter Lifespans.
Pushing the Limits of Technology
SpaceX is pushing the limits of technology in several areas at the same time. Their use of phased array wireless links to steer narrow beams to and from the satellites will be pushing the limits of what has been done. This is mostly known technology, but doing it to the degree they’re doing it will be challenging. The use of free-space laser links between satellites is relatively unknown technology. The European Space Agency previously demonstrated that it was possible, but SpaceX will need to track more targets simultaneously and achieve higher data rates.
Starlink will send messages via a series of ground stations that will transmit information through radio waves to the satellites above. These satellites would then relay the messages using lasers it reaches the one above the recipient’s destination, where the data would then be beamed down to the correct station using radio waves again.
Getting High Bandwidth and Half the Latency on Earth
The speed of light in a vacuum is ≈ 47% higher that in glass (fiber cables). In the Mark Handley paper, charts show 36 ms latency for some routing for SpaceX Starlink network. Starlink would be almost twice as fast as communication on earth. There is 76 ms latency on earth.
Modification to the Plan for Phase 1a
There are currently 4,857 satellites in orbit of Earth. The original SpaceX plan would nearly triple this number but the current plan would double it.
According to the SpaceX FCC StarLink filing, the plan was to initially deploy 4425 satellites to orbits of between 1100 and 1300 km (680 and 800 mi). SpaceX has since indicated that they will be deploying their first 1600 satellites to an altitude of 550 kilometers (340 mi) to avoid adding to the space debris problem.