51–60 of 469 posts
Earlier quoted context omitted.
Is this a serious question? You think SpaceX developed the industry-leading orbital rocket, launched hundreds of times to deliver thousands of in-house developed satellites utilizing homegrown, novel argon gas ion thrusters, to develop a global satellite internet system using inter-satellite laser links, their own in-house developed, incredibly inexpensive phased array antenna system, and everything else, and they fo…
"industry-leading" [citation needed]
You don't need to be a rocket scientist to see that the sole provider, globally, of a reliable, reusable, orbital launch platform--also a proven heavy and in-development unprecedented super-heavy--is industry leading. SpaceX is at least a generation ahead of not only every other commercial competitor, but also every national space programme the world over.
> The lasers, which can sustain a 100Gbps connection per link > Brashears also said Starlink’s laser system was able to connect two satellites over 5,400 kilometers (3,355 miles) apart. The link was so long “it cut down through the atmosphere, all the way down to 30 kilometers above the surface of the Earth,” he said, before the connection broke. How do these tiny satellites achieve this kind of accuracy and link qua…
Phased array antennas probably have a lot to do with this. You can aim the signal more accurately and faster than any mechanical system ever could.
[dupe] https://news.ycombinator.com/item?id=39199368
Earlier quoted context omitted.
Is this a serious question? You think SpaceX developed the industry-leading orbital rocket, launched hundreds of times to deliver thousands of in-house developed satellites utilizing homegrown, novel argon gas ion thrusters, to develop a global satellite internet system using inter-satellite laser links, their own in-house developed, incredibly inexpensive phased array antenna system, and everything else, and they fo…
This is HN. Everyone here is more intelligent, capable and aware than people who are industry professionals in their specific field.
So which points are getting “faster than fibre” latency because of this? Extra distance up and down, but make up for it on the long-haul. Won’t beat HF radio though.
Optical fiber has an index of refraction of around 1.6, so signals travel at around 0.6c. For a perfectly straight cross-continental link (5,000km) with no delays from amplification/retransmission, that's about 26 milliseconds. Assuming the satellites are directly overhead, Starlink adds another 500km up and down, making the minimum possible latency around 20 milliseconds. The real number might be slightly higher or…
My understanding of the state of the art of inter-satellite optical links is that they have only been used between satellites that are basically in the same orbital plane and in more or less the same orbit. That is, the angle from one satellite to the other changes very very slowly, so that the optics don't have to do much tracking -- and consequently satellites can only form an optical link with other satellites tha…
So which points are getting “faster than fibre” latency because of this? Extra distance up and down, but make up for it on the long-haul. Won’t beat HF radio though.
Why would we expect faster than fibre?
Are they using Mynaric technology?
My understanding of the state of the art of inter-satellite optical links is that they have only been used between satellites that are basically in the same orbital plane and in more or less the same orbit. That is, the angle from one satellite to the other changes very very slowly, so that the optics don't have to do much tracking -- and consequently satellites can only form an optical link with other satellites tha…
Take a look at the slides from the presentation, I think the geometry clearly shows cross-plane links in the mesh. Having worked on these types of systems, I've had more difficulty with the lookahead angles (rx from where the target was, tx to where it will be due to speed of light) than the tracking -- fine tracking performance was required for all modes, and it largely became a GNC and acquisition time issue (since…