Still far from what you would expect from a truly automated production line, but it has dedicated stations that allows workers to assemble multiple satellites in parallel.
A satellite dish does not transmit any information to the satellite. Satellite TV is a pure broadcast system in the forward direction.
Moreover, comparing a parabolic receiver with a phased array is quite unfair. The amount and complexity of the electronics and processing power required is several orders of magnitude different.
I agree, this was the real reason why the project failed. Moreover, it was not clear at all that fractionation would bring any lifecycle costs savings, neither that any of the alleged extra flexibility (and maneuverability, resiliency, maintenability, and other -ilities) would result in any added value for the missions.
Fractionation is very hard,it introduces a lot of complexity in the design and interfaces, and it requires lots of coordination between multiple vendors. Project Ara by Google (a modular cellphone similar to Phoneblocks) also vouched for this idea of fractionation (and in fact was also led by Paul Ermenko) and was also cancelled.
I think so too. In addition, they seem to have regenerative payloads on-board (otherwise I don't get how they get ~20Gbps/sat with a single Ka-band antenna), so they need to do full decoding + encoding on the satellite. Not sure how fast that can be done, but it will add some latency ms probably.
Thanks for your reply. I agree with you, using user-terminals is extremely challenging, especially from a link-budget perspective. You cannot pump enough data to make it worth it. For the gateways, my main concern is that the Ka-band spectrum would have to be shared between user-data and "inter-satellite" data.
Finally, I think that the use-case your described for those latency-sensitive customers is going to be hard to pull off, mainly because of link-availability concerns. There are too many "passes" through the atmosphere to guarantee the availability numbers that a user of such a service requires (99.5%?). Rain in any of these links might cause an outage or a re-route (causing too high jitter). Plus, it would be extremely difficult to have signals traveling from one continent to another.
These analyses are quite optimistic as they only consider propagation delay.
Moreover, the idea of using user-terminals/gateways as ground-relays to bounce signals up-and-down is quite impractical, since you would be greatly reducing the capacity available to satellites on those "intermediate" satellite.
That is not the round trip time, it's the one-way delay. Also, processing time can be significant in satellite networks. Finally, given the current architecture of SpaceX without crosslinks, the total RTT will be ~30 ms + processing time + whatever is the RTT of the backbone network they deliver the traffic to.
It will not work. Their use case is low data rate applications. It's one of those case where you pick 2 among high number of users, high bandwidth, and low gain user terminals.
> to a self-described expert, who unfortunately didn't provide a ton of context),
Are you questioning the expertise of Tim Farrar? If that is the case, you couldn't be more wrong. Check his blog and you will see he has been doing this thing for more than 20 years...
Also, lynk will never be able to provide enough bandwidth to deliver internet connectivity. It is envisioned to be used for short messages.
In their original FCC filing, they were estimating 386 kg per satellite. The ones launched in May were 227 kg each, and those last month 260 kg (they added the Ka-band antennas).
I am not sure how much heavier will the satellites be when they integrate the ISLs (if they do), but I believe that in any case they will be under 330 kg.
I am the author of the slides/paper. The analysis was done with the best data available at the time, but I am interested in knowing what parameters you think are off / have changed substantially since then.
I can say that the mass and volume of the satellites has changed quite a lot, and therefore the number of rocket launches required is pretty off in the paper. But I have not seen much info to invalidate the rest of results.
NSR estimates for SpaceX are higher than what SpaceX claims (Gwynne Shotwell just claimed some Morgan Stanley estimates of $1M launch + $1M to be way off [1]), but still, I wouldn't expect them to be able to launch the 4,409 satellites of their intial design for less than $10B. And it's not clear that they will be able to raise such amount of money without a clear path towards profitability.
I agree with the shaklee3, Tim's blog is very legit. As full disclosure, I am the first author of the MIT study he mentioned, and the more I look into LEO mega-constellations, the more skeptical I become.
It will only have lower latency when they have the inter-satellite links. Until then, they will have the latency of fiber PLUS the RTT from the user terminal - satellite - gateway path.
I would bet that there will be no more than 1,200 (if they raise the money needed to launch and manufacture that many).
And I would also bet that even in an 8 year time-horizon, they will not launch 12,000 satellites for Starlink because simply, there will be no market for so much capacity. In my opinion, we are heading towards an Iridium, Teledesic, Globalstar 2.0 scenario.
This is, in my opinion, kind of a myth. In the markets where the average revenue per user is high (Europe, USA, Canada, Australia) there is already (or there will be very shortly when Viasat3 is fully launched) high-speed reliable Internet connectivity through GEO satellites. And yes, the latency is huge and there are data-caps (which are pretty low if you want to binge-watch Netflix). But I am not sure that LEO constellations will be able to compete with GEO vHTS in price (not to mention the huge challenge of getting the price of the phase array user terminals cheap enough), so I am skeptical they will be able to capture a significant fraction of the market share.
In the rest of the world, the ARPU is so low that it's hard to have a viable business model for broadband satellite connectivity (for all orbits GEO, MEO, or LEO). Furthermore, 90% of the population is currently covered by 3G/4G networks, so I would argue that for most of the 3.5 billion people currently unconnected, the issue is not infrastructure (but other factors such as affordability, relevance, or readiness). Finally, populations in those countries connect largely using mobile broadband (i.e., in Southeast Asia 75% of the population only use cellphone to access the Internet), so I think that fixed-broadband will have a limited impact in those places. (Maybe they can get a higher share of the cellphone tower backhauling market, but it will depend on the price per Mbps/month they can offer to MNOs).
I think that 5M is a high number (at least with the current number of satellites and their architecture), specially if they do not apply data caps.
I would say that 1M customers in the US is a more reasonable figure. If they hit these number, I expect the performance to degrade significantly.