Author Topic: Starlink : General Discussion - Thread 2  (Read 1076512 times)

Offline Hummy

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Re: Starlink : General Discussion - Thread 2
« Reply #1380 on: 04/23/2020 05:58 am »
The simulation doesn't match current deployment plan and what is more important it assumes 25 degrees elevation angle. That would require user antenna to tilt very often. Some people believe antenna will tilt only once ever. In that case coverage of a Starlink satellite is significantly smaller than what is shown in the simulation.
« Last Edit: 04/23/2020 06:01 am by Hummy »

Offline meberbs

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Re: Starlink : General Discussion - Thread 2
« Reply #1381 on: 04/23/2020 07:04 am »
The simulation doesn't match current deployment plan and what is more important it assumes 25 degrees elevation angle. That would require user antenna to tilt very often. Some people believe antenna will tilt only once ever. In that case coverage of a Starlink satellite is significantly smaller than what is shown in the simulation.
Current plans are for triple the number of planes with one third the number of satellites per plane. The actual initial coverage should be similar or slightly wider.

As I understand some recent filings, they plan to keep the 25 degree minimum elevation. This is still reasonable for a phased array with no mechanical motion.

Online FutureSpaceTourist

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Re: Starlink : General Discussion - Thread 2
« Reply #1382 on: 04/23/2020 09:12 am »
https://twitter.com/elonmusk/status/1253249276509130753

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Good summary

https://www.teslarati.com/spacex-starlink-internet-service-beta-program/

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SpaceX Starlink a step closer to internet service and Elon Musk has beta test details
By Eric Ralph
Posted on April 23, 2020

SpaceX’s successful April 22nd Starlink launch has brought the nascent constellation another step closer to serving customers internet and CEO Elon Musk has revealed the first significant beta test details.

Online FutureSpaceTourist

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Re: Starlink : General Discussion - Thread 2
« Reply #1383 on: 04/23/2020 09:27 am »
For context:

[...]

twitter.com/elonmusk/status/1253115727965491202

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Private beta begins in ~3 months, public beta in ~6 months, starting with high latitudes

twitter.com/flcnhvy/status/1253252054589595649

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Does Germany count as high latitude? 🤞

https://twitter.com/elonmusk/status/1253253205963804673

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Yes

Offline RedLineTrain

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Re: Starlink : General Discussion - Thread 2
« Reply #1384 on: 04/24/2020 03:52 pm »
Going down memory lane a bit, I was curious about the original Iranian RFIC team that Musk poached from Broadcom.  It is a little hard to know where all of them are now, but of the four, only one obviously remains at SpaceX (now a Senior Manager).  The manager who recruited the team appears to have shaken out when in June 2018 Musk cleaned house in the top manager ranks in Redmond, leading to a change in plans with regard to the antennas.

The ASIC/RFIC/FPGA teams do seem stable and they keep hiring, so I'm hoping that we will be pleased at the results.
« Last Edit: 04/24/2020 03:59 pm by RedLineTrain »

Offline Hummy

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Re: Starlink : General Discussion - Thread 2
« Reply #1385 on: 04/24/2020 10:14 pm »
The principal RF engineer, Mihai Albulet, remains the same. He has signed all SpaceX space station FCC filings including the latest one. He was hired in Sep 2014. He was a professor in a Romanian University then migrated to the US to work for Microsoft on Zune media player. I hope we will be pleased at the results of his 6 years of work at SpaceX.

Online wannamoonbase

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Re: Starlink : General Discussion - Thread 2
« Reply #1386 on: 04/24/2020 11:18 pm »
The principal RF engineer, Mihai Albulet, remains the same. He has signed all SpaceX space station FCC filings including the latest one. He was hired in Sep 2014. He was a professor in a Romanian University then migrated to the US to work for Microsoft on Zune media player. I hope we will be pleased at the results of his 6 years of work at SpaceX.

I'm surprised that it's already been 6 years.  It feels like it happened quickly.  But like Raptor, there were years of quiet development.

I'm sure we are all hoping for Starlink to be wildly more successful than Zune.
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Online LouScheffer

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Re: Starlink : General Discussion - Thread 2
« Reply #1387 on: 04/26/2020 04:19 pm »
The gateway map: https://www.google.com/maps/d/viewer?mid=1H1x8jZs8vfjy60TvKgpbYs_grargieVw&ll=30.479815690358823%2C-70.95175456250001&z=3
shows most of Mexico covered, and southern Canada as well. Whilst covering Mexico may be "incidental" due to Gateways in BC etc, covering Canada is "surely" imo intentional as Gateways are placed close to the Canadian Border. Elon is a Canadian Citizen, lived there, and has family links there. There must imo be an intention to roll out the service to Canada with or soon after the US.
The service area in Canada accessible from the northern USA ground stations has at least 90% of the country's population (depending on the exact source, >90% live within about 200 km of the border).  On the other hand, Canada tends to enforce rules that require telecom carriers to service ALL of Canada, if they want to sell service.  Otherwise the rural regions would get no coverage at all.   So selling in Canada may well require some more northern ground sites, and at least some high inclination orbits.   On the other hand, StarLink would clearly be helpful towards the goal of getting broadband into rural areas in general, so maybe they would accept the promise of future expansion of the service area northward.

Offline joek

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Re: Starlink : General Discussion - Thread 2
« Reply #1388 on: 04/26/2020 04:45 pm »
The service area in Canada accessible from the northern USA ground stations has at least 90% of the country's population (depending on the exact source, >90% live within about 200 km of the border).  On the other hand, Canada tends to enforce rules that require telecom carriers to service ALL of Canada, if they want to sell service.  Otherwise the rural regions would get no coverage at all.   So selling in Canada may well require some more northern ground sites, and at least some high inclination orbits.   On the other hand, StarLink would clearly be helpful towards the goal of getting broadband into rural areas in general, so maybe they would accept the promise of future expansion of the service area northward.

Or maybe Starlink partners with a Canadian provider who covers the entire country?  Not familiar with Canada's rules... do they require the same level of service  to everyone?

Offline vsatman

Re: Starlink : General Discussion - Thread 2
« Reply #1389 on: 04/26/2020 05:08 pm »
The service area in Canada accessible from the northern USA ground stations has at least 90% of the country's population (depending on the exact source, >90% live within about 200 km of the border).  On the other hand, Canada tends to enforce rules that require telecom carriers to service ALL of Canada, if they want to sell service.  Otherwise the rural regions would get no coverage at all.   So selling in Canada may well require some more northern ground sites, and at least some high inclination orbits.   On the other hand, StarLink would clearly be helpful towards the goal of getting broadband into rural areas in general, so maybe they would accept the promise of future expansion of the service area northward.
Or maybe Starlink partners with a Canadian provider who covers the entire country?  Not familiar with Canada's rules... do they require the same level of service  to everyone?

Sorry, somebody knows  that Space X  has applied  for  frequency approval for Canada??  Here is Approval for TeleSat LEO https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf11064.html
or Mexico?
« Last Edit: 04/26/2020 08:21 pm by vsatman »

Online meekGee

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Re: Starlink : General Discussion - Thread 2
« Reply #1390 on: 04/27/2020 01:25 am »
Hey - if I have it right, SF bay area peeps will get a high and bright Starlink view tomorrow around 9 pm, so just a heads up!
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Offline Robotbeat

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Re: Starlink : General Discussion - Thread 2
« Reply #1391 on: 04/27/2020 10:53 am »
Have we seen any glimpses of the user terminals, yet?
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Online gongora

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Re: Starlink : General Discussion - Thread 2
« Reply #1392 on: 04/27/2020 07:46 pm »
Have we seen any glimpses of the user terminals, yet?

No

Online gongora

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Re: Starlink : General Discussion - Thread 2
« Reply #1393 on: 04/27/2020 07:59 pm »
There was a meeting today of the Steering Committee of the Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020) on "Optical Interference from Satellite Constellations Agenda".  SpaceX participated, with Elon and about 5 other SpaceX employees presenting and answering questions.

https://twitter.com/CatHofacker/status/1254821075176886285
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Elon Musk giving a short presentation at a meeting for the Astro 2020 decadal, says we'll have a "VisorSat" on the next Starlink launch that has a sunshade to reduce the satellites' brightness.

https://twitter.com/JohnBarentine/status/1254817281823014918
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[email protected]: The goal of @SpaceX is to make Starlink satellites "invisible to the naked eye within a week of launch". Also notes that the brightness of the objects is directly related to their configuration/orientation on orbit, which they continue to work on. #Astro2020

Elon mentioned that long-term a size of 20k-30k satellites would be a good size for a broadband constellation.

SpaceX reiterated they'd like their whole constellation to be under 600km altitude. [as we saw in the recent FCC filing]

Early satellites will probably be replaced within 3-4 years, after that probably 4-5 years.  Future versions will have higher throughput.  [I think that may say more about the performance of the current version than the performance of the future versions.]

SpaceX employees said they are willing to work with astronomers on tracking the satellites better, performing observations on the brightness, and modelling the brightness.

Offline su27k

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Re: Starlink : General Discussion - Thread 2
« Reply #1394 on: 04/28/2020 03:45 am »
FutureSpaceTourist collected all the Astro2020 tweets about impacts to astronomy at the Impacts of Large Satellite Constellations on Astronomy thread, here's some additional tweets about Starlink General:

https://twitter.com/jeff_foust/status/1254822296306491396

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Musk estimates the existing Starlink satellites, including those without any brightness mitigations, will be deorbited in 3-4 years, in part because they’ll be rendered obsolete by v2 satellites with “far greater throughput.”

https://twitter.com/JohnBarentine/status/1254821665264959498

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[email protected]: We're interested in replacing the earliest Starlink sats we launched as the tech progresses. We expect the 1st generation sats to be replaced on a timescale of 3-4 years. We do not want 'ancient electronics' in orbit like GEO sats up there for 15, 20 years. #Astro2020

https://twitter.com/jeff_foust/status/1254824905889189893

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Musk: think 550 km altitude is the right approach for LEO broadband constellations, but don’t know if there will be a lot of other systems. “The big challenge is not going bankrupt.”

https://twitter.com/JohnBarentine/status/1254824707787911168

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[email protected]: "The big challenge for LEO constellations is not going bankrupt. This is quite hard. I wouldn’t say we’re out of the woods in this regard.” Wouldn’t expect to see a large number of LEO constellations. Hopes for just one (presumably his). #Starlink #Astro2020

--------------------------------------------------------------------------------------------------------------------

My comment: I'm pretty sure Elon mentioned Starlink v2 will launch on Starship, so I think the “far greater throughput.” is going to come from a bigger Starlink design that will take full advantage of the fairing size and LEO capability of Starship.
« Last Edit: 04/28/2020 03:46 am by su27k »

Online FutureSpaceTourist

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Re: Starlink : General Discussion - Thread 2
« Reply #1395 on: 04/28/2020 06:52 pm »
Eric Ralph has written up Elon’s presentation yesterday and included a SpaceX graphic on the sun visor design (attached):

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SpaceX’s Starlink “VisorSat” launch plans revealed by Elon Musk
By Eric Ralph
Posted on April 28, 2020

CEO Elon Musk has revealed more details about SpaceX’s plans to build and launch upgraded “VisorSat” Starlink satellites, part of the company’s work to ensure that the internet constellation can coexist with astronomy.

https://www.teslarati.com/spacex-starlink-visorsat-elon-musk-launch-plans/
« Last Edit: 04/28/2020 06:53 pm by FutureSpaceTourist »

Offline Tulse

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Re: Starlink : General Discussion - Thread 2
« Reply #1396 on: 04/28/2020 07:04 pm »
Is it well understood what parts of the satellites are doing the reflecting?

Online gongora

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Re: Starlink : General Discussion - Thread 2
« Reply #1397 on: 04/28/2020 07:12 pm »
It seems to be the antennas, those were mentioned several times.  (I missed Elon's initial presentation but caught the last 50 minutes of Q&A)

Offline theinternetftw

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Re: Starlink : General Discussion - Thread 2
« Reply #1398 on: 04/29/2020 02:02 am »
Sun reflection comes from antennas when on station and from antennas and solar panels combined when orbit raising.  There's a slide a few posts up that says this.  (And if you look at the visors, you can see that they're shaped specifically to cover the antennas, which are the window looking things with rounded edges in the model)
« Last Edit: 04/29/2020 02:08 am by theinternetftw »

Offline Rondaz

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Re: Starlink : General Discussion - Thread 2
« Reply #1399 on: 04/29/2020 02:22 am »
Since February @SpaceX has asked the @FCC for authorization for 18 new @SpaceXStarlink earth stations bringing total to 23 gateways across US of which 5 are dual band (Ku+Ka). 6 Ku-band gateways with 4 antennas each = 24 22 Ka-band gateways with 8 Ka antennas each = 176

https://twitter.com/Megaconstellati/status/1255181392964698113

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