Posted on 06/03/2020 6:48:55 PM PDT by Moonman62
SpaceX launched its second Falcon 9 rocket in the span of just four days on Wednesday at 9:25 PM EDT (6:25 PM PDT). This one was carrying 60 more satellites for its Starlink constellation, which will bring the total currently in operation on orbit to 480. The launch took off from Florida, where SpaceX launched astronauts for the first time ever on Saturday for the final demonstration mission of its Crew Dragon to fulfill the requirements of NASA’s Commercial Crew human-rating process.
Today’s launch didn’t include any human passengers, but it did fly that next big batch of Starlink broadband internet satellites, as mentioned. Those will join the other Starlink satellites in low Earth orbit, forming part of a network that will eventually serve to provide high-bandwidth, reliable internet connectivity, particularly in underserved areas where terrestrial networks either aren’t present or don’t offer high-speed connections.
This launch included a test of a new system that SpaceX designed in order to hopefully improve an issue its satellites have had with nighttime visibility from Earth. The test Starlink satellite, one of the 60, has a visor system installed that it can deploy post-launch in order to block the sun from reflecting off of its communication antenna surfaces. If it works as designed, it should greatly reduce sunlight reflected off of the satellite back to Earth, and SpaceX will then look to make it a standard part of its Starlink satellite design going forward.
Part of this launch included landing the first stage of the Falcon 9 rocket used for the launch, which has already flown previously four times and been recovered – that makes this a rocket that has now flown five missions, and today it touched down safely once again on SpaceX’s drone landing barge in the ocean so it can potentially be used again.
SpaceX will also be attempting to recover the two fairing halves that form the protective nose cone used during launch at the top of the rocket to protect the payload being carried by the Falcon 9. We’ll provide an update about how that attempt goes once SpaceX provides details.
Tomorrow, June 4, actually marks the 10-year anniversary of the first flight of a Falcon 9 rocket – between this reusability record, and the much more historic first human spaceflight mission earlier this week, that’s quite the decade.
Starlinks don’t have optical sensors suitable for orbit to surface surveillance.
That’s for the entire global network. As many US Telcos, SiriusXM, DirecTV/Dish and others can tell you, you don’t need to have the entire global network up to make money off it.
Also, Starlink satellites are cheap.
SkyNet ?
They are wrecking the view of the skies.
Like those windmills on the land here.
7000 is for global coverage. Spacex already has confirmed that north America service will be in final beta test with 12 launches total for 720 birds this was the 8th launch they only need 4 more to offer service to most of north America they got approval for 22 gateways and 18 are already up and running. Elon has used the network to tweet with it. The air force recently tested it on a C130 at 600+mbits/sec and I believe an F35 in flight. This is a drone control network par excellence Ku and V band antennas with military grade phased arrays will be under 30cm in diameter totally flat or can be curved to an radius for conforming to a upper fuselage. The military doesn’t have a price limit on antenna technology they will use $30,000+ systems that civilians could only dream of.
Starlink satellites are mass produced they are cheaper than the $/pound launch cost Elon confirmed that twice before. Put another way it costs more to launch them then to make them. The current estimate for thw internal cost to spacex for the satellite is $500k that’s a fraction of what a iridium bird would cost and starlink birds have 60+gigabit per second in bandwidth where’s an iridium bird has an order of magnitude less bandwidth. Ku & V band vs iridum L band so apples to oranges in spectrum bandwidth but costs are actually significantly higher for the electronics needed for Vband 50ghz vs L band 1.5ghz
I’m wondering what the SNR ratio at Ku would be for an omni directional 3dbi antenna why you ask because that’s what a handheld device would have. Shannons law dictates the minimum SNR for a given bit rate I wonder with there’s enough SNR to support a 50 to 100kbs 3dbi signal bidirectionally that’s about the minimum needed for VOIP voice and 24fps video @480p they could be a real competition to iridium if so at a fraction of the total cost to the user.
The one time I saw the last group (at dusk, “winking out” one by one as they passed into Earth’s shadow - very cool!) they were very easily visible.
I’m not sure I can get from n2yo.com tracks to whether any given sat will be visible, as that will depend on the track, time, altitude and Earth’s shadow. I think I’d need a short course in it to work with that...!
The site would do well to add a simple “should be visible at (time of next near & readily visible pass)”. It (the site) already has my location.
Approx. 90 minutes from now actually looks pretty good, as best as I can presently guess, but, it is cloudy...
Cool the way they deploy these things too. They spin the craft so that centrifugal force kind of tosses them out.
Cool the way they deploy these things too. They spin the craft so that centrifugal force kind of tosses them out.
...
Agreed. Figuring out a way to pack 60 satellites in the fairing and getting them deployed took some creative thinking and risk taking.
It’s what Musk calls engineering from first principles.
It’s heading down the Baja Peninsula right now.
They can track all the cellphones though. That’s how China does it.
No, Starlink sats cannot track existing cell phones as they are on a different radio band entirely. Satellite phones are a completely different and at the current time very expensive proposition that few people have. Cell phones do not talk to satellites, they talk to towers on earth’s surface.
Additionally, neither China nor anyone else has to use a satellite to track a cell phone. You do that using the existing network of cell towers or simply query the phone for its GPS location. GPS, by the way, is receive only on a phone or other device, so a GPS satellite can’t track you either.
I'm wondering if he has enough up yet to start offering limited service to select customers, like ships at sea?
https://www.satelliteinternet.com/providers/starlink/
the SpaceX LEO satellite internet service, dubbed Starlink, is set to launch a private beta sometime in July. If the private beta goes off without a hitch, a public beta could start as soon as November 2020.
What they CAN do is allow for a ground cell tower in a remote location to offer cell service via the satellite system.
Not as of yet - though that is one option being discussed between SpaceX and potential customers. Point is that Starlink isn’t physically capable of “tracking all the cell phones” as E. Pluribus there seems to think it is.
Of course, we can only see a satellite at night because the sun is still shining on it (although the sun at night is below our horizon, it is still able to illuminate a satellite). Back in the day, it was said that any satellite still visible after 10:00PM must be Russian, because Russia used a much higher orbit than us. This may be outdated info by now. But even a long time ago it was a rare, good visibility night that you wouldn’t see a satellite.
Ships at sea will have to wait for second generation starlink with the laser links. Right now the sats have to be in range of not only the mobile transceiver but also a gateway at the same time and continuously. This is due to the first gen birds only having gateway antennas and no sat to sat laser links. The fcc has allowed starlink to use 22 gateways so far and some are near the coasts so for limited offshore range like inside our 12 mile limits it might work. The footprint of a LEO bird is around 1200km in diameter so assuming you have a bird directly above a gateway on the coast and a transceiver offshore 600km would be about max range offshore without some gateways on ships or large discus buoys which Musk has talked about doing for the north Atlantic great circle aircraft corridor. the FAA already has 12 wide meter deep water bouys for vhf aircraft coms over the gulf of Mexico that survive hurricane sized waves. so that tech could be anchored in the north Atlantic for a down up hop gateway to link north America to Europe. These bouys have solar panels and back diesel engine with a multiyear lifespan putting two gateway antennas would form a down up link to two birds linking them in a daisy chain across the Atlantic. Any ships within 600km of each of the bouys could tie in.
Starlink uses Ku band and V band for terminal links thats 18ghz and 40ghz. Cellphones use UHF, L band and some S band particularly 5G and iridium & globalstar sat phones use Lband and Sband respectively. There’s no what via physics that starlinm could track a conventional or even a sat phone. Sorry thats just tinfoil nuttery.
Iridium absolutely tracts the position of it’s mobile phones it must do so for billing, compliance with national frequency and security restrictions and also as a function of the spotbeam and handoff requirements of the coms link itself. Globalstar also must track the location of it’s phones for the same reasons. I’m a operations and field geologist I use iridium on the regular as well as inmarsat and globalstar spot 3 beacon for tracking and SOS beacon. I’m hoping that spacex will come up with a bgan like terminal that can hookup to starlink at anything above 50kbps which is where voip, email,sms, and slow scan 10fps vidcoms is possible for moral reason back to home office.
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