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Benz
Active Member
They have joined forces (Richard Branson, Greg Wyler, Qualcomm).
Link: http://www.latimes.com/business/la-fi-satellite-entrepreneurs-20150117-story.html
Link: http://seattletimes.com/html/businesstechnology/2025480750_spacexmuskxml.html
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Musk and Wyler have known each other for years. Musk, in fact, used to crash at Wyler’s guest house in Atherton, Calif. While there are major similarities between the two ventures, Musk says he’ll have an edge through SpaceX’s smarts and manufacturing techniques. “Greg and I have a fundamental disagreement about the architecture,” Musk says. “We want a satellite that is an order of magnitude more sophisticated than what Greg wants. I think there should be two competing systems.”
Link: http://www.latimes.com/business/la-fi-satellite-entrepreneurs-20150117-story.html
Link: http://seattletimes.com/html/businesstechnology/2025480750_spacexmuskxml.html
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Musk and Wyler have known each other for years. Musk, in fact, used to crash at Wyler’s guest house in Atherton, Calif. While there are major similarities between the two ventures, Musk says he’ll have an edge through SpaceX’s smarts and manufacturing techniques. “Greg and I have a fundamental disagreement about the architecture,” Musk says. “We want a satellite that is an order of magnitude more sophisticated than what Greg wants. I think there should be two competing systems.”
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I was there last night! It was a great event. Elon presented a very clear picture of what the plan is. Here is an article that was in the local paper:
Elon Musk touts launch of | Business & Technology | The Seattle Times
From the article: "Musk outlined an audacious plan to build a constellation of some 4,000 geosynchronous satellites".
I doubt there are 4000 geosynchronous orbital slots available. I read somewhere else that instead they would be in low orbit to reduce the latency.
Right. You can't do a geosynchronous orbit for internet because it takes 1/4 second each way. Geosynchronous is only for one way transmissions or two way when you don't care about lag time.
Can you provide more details about the satellite plan than the news stories have so far? This is a very exciting development.
How is SpaceX going to fund this project? The capital costs will be immense. Any partners mentioned?
Is the primary goal to generate revenue that will then be used to fund missions to Mars and supporting a permanent colony on Mars? That is what the news report seems to say, but it seems like an odd way to generate such critically needed revenue, since the profitability of such a satellite network hardly seems assured. I would have thought that the nearer term SpaceX goal of reusing first stage rockets to dramatically lower the cost of space flight would also significantly increase profit margins on commercial and NASA launches and that would be a more secure source of revenue than a speculative satellite internet venture.
Does that type of satellite communications network also require multiple ground-based uplink/downlink stations that then are tied into existing fiber optic networks?
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Actually, internet is a significant and growing aspect of the commercial GEO market--theres Hughesnet, Dish, Wild Blue, and Viasat, just to name a few servicing north America, but every major population center around the world has or is getting access. Latency is an issue, but its about a quarter second round trip, not one way. The bigger issue is bandwidth, but that's another topic...
A mega-leo constallation is where a lot of space segments are going (internet, weather, imaging, etc) because it solves a lot of problems of which latency is only one. Cost of course, but theres also easier regulatory issues, redundancy comes via quantity instead of quality, its easier to keep up with technological advancements, coverage obviously increases ('O3B', anyone...), and the production schedule decreases through economies of scale and more assembly line type opetations.
Just to comment on one part of the previous post. I think @bxr140 implied this, but for benefit of others I'm going to spell it out
the latency to geostationary satellites is indeed about 1/4 second at best. This is because the geostationary satellites are on ~35700 km (about 22K miles) orbit above equator. So, to reach them one way, light takes slightly longer than 1/10 second (exact delay depends on the client station location). Then the signal needs to get to the ground station (another 1/10th), then routed to the server (depends how far the server is from the ground station). The server response comes back via the same channel. In the very best case the signal covers 4 * 35700 km, which means the very best round trip time possible due to the speed of light is 1/2 second.
Some satellite internet providers cut this time in half by using dialup for upstream. So, the first part of the process I described above, doesn't go to space, but instead is routed through the ground-based phone network. Since most of the traffic is usually on the down leg, the slow dialup connection is used to send a small request (which works fast even via dialup), but the wide satellite connection is used to download pages, pictures and movies. This cuts the round-trip time in half. This is why the satellite internet is usually thought of as 1/4 sec roundtrip. Compare it with ~1/15 sec round-trip up and down Eastern or Western seaboard and up to 1/10 sec cross-country ping.
All the above applies to geostationary satellites. What Elon is proposing is much-much lower orbit constellation. With 4000 satellites on 1200km orbits there's always one overhead and the light flight time to it is just 1/250 sec. If the constellation does the routing without help of the ground stations (that's an IF), then we only pay ~4/250 sec (about 16ms) per roundtrip for using this network as opposed to the ground-based network. However, this network is MUCH faster: it's medium is vacuum and the signal always goes straight (as opposed to follows the route of the cable on the ground, which is never straight). I think this network architecture has potential to be faster than existing internet. This is going to be very big. Routing is a very interesting problem to solve in this case. And security, too. And stationkeeping.
the latency to geostationary satellites is indeed about 1/4 second at best. This is because the geostationary satellites are on ~35700 km (about 22K miles) orbit above equator. So, to reach them one way, light takes slightly longer than 1/10 second (exact delay depends on the client station location). Then the signal needs to get to the ground station (another 1/10th), then routed to the server (depends how far the server is from the ground station). The server response comes back via the same channel. In the very best case the signal covers 4 * 35700 km, which means the very best round trip time possible due to the speed of light is 1/2 second.
Some satellite internet providers cut this time in half by using dialup for upstream. So, the first part of the process I described above, doesn't go to space, but instead is routed through the ground-based phone network. Since most of the traffic is usually on the down leg, the slow dialup connection is used to send a small request (which works fast even via dialup), but the wide satellite connection is used to download pages, pictures and movies. This cuts the round-trip time in half. This is why the satellite internet is usually thought of as 1/4 sec roundtrip. Compare it with ~1/15 sec round-trip up and down Eastern or Western seaboard and up to 1/10 sec cross-country ping.
All the above applies to geostationary satellites. What Elon is proposing is much-much lower orbit constellation. With 4000 satellites on 1200km orbits there's always one overhead and the light flight time to it is just 1/250 sec. If the constellation does the routing without help of the ground stations (that's an IF), then we only pay ~4/250 sec (about 16ms) per roundtrip for using this network as opposed to the ground-based network. However, this network is MUCH faster: it's medium is vacuum and the signal always goes straight (as opposed to follows the route of the cable on the ground, which is never straight). I think this network architecture has potential to be faster than existing internet. This is going to be very big. Routing is a very interesting problem to solve in this case. And security, too. And stationkeeping.
Musk told BusinessWeek he wants to create a global communications system that would be
"larger than anything that has been talked about to date," that would take at least five years and $10 billion to build.
Read more: SpaceX Just Raised $1 Billion From Google And Fidelity - Business Insider
SpaceX Just Raised $1 Billion From Google And Fidelity - Business Insider
"larger than anything that has been talked about to date," that would take at least five years and $10 billion to build.
Read more: SpaceX Just Raised $1 Billion From Google And Fidelity - Business Insider
SpaceX Just Raised $1 Billion From Google And Fidelity - Business Insider
Benz
Active Member
Looks like SpaceX is making some headway with their satellite system!!!
SpaceX Files for FCC Approval for 4,425 Satellite Global Broadband Constellation at Parabolic Arc
SpaceX Files for FCC Approval for 4,425 Satellite Global Broadband Constellation at Parabolic Arc
mspohr
Well-Known Member
Another article in BI:
SpaceX just asked permission to launch 4,425 satellites — more than currently orbit Earth
SpaceX just asked permission to launch 4,425 satellites — more than currently orbit Earth
And that is the only way in which poor sods like those of us living not just remote but at 63.02ºN lat ever have a chance of obtaining reasonable internet connection.
Just think: if that swarm of satellites were to exist, then Lord Vetinari could function as a moderator year-round!
Just think: if that swarm of satellites were to exist, then Lord Vetinari could function as a moderator year-round!
Musings more important than our own connectivity:
* Google invested $900mm in SpaceX in January, 2015, for an even 9% stake, and landed a SpaceX board seat for its VP of Corp. Development.
* The SpaceX satellite program went low profile until mid-summer this year, when, apparently in response to Dish Network and allies' petition to the FCC to reallocate to it for 5G what had been reserved for satellite broadband: the 12.2-12.7kHz Ku frequency, SpaceX wrote to the FCC that the Multi-Channel Video Distribution and Data Service Coalition's request “comes at precisely the wrong time, given the ongoing, active investment and technological developments” (from SpaceX's June 7 filing with the FCC: ECFS)
* In the past month, Google has terminated all further roll-out of its super high-speed cable projects in a number of US cities: Google Fiber Halts Operations In Phoenix
I am seeing a direct link between these: Google has determined that SpaceX's satellite project has legs, and it has cast its lot with Mr Musk & co.
* Google invested $900mm in SpaceX in January, 2015, for an even 9% stake, and landed a SpaceX board seat for its VP of Corp. Development.
* The SpaceX satellite program went low profile until mid-summer this year, when, apparently in response to Dish Network and allies' petition to the FCC to reallocate to it for 5G what had been reserved for satellite broadband: the 12.2-12.7kHz Ku frequency, SpaceX wrote to the FCC that the Multi-Channel Video Distribution and Data Service Coalition's request “comes at precisely the wrong time, given the ongoing, active investment and technological developments” (from SpaceX's June 7 filing with the FCC: ECFS)
* In the past month, Google has terminated all further roll-out of its super high-speed cable projects in a number of US cities: Google Fiber Halts Operations In Phoenix
I am seeing a direct link between these: Google has determined that SpaceX's satellite project has legs, and it has cast its lot with Mr Musk & co.
