Jump to content

SpaceX Discussion Thread


Skylon

Recommended Posts

14 minutes ago, Green Baron said:

A single (big) satellite can cover half a continent with 100 TV programs and high speed internet for millions. ...

A lower flying swarm might actually improve link times, but buffering and broader services are not their thing, too small. ...

Well, cell towers don't have to serve millions either.

One of my thinking is : Given the fact that each satellite would serve an area around 115 km in radius, would it be cheaper just to deploy them down here on top of masts rather than creating a semi-chaotic swarm of 12,000 satellites ?

 

If yes, why not ?

Link to comment
Share on other sites

1 minute ago, YNM said:

Well, cell towers don't have to serve millions either.

One of my thinking is : Given the fact that each satellite would serve an area around 115 km in radius, would it be cheaper just to deploy them down here on top of masts rather than creating a semi-chaotic swarm of 12,000 satellites ?

 

If yes, why not ?

For one the cable going to Africa has been cut twice. The problem is that in a very tight supply market, ISPs can charge whatever they want, where as if any joe wants to launch a bunch of satellite he can practically cover every market on Earth.

http://www.africabandwidthmaps.com/fibrereach/

 

Link to comment
Share on other sites

Its showing Spacenet is a provider for my area, almost twice as fast as my laggy DSL connection. Yeah, satellite broadband is here even though I don't need it.

Alot of negative reviews on Starband.

Edited by PB666
Link to comment
Share on other sites

20 minutes ago, YNM said:

If yes, why not ?

I am not an engineer, but i can imagine that a sophisticated software and protocol for the handshake between a fixed groundstation and a buzzing swarm, based on a single license is easier to establish than a uniform grid of masts and corresponding infrastructure. Just think of all the national treaties and licenses one would need, and the competition with indigenous technology and companies, often owned by ... ah politics ... :-)

But this is just a guess. It is a space company. (Their boring department sells silly party toys).

 

9 minutes ago, Elthy said:

You need realy high masts for such a large area, otherwise you get below the horizon.

Navigator's rule of thumb for the distance to a lighthouse:

Distance in NM = 2.075 * ( sqrt(height of eye) + sqrt(height of light) ).

Objects are closer than one might think ! And that is not only valid for T-rex ;-)

Edited by Green Baron
wrong forumla formula whatever
Link to comment
Share on other sites

8 minutes ago, Green Baron said:

I am not an engineer, but i can imagine that a sophisticated software and protocol for the handshake between a fixed groundstation and a buzzing swarm, based on a single license is easier to establish than a uniform grid of masts and corresponding infrastructure. Just think of all the national treaties and licenses one would need, and the competition with indigenous technology and companies, often owned by ... ah politics ... :-)

But this is just a guess. It is a space company. (Their boring department sells silly party toys).

He's a jack of all trades. Just parked a car  in trans-martian orbit.

Link to comment
Share on other sites

3 minutes ago, YNM said:

Get a long-wave version ?

Longer waves limit bandwidth. The higher the frequency, the higher the throughput ...

Also: atmospheric reflections are as unpredictable as SpaceX timelines ?

5 minutes ago, PB666 said:

He's a jack of all trades. Just parked a car  in trans-martian orbit.

True.

"Not for long !" - Shinzon

Link to comment
Share on other sites

9 minutes ago, Green Baron said:

Longer waves limit bandwidth. The higher the frequency, the higher the throughput ...

Ah, right. Wi-Fi, Ku-band are in GHz, skywaves only reliably goes to MHz.

Cut them up into smaller pieces/distance ?

Or just lay cables along the road...

 

But in all seriousness, I guess there's a cutoff whether you'd just put up plinths or you fling them off. 12000 is quite close to that limit.

Edited by YNM
Link to comment
Share on other sites

1 hour ago, Green Baron said:

A single (big) satellite can cover half a continent with 100 TV programs and high speed internet for millions. Only problem: it is in GSO, aka far away. One needs a dish in the garden. But they have immense capabilities to buffer content, think pages in advance, etc. It is just, dynamically built pages, like news pages, pub science, etc. take time.

A lower flying swarm might actually improve link times, but buffering and broader services are not their thing, too small. At least i can't imagine how ... we must wait & see :-)

An big geo satellite works well for broadcast, you transmit an signal to an continent, its not so good for broadband, transfer is is limited to the satellite bandwidth, ping is bad and you need an strong transmitter and large antenna to send high speed back and bandwidth is again limited. 

Linking and buffering has become much smaller and simpler over the years. assuming the satellites will use lasers to link. 

Edited by magnemoe
Link to comment
Share on other sites

3 minutes ago, magnemoe said:

An big geo satellite works well for broadcast, you transmit an signal to an continent, its not so good for broadband, transfer is is limited to the satellite bandwidth, ping is bad and you need an strong transmitter and large antenna to send high speed back and bandwidth is again limited. 

c = 300,000,000 meters per second. Assuming that signal and destination are within 45' then up and down link from a 1000 km orbit are  1,000,000/ 100,000,000 = 0.01 second. It get better on the send because if you are loading something big, it can upload to the satellite and then you only have 1 direction send. 

Link to comment
Share on other sites

13 minutes ago, PB666 said:

c = 300,000,000 meters per second. Assuming that signal and destination are within 45' then up and down link from a 1000 km orbit are  1,000,000/ 100,000,000 = 0.01 second. It get better on the send because if you are loading something big, it can upload to the satellite and then you only have 1 direction send. 

Satellites partly prepare pages "in orbit" before they send them to the recipient. That frequently makes for a long wait-time (satellite is gathering and distributing all that google and facebook and ad nonsense the enduser has absolutely no benefit from) when nothing happens. Then they send the package down. Javascripts on the client then send request back based on where you've been before and so on ping pong.

Best: disable Javascript and block all the social stuff. That accelerates things a lot, but also some pages don't work any more. You literally communicate 3 Mbyte for a content of maybe 800 Bytes.

Edited by Green Baron
Link to comment
Share on other sites

1 hour ago, Green Baron said:

Satellites partly prepare pages "in orbit" before they send them to the recipient. That frequently makes for a long wait-time (satellite is gathering and distributing all that google and facebook and ad nonsense the enduser has absolutely no benefit from) when nothing happens. Then they send the package down. Javascripts on the client then send request back based on where you've been before and so on ping pong.

Best: disable Javascript and block all the social stuff. That accelerates things a lot, but also some pages don't work any more. You literally communicate 3 Mbyte for a content of maybe 800 Bytes.

You should read the scripts behind some of your trusted web pages, its more like 5% content 95% scripting for adds. The lead add for BBC World today had an image with 40 sublink addresses. Some of the more nepharious web scams are fed by click-bait on some of the most trusted websites. Why I don't go to BBC anymore. The website itself has no idea what add is being fed, that is generally fed by google "googlesyndication.com" as google tracks you around and tries to coerce you to buy stuff you don't need. There are services that filter all this stuff out and essentially whitewash your location and identity, like 30$ per year. New groups, Reddit,  and groups like this are better forums . . . .
Fortunately for most of the poorer Africans their access to the biggest offenders, but there could be advertisements for cigarettes, alcohol or things we may never see. Wikipedia has one advantage of other sources of information, most of its content is kosher, even reddit there is a fair amount of stuff. If wiki is the only service that they can get, they have the best of the internet.

Edited by PB666
Link to comment
Share on other sites

Interesting: An as yet unpublished paper "The random walk of cars and their collision probabilities with planets" by Hanno Rein, Daniel Tamayo, David Vokrouhlicky at the University of Toronto suggests that Musk's Tesla has a 6% chance of colliding with the Earth and 2.5% chance of colliding with Venus in the next couple of million years. The article that I read about it says that the paper has submitted to the UK's Monthly Notices of the Royal Astronomical Society. 

Edited by PakledHostage
Link to comment
Share on other sites

5 hours ago, PakledHostage said:

Interesting: An as yet unpublished paper "The random walk of cars and their collision probabilities with planets" by Hanno Rein, Daniel Tamayo, David Vokrouhlicky at the University of Toronto suggests that Musk's Tesla has a 6% chance of colliding with the Earth and 2.5% chance of colliding with Venus in the next couple of million years. The article that I read about it says that the paper has submitted to the UK's Monthly Notices of the Royal Astronomical Society. 

Whoa! Venus? That would require some wonky orbit-wrangling by Earth and Mars. Really, was there no way to put a single solar panel and a radio beacon on Space Tesla? It would be interesting to keep track of its orbit as it dances between Earth and Mars.

Link to comment
Share on other sites

5 minutes ago, DAL59 said:

AHAHAHAHAHAHAHAHAHAHAHAHAHAHA

His company is a failure. They promised to launch tourists a decade ago, and are still testing their suborbital space plane, which can no longer reach space because it's too heavy. Their orbital rocket cannot use White Knight to launch, and is smaller than Electron.

If he wants to upstage Elon, maybe he should actually put real money into his project and re-evaluate his goals.

Link to comment
Share on other sites

4 hours ago, Scotius said:

It would be interesting to keep track of its orbit as it dances between Earth and Mars.

I would imagine that the time spans involved are just too long to warrant it. The article predicts that the Tesla's next close encounter with the Earth (when it will pass within a couple of hundred thousand kilometers) will be in 2091. Presumably Starman's orbit has already been characterized well enough that we know where it will be between now and then, and beyond that probably nobody will really care.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...