SpaceX Internet Satellite Network: Starlink

[dhanson865]

Interesting! I thought space lasers would only be needed for the arctic regions, but it appears there are several regions in the world that will use it.

Yes, I think it'll be a factor in much of South America, Africa, Australia, and Asia (out and in the artic regions).

Anywhere with low population density not sitting on top of a fiber line.

Oh and that's just for basic connectivity.

The US and Europe will also make use of it to reduce latency on long paths in locations that are high population density sitting on top of fiber lines.

 

[dhanson865]

https://www.reddit.com/r/spacex/comments/13z3g3m

SCS = Supplemental Coverage from Space this is FCC's name for this new capability of connecting unmodified cellphones to satellites

tables below present illustrative information for proposed form factors of SpaceX Gen2 satellites with SCS capabilities: one of which will be launched on Falcon 9 rockets and one that will be launched on Starship. For convenience, these satellites are labeled satellites F9-3 and Starship-2, respectively, following the naming convention SpaceX used for its authorized Gen2 satellites. Note that to better reflect a non-maneuverable satellite in a tumbling deorbit a 0.5 scaling factor has been applied to the area-to-mass ratios used with NASA’s Debris Assessment Software (“DAS”). Further note that while the specific dimensions of the bus of the Starship-2 satellite is larger than the Starship-1 satellite, reflecting a deployed SCS antenna, the DAS analysis of the Starship-2 satellite is identical to the Starship-1 analysis that the Commission approved in the Gen2 Order because the area-to-mass ratio used for the analysis is the same.

So we now have 5 different Starlink V2s:

Name​	Component​	Length (m)​	Width (m)​	Number​	Area (m2)​	DAS Area (m2)​	DAS Mass (kg)​
F9-1​	Solar Array​	8.1​	2.8​	1​	22.68​	​	​
​	Bus​	2.8​	1.3​	1​	3.64​	​	​
​	Total​	​	​	​	26.32​	30​	303​
F9-2​	Solar Array​	12.8​	4.1​	2​	104.96​	​	​
​	Bus​	4.1​	2.7​	1​	11.07​	​	​
​	Total​	​	​	​	116.03​	120​	800​
F9-3 (SCS)​	Solar Array​	12.8​	4.1​	2​	105​	​	​
​	Bus​	7.4​	2.7​	1​	20​	​	​
​	Total​	​	​	​	125​	130​	970​
Starship-1​	Solar Array​	20.2​	6.36​	2​	256.94​	​	​
​	Bus​	6.4​	2.7​	1​	17.28​	​	​
​	Total​	​	​	​	274.22​	294​	2000​
Starship-2 (SCS)​	Solar Array​	20.2​	6.36​	2​	256.94​	​	​
​	Bus​	10.1​	2.7​	1​	27.27​	​	​
​	Total​	​	​	​	284.21​	294​	2000​

Note the V2 Mini with SCS capability (F9-3) has a mass of nearly 1 metric ton, 170kg heavier than regular V2 Mini (F9-2).

 

[scaesare]

Yes, I think it'll be a factor in much of South America, Africa, Australia, and Asia (out and in the artic regions).

Anywhere with low population density not sitting on top of a fiber line.

Oh and that's just for basic connectivity.

The US and Europe will also make use of it to reduce latency on long paths in locations that are high population density sitting on top of fiber lines.

Given the lesser latency of laser light not having to travel through glass fibers as media, would there be any reason why the goal wouldn't be to use ISLL's 1] for all traffic to the extent possible, and then only downlink to the closest ground station?

Obviously total ISLL bandwidth, cost, etc... are factors, but from a pure performance perspective....


[1] Inter-Satellite Laser Links, I'm sure there's a real term for this rather than the one I just fabricated

 

[mongo]

Given the lesser latency of laser light not having to travel through glass fibers as media, would there be any reason why the goal wouldn't be to use ISLL's 1] for all traffic to the extent possible, and then only downlink to the closest ground station?

Obviously total ISLL bandwidth, cost, etc... are factors, but from a pure performance perspective....


[1] Inter-Satellite Laser Links, I'm sure there's a real term for this rather than the one I just fabricated

Yep, buddy to buddy pew-pew keeps data usage internal to SpaceX until the final destination.
Algorithm needs to know geographic end point and adjust for ground link saturation.
For shorter distances, laser can have higher latency than fiber depending on number of hops and gross distance.

Easier when data centers have Starlink links on site.

 

[scaesare]

buddy to buddy pew-pew

And an even better "informal" term, lol

 

[mongo]

And an even better "informal" term, lol

Realization I just had.
Max sat to ground is limited by total power limits and frequency bands. However, max ground to sat is only limited by number of ground antennas and sats visible. Ground can uplink to multiple sats on the same channel simultaneously from separate antennas.

Buddy & pew are Starlink nomenclature

https://twitter.com/x/status/1663914514520186884

https://twitter.com/x/status/1662642250017382400

 

[bxr140]

Given the lesser latency of laser light not having to travel through glass fibers as media, would there be any reason why the goal wouldn't be to use ISLL's 1] for all traffic to the extent possible, and then only downlink to the closest ground station?

• Ground station capacity
  • I don't know exactly where they are right now, but last I heard the gateway antennas were maxing at something like 4-5 gigs.
• Lawful intercept type requirements.
  • There are some places that require ground stations to be in-country.
• ISL link capacity
  • A less significant issue, but still a chokepoint that needs to be managed
• Routing complexity/capacity
  • Certainly not the order of magnitude as above, but its not a trivial effort to get all the packets to the right places--again something to be managed
• Real world latency
  • A rack up of all of the above dumps out an "ok" latency for a lot of practical scenarios (vs a similar "ok" for a terrestrial equivalent), which significantly reduces the upside of the theoretical low latency of traveling through space.

[1] Inter-Satellite Laser Links, I'm sure there's a real term for this rather than the one I just fabricated

ISL is the appropriate name/acronym. In the olden days (5 years ago) we used to call them OISL (O = optical), but pretty much nobody is planning to use RF ISLs so the differentiator became superfluous. (iridium Next uses RF ISLs, FTR)

 

[scaesare]

• Ground station capacity
  • I don't know exactly where they are right now, but last I heard the gateway antennas were maxing at something like 4-5 gigs.
• Lawful intercept type requirements.
  • There are some places that require ground stations to be in-country.
• ISL link capacity
  • A less significant issue, but still a chokepoint that needs to be managed
• Routing complexity/capacity
  • Certainly not the order of magnitude as above, but its not a trivial effort to get all the packets to the right places--again something to be managed
• Real world latency
  • A rack up of all of the above dumps out an "ok" latency for a lot of practical scenarios (vs a similar "ok" for a terrestrial equivalent), which significantly reduces the upside of the theoretical low latency of traveling through space.

ISL is the appropriate name/acronym. In the olden days (5 years ago) we used to call them OISL (O = optical), but pretty much nobody is planning to use RF ISLs so the differentiator became superfluous. (iridium Next uses RF ISLs, FTR)

Your point about ground station capacity is interesting... raises a couple more questions:

1) While there's limited allocated bandwidth to a ground station up/downlink, is there any regulatory limit on the ISL bandwidth that can be implemented?

2) That sessions need to be ground linked at some point, I assume the ground station capacity issue would involve ensuring no single station is saturated?

 

[mongo]

Your point about ground station capacity is interesting... raises a couple more questions:

1) While there's limited allocated bandwidth to a ground station up/downlink, is there any regulatory limit on the ISL bandwidth that can be implemented?

2) That sessions need to be ground linked at some point, I assume the ground station capacity issue would involve ensuring no single station is saturated?

1) Nope, purely Starlink hardware limited.

2) Correct, though ground stations probably have a lot more uplink capacity than downlink. So a lot of people watching YouTube is easier to handle than a lot of people uploading their videos to YouTube.

 

[scaesare]

1) Nope, purely Starlink hardware limited.

2) Correct, though ground stations probably have a lot more uplink capacity than downlink. So a lot of people watching YouTube is easier to handle than a lot of people uploading their videos to YouTube.

It will be interesting to see what ultimate ISL bandwidth they are able to implement.

 

[mongo]

Supporting the Titanic exploration

https://twitter.com/x/status/1666911689344962576

 

[dhanson865]

Singapore live

 

[mongo]

Now with stickers:

https://twitter.com/x/status/1668376654438334464

 

[Grendal]

https://twitter.com/x/status/1664717672104198147

 

[mongo]

https://twitter.com/x/status/1664717672104198147

Go Dishy!

 

[Surfer of Life]

Just ordered a Residential Starlink but don’t want to wait.

Are business Starlinks portable like Residential version? Is there any other noticeable difference for day-to-day, light homeowner-type use? (Other than accessing more satellites at once with the wider angle).

Much TIA!

(Concerned about value for my money; do both models come with cat stickers?)

 

[mongo]

Just ordered a Residential Starlink but don’t want to wait.

Are business Starlinks portable like Residential version? Is there any other noticeable difference for day-to-day, light homeowner-type use? (Other than accessing more satellites at once with the wider angle).

Much TIA!

(Concerned about value for my money; do both models come with cat stickers?)

Are you in a waitlist area?
Order a roam system also. That is $30 or so more a month and mon priority data, but also no waiting.
Worst case, you'll need to buy duplicate HW if you address has limited spare bandwidth. Best case, once your area gets residential coverage sign ups, you can move the HW to that new subscription (I did this).

Residential has been great in my area (so was roam).

The temporary portability option has been discontinued.

Cat stickers can be ordered separately.

 

[Surfer of Life]

Thank you, @mongo .

Still curious if there any other noticeable differences between Business vs. Residential versions for day-to-day, light homeowner-type use? (Other than accessing more satellites at once with the wider angle)?

The upload or download rate was about double… but I’m not sure if the difference would be noticeable to anyone in my small household.

 

[Grendal]

Supporting the Titanic exploration

https://twitter.com/x/status/1666911689344962576

Ouch. Isn't this the missing submersible?

 

[willow_hiller]

Ouch. Isn't this the missing submersible?

Unfortunately I've seen discourse online implying that Starlink is to blame, but that's a bit ridiculous. They must have been using Starlink solely for communications while above water. Once the craft was underway, I don't think RF can penetrate that massive volume of water.