46
votes
Accepted
What impact will the deorbiting of thousands of satellites have on the atmosphere?
Not much research has been done on this question in recent years, but some researchers are worried enough to research into wooden satellites.
The question on the environmental impact of deorbiting ...
- 11.4k
35
votes
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How do the Starlink satellites shine?
Starlink (and other satellites) categorically do not have exterior lights or illumination, that would be a waste of power for no particular benefit.
The reason that we can sometimes see satellites ...
- 16.9k
33
votes
Accepted
Why will Starlink satellites use krypton instead of xenon for electric propulsion?
It's the same reason SpaceX often does things differently: Krypton is a lot cheaper.
The satellites are designed to control costs. For example, each will maneuver with Hall-effect thrusters—ion ...
- 124k
33
votes
What impact will the deorbiting of thousands of satellites have on the atmosphere?
The mass of Earth's atmosphere is 5E+18 kg and the Troposphere alone has 3/4's of that. With an average height of 13 km that makes its volume $4 \pi r^2 h$ or about 6.6E+18 m^3.
If we break up one ...
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28
votes
Are the things I'm seeing satellites?
This is almost certainly a Starlink train.
These look something like this (see image) and are usually seen shortly after a Starlink launch. There have been a few Starlink launches this week, so it is ...
25
votes
Accepted
Why does the Falcon 9 launch 60 instead of 100 Starlink satellites at a time?
To begin with, Starlink sats have a mass of ~260kg not 227kg.
Secondly, the reusable Falcon 9 LEO payload has a limit of around ~15600kg; the 22,800kg payload is for expendable Falcon 9.
60sats*260kg =...
- 3,991
15
votes
Accepted
Is it feasible to paint SpaceX Starlink satellites black so as not to frequently saturate the CCDs of the Large Synoptic Survey Telescope?
In general satellites are not "painted". They are covered in a variety of Multi-Layer Insulation (MLI) blankets with varying optical qualities. I have seen MLI in silver, black, and gold - sometimes ...
- 4,424
15
votes
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Main differences between 5G and Starlink?
Starlink and 5G don't have that much to do with each other--they compete for different customers.
Starlink systems currently require a large receiver the size of a pizza box to uplink to satellites. ...
- 16.9k
14
votes
Accepted
Is the Starlink array really visible from Earth?
Yes, the Starlink satellites were visible from earth with your naked eye and have been seen and recorded by several people.
See also https://vimeo.com/338361997 and read about it here.
Gizmodo: ...
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14
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Does SpaceX expect 1 collision involving one of their Starlink satellites every 2 years?
I think you've made a bit of a logical/statistical misstep.
Primarily, the "1 in 100,000" figure is a bit misleading because it's not a statistic. It's an operational risk level threshold ...
- 16.9k
13
votes
Accepted
Which satellite constellations are already operational in LEO (Low Earth Orbit)?
Is there a webpage where I can see the list of LEO satellite constellations?
Yes! Celestrak has several pre-arranged groups of satellites and many of those groups can be seen as constellations, and a ...
- 149k
13
votes
Accepted
Satellites - predominant apparent motion?
Launching west to east requires less fuel.
An object in low earth orbit is moving horizontally at around 8km/s. Launching a satellite in the west-east direction allows you to take advantage of the ...
- 3,587
13
votes
Accepted
How long can the SpaceX Starlink satellites survive before they deorbit?
Around 5 Years
Starlink satellites are launched into orbits between 335 and 354 miles above the Earth. SpaceX had originally planned to fly some of their constellation at 800 miles, but petitioned ...
- 2,193
13
votes
Weaponizing the Starlink constellation
I'm going to restrict my answer to only the question of "can Starlink satellites be used as kinetic weapons." I'm pretty sure the answer is "not in any practical sense."
The ...
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11
votes
What are the bottlenecks stopping SpaceX from launching more frequent batches of Starlink?
The answer, like many things in the business world, revolve around money and time. Building/developing a satellite, let alone a satellite assembly line capable of pumping out thousands of satellites, ...
- 16.9k
11
votes
Accepted
Can the Indian government ask SpaceX to pay for bandwidth usage in its airspace?
In order to transmit from a country, one must have a license to do so, with the exception of some spaces without specific owners, like WiFi's 2.4 GHz that allows small narrow transition can work. It ...
- 121k
10
votes
Why is one Starlink satellite not following the adjacent one in this image?
Basically they are not quite in the same plane. As a satellite raises or lowers, not only does it change the relative position within an orbital plane, it also will slowly shift the longitude of the ...
- 121k
10
votes
Accepted
Is SpaceX propulsively deorbiting a Starlink satellite already?
Yes!
The current status (end of June 2019) according to a SpaceX statement via Michael Sheetz
is:
45 in final orbits
5 still raising, in final orbits shortly
5 paused during raise for adjustments, ...
- 5,118
10
votes
How do the Starlink satellites shine?
I'm going to answer a slightly different question from the other answer: "why are Starlink satellites so visible, compared to other satellites?"
The answer is that they're very close to the earth; ...
- 201
10
votes
Can the Indian government ask SpaceX to pay for bandwidth usage in its airspace?
The answer is No, largely based on the fact that India is a signatory to the 1967 Outer Space Treaty. If you pick a country that didn’t sign any of the patchwork of treaties covering space, it could ...
- 1,221
10
votes
Why will Starlink Gen2 be so big and heavy?
"Just a Flying Router"
This is... not the half pound plastic wifi router in your house.
I don't think there are firm numbers out yet, but the speculation I've seen is that bandwidth on a ...
- 1,348
10
votes
Something doesn't add up when calculating thrust for Starlink satellites
I see quite a couple of problems with this calculation, let me list them for further investigation:
The difference between air drag at 550 km and 210 km seems to be off. Air density changes by a ...
- 14.6k
9
votes
Accepted
Have astronauts seen Starlink trains?
Yes, it happened at least on 13th April 2020 at 21:25:02 UTC:
https://sattrackcam.blogspot.com/2020/04/starlink-train-photographed-from.html
The image above (image ISS062-E-148365, original at high ...
- 984
9
votes
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How close were Starlink-1095 and Starlink-2305 to the Tiangong Chinese Space Station?
Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, did calculations regarding how close the Chinese Space Station came to S-2305, and it's quite close.
A reply in ...
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9
votes
What did I see in the SpaceX Starlink launch stream 12/17/2022
Here is an clip of the event:
This is probably a vaguely crescent-shaped chunk of ice that's fallen off the rocket. It spins, and either due to atmospheric drag or being pushed by one of the first-...
- 16.9k
8
votes
Delta-V of Starlink Satellites
update: It's been two years and Starlinks are now being deployed at much lower altitudes! I am revising this "ballpark spherical-cow envelope-back estimate" based on @BrendanLuke15's answer ...
- 149k
8
votes
Accepted
Do the latest Starlink satellites use inter-satellite laser communications?
All I could find was here which led to a variety of articles which explain the technology in depth. Not that Wikipedia is always reliable, however it stated that:
The satellites will employ optical ...
- 9,367
8
votes
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Starlink's autonomous collision avoidance
I don't think there are any papers about it, but here's what I've gleamed from my studies on it.
As you mentioned, they use information from the DOD, specifically Space-Track, or C-SPOC, or J-SPOC. ...
- 121k
8
votes
Why is SpaceX deploying Starlink satellites without inter-satellite communication capability?
Without the mesh network SpaceX cannot provide global service as originally assumed. A potential (but unsourced) model for what they have is similar to terrestrial mobile internet with ground stations ...
- 20.9k
8
votes
Accepted
How does the current or future network latency of SpaceX Starlink compare to wired internet?
Not Yet
As of early June 2023, satellite to satellite comms are not enabled on Starlink, which means currently packets hit the satellite and then return to a ground station for further on transmission....
- 1,348
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