49
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Accepted
What impact will the deorbiting of thousands of satellites have on the atmosphere?
Update 2024
Ferreira et al. (GRL, 2024) simulate the increase in AlO (Alimunium Oxide) from satellite re-entry. From the abstract:
We find that the demise of a typical 250-kg satellite can generate ...
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36
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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 ...
- 21.7k
34
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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 ...
- 151k
33
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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 ...
- 130k
27
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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 ...
- 1,235
25
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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 =...
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25
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Starlink Satellite Orbits
From the Wikipedia article on Geostationary orbit:
A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 km (22,236 mi) in ...
18
votes
Would a Starlink mini placed inside a plane's cabin be able to get an Internet connection?
Nope!
Starlink units require a clear view of the sky, and preferably a large portion of the sky. The metal body of the aircraft will block the signal. Specifically, Starlink uses Ku-band frequencies ...
- 21.7k
16
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. ...
- 21.7k
15
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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 ...
- 4,504
14
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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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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 ...
- 2,258
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 ...
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13
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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 ...
- 151k
13
votes
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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 ...
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13
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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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13
votes
Does it make sense to use a skyhook to launch and deorbit mega-satellite constellations now?
Answer: No, it doesn’t make sense.
A Skyhook's center of mass orbits at (roughly) half the altitude of the point for pick-up of descending cargo. The altitude of satellite constellations in LEO orbit ...
- 27.5k
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, ...
- 21.7k
11
votes
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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 ...
- 122k
11
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 ...
- 1,743
11
votes
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How does changing the elevation angle allow starlink to improve line of sight communications
I think image should clarify what the angle means.
The elevation angle is counted from "horizontal" and so the antenna of the satellite can "see" a cone underneath, with tip angle ...
- 56k
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 ...
- 122k
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, ...
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10
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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; ...
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10
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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 ...
- 1,231
10
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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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 ...
- 15.2k
10
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....
- 1,743
10
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Starlink Satellite Orbits
The low earth orbits mean that they are more responsive. The round-trip from earth-to-GEO-to-Earth is typically around a half a second. The LEO delay for Starlink is closer to 1/10th of a second. ...
- 1,219
9
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 ...
- 151k
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