Those long, straight-line convoys of Starlink satellites are fascinating. There's a few of them I could see scattered around the Earth. At what point do they start breaking up into unrelated orbits?
Looking forward to using this website to try spotting satellites at night. There's something strangely thrilling about seeing objects in the night sky that were placed there by people.
Most of the satellites shown on the Leolabs site are too dim to see without a telescope because they don't reflect enough light. My site calculates brightness and filters down to the ones that you can see with the unaided eye.
There are still quite a few! ISS in particular is very bright and can even be seen before sunset. The new Chinese space station Tiangong is also a good one to try. In the next few weeks it's expected that the recently launched BlueWalker-3 will become quite bright too as it expands its enormous phased array antenna (64 square meters!). But the coolest is probably if you can catch a recently launched Starlink train, 50 satellites all visible simultaneously or within seconds of each other. (A few weeks after launch the Starlink satellites are no longer visible as they reach their operational orbits.)
Scroll down to the individual launches and there's images you can click on of the orbit raising progress of each launch.
Example of the Starlink 4-21 mission that launched on July 7th of this year: https://planet4589.org/space/stats/star/spl51.jpg (One satellite failed, which isn't that unusual, and will de-orbit probably sometime early next year if they don't recover it.)
> At what point do they start breaking up into unrelated orbits?
I can't speak with any authority, but in general a train of satellites would likely be moving in an orbit with either the apogee/perigee similar to the target orbits, but the other end of the orbit being higher or lower. Each time the train reaches the extremum at the target altitude, one of the satellites thrusts to adjust the other side of its orbit to target, which pushes it out of the pack.
The specifics may be so different as to make that explanation totally wrong but it's probably not too far from the general principle.
I don't really know what I'm looking at here, but it feels very sci-fi and I'm into it.
I also wonder, how do they track so many objects? Who actually tracks them? How much does it cost (energy, engineers) to maintain the tracking systems?
Edit: Are these all simulated orbits? Is there a big "orbit registry" somewhere? And what are the "beams"?
LEOlabs operates its own radar systems that point upwards-ish. The "beams" you see are the fields of view of their radars. When an object crosses that field of view going at orbital speeds, LEOlabs tracks it and uses the partial trajectory information to figure out the orbit of the object. From there, it can potentially associate that object with existing objects in its own and other databases (the US Space Force, which operates its own radars, is one of the best-known).
It then sells that information to spacecraft operators, who may be using the orbital information to determine if their spacecraft has a risk of hitting another object in space, or to figure out where their spacecraft are in the first place (usually when they're not talking to the ground).
Is there a big orbit registry somewhere? Yes. https://www.unoosa.org/oosa/osoindex/search-ng.jspx Each individual object is observed every few weeks, and then they estimate its current position with math and physics.
The US Air Force, for one, is responsible for tracking everything it sees. That generally means computing TLAs for each object. Whether they release this info, I don't know.
This made me look up a link to my old favourite for this kind of thing, CelesTrak.org . Unfortunately, they discontinued their visualizer due to licensing problems.
Right, because apart from the moon, all objects orbiting the earth are considerably smaller than the New York Metropolitan Area which would not be your understanding if you took the visualization to be a scale representation.
That's really cool. I know this comment is low-effort, but I don't really care - this type of real-time visualization is really interesting and I want to see more of this sort of thing going forward.
That said, the blue dots are "unknown" - what could those possibly be? Not trying to be conspiratorial or anything, but is it some sort of debris from classified operations or foreign intelligence operations?
Often you can figure out what spacecraft/rocket a piece of debris came from with a good catalogue of orbits and some math - these are labeled "Debris." Often you just can't - these are labeled "Unknown."
The US Space Force does a lot of the object cataloging, and they occasionally will pretend one of their classified satellites doesn't exist, but there's only a handful of these.
I only saw one blue dot while looking around (briefly on a laggy computer, so there are probably plenty of others): "L6188942", which you can isolate in the view by searching for it. https://www.n2yo.com/database/?id=81078#results shows there are no results for the "NORAD ID" for that same object.
I don't have any domain knowledge here, so can't argue either way, but one possibility I can imagine is it's a place holder for "somebody launched something and we just don't have the records yet". No clue how realistic that is, and I'd trust my sibling comment's explanation more, but it wouldn't shock me if it takes time for info to propagate.
Scott Manley, unsurprisingly, did a nice video showing what it'd look like if you could see all the satellites and debris in space from the surface of Earth. It's scary how much stuff there is up there.
Not really. Even low Earth orbit is absolutely gigantic. It’s considerably larger than the surface of the Earth after all. Scott Manley has the same issue that this website: for things to be seen, you need to magnify them extremely.
Each dot here represents things at most meters large. Most are centimetres large especially if you look at debris. Yet each dot is the size of a large urban area on Earth. Do the same thing with planes or boats and the Earth will be close to painted a solid colour.
Obviously, to size, you would see nothing from this distance which would be a lot less impressive, a lot less useful but a lot less scary.
No more scary than the number of airplanes in the air at any given time, which is a similar order of magnitude. flightradar24 tracks around 200k flights per day — there's probably ~10k–20k aircraft in the air at any time.
How do you launch a satellite without risking running into one of these things on the way up? Do you have to calculate the trajectories of all of them individually?
Regarding launching and collisions: You mostly don't have to worry about it. The visualization makes space look crowded, but each satellite is over 150,000 times smaller than what is visualized. Space is very very big and very very empty. LEO is bigger than the surface of the earth and dozens of times thicker than the earth's crust.
It only takes a few radar stations to track all the satellites, and the US Space Force makes their data public.[1][2] Most satellites don't have much in the way of maneuvering capabilities, so you don't need continuous tracking, just updates every few days or so.
Yes they do know the trajectories so you put yours in a one where it should not hit anything. Most modern satellites also have engines so they can move on their orbit to dodge stuff if needed. Also remember that space is 3 dimensional so you can be at the same exact "spot" on this map but still be few kilometers apart.
Also this visualization is kind of misleading as it makes the satellites look way too big. In reality you could not even see them from even from the closest zoom available.
This is fascinating. Can someone point me to resources that explain Starlink's seemingly (but obviously not) random trajectories as well as their positions (some in a line, some on individual trajectories).
The ones all in a line are recently launched. They are launched ~50 at a time into a low orbit and use thrusters to raise themselves up over the course of a few weeks or months. During that process they are all lined up in a row which slowly lengthens over time. As they reach operational altitude they separate into groups and each group spaces itself evenly around one orbit for even coverage.
Imagine a visualization of all debris and litter that’s on the ground. Low Earth Orbit is very clean by comparison. This visualization makes it seem impassable and treacherous.
Imagine if this was to scale and each of the satellites was a giant floating city the size of Tokyo or LA? I wonder how many centuries will pass before that becomes a reality.
It's sort of interesting that there's been a wonky steam punk movie about battling cities roaming the Earth, gobbling each other up, but none about the more plausible future where there are battles between giant orbiting cities who pass their hated rivals once every certain number of years.
This looks extremely crowded - but reminds me of how apparently hard it was to find or bump into another ship crossing even a confined sea like the Med before sonar. With three dimensions here and more avoidance planning, even this level of space probably looks very empty still.
It is of course not to scale. You simply couldn't see any satellites unless looking at ridiculously small areas. Most of them measure a few meters at best.
I'm amazed how large satellites have become. They are larger than small countries, like Luxembourg, Cyprus, Trinidad, ... How do they get these huge satellites up in space? Unbelievable...
[+] [-] ubj|3 years ago|reply
Looking forward to using this website to try spotting satellites at night. There's something strangely thrilling about seeing objects in the night sky that were placed there by people.
[+] [-] modeless|3 years ago|reply
Most of the satellites shown on the Leolabs site are too dim to see without a telescope because they don't reflect enough light. My site calculates brightness and filters down to the ones that you can see with the unaided eye.
There are still quite a few! ISS in particular is very bright and can even be seen before sunset. The new Chinese space station Tiangong is also a good one to try. In the next few weeks it's expected that the recently launched BlueWalker-3 will become quite bright too as it expands its enormous phased array antenna (64 square meters!). But the coolest is probably if you can catch a recently launched Starlink train, 50 satellites all visible simultaneously or within seconds of each other. (A few weeks after launch the Starlink satellites are no longer visible as they reach their operational orbits.)
[+] [-] mlindner|3 years ago|reply
It's not as easy to see as in this visualization, but Jonathan McDowell (https://twitter.com/planet4589) posts graphs on his website of each launch of starlink satellites as they raise orbits. https://planet4589.org/space/stats/star/starstats.html
Scroll down to the individual launches and there's images you can click on of the orbit raising progress of each launch.
Example of the Starlink 4-21 mission that launched on July 7th of this year: https://planet4589.org/space/stats/star/spl51.jpg (One satellite failed, which isn't that unusual, and will de-orbit probably sometime early next year if they don't recover it.)
[+] [-] dwringer|3 years ago|reply
I can't speak with any authority, but in general a train of satellites would likely be moving in an orbit with either the apogee/perigee similar to the target orbits, but the other end of the orbit being higher or lower. Each time the train reaches the extremum at the target altitude, one of the satellites thrusts to adjust the other side of its orbit to target, which pushes it out of the pack.
The specifics may be so different as to make that explanation totally wrong but it's probably not too far from the general principle.
[+] [-] bagels|3 years ago|reply
[+] [-] stvnbn|3 years ago|reply
[+] [-] kidme5|3 years ago|reply
https://youtu.be/fEkXTV69yo4?t=22s
[+] [-] jcims|3 years ago|reply
[+] [-] nerdponx|3 years ago|reply
I also wonder, how do they track so many objects? Who actually tracks them? How much does it cost (energy, engineers) to maintain the tracking systems?
Edit: Are these all simulated orbits? Is there a big "orbit registry" somewhere? And what are the "beams"?
[+] [-] tullianus|3 years ago|reply
It then sells that information to spacecraft operators, who may be using the orbital information to determine if their spacecraft has a risk of hitting another object in space, or to figure out where their spacecraft are in the first place (usually when they're not talking to the ground).
[+] [-] ahazred8ta|3 years ago|reply
How do they track them? With big expensive radar systems, mostly paid for by the military. It's an international collaboration. https://en.wikipedia.org/wiki/Space_domain_awareness#Systems
[+] [-] beardyw|3 years ago|reply
[+] [-] sizzzzlerz|3 years ago|reply
[+] [-] geenew|3 years ago|reply
For posterity, this was the tutorial: https://www.youtube.com/watch?v=wC90GyHMabk
The announcement is here: https://twitter.com/CelesTrak/status/1547264390650527744
For now, the person behind it's got a (informative) error message showing up: https://celestrak.com/cesium/orbit-viz.php
He's asking for donations, might be worth it. It was a good tool.
[+] [-] daveslash|3 years ago|reply
https://news.ycombinator.com/item?id=24773462
https://news.ycombinator.com/item?id=26309367
[+] [-] dang|3 years ago|reply
LeoLabs: Low Earth Orbit Visualization - https://news.ycombinator.com/item?id=31413373 - May 2022 (3 comments)
LeoLabs: low earth orbit visualization - https://news.ycombinator.com/item?id=31180865 - April 2022 (1 comment)
Low Earth Orbit Visualization - https://news.ycombinator.com/item?id=26309367 - March 2021 (93 comments)
Monitoring a high risk conjunction between two large defunct objects in LEO - https://news.ycombinator.com/item?id=24773462 - Oct 2020 (150 comments)
Low Earth Orbit Visualization - https://news.ycombinator.com/item?id=22165645 - Jan 2020 (1 comment)
[+] [-] baron816|3 years ago|reply
[+] [-] dasil003|3 years ago|reply
[+] [-] itslennysfault|3 years ago|reply
[+] [-] NickC25|3 years ago|reply
That said, the blue dots are "unknown" - what could those possibly be? Not trying to be conspiratorial or anything, but is it some sort of debris from classified operations or foreign intelligence operations?
[+] [-] tullianus|3 years ago|reply
The US Space Force does a lot of the object cataloging, and they occasionally will pretend one of their classified satellites doesn't exist, but there's only a handful of these.
[+] [-] maicro|3 years ago|reply
I don't have any domain knowledge here, so can't argue either way, but one possibility I can imagine is it's a place holder for "somebody launched something and we just don't have the records yet". No clue how realistic that is, and I'd trust my sibling comment's explanation more, but it wouldn't shock me if it takes time for info to propagate.
[+] [-] fnordpiglet|3 years ago|reply
[+] [-] matheusmoreira|3 years ago|reply
Do you know if there's been any news on KSP2? At this point I'm not sure it will ever happen.
[+] [-] johnklos|3 years ago|reply
https://www.youtube.com/watch?v=dJNGi-bt9NM
[+] [-] WastingMyTime89|3 years ago|reply
Each dot here represents things at most meters large. Most are centimetres large especially if you look at debris. Yet each dot is the size of a large urban area on Earth. Do the same thing with planes or boats and the Earth will be close to painted a solid colour.
Obviously, to size, you would see nothing from this distance which would be a lot less impressive, a lot less useful but a lot less scary.
[+] [-] simias|3 years ago|reply
[+] [-] perilunar|3 years ago|reply
No more scary than the number of airplanes in the air at any given time, which is a similar order of magnitude. flightradar24 tracks around 200k flights per day — there's probably ~10k–20k aircraft in the air at any time.
[+] [-] hammock|3 years ago|reply
[+] [-] chroma|3 years ago|reply
It only takes a few radar stations to track all the satellites, and the US Space Force makes their data public.[1][2] Most satellites don't have much in the way of maneuvering capabilities, so you don't need continuous tracking, just updates every few days or so.
1. https://en.wikipedia.org/wiki/United_States_Space_Surveillan...
2. https://www.space-track.org/documentation#api
[+] [-] doikor|3 years ago|reply
Also this visualization is kind of misleading as it makes the satellites look way too big. In reality you could not even see them from even from the closest zoom available.
[+] [-] iandanforth|3 years ago|reply
[+] [-] MR4D|3 years ago|reply
Even 10 years ago, that thought would have been ludicrous.
[+] [-] barbazoo|3 years ago|reply
[+] [-] modeless|3 years ago|reply
For more detail than you ever wanted, check here: https://mikepuchol.com/modeling-starlink-capacity-843b2387f5...
[+] [-] Diederich|3 years ago|reply
[+] [-] xwdv|3 years ago|reply
[+] [-] russellbeattie|3 years ago|reply
It's sort of interesting that there's been a wonky steam punk movie about battling cities roaming the Earth, gobbling each other up, but none about the more plausible future where there are battles between giant orbiting cities who pass their hated rivals once every certain number of years.
[+] [-] rajeshp1986|3 years ago|reply
[+] [-] runlevel1|3 years ago|reply
[1]: https://github.com/mrdoob/three.js/
[2]: https://github.com/mkkellogg/Photons
[3]: https://github.com/shashwatak/satellite-js
[+] [-] pbmango|3 years ago|reply
[+] [-] Tepix|3 years ago|reply
[+] [-] mortenjorck|3 years ago|reply
[+] [-] spaceman33|3 years ago|reply
[+] [-] gtirloni|3 years ago|reply
[+] [-] ourmandave|3 years ago|reply
It looks like Asteroids after you've shot them into 10,000 micro asteroids.
Just needs a UFO going pew-pew...
[+] [-] squarefoot|3 years ago|reply
[+] [-] noud|3 years ago|reply
[+] [-] simlevesque|3 years ago|reply
[+] [-] detaro|3 years ago|reply