# Have astronauts seen Starlink trains?

Starlink satellites move in the same altitude region as the ISS (on their way up and eventually back down) and are particularly noticeable for weeks after deployment as "trains".

Have one of these trains been spotted by astronauts on the ISS?

Considering the potential vantage point in Earth's shadow looking towards the direction where the Sun has just set or will soon rise, it's seems like this is inevitable.

• OscarSmith I think the geometry can work; the ISS could be in Earth's shadow and easily see LEO objects if they were bright enough, and they have several flat reflective surfaces that these days are oriented during raising to avoid reflecting towards Earth so no need to view them overhead for them to be bright necessarily. I have a hunch that SpaceX could even choreograph a light show for ISS specifically using synchronized attitude controls if they wanted to. – uhoh May 7 '20 at 3:50
• Out of curiosity: have you tried to google "starlink iss" (a.k.a "show any research effort") just to see pictures of starlink satellites taken from ISS-astronauts ;-) ? – CallMeTom May 7 '20 at 4:23
• I wrote a quick answer, but indeed a simple Google search would have provided OP with an answer ;) – yzokras May 7 '20 at 7:22
• I have a vid recorded from the ISS Live stream HD camera on a dawn that is most likely one of the starlink trains passing by. I tracked both and their position was exactly what I saw. About 30 km away (highest ISS 30 km). My only question would be whether it could be the starlink by the distance. – Apaiss May 22 '20 at 4:35
• @Apaiss if you can post all the relevant information which is mostly the time that the video represents and a screen shot, that can be checked based on the TLEs of the ISS and satellites. But if you don't know the time that the ISS Live stream was being generated, then it probably can't be checked. – uhoh May 22 '20 at 4:54

## 2 Answers

Yes, it happened at least on 13th April 2020 at 21:25:02 UTC:

The image above (image ISS062-E-148365, original at high resolution here) was shot from the International Space Station (ISS) on 13 April 2020, 21:25:02 UT. It shows the Aurora Australis (southern lights) and a train of SpaceX Starlink satellites.

The presence of the Starlink train in this image was first noted by Twitter user Riccardo Rossi (@RikyUnreal) and brought to my attention by Huub Eggen (@phi48). It is present in two earlier images as well, taken the preceeding minute (images ISS062-E-148363 and ISS062-E-148364).

ISS was at 48.25 S, 81.03 E and 440 km altitude at the time the photo above was taken. With this information, I came to the following probable satellite ID's (annotations in image below) for the objects in the imaged "train": these are all objects from the 17 February 2020 launch ("Starlink 4").

• +1 Thanks! I like the 2nd image in the blog post showing the tentative identifications. We can probably call these Starlinks because "if not, what else?" but it's better to see that their apparent position and time corresponds with known TLE data. – uhoh May 7 '20 at 7:32
• This is by far the most epic photograph of a Starlink train. – Everyday Astronaut May 7 '20 at 13:38

Have astronauts seen Starlink trains?

## Technically, No.

Of course @X's affirmative answer is basically right, but viewed from Space at 17500 MPH things move differently.

Since the ISS is moving just as fast as they are and in a different direction, the apparent motion of the satellites is oblique to the orbit they travel on.

Seen this way it's not a "train" with each satellite as a car moving (roughly) along the same track, but instead looks more like echelon formation flying.

See also here

Cropped and rotated NASA photo ID: ISS062-E-148365 from here

Example: USAF Fighter School Acrojets demonstration team - 1950, flying in echelon formation Source

• I had to re-read the answer. I think this answer might give people [who are reading in haste] the wrong idea that you're dismissing that orbital photograph as a formation-flying squadron of jets. Could you reword it? (P.S. I'm not the downvoter :) – William R. Ebenezer May 7 '20 at 16:49
• @WilliamR.Ebenezer I don't know how to write for people who are reading in haste any better than this; the first sentence says the other answer is basically right, the second sentence "the apparent motion of the satellites is oblique to the orbit they travel on" calls the satellites satellites. I will make the image illustrating the echelon formation smaller. – uhoh May 7 '20 at 20:34
• Much better! :) – William R. Ebenezer May 8 '20 at 1:56
• @WilliamR.Ebenezer thanks! Please feel free to edit further, sometimes I don't have a good feel for how things look to other readers, especially the "hasty" ones ;-) – uhoh May 8 '20 at 3:06
• ... so if you cross a bridge over a train track while the train is passing under the bridge, you don't see a train, because your relative motion stops it from being one. Right. – user20636 May 8 '20 at 9:51