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Time-lapse video of a rocket launch seen from space (syfy.com)
341 points by slyall on Nov 23, 2018 | hide | past | favorite | 57 comments

Exactly what I came to the comments section to post. Huge pet peeve of mine is "articles" that are just a YouTube video with some redundant commentary underneath that offers zero value beyond the video itself.

In this case, though, I don't mind because Phil Plait is a well known science communicator whose articles actually add useful context. I don't mind that his article is linked (although I did go straight to the video first, but I am not the target audience for the commentary).

The article goes into a great deal of detail about how the video was made, the rocket involved, various points of interest throughout the video, etc... You don't think that adds any value?

Yeah but that’s not the case here though. The commentary is interesting IMO.

Pardon my extreme ignorance, but what is the greenish/yellowish band?

That's not ignorance, that's curiosity. And it's nothing to be ashamed of.

It is really hard to post a comment without being afraid of being ridiculed these days.

Reminds me of this video of the cameras on a booster during launch and reentry.


This one is incredible.

More timelapses from the Crew Earth Observation programs are available here, along the raw frames: https://eol.jsc.nasa.gov/BeyondThePhotography/CrewEarthObser... (remember to click in the map to find all the available videos at each region, there are a lot more than those of the landing page)

What are the red blinking lights that enter the view at 1:10 ? It seems huge.

From the video comments the author noticed these and tracked them down. They seem to be power lines and a huge wind generation project in China:

"I asked myself exactly the same thing when editing the video.

I spent several time on Google Earth and I found it's something around the city of Zalantun (Inner Mongolia); in all likelihood, the red lights are mounted on huge power-line trusses or wind turbines. For example, look at this coordinates for power-lines: 47.761390, 123.026970 And wind turbines here: 47.5641695, 122.9092991"


If you go to isstracker.com/historical and search for the time 2018-11-16 18:25:44+0000 you'll see the ISS right above this area. Pretty interesting.

There's a problem with the google maps API key for that website :/.

The wind farm theory others, including the author, have floated looks about right. Here's a video of a wind farm at night elsewhere: https://www.youtube.com/watch?v=bABhodyX2nY

That whole area was really brightly lit.

Amazing! Why does it look so much like computer graphics? I would't expect to see it like that with my own eyes.

Lack of ambient light and atmospheric attenuation. Significantly more direct light vs indirect light.

If you fly at 35,000 ft the horizon is at 221.3 miles and most of it is dense air. If you look directly downwards from ISS there is less than ten miles of thick atmosphere between the camera and the target.

If you do ray tracing from single light source with few objects and without effects that simulate atmosphere you simulate how the scene looks in vacuum.

I suspect also contributing is that the setting here is more like what you usually see with computer graphics than in real life. Very few moving parts.

In real life there are insects, and birds moving around. Wind blowing all sorts of things (leaves, blades of grass, trash, etc), etc. Individual strands of hair. Etc. All things we can't really reproduce with graphics.

Here there is just a sphere with a surface texture and some volumetric effects.

1) longer exposure, "averaging" neighboring pixels

2) noise reduction making it look "plasticky"

3) attempts to increase dynamic range with filters that favor certain color hues

That would be my list of possible explanations as a photographer.

I imagine the launch was timed so that this video could be taken. I doubt it’s just coincidence.

Or perhaps they’re launching so the vehicle will end up in orbit close to the ISS and not have to take so long, I believe they’re doing with this with manned launches so they can dock quite quickly.

They've been playing with quick launch-to-dock launches lately, so I doubt they did it just for the video.


> NASA confirmed on June 28 that if Progress MS-09 launches on July 9, it will attempt a super fast-tracked rendezvous with the Station, docking to the ISS just 3 hours (2 orbits) after launch - making it the fastest orbital rendezvous ever-attempted with the Station.

If I remember correctly, ISS makes a full circle of Earth every 90 minutes. Having planned the lift of with 45mins lag/difference would make it "so much" more difficult/challenging/risky to connect. And I guess every second counts when you're up there.

I've seen many videos of lift-offs etc (plus I'm huge Star Trek fan), but this one, made me hold my breath for a good 45 seconds (thank you yoga!)

The topic here is phasing. The two orbit approach requires exact alignment of orbital path and correct phasing, which both translate to an exact point in time when you need to launch the rocket (instantaneous launch window, i.e. when you delay by a second you need to scrub the launch). That window does not repeat every ~90 minutes (i.e. orbital period), since the ground track of the ISS moves West (relative to Earth‘s surface). It does repeat roughly every ~24hrs (not quite true and hence you cannot launch every day of the year), so you can re-attempt the next day only.

For the longer approaches, the rocket launches with an offset of several (tens of) minutes of that instantaneous launch window (that mostly means you have a launch window of several minutes, i.e. short delays do not abort your launch), so the spacecraft comes up significantly „in front of“ or „behind“ the ISS. As with the fast approach, the spacecraft will still not launch into the same orbit (i.e. mostly lower and more elliptical than the ISS orbit). But this is more important for the slow approach: Due to orbit dynamics, the difference in orbit will make you „catch“ up with the other space vehicle over time – this is what is called „phasing“. When you’ve aligned the phases, you raise/align the spacecraft’s orbit to the ISS and are thus very close and in final approach.

If your phase is not well aligned at orbit insertion (i.e. just after the launch), you need to do more and thus longer phasing. I.e. the bottom line is that you need a high precision launch, precise navigation sensors & enough computational power on the rocket and spacecraft to be able to do a fast approach in 2-3 orbits, plus the ISS orbit must align very well with your launch site at launch time. It is simply more complex and thus more risky as the slow approach, but then again you are faster if everything works out perfectly. The safer bet is the slow approach, though, as it gives you more margin and more time to fix any issues that arise.

Thank you for posting this.

Watching it elicited in me a sense of awe and wonder at both human ingenuity and the almost unimaginable scale of the universe.

I love coming across postings like this one on HN!

That is an amazing video, the way those cities roll away under the camera, at any point in time you are looking at a few hundred million people at the same time.

For me, that was hands-down the craziest part of this video. I've seen the numbers for the velocity of orbiting bodies, but seeing just how quickly the camera was moving - wow.

It is a time-lapse, so the video appears sped up compared to realtime.

Yeah, even though it's a time lapse, it conveys pretty well the fact that the ISS is going 5. miles. every. second.

If I left my home right now at that speed for San Francisco (~36 miles), I'd be ready to park in ~ 7 seconds.

Most of the universe operates at velocities and under conditions we can barely imagine.

Relevant xkcd, https://what-if.xkcd.com/58/

> Let's imagine what it would look like if you were speed-walking across the Earth's surface at 8 km/s.

> To get a better sense of the pace at which you're traveling, let's use the beat of a song to mark the passage of time.[9] suppose you started playing the 1988 song by The Proclaimers, I'm Gonna Be (500 Miles). That song is about 131.9 beats per minute, so imagine that with every beat of the song, you move forward more than two miles.

> In the time it took to sing the first line of the chorus, you could walk from the Statue of Liberty all the way to the Bronx.

Watching the earth from above like this always reminds me of what Carl Sagan used to say about it:

"It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known."

I think this is synonymous with the “overview effect”[0] that astronauts experience (or at least as close as one might get without being in space). If only we could send half of congress to space...

[0] https://en.m.wikipedia.org/wiki/Overview_effect

if it comes, the last day of our civilization with thousands of ICBM launching is going to look spectacular.

I was thinking the same thing when I saw the smoke plume. Imagine watching hundreds of those plumes litter the sky from above.

Iron Sky End Sequence tries to show how those plumes would look like. Although, there's only a handful of them. https://www.youtube.com/watch?v=zvtxFnG9pD8

Thanks, awe inspiring video!

>When you compress a gas it heats up, and eventually the compression is so violent that that air heats up enough to start vaporizing the booster.

I don't think this is an accurate description of what happens on re-entry.

Most of the heat does indeed come from compressing the air in front of the booster. The inverse of what happens when you use a compressed air can for a while and it gets very, very cold.

I don't know about vaporizing the booster though. It sure gets hot.

It actually is. People call it friction, but that’s not right. It’s adiabatic compression heating.

> It’s adiabatic compression heating.

If we're being pedantic (and I don't mean that pejoratively), this would have been more correct if you'd left out "adiabatic". If gasdynamic compression heating is being induced by a fast-moving body in the open atmosphere, it's not strictly adiabatic.

Is your disagreement with characterizing the air compression as "violent", or do you have a different understanding of what causes the heating during re-entry?

It’s pushing 10 gs or so. It is burning up.

Imagine what an observing alien species might be thinking as they watch this.

For some, "Cool!". For others, "What's the ETA on those impactors?".

I'd imagine it'd be like watching a moldy blueberry shoot a spore... "Whoa, thats pretty cool but I better toss this thing in the garbage before someone gets sick."

0:49 Something that we won't see for SpaceX rockets.


Except of course, on failures of the launch or a purposeful non-recoverable mission

Of course its just a dot most of the time. Unlike every sci-fi movie / tv show.

Well, in sci-fi movies/tv-shows they're supposed to be closer.

If the ISS was much closer (which happens, when the crew finally connects), it wouldn't be a dot.

No crew in this one, it is a Progress [1] freighter.

[1] https://en.wikipedia.org/wiki/Progress_(spacecraft)

Fortunately, videos like this getting visibility means it's more likely next sci-fi movies/shows will make more realistic shots.

It was the most inspiring light dot I've seen, I didn't expect I'd watch in awe a light dot today.

This is absolutely beautiful, it's exactly what I needed to see tonight.

Dear lord, awe inspiring.

Where are the turtles?

They're all the way down

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