In the soaring community, we sometimes refer to the Shuttle as the world's highest performance motorglider. The power-off glide ratio is absolutely atrocious, though.
I feel like the rotation clamp was too firm, and perhaps the camera could have had a mass on a torque arm to give it more angular inertia. This was SUPER distracting early in the presentation before the presenter was scaled down.
This was great! I love coming across great, short talks like this that elaborate on a very interesting problem that laypeople like myself would never otherwise have even known existed.
What surprised me the most, the difference between being in orbit and starting to reenter is only 362 km/h but it takes a three minute burn to decelerate which I guess is a 0.5mv² thing with big m and huge v.
EDIT: My intuition was wrong, this has nothing to do with a large kinetic energy due to a large velocity.
The reentry burn is done with the teeny little OMS engines rather than the big main engines. If you look at the back of the Shuttle (such as https://i0.wp.com/amazingstoriesmag.com/wp-content/uploads/2...), the OMS engines are the two little ones in the upper corners. Once you're in orbit, there's usually no hurry to make changes, so you don't need much acceleration. For getting to orbit, you want to stop fighting gravity as fast as possible, so powerful engines are a must.
Tiny is pretty relative [1]. I expected them to be more powerful and - mistakenly - thought the small acceleration is due to the large kinetic energy due to the large velocity.
Right, rockets provide the same acceleration regardless of speed, since there's no way for the engine to "know" how fast the vehicle is moving. Acceleration is basically exhaust velocity times mass flow divided by vehicle mass.
With an 84cm diameter and weighing about 200 pounds, I'm OK calling them "tiny."
I missed that, I only looked at the image and there it looks way more massive and larger than what the dimensions table says. Even taking into account that the image depicts an entire stage and not just the engine, 0.84 m and 100 kg is a lot less than I would have expected or guessed based on the image.
Agreed. I first saw the image and thought wow, that really is big. Then I saw the specs.
I guess it's misleading because the engine is much closer to the camera than the background, but nothing makes that obvious. There's a tiny little person behind it, and if you don't realize the perspective difference, that would look like the engine is pretty huge.
Rocket exhaust starts with the same velocity as the shuttle which makes the v^2 part of that equation less meaningful. They use a much smaller engines to among other things add precision.
Just realized that myself by doing the actual calculations, the Space Shuttle would need the same three minutes to come to halt from 362 km/h. In comparison, a Bugatti Veyron will do that in less than 10 seconds. So the OMS Engine are really not that powerful, at least relative to the mass of the Space Shuttle.
If I wanted to make a presentation like that what tools would I need to use? That was way more engaging than a powerpoint presentation. It almost seems like an animated video that pauses itself rather than a slideshow.
He lists the tools he used in the YouTube description of the video:
"All real-life photos and videos (except the last slide) were produced by NASA. Everything that looks hand-drawn was done by me on a Wacom Intuos Pro tablet in ArtRage. Animations were done in After Effects. Between the concept, outline, script, artwork, animations, rehearsals, and editing, I spent somewhere around 200 hours over two months working on it."
It really is just a series of animations. It's basically a time lapse of drawing. You can look at how Henry from MinutePhysics does his videos[1] (and if you like how this presentation is done, I highly recommend looking into MinutePhysics). These were probably done in something similar to flash. For open source programs, I'd probably look at Synfig[2] or Pencil2D[3].
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[ 2.5 ms ] story [ 48.2 ms ] threadEDIT: My intuition was wrong, this has nothing to do with a large kinetic energy due to a large velocity.
[1] https://en.wikipedia.org/wiki/AJ10
With an 84cm diameter and weighing about 200 pounds, I'm OK calling them "tiny."
I guess it's misleading because the engine is much closer to the camera than the background, but nothing makes that obvious. There's a tiny little person behind it, and if you don't realize the perspective difference, that would look like the engine is pretty huge.
"All real-life photos and videos (except the last slide) were produced by NASA. Everything that looks hand-drawn was done by me on a Wacom Intuos Pro tablet in ArtRage. Animations were done in After Effects. Between the concept, outline, script, artwork, animations, rehearsals, and editing, I spent somewhere around 200 hours over two months working on it."
[1] https://www.youtube.com/watch?v=GhZ3naSgJg4 [2] http://synfig.org/ [3] https://www.pencil2d.org/