Comments and questions about the
APOD on the main view screen.
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Aleksander Trębacz
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by Aleksander Trębacz » Sat Jan 20, 2024 12:46 pm
Isn't this photo upside down?
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johnnydeep
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by johnnydeep » Sat Jan 20, 2024 6:07 pm
I have no idea what I'm looking at here. This captures the pair of booster burns during launch while still attached to the core stage, right? I can't get the orientation to make sense.
EDIT: ok, I got that exactly wrong. It depicts the booster separation and subsequent burn to bring them down for landing. But I still can't make sense of the orientation! But perhaps the image linked to - with the strange loop - combined with a view from far away, in which higher up equates to appearing "lower down" (due to being so high and even farther away) sort of explains things? :
Last edited by
johnnydeep on Sat Jan 20, 2024 11:13 pm, edited 3 times in total.
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
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SeedsofEarfth
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by SeedsofEarfth » Sat Jan 20, 2024 10:19 pm
Looks upside down. How can rockets fall and then shoot back up into the sky?
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JimB
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by JimB » Sun Jan 21, 2024 9:26 am
SeedsofEarfth wrote: ↑Sat Jan 20, 2024 10:19 pm
Looks upside down. How can rockets fall and then shoot back up into the sky?
It makes more sense if the camera is pointing more or less overhead tilted, with the launch site to the top left of the frame. The white fluffy trails are where there is side thrust to control booster orientation as it turns over (don't forget they are still probably travelling upward at this stage). Then the two boosters start to arc back in the direction of the launch site, while the next stage continues on up in the bottom right of the frame.
It might be easier to lie on the floor and imagine the image projected onto the ceiling.
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johnnydeep
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by johnnydeep » Sun Jan 21, 2024 2:51 pm
JimB wrote: ↑Sun Jan 21, 2024 9:26 am
SeedsofEarfth wrote: ↑Sat Jan 20, 2024 10:19 pm
Looks upside down. How can rockets fall and then shoot back up into the sky?
It makes more sense if the camera is pointing more or less overhead tilted, with the launch site to the top left of the frame. The white fluffy trails are where there is side thrust to control booster orientation as it turns over (don't forget they are still probably travelling upward at this stage). Then the two boosters start to arc back in the direction of the launch site, while the next stage continues on up in the bottom right of the frame.
It might be easier to lie on the floor and imagine the image projected onto the ceiling.
Hmm. So the "booster burn ends" point is where the boosters have landed?
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
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rSherwood
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by rSherwood » Sun Jan 21, 2024 8:47 pm
At the "boostback burn ends" point, the boosters are still at high elevation. Booster separation occurred shortly after the rocket entered the picture frame at upper left when it was above most of the atmosphere. The launch pad was way beyond the top left corner of the picture; it could have only been shown with an extremely wide-angle lens. After the boostback burn ended, the boosters were in free-fall, unseen as they traveled down, off the top of the image back toward the launch pad. They reentered the atmosphere at supersonic speed, and a second burn, the reentry burn, reduced their velocity. After additional free-fall, a third burn slowed the boosters to landing velocity. The APOD image shown neither of these later two burns.
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johnnydeep
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by johnnydeep » Sun Jan 21, 2024 10:42 pm
rSherwood wrote: ↑Sun Jan 21, 2024 8:47 pm
At the "boostback burn ends" point, the boosters are still at high elevation. Booster separation occurred shortly after the rocket entered the picture frame at upper left when it was above most of the atmosphere. The launch pad was way beyond the top left corner of the picture; it could have only been shown with an extremely wide-angle lens. After the boostback burn ended, the boosters were in free-fall, unseen as they traveled down, off the top of the image back toward the launch pad. They reentered the atmosphere at supersonic speed, and a second burn, the reentry burn, reduced their velocity. After additional free-fall, a third burn slowed the boosters to landing velocity. The APOD image shown neither of these later two burns.
Thanks. Makes a lot more sense now.
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}