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APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sat Jan 20, 2024 5:05 am
by APOD Robot
Falcon Heavy Boostback Burn
Explanation: The December 28 night launch of a
Falcon Heavy rocket from Kennedy Space Center in Florida marked the fifth launch for the rocket's reusable side boosters. About 2 minutes 20 seconds into the flight, the two side boosters separated from the rocket's core stage. Starting just after booster separation, this three minute long exposure captures the pair's remarkable
boostback burns, maneuvers executed prior to their return to
landing zones on planet Earth. While no attempt was made to recover the Falcon Heavy's core stage, both side boosters landed successfully and
can be flown again. The four previous flights for these side boosters included last October's launch of NASA's
asteroid-bound Psyche mission.
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sat Jan 20, 2024 12:46 pm
by Aleksander Trębacz
Isn't this photo upside down?
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sat Jan 20, 2024 6:07 pm
by johnnydeep
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? :
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sat Jan 20, 2024 10:19 pm
by SeedsofEarfth
Looks upside down. How can rockets fall and then shoot back up into the sky?
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sun Jan 21, 2024 9:26 am
by JimB
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.
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sun Jan 21, 2024 2:51 pm
by johnnydeep
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?
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sun Jan 21, 2024 8:47 pm
by rSherwood
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.
Re: APOD: Falcon Heavy Boostback Burn (2024 Jan 20)
Posted: Sun Jan 21, 2024 10:42 pm
by johnnydeep
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.
