Astronomy Picture of the Day - 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. Their next planned flight is on the Europa Clipper mission scheduled for launch in October 2024.

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For more detail go to the link and click on the image for a high definition image. You can then move the magnifying glass cursor then click to zoom in and click again to zoom out. When zoomed in you can scan by moving the side bars on the bottom and right side of the image.

Pretty cool, but it seems to be upside down, if one assumes gravity should point down.

Flip it around and you see:
The stack entering from bottom left corner.
Burnout and separation of the two side boosters which continue to coast upwards for a while.
The side boosters initiate boost-back burn and turn back towards Earth.
Core booster keeps burning through all this and exits top center right.

All of this action is highlighted by being in sunlight while the foreground atmosphere is in darkness and thus transparent.

Really beautiful.

Pretty cool, but it seems to be upside down, if one assumes gravity should point down.

The photo is not inverted, because while gravity indeed points down, the initial part of the boostback trajectory is up.

Look at the the thin line coming down from the upper left- that's the trace of the main vehicle. You can find it down in the lower right as well.

It's a problem of perspective: the rocket stack is going slightly up and mostly away from the observer. In this case, from the perspective the photo was taken and due to the rockets' motion (mostly lateral/orbital at this phase), it's the away that's more important- as the vehicle goes downrange, it's going from upper left to lower right, with the translational (horizontal) element showing up more than the vertical, which is 'stacked' on itself and therefore foreshortened, in addition to already being the minor component.

Phrased differently, the big blossomy blue clouds of rocket exhuast are laid down almost horizontally: the vehicle has done almost all of the climbing it needs to, and is now 'focused' on gaining horizontal speed in order to achieve orbit. The trajectory in the photo is 'down' because moving horizontally away from the observer necessarily means moving down toward the horizon.

Finally, the initial boostback maneuver for the boosters is actually up from the vehicle trajectory, which is exactly what we see in the photo. Perhaps this will help:

The photo would've been taken from somewhere off to the left of the above diagram...

There’s technically correct, and then there is human perception.

Upside down or not boils down to perception and how we read information. Most people perceive rockets as going generally UP. Which means in a time lapse photo of a rocket, the flow of time is generally assumed to proceed from bottom to top, or alternatively from left to right.

Those who learned Hebrew as a first language may have different perceptions, I don’t know. My Jewish friend only learned Hebrew late in life, so I can’t go by him.

There’s technically correct, and then there is human perception.

Upside down or not boils down to perception and how we read information. Most people perceive rockets as going generally UP. Which means in a time lapse photo of a rocket, the flow of time is generally assumed to proceed from bottom to top, or alternatively from left to right.

Looking at the photo, when the rockets go up in the photo is when they're going up in reality as well.

And that's my point- the photo does, in fact, match intuitive human perception.

There's simply no need to construct some 'understanding' of the photo inverted, and in doing so you've actually "explained" a trajectory that doesn't exist:

Flip it around and you see:

The stack entering from bottom left corner. Not what an observer on the ground is seeing...
Burnout and separation of the two side boosters which continue to coast upwards for a while. They're moving horizontally and then actively change direction under thrust to upwards
The side boosters initiate boost-back burn and turn back towards Earth. The boostback burn boosts them upward and turns them slightly back along the horizontal trajectory (thus the name!); the turn back toward Earth is simply due to gravity. Put another way, the boostback burn and associated change of direction have already been completed before the change of direction you're describing, which is a subsequent event.
Core booster keeps burning through all this and exits top center right.But is no longer climbing, nor has it been doing so noticeably at any point during the processes documented in the photo... it's flying virtually horizontally, whereas you're implying it's climbing, when it simply isn't.

I truly mean you no offense, but you're entire explanation of the photo is simply wrong. Which is why it requires a change of perspective.

Or to put it another way: you're explaining from the perspective that the main payload and booster are mainly climbing in this photo, or as you put it 'people perceive rockets as generally going UP'.
But they simply aren't. Their trajectory is already virtually the same as that of orbit: parallel to the ground, not 'UP.'

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