After MECO, stage 1 of Falcon 9 does up to three engine burns: a boostback burn followed by a reentry burn followed by a final landing burn.

I'm interested here in the reentry burn. How high and how fast is stage 1 going when it begins the reentry burn? How high and how fast when it ends the burn? How long does the burn last?

  • $\begingroup$ See this flightclub.io-based answer which provides some pretty close simulations based on those SpaceX videos where we can also see this information for each launch. I think an answer to this question can pull a few screenshots and compile the numbers. $\endgroup$
    – uhoh
    Jan 15, 2021 at 23:44
  • 1
    $\begingroup$ Thanks, @uhoh! I'll check it out. I keep forgetting about flightclub. $\endgroup$
    – user36480
    Jan 15, 2021 at 23:46

1 Answer 1


If you search on YouTube "SpaceX NROL" then you get videos like this one

The video only contains first stage recordings.

When the engines start:

  • T + 6:30 min
  • 58.1 km
  • 4,757 km/h

When the engines stop:

  • T + 6:58 min
  • 31.1 km
  • 2,245 km/h

Then the speed increases until:

  • T + 7:12 min
  • 21.9 km
  • 2,495 km / h

Then the speed decreases from the friction with the more thick atmosphere until the landing burn starts at:

  • T + 7:47 min
  • 4.6 km
  • 1,102 km / h

Touchdown at T + 8:18 min

Similar question:

What is the return speed of the Falcon 9 booster?

  • $\begingroup$ Oh wow! Thank you, @JoeJobs! I've watched launch videos but hadn't noticed this info before. This is great. Thanks for sharing. $\endgroup$
    – user36480
    Jan 16, 2021 at 2:39

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