The big news yesterday and today is that SpaceX had a successful launch, payload delivery, and landing of the Falcon 9 stage 1 rocket. My question is, where is the second stage of Falcon 9 now, and where will it ultimately end up? I read on Wikipedia that SpaceX would like to be able to land all stages of the spacecraft, but I'm having a hard time discovering what happened (or what will happen) to stage two of Falcon 9's flight 20? Is it supposed to land vertically as well, or parachute into the ocean at some point (or did it already)? Is it a big deal either way what happens to stage two after successful payload delivery?

Note to flaggers, this is not a dupe of this question, as I am asking what actually happened, not for all the different possibilities.

up vote 24 down vote accepted

The second stage performed an engine relight test and re-entered over the Indian Ocean about an hour after launch. Below is the reentry region defined by a NOTAM (Notice to Airmen).

Relighting the second stage is an important step in launching satellites to geostationary orbit, so their successful test is promising.

The payload penalty to recover the second stage turned out to be more than they initially expected, and as such, SpaceX has given up on second stage recovery for the Falcon 9 booster.

The problem is, the first stage is only 160K up, Mach 5 or so which is very fast and high, but the second stage is basically orbital, which is much higher (maybe) and faster. Which means it needs to return all the way from orbit, which is much trickier. Need a heat shield, and more fuel/oxidizer to get back to the launch site (or really anywhere under control).

SpaceX has hinted that their next major booster (BFR/MCT not Falcon Heavy) will have second stage recovery, since that is meant to be their Mars booster, and they intend to recover the entire vehicle.

There is a really fun discussion of the math of second stage recovery on Reddit that is worth reading.

  • 3
    The first stage hit a top speed of 4.8 Mach – kim holder Dec 22 '15 at 17:46
  • Thanks for your response. Could you expand your answer to include what happened (what they decided to do instead) since second stage recovery was not possible? – n00b Dec 22 '15 at 17:54
  • 7
    What rocket launches have been doing for decades, crash it into the ocean. – Kaz Dec 22 '15 at 18:32

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