My son really was upset he missed the launch live, so we re-watched the video at breakfast and I noticed starting at 3:27 in the video a few seconds after MECO, and stage separation, you can see the first stage firing thruster till it goes out of frame around 3:34.

Now I am sure they use the thrusters to make sure they DO not repeat the stage collision from flight 3 of the Falcon 1 launch, but these firings were already after the stage was pretty clear of the second stage.

I am happy to see them using the thrusters, since it means they are doing 'something' with it, even if full recovery testing is not an option due to lack of reserve propellant. (SpaceX said they would not test recovery per se, on flight 2 and 3 of the F9 1.1, since they had booked full reserves to the customers).

I am curious if we know what they were testing. I would be happy to see that they are just exercising the thrusters to determine limits of control at different altitude densities. Every bit of data helps, and the ability to test on each launch means they learn faster.

Lousy screen grabs from said video:

Immediately after stage separation

Immediately after stage separation, (The right side of the split screen showed the M1-D Vac being exposed to space as the stages separated.) Oddly, looking at just the picture, the second stage is actually the object at the bottom in this view.

Second or two later, you can see the distances apart

A second or two later, you can see the stages separate from each other.

First firing from first stage

Then we have a visible thruster firing from the first stage.

Second firing from first stage

And another firing off to the right.

Third firing from first stage

And another this time, sort of down and to the left.

This one was pulsing

This one was hard to capture, but it pulsed its firing 3-4 times. The same direction as the previous one. Down and to the left.

An article at NASASpaceflight.com reported that:

The CASSIOPE mission also involved the first “boost back” test of the first stage, while sources note there was also a boost back test during the SES-8 mission, or at least the restart of the first stage post staging.

So sources (unidentified in the article) suggest something was tested. That is the info I am looking for in this question.

NasaSpaceflight.com thread suggests that they did use the ACS to test orienting the stage, but did not actually relight the engines.


1 Answer 1


From Elon Musk, via NasaSpaceFlight.

Musk indicated that SpaceX would not attempt to recover the first stage for the SES and Thaicom flights, instead “(for) the next two launches, we are going to gather data from the first stage but we are not going to attempt to recover it because we’ve committed to give the customers on the next two flights maximum performance of the rocket. The next recovery attempt for the first stage will be the fourth flight of this version.”

Bottom line is, if they tried anything, it was a very small attempt, and they won't try it completely until CRS-3 again. There are rumors that I've heard that there was an attempt to simply restart the engine multiple times, but that there was only a few seconds of fuel in the rockets. Not sure what else if anything there was today on the matter.

  • $\begingroup$ So that's side thrusters only on those pics? Looks like it... $\endgroup$
    – TildalWave
    Dec 5, 2013 at 22:05
  • $\begingroup$ As Elon stated, they might be trying to get a bit more data, but there was no serious attempt to recover the first stage. $\endgroup$
    – PearsonArtPhoto
    Dec 5, 2013 at 22:07
  • $\begingroup$ I know, but from the pics in the question, those burns all seem to be spread roughly 120° between them so to me it looks like ACS thrusters firing. They might have burnt the 1st stage to depletion but wouldn't ACS have its own tanks? $\endgroup$
    – TildalWave
    Dec 5, 2013 at 22:09
  • $\begingroup$ NasaSpaceflight.com claims 'sources' suggest that they did test 'something'. Be nice to see more info on that. (That is why I am not yet accepting this answer) $\endgroup$
    – geoffc
    Dec 8, 2013 at 18:09
  • 1
    $\begingroup$ @PearsonArtPhoto Well I can always hope 'sources' leak more info. :) $\endgroup$
    – geoffc
    Dec 8, 2013 at 18:11

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