Two flights of a single stage of Falcon 9 on one video / SurprizingFacts

An interesting visual comparison has already been done on YouTube, combining in one frame both flights of the first stage Falcon 9, which last week made the second flight


It is interesting to look at the differences in the video:

First, there is a difference in the trajectories – the launch from Dragon CRS-8 was performed on the ISS, and from SES-10 to the geo-transfer orbit. In the latter case, because of the insertion into an intermediate orbit with an 18-minute pause between the first and second inclusion of the second stage, the trajectory turns out to be more shallow, so in the start with SES-10 the speed increases faster and the height slower.
Secondly, the shutdown of the engines of the first stage in the case of SES-10 occurred about four seconds later. Most likely, this is due to the fact that the over-caliber fairing experiences increased aerodynamic loads, and at the maximum speed head (Max-Q), the thrust of the first-stage engines decreases more strongly or for a longer time. UPD : in the comments in LJ found an analysis with Reddit, and on it, on the contrary, missions with the Dragon, including CRS-8, reduce traction for a longer time, and according to the scheme it turns out that the step with SES-10 simply ran longer, and more fuel remained in the tanks at the start of the CRS-8.
Thirdly, from a flat trajectory it would be logical to expect an earlier landing, but here in the case of SES-10, the level of the village is about ten seconds later than the CRS-8. Here everything rests on concrete inhibition algorithms, and, without an exact knowledge of the flight parameters, it is difficult to say why it happened.

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