12
votes
Accepted
Why were three engines used for the F9 1st stage landing burn (BulgariaSat-1)?
Falcon 9 FT has demonstrated the ability to do a drone ship landing after launching a 5.3 ton payload into geosynchronous transfer orbit.
BulgariaSat-1 is only 3.7 tons, but was launched into a ...
- 172k
9
votes
Accepted
What is the extra moving and disappearing line in the animation in the BulgariaSat-1 webcast?
The blue line represents the part of the satellite's trajectory after it traveled once around the earth, so it's basically the continuation of the 2nd stage track (except that the payload will have ...
- 1,479
7
votes
Accepted
From which direction was the Falcon 9 1st stage's landing approach (BulgariaSat-1)?
The landing had tighter timing than usual (see Why were three engines used for the F9 1st stage landing burn (BulgariaSat-1)?), which means less room for corrections.
Elon Musk tweeted: Rocket was ...
- 12.6k
3
votes
What is the extra moving and disappearing line in the animation in the BulgariaSat-1 webcast?
That should be the projected future path on the second orbit. It looks like it is drawn relative to Earth surface (otherwise it would connect directly to current position of the second stage) and that ...
- 5,148
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