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#100
by
Jansen
on 20 Jan, 2021 13:01
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Acquisition of signal Tasmania
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#101
by
RocketLover0119
on 20 Jan, 2021 13:07
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Starlink deploy confirmed! Another 60 happy sats on their way.
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#102
by
Jansen
on 20 Jan, 2021 13:09
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Successful payload deployment just SE of Australia
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#103
by
FutureSpaceTourist
on 20 Jan, 2021 13:09
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#104
by
eeergo
on 20 Jan, 2021 13:09
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Deployment of the 60 spacecraft.
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#105
by
zubenelgenubi
on 20 Jan, 2021 13:15
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Some observations leading to satellites deployment:
Solid oxygen "flower" grown on a second stage valve.
"Tiny" Moon passing through camera view as the stage rotated on its pitch axis.
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#106
by
FutureSpaceTourist
on 20 Jan, 2021 13:40
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twitter.com/nextspaceflight/status/1351900535738142721
With today's launch, Falcon 9 now has the highest number of consecutive fully successful missions of any active orbital-class rocket. Falcon's 77 consecutive successes in a row move it ahead of Atlas V by one mission.
https://twitter.com/nextspaceflight/status/1351901482501763074This tally does include Crew Dragon's Inflight Abort Test, which is a debatable inclusion due to the suborbital nature of the flight. I include it as it utilized a very close to standard Falcon 9. However, if you disagree with it, just wait a few days.
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#107
by
FutureSpaceTourist
on 20 Jan, 2021 13:48
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SpaceX launch photo by Ben Cooper
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#108
by
FutureSpaceTourist
on 20 Jan, 2021 14:32
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#109
by
scr00chy
on 20 Jan, 2021 15:27
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This launch also marked the shortest time between JRTI landings at 12 days.
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#110
by
zaitcev
on 20 Jan, 2021 16:32
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In the mission video for Starlink L16 it was plainly noticeable that the rocket dialed a significant angle of attack after MaxQ, which continued almost until the separation. The most obvious confirmation that it wasn't just an artifact of the view from the ground came when the booster straightened itself out right before the separation. You can see Earth moving in the background together with the plume becoming symmetric.
Anyone has a good guess what this strange maneuver is for?
The screencaps show the visible angle between the exhaust and the rocket body and the 2 back-to-back captures before and after the moment when the rocket straightened up ahead of the MECO.
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#111
by
zaitcev
on 20 Jan, 2021 16:37
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My personal guess is that one of the Merlins did not come out of the lower throttle setting after MaxQ. The rest of them tilted to compensate. The engine continued to operate at reduced thrust until MECO. As other 8 engines started to throttle down ahead of MECO, their thrust equated that of the underperforming engine and the rocket straightened out.
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#112
by
the_other_Doug
on 20 Jan, 2021 16:40
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Whereas I would guess it's due to upper level winds. Or a programmed lofting of the trajectory just before MECO, perhaps to shape the F9 first stage's recovery trajectory.
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#113
by
soltasto
on 20 Jan, 2021 16:48
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This happens most of the times, especially for mission with ADSD landings.
My guess is that they take advantage of the little available lift to compensate a bit of gravity losses
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#114
by
zaitcev
on 20 Jan, 2021 16:52
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Thanks. I also thought that the direction of the tilt seemed suspiciously convenient.
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#115
by
ugordan
on 20 Jan, 2021 17:05
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F9 is far from the only rocket that does this, see a very obvious case of Delta II:
That one only had 3 solids so the trajectory shaping was very obvious.
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#116
by
ZachS09
on 20 Jan, 2021 17:16
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#117
by
wannamoonbase
on 20 Jan, 2021 19:59
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Thanks. I also thought that the direction of the tilt seemed suspiciously convenient.
I noticed it too and thought it was the camera angle. Interesting to know that they can be that flexible on using the vehicle's body. Pretty cool.
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#118
by
vaporcobra
on 20 Jan, 2021 20:59
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LauncherOne was an extreme example but it also just demonstrated the use of a high-alpha maneuver to generate vertical lift.
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#119
by
zaitcev
on 20 Jan, 2021 21:04
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I noticed it too and thought it was the camera angle.
We can see how the attitude changes a few seconds before MECO, and the plume shape changes with it. So it's most definitely not just the camera. But as others mentioned, this sort of thing is rather common. I just wish to know what the benefit is.
Regarding the interaction with the relative wind, I thought it odd that the program calls for the rocket to tilt to a set angle, stay like that for a good minute, then abruptly return to centered attitude before MECO. If this were an airplane, the angle of attack would be changing gradually according to the airspeed and thickness of the atmosphere.
