SpaceX F9: Starlink v1 Flight 1 : November 11, 2019 - DISCUSSION

[old_geez]

Does anyone have a mass to orbit vs mass expended vs mass recovered ration for this mission?

[niwax]

Does anyone have a mass to orbit vs mass expended vs mass recovered ration for this mission?

My estimation:
Total launch mass: 579.4t

of which

Fuel: 530.2t
Payload: 15.6t

Reused: 29.1t
New: 4.5t

Recovered: 27.2t
Expended: 6.4t

Assuming they don't retrieve the fairings.

[exilon]

There's something quite satisfying about the authoritative engine gimbal to straighten the booster right before touchdown. 

[edzieba]

Both the (looking down at the plume) and the (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

[ugordan]

Both the webcast (looking down at the plume) and the USLR tracking cam (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

Nothing really out of the ordinary for F9 nor, for that matter, other rockets.

[vanoord]

2. There were several landings throughout 2016 and 2017 which didn't have an Octagrabber but the booster never fell over in those landings. Heck even Iridium-7 with one of the harshest seas on landing, had no Octagrabber but returned fine and that booster flew again for the fourth time today.

Excluding this launch, there have been 25 successful ASDS landings with the Octagrabber used 11 times - so 14 times that it hasn't been used (7 on each droneship).

[Zed_Noir]

Is there any update from SpaceX about fishing the payload fairing halves out of the water like the fairings' previous flight on the Arabsat-6A mission?

[scr00chy]

Is there any update from SpaceX about fishing the payload fairing halves out of the water like the fairings' previous flight on the Arabsat-6A mission?

Both ships were recalled to port hours before the launch so there was no way to fish the fairings out. SpaceX saying they'd try was some kind of miscommunication, I guess.

[Danderman]

These satellites were injected into a 280 km parking orbit, compared to 350 km for the previous mission, or is my memory failing me?

The slightly lower injection orbit might account for additional payload capability.

[erv]

And also less time to decay for [potentially] malfunctioning ones and less interference with other LEO stuff.

[Lars-J]

Both the webcast (looking down at the plume) and the USLR tracking cam (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

This is normal, F9 usually flies at a slight angle of attack on purpose near the end of the stage 1 flight, presumably to take advantage of some slight aerodynamic lift.

[ugordan]

Both the webcast (looking down at the plume) and the USLR tracking cam (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

This is normal, F9 usually flies at a slight angle of attack on purpose near the end of the stage 1 flight, presumably to take advantage of some slight aerodynamic lift.

There's no useful aerodynamic lift at that point, it's purely for trajectory optimizing purposes.

[sevenperforce]

Both the webcast (looking down at the plume) and the USLR tracking cam (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

This is normal, F9 usually flies at a slight angle of attack on purpose near the end of the stage 1 flight, presumably to take advantage of some slight aerodynamic lift.

Residual from the powered change to the landing spot. The stage has to translate over to land on the surface.

[ZachS09]

Have there been any TLEs recorded for the Starlink sats?

[rsdavis9]

Have there been any TLEs recorded for the Starlink sats?

From heavens above

1 70003U 19999A   19315.62222222  .00000000  00000-0  00000-0 0    09
2 70003 053.0000 171.4040 0001502 047.3044 323.7123 15.97988880    01

Maybe newer ones on other sites.

[abaddon]

There's no useful aerodynamic lift at that point, it's purely for trajectory optimizing purposes.

Then why not just point in the direction you want to go?

[gongora]

Have there been any TLEs recorded for the Starlink sats?

From heavens above

1 70003U 19999A   19315.62222222  .00000000  00000-0  00000-0 0    09
2 70003 053.0000 171.4040 0001502 047.3044 323.7123 15.97988880    01

Maybe newer ones on other sites.

The stuff on Heavens Above is a pre-launch guess (although it works pretty good).

[AC in NC]

There's no useful aerodynamic lift at that point, it's purely for trajectory optimizing purposes.

Then why not just point in the direction you want to go?

Trajectory optimization is "the direction you want to go".

[ugordan]

Both the webcast (looking down at the plume) and the USLR tracking cam (compare rocket body angle to plume trail angle. Ignore the 'glow' portion, look at the longer gas trail) show the stage ending the burn at an extremely jaunty angle.

This is normal, F9 usually flies at a slight angle of attack on purpose near the end of the stage 1 flight, presumably to take advantage of some slight aerodynamic lift.

Residual from the powered change to the landing spot. The stage has to translate over to land on the surface.

Huh. I assume that's the same reason for example this Delta II can be seen flying at a significant AoA at 0:56 in the video?

[envy887]

There's no useful aerodynamic lift at that point, it's purely for trajectory optimizing purposes.

Then why not just point in the direction you want to go?

The nice thing about being outside the sensible atmosphere is that you can point your thrust in the direction you want to go, but you can point the rocket itself in other directions.

For instance, if you want to thrust purely horizontally without gravity pulling the nose of the rocket down below the horizon, you point the thrust horizontal and the nose slightly up, offsetting the thrust vector from the CG by the exact amount that gravity is pulling down on the CG. This eliminates gravity losses for that part of the trajectory, since all the the thrust is going to horizontal acceleration and none of ti is fighting gravity directly.