SpaceX F9 : Starlink v1.0 Flight 2 : January 6/7, 2020 : Discussion

[Steven Pietrobon]

Congratulations to SpaceX for the successful launch! Thanks also to Chris and NSF for providing their stream.

View of first stage separation that I missed capturing.

[matthewkantar]

Ah. I think they said "Space Force inaugural launch."

[tleski]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

[Phillipsturtles]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

I'm beginning to believe the tension rods/separation system is proprietary which is why the video cuts.

[Draggendrop]

Just for reference...

https://twitter.com/SpcPlcyOnline/status/1214369681412435968

Sounds like they’re enjoying their new name.

edit..forgot another quote..

We are live! Join us as we watch history in the making. First launch of US Space Force!

[John Alan]

Why is it so hard to catch the fairing? Is it the wind or something?

My guess is yes... wind

Go watch some early films of light slow airplanes trying to land on early aircraft carriers...


There is a learning curve is my guess... give em time... 

[su27k]

Just for reference...

https://twitter.com/SpcPlcyOnline/status/1214369681412435968

Sounds like they’re enjoying their new name.

edit..forgot another quote..

We are live! Join us as we watch history in the making. First launch of US Space Force!

I wish they'd word it differently, like "First launch supported by US Space Force", otherwise people may misunderstand that it is a launch for or by the Space Force while in reality it's a commercial launch of commercial satellites.

[luinil]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

I'm beginning to believe the tension rods/separation system is proprietary which is why the video cuts.

Same here, I just wish they would say it instead of saying "lets watching it live" and fake a transmission problem (if they are faking it, the possibility that it is a transmission problem remains but 3 time just a the moment of the release is strange)

[Zeitmas]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

I'm beginning to believe the tension rods/separation system is proprietary which is why the video cuts.

I had thought it was avoiding public outcry over releasing space junk. It is cool that you can see the tension rod floating away in this stream.

Quick thought, would it be too much risk to the deorbit burn to loosely tether them to S2 with a cord?

[Orbiter]

My shot of the launch. Two picture composite (one of some star trails I took an hour beforehand, and the launch itself).

[CorvusCorax]

Despite the slightly higher satellite deployment altitude, SpaceX appear to have performed essentially the same launch profile for their first two Starlink 1.0 missions. I can't split them.

Considering S2's thrust 2 weight ratio at the end of its first burn, the difference in orbits might be as little as burning only a split second longer to push apoapsis a bit higher - and the 2nd burn is so short, half of the delta-V seems to come from spool-up and spool-down residuals.

So the final orbit can differ quite a bit without any change to trajectory at all and miniscul changes to S2 burn time,

That's the advantage of doing a circularization burn, you have a lot of freedom to fly the most optimal insertion trajectory (which there is little reason to change)

if they were doing a single burn direct insertion, they'd have to fly steeper to end up higher, but then it's no longer  Hohmann transfer and more wasteful and might be less precise, too.

If there was a change in payload mass, we'd probably also see a change in trajectory, but I assume the changes in payload mass are too small to show between these flights.

[edkyle99]

This was the 48th Falcon 9 launch from SLC 40, not including the AMOS 6 accident.  Titan 3C/34D/4 flew 55 times from this site from 1965 to 2005.  Soon, probably this year, Falcon 9 will surpass the Titan numbers (after only a decade of service).  (Atlas 5 has long-surpassed Titan at SLC 41 - there've been 66 Atlas 5 launches versus only 27 for Titan 3C/3E/4.)

 - Ed Kyle

[Ronsmytheiii]

This was the 48th Falcon 9 launch from SLC 40, not including the AMOS 6 accident.  Titan 3C/34D/4 flew 55 times from this site from 1965 to 2005.  Soon, probably this year, Falcon 9 will surpass the Titan numbers (after only a decade of service).  (Atlas 5 has long-surpassed Titan at SLC 41 - there've been 66 Atlas 5 launches versus only 27 for Titan 3C/3E/4.)

 - Ed Kyle

And off topic but to round it up, Saturn I/IB launched 8 times from SLC-37, while Delta IV/Heavy has flown 32 times.

[thirtyone]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

Yeah, seriously, I'd rather they just say it's proprietary or whatever instead of saying the transmission cuts.

One final possibility, though - haven't all three Starlink launches so far been launched in exactly the same initial orbit? Is it possible that there really is a coverage blackout at exactly that point? Maybe someone could check the ground station callouts to get a sense if that's possible?

[gongora]

https://twitter.com/TSKelso/status/1214562257889136645

Latest @SpaceX ephemerides are available for 57 of the 60 latest #Starlink satellites, including STARLINK-1130 (DARKSAT): https://celestrak.com/NORAD/elements/supplemental/table.php?tleFile=starlink&title=Starlink&orbits=0&pointsPerRev=90&frame=1

[meberbs]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

Yeah, seriously, I'd rather they just say it's proprietary or whatever instead of saying the transmission cuts.

One final possibility, though - haven't all three Starlink launches so far been launched in exactly the same initial orbit? Is it possible that there really is a coverage blackout at exactly that point? Maybe someone could check the ground station callouts to get a sense if that's possible?

They haven't lost telemetry, there was a clear callout for confirmation of tension rod release during the video cutout, it is possible that the spinning of the stage puts the high data rate antenna out of position at the moment of deployment. I agree 3 times in a row is getting suspicious. It might really be due to unintended datalink issues, but it is not coincidence whether intentional or not.

What I would like to know (and if there was an explanation, I missed it) why do they wait 15 minutes between the final burn and separation? Typically this isn't immediate, as the stage does final checks and changes to the desired deployment orientation, but this seems unusually long, and has been consistent for each Starlink launch.

[AndrewRG10]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

Yeah, seriously, I'd rather they just say it's proprietary or whatever instead of saying the transmission cuts.

One final possibility, though - haven't all three Starlink launches so far been launched in exactly the same initial orbit? Is it possible that there really is a coverage blackout at exactly that point? Maybe someone could check the ground station callouts to get a sense if that's possible?

They haven't lost telemetry, there was a clear callout for confirmation of tension rod release during the video cutout, it is possible that the spinning of the stage puts the high data rate antenna out of position at the moment of deployment. I agree 3 times in a row is getting suspicious. It might really be due to unintended datalink issues, but it is not coincidence whether intentional or not.

What I would like to know (and if there was an explanation, I missed it) why do they wait 15 minutes between the final burn and separation? Typically this isn't immediate, as the stage does final checks and changes to the desired deployment orientation, but this seems unusually long, and has been consistent for each Starlink launch.

IIRC didn't they say on Starlink V0.9 they expect to lose video coverage due to going to a place with bad connection. I agree 15 minutes is quite long especially seeing how they've done it a lot now. I have a feelings it's done intentionally there to avoid having to intentionally cut feed and also hide deployment. Whether to hide company secrets, or avoid bad PR by releasing two bits of debris, I don't know.

[niwax]

It is interesting that this is the third time we have a loss of video exactly when deployment occurs.

Yeah, seriously, I'd rather they just say it's proprietary or whatever instead of saying the transmission cuts.

One final possibility, though - haven't all three Starlink launches so far been launched in exactly the same initial orbit? Is it possible that there really is a coverage blackout at exactly that point? Maybe someone could check the ground station callouts to get a sense if that's possible?

They haven't lost telemetry, there was a clear callout for confirmation of tension rod release during the video cutout, it is possible that the spinning of the stage puts the high data rate antenna out of position at the moment of deployment. I agree 3 times in a row is getting suspicious. It might really be due to unintended datalink issues, but it is not coincidence whether intentional or not.

What I would like to know (and if there was an explanation, I missed it) why do they wait 15 minutes between the final burn and separation? Typically this isn't immediate, as the stage does final checks and changes to the desired deployment orientation, but this seems unusually long, and has been consistent for each Starlink launch.

IIRC didn't they say on Starlink V0.9 they expect to lose video coverage due to going to a place with bad connection. I agree 15 minutes is quite long especially seeing how they've done it a lot now. I have a feelings it's done intentionally there to avoid having to intentionally cut feed and also hide deployment. Whether to hide company secrets, or avoid bad PR by releasing two bits of debris, I don't know.

I have wondered if it's IP protection. The strongest protection you can get for innovative stuff, often better than filing for a patent, is treating it as a trade secret. But that means actually keeping it secret or the protection vanishes. As the first mover, it may be desirable to do so.

As for the fifteen minutes between the burn and deployment, there's all sorts of stuff that needs to happen until the stack is spun up properly. The whole thing weighs over 20 tons, with 30 joints in a row at one end, sloshing fuel in the other and not a lot of maneuvering thrust.

[wannamoonbase]

As for the fifteen minutes between the burn and deployment, there's all sorts of stuff that needs to happen until the stack is spun up properly. The whole thing weighs over 20 tons, with 30 joints in a row at one end, sloshing fuel in the other and not a lot of maneuvering thrust.

Seems like something that can be trimmed back with time once they learn how these stacks fly.  Who's ever launched and deployed 60 birds like this at once.

I want to see if they reach a point where 60 out of 60 satellites work with each launch.

Dragon 2, Starship and Starlink, this is going to be a very exciting year to be watching SpaceX.

Edit: Any word or video on fairing recovery?

[Norm38]

Are we not expecting all 60 to work?
What yield are you expecting?