SpaceX Falcon 9 : GovSat-1 (SES-16) : Jan 31. 2018 - Discussion

[RocketLover0119]

Per ken kremers photos released of the booster vertical on the pad, this booster has the soot like CRS 13, should be fun seeing where the landing legs were. (Pics in FH update thread)

[Johnnyhinbos]

While SES-16’s weight compared to other SES satellites would likely allow SpaceX to recover the booster on the Of Course I Still Love You drone ship, SpaceX will likely use the expendable nature of this booster to test landing and atmospheric entry techniques while ditching the booster in the Atlantic in an effort to clear out the Block 3 Falcon 9 stock in favor of the currently operational Block 4s and soon-to-be-operational Block 5s.

Did anyone else get that cognitive dissonance where the thoughts "of course boosters end up in the ocean" and "hey, stop littering!" start competing for headspace?

no, because it is insignificant

If I throw a coke can in then that's insignificant as well but I expect to be judged harshly for it.
In the case of aerospace, whether insignificant or not, there is a leadership aspect to throwing things in the ocean that shouldn't be dismissed out of hand.
You shouldn't expect non engineers to have reached your level of enlightenment and that can be a good thing as well as a bad thing.

Ironically (considering my background) tossing spent boosters in the ocean may not be a terrible thing for the marine environment. I’ve been involved with some studies of man-made (deliberately or not) fish aggregation devices (FAD), and the large, partially destroyed, cylinder of a booster resting on the bottom could work nicely as a FAD. Provided it’s not leaching caustic substances of course.

Now, tossing away a booster instead of reusing it has become reprehensible to me - which I love because it indicates there’s now an alternative...

[ZachS09]

Since the first stage is being expended, and considering that SES-16/GovSat 1 is 4,000 kilograms, is it possible for the second stage to inject the payload into a supersynchronous transfer orbit?

If yes, then I'm assuming the apogee would range from 55,000 to 60,000 kilometers.

[Elthiryel]

Yes, this is definitely possible and I expect an orbit of GovSat-1 to be supersynchronous. They have done it before, even when the first stage landed (or tried to land, at least). Such data for previous SpaceX GTO missions can be found within /r/spacex wiki/FAQ:
https://www.reddit.com/r/spacex/wiki/launches/gto_performance

[Ben the Space Brit]

Given the range weather reports, I'm just waiting for the official confirmation of a slip to Wednesday.

That aside, with regard to the recovery ships heading out, seemingly for the SES-16 launch: Are they also used as post-launch tracking assets?

[cscott]

Given the range weather reports, I'm just waiting for the official confirmation of a slip to Wednesday.

That aside, with regard to the recovery ships heading out, seemingly for the SES-16 launch: Are they also used as post-launch tracking assets?

The last expendable launch also had a full recovery flotilla.  My theory would be that since the booster hardware won't be recovered they make an effort to downlink more of the normally-stored-not-transmitted telemetry during descent, and a support ship over the horizon from the launch pad helps with this.

[rockets4life97]

Is the Falcon 9 vertical on the pad with the payload? I haven't seen an update.

Edit: Got my days mixed up, launch isn't until tomorrow. Plenty of time.

[ChrisGebhardt]

Given the range weather reports, I'm just waiting for the official confirmation of a slip to Wednesday.

The weather reports that says there's a 40% chance of acceptable weather conditions -- with only one area of concern, ground winds -- throughout a more than 2hr long launch window?  What, based on a 40% go forecast and a 2+hr launch window, is causing you to be "waiting for the official confirmation of a slip to Wednesday"?

[IanThePineapple]

Given the range weather reports, I'm just waiting for the official confirmation of a slip to Wednesday.

The weather reports that says there's a 40% chance of acceptable weather conditions -- with only one area of concern, ground winds -- throughout a more than 2hr long launch window?  What, based on a 40% go forecast and a 2+hr launch window, is causing you to be "waiting for the official confirmation of a slip to Wednesday"?

Honestly, why wouldn't SpaceX give it a try. I think the only reason they wouldn't is if the range says no or if there's multiple factors at play (rain, ground winds, upper winds, etc).

Worst that could happen is pushing the launch back a day.

[FutureSpaceTourist]

What about upper level winds? They are high both Tuesday and Wednesday, so not sure the 2 hour launch window helps much with those. Or is 110 kts doable?! IIRC Zuma had a delay - not a scrub - for upper level winds.

[ZachS09]

I doubt that 110 knots is doable because it's above the upper level wind limits.

[ChrisGebhardt]

What about upper level winds? They are high both Tuesday and Wednesday, so not sure the 2 hour launch window helps much with those. Or is 110 kts doable?! IIRC Zuma had a delay - not a scrub - for upper level winds.

Zuma was delayed when ULWs were predicted to 150 kts.

EDIT: Where on here was the discuss and analysis of ULWs for F9?  I swear I saw those when Zuma was delayed, but I can't find them now.

[cppetrie]

What about upper level winds? They are high both Tuesday and Wednesday, so not sure the 2 hour launch window helps much with those. Or is 110 kts doable?! IIRC Zuma had a delay - not a scrub - for upper level winds.

Zuma was delayed when ULWs were predicted to 150 kts.

EDIT: Where on here was the discuss and analysis of ULWs for F9?  I swear I saw those when Zuma was delayed, but I can't find them now.

I think it was in the Zuma discussion thread and now likely lost in what that thread became after the launch. My recollection is that shear was just as, if not more, important than absolute velocity. Also, the discussion revealed that ULW are not a weather commit criteria as far as the range is concerned. They report the values to SpaceX, which has internal parameters for launching or not. As such, we do not have public (or L2 as far as I’ve seen) info on what the ULW constraints (velocity or shear) actually are. We can only infer based on what they have previously launched in. And that info I do not have but others might.

[FutureSpaceTourist]

What about upper level winds? They are high both Tuesday and Wednesday, so not sure the 2 hour launch window helps much with those. Or is 110 kts doable?! IIRC Zuma had a delay - not a scrub - for upper level winds.

Zuma was delayed when ULWs were predicted to 150 kts.
W
EDIT: Where on here was the discuss and analysis of ULWs for F9?  I swear I saw those when Zuma was delayed, but I can't find them now.

Thanks for that Chris. I’d misremembered the ULWs as 120 kts, not 150.

Not sure precisely what discussion you’re referring to. You did have a twitter discussion with CRS-13, which was captured at http://forum.nasaspaceflight.com/index.php?topic=42775.msg1757982#msg1757982

[ChrisGebhardt]

What about upper level winds? They are high both Tuesday and Wednesday, so not sure the 2 hour launch window helps much with those. Or is 110 kts doable?! IIRC Zuma had a delay - not a scrub - for upper level winds.

Zuma was delayed when ULWs were predicted to 150 kts.
W
EDIT: Where on here was the discuss and analysis of ULWs for F9?  I swear I saw those when Zuma was delayed, but I can't find them now.

Thanks for that Chris. I’d misremembered the ULWs as 120 kts, not 150.

Not sure precisely what discussion you’re referring to. You did have a twitter discussion with CRS-13, which was captured at http://forum.nasaspaceflight.com/index.php?topic=42775.msg1757982#msg1757982

Yeah, I remember -- and maybe it's in the CRS-13 threads, not the Zuma threads.  Good catch -- that there was an in-depth discussion here about previous F9 ULW scrubs and what we thought the limits where.  I'll go look through the CRS-13 threads.  Thanks!

EDIT:  And that's where they are!  http://forum.nasaspaceflight.com/index.php?topic=42775.msg1758033#msg1758033

SES-9 scrubbed for ULWs at 136 kts out of the west at 32,800 ft.  So if Zuma was 95 kts out of the west and went just fine, and there's no informal talk from what I'm hearing currently that ULWs of 110 kts out of the west are an issue for SES-16, maybe that gives us us some sense of the limit being greater than 110 kts but less than 136 kts? 

Of course, this could all change tomorrow.

[vaporcobra]

Presskit is up

It bothers me more than it should that the patch shows a booster with legs and grid fins

[stcks]

Presskit is up

It bothers me more than it should that the patch shows a booster with legs and grid fins

The MECO time indicates that the grid fins will likely be used, but yeah those legs are bothering me too 

[FutureSpaceTourist]

Presskit is up

It bothers me more than it should that the patch shows a booster with legs and grid fins

  So presumably the patch was designed before agreement to use a flight proven booster?

[RocketLover0119]

Who knows? Maybe they actually will use the legs as extra testing, and that the patch was not a mistake.

[IanThePineapple]

Who knows? Maybe they actually will use the legs as extra testing, and that the patch was not a mistake.

And throw out the old Block 3 legs before Block 5 comes out with the new legs.