Author Topic: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION  (Read 235472 times)

Online Welsh Dragon

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #540 on: 05/02/2017 01:35 PM »
<snip>

Naysayers... any last words?
(other than ULA's 'wet blanket/lost performance' comment yesterday at #ulcats)
Technical naysayers should be shut up by now yes. Economical naysayers? Remains to be seen. I'm crossing all my appendages for it to work out financially as well, but we don't know yet.

Offline Tuts36

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #541 on: 05/02/2017 01:41 PM »
We've come a long way from reconstructing the landing footage of CRS-3, haven't we? :)

Congratulations to SpaceX on their first DoD flight and for a spectacular depiction of how our robot overlords will soon invade us. I, for one, welcome more simulations.

Nice reminder... CRS-3 was April 18, 2014. 
Three years to go from seemingly impossible to routine!
First half (1y8m) got us to first land landing -- now (1y4m later) a core has been reflown, a handful are scheduled this year, and landing is routine -- though not boring.  Final upgrade of F9 is being fab'd to incorporate lessons learned.
Brilliant test program. 

Naysayers... any last words?
(other than ULA's 'wet blanket/lost performance' comment yesterday at #ulcats)

All good except for the Elon TimeTM factor, if you look back at the interview after CRS-3, the plan was successful landing in 2014 and refly in 2015, so it took them twice as long to accomplish what they set out to do.

I don't think his original timeline included the two RUD's.  If you took the resulting delays out, how close would his estimate have been?

Online mme

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #542 on: 05/02/2017 02:01 PM »
...
All good except for the Elon TimeTM factor, if you look back at the interview after CRS-3, the plan was successful landing in 2014 and refly in 2015, so it took them twice as long to accomplish what they set out to do.
I can't even imagine thinking that matters compared to the value of the actual accomplishments.  SpaceX would not exist if Elon Musk was not a slightly insane optimist.  It's a feature not a bug...

It reminds me of the Louis C.K. rant, " Everything Is Amazing And Nobody Is Happy."
Space is not Highlander.  There can, and will, be more than one.

Offline gospacex

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #543 on: 05/02/2017 02:03 PM »
All good except for the Elon TimeTM factor, if you look back at the interview after CRS-3, the plan was successful landing in 2014 and refly in 2015, so it took them twice as long to accomplish what they set out to do.

As opposed to, say, JWST schedule, or Constellation-nee-SLS schedule?
Allow me to remind you that first manned Ares I launch was supposed to happen in 2014.

Don't get me wrong, I also would prefer than everything SpaceX plans to do always happens exactly as planned, no delays of any sort. But the reality of aerospace is that all future dates are only NET, and usually slip.

Offline gospacex

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #544 on: 05/02/2017 02:06 PM »
<snip>

Naysayers... any last words?
(other than ULA's 'wet blanket/lost performance' comment yesterday at #ulcats)
Technical naysayers should be shut up by now yes. Economical naysayers? Remains to be seen. I'm crossing all my appendages for it to work out financially as well, but we don't know yet.

There is a "naysayer roadmap" on the Internet for it :D

Falcon 1 is not proven
Contract with NASA is not proven
Falcon 9 is not proven
Dragon is not proven
ISS resupply is not proven
1st stage return is not proven
Barge landing is not proven
Reuse is not proven
=== You are here ===
Falcon Heavy is not proven
Economy of reuse is not proven
Dragon 2 is not proven
Crewed flights are not proven
Lunar flyby is not proven
Capsule propulsive landing is not proven
Red Dragon is not proven

Online Welsh Dragon

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #545 on: 05/02/2017 02:12 PM »
Yup entirely correct. I'm optimistic it'll all be ticked off soon enough, but I'm still a scientist. It's not true until I've observed it!

Offline spacekid

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #546 on: 05/02/2017 02:19 PM »
I have the longest boostback, at 45 seconds or longer, taking place during the CRS-9 flight, during which the first stage returned to LZ 1.  For some reason, a shorter 33 second burn was used for CRS-10, which also returned to LZ 1.  Both of these flights had a 141 second first stage MECO.

Didn't CRS-10 have a much higher lofted trajectory than CRS-9? If so,  less horizontal velocity and shorter distance to fly back. 2nd stage has to work a bit harder but as long as it has enough fuel, then that allows for a shorter burn for the boostback.

May require a longer re-entry burn due to heating issues (falling at a steeper angle, from higher altitude) if the heating level is a concern for multiple re-use or minimal refurbishment/parts replacement.

Took a quick look at Flight Club videos, MECO for CRS-9 seemed to be at about 58-58.5 km, CRS-10 at about 64 km.  I'm sure much better detailed info is available, but that seems to confirm a higher lofted trajectory
Viewing it from the Fla west coast, it went up much higher than a normal launch.

Offline Star One

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #547 on: 05/02/2017 02:28 PM »
Yup entirely correct. I'm optimistic it'll all be ticked off soon enough, but I'm still a scientist. It's not true until I've observed it!

All timescales in the space industry as in many others in my view should be treated with the upmost scepticism when it comes to big projects.

Online whitelancer64

Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #548 on: 05/02/2017 02:44 PM »
All good except for the Elon TimeTM factor, if you look back at the interview after CRS-3, the plan was successful landing in 2014 and refly in 2015, so it took them twice as long to accomplish what they set out to do.

I don't think his original timeline included the two RUD's.  If you took the resulting delays out, how close would his estimate have been?

From CRS-7 to RTF was 173 days. From Amos-6 to RTF was 133 days. Adds up to 306 days, almost exactly 10 months.

It's worth noting that no landing attempts with a chance of recovery happened in 2014, there were three "soft splashdowns" in the ocean. The first successful 1st stage recovery did happen in 2015, and it was the first launch after CRS-7. If not for Amos-6 I think it's reasonable to say we would have seen a reflown booster in 2016, it would probably still have been SES-10, late in the year.
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Online AncientU

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #549 on: 05/02/2017 02:58 PM »
Yup entirely correct. I'm optimistic it'll all be ticked off soon enough, but I'm still a scientist. It's not true until I've observed it!

As another scientist, it isn't 'true' when you observe it... quantum mechanics aside.
You just have another data point that shows it has likely been true all along. 

I think we have sufficient data to avoid the knee jerk naysaying that assumes it is false (instead of unknown to us) until proven otherwise.  There aren't many data supporting this version of reuse being uneconomical (spreadsheets used to support your opinion are not data).
« Last Edit: 05/02/2017 03:00 PM by AncientU »
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Online Kansan52

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #550 on: 05/02/2017 03:00 PM »
Yup entirely correct. I'm optimistic it'll all be ticked off soon enough, but I'm still a scientist. It's not true until I've observed it!

All timescales in the space industry as in many others in my view should be treated with the upmost scepticism when it comes to big projects.

And if we had followed the time table of the Apollo days, the first Mars landing would have been in the 1980's. So I'm also in the camp of hope it happens but don't expect it to happen as quickly as Elon states.

Offline envy887

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #551 on: 05/02/2017 03:01 PM »
Yup entirely correct. I'm optimistic it'll all be ticked off soon enough, but I'm still a scientist. It's not true until I've observed it!

As another scientist, it isn't 'true' when you observe it... quantum mechanics aside.
You just have another data point that shows it has likely been true all along. 

I think we have sufficient data to avoid the knee jerk naysaying that assumes it is false (instead of unknown to us) until proven otherwise.  There aren't many data supporting this version of reuse being uneconomical (spreadsheets used to support your opinion are not data).

There is data supporting both opinions, but it's proprietary to the private companies that operate the vehicles that are the source of the data.

Online AncientU

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #552 on: 05/02/2017 03:08 PM »
There are flight data for only one of those 'opinions'(1)

(1) Equating an extensive flight test and demonstration program with a PowerPoint concept that won't fly for a decade is a bit disingenuous
« Last Edit: 05/02/2017 03:11 PM by AncientU »
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Offline edkyle99

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #553 on: 05/02/2017 03:10 PM »
Although Space-Track will never show orbits for the NROL 76 payload or its Falcon 9 second stage, it should list a "decay date" for the stage if and when it deorbits.  As of today it does not show a decay date, but these updates have sometimes proven to lag reality by a day or days.  Keeping an eye out.

 - Ed Kyle

Online AncientU

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #554 on: 05/02/2017 03:22 PM »
Although Space-Track will never show orbits for the NROL 76 payload or its Falcon 9 second stage, it should list a "decay date" for the stage if and when it deorbits.  As of today it does not show a decay date, but these updates have sometimes proven to lag reality by a day or days.  Keeping an eye out.

 - Ed Kyle

Is there any chance the second stage could still be alive and planning de-orbit burn?
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Offline andrewsdanj

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #555 on: 05/02/2017 03:49 PM »
LEO mission so the 2nd stage should have deorbited before making a single orbit - into the danger area in the Indian ocean posted a ways back?

Offline Star One

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #556 on: 05/02/2017 03:55 PM »
LEO mission so the 2nd stage should have deorbited before making a single orbit - into the danger area in the Indian ocean posted a ways back?

You need L2 access.

Offline pospa

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #557 on: 05/02/2017 04:01 PM »
Btw, Spaceflight 101 prepared nice graphs from 1st stage flight data. Speed, altitude, acceleration, vertical velocity vs. time with burns highlighted.
Here just speed vs. time plot, more here:  http://spaceflight101.com/falcon-9-nrol-76-flight-data/
« Last Edit: 05/03/2017 04:29 AM by pospa »

Offline andrewsdanj

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #558 on: 05/02/2017 04:02 PM »
Oooooo might have to run that one past the wife... It does sound like there is mystery afoot.

Offline neoforce

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Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #559 on: 05/02/2017 04:03 PM »
All good except for the Elon TimeTM factor, if you look back at the interview after CRS-3, the plan was successful landing in 2014 and refly in 2015, so it took them twice as long to accomplish what they set out to do.

Yeah, I agree that Elon Time is frustrating.  He always is two years late to being ten years early.     ;)

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