Author Topic: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION  (Read 233263 times)

Offline Star One

  • Senior Member
  • *****
  • Posts: 8249
  • UK
  • Liked: 1333
  • Likes Given: 168
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #420 on: 05/01/2017 11:41 AM »
Staged 10 m/s faster than CRS-10, and 4 seconds earlier. Seems very likely to be an upgraded booster.

Unfortunately that's the kind of thing the NRO get tetchy about so I wonder if we'll ever hear anything about this in relation to this flight.

Offline Unobscured Vision

Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #421 on: 05/01/2017 11:43 AM »
Staged 10 m/s faster than CRS-10, and 4 seconds earlier. Seems very likely to be an upgraded booster.

Lighter payload or are you implying Block 4? My bet will be lighter payload ... the Apogee was looking a bit high on the S1, like they were expecting 130-ish km when they were at 160-ish at the peak.
Yep ... just ... yep.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8654
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5394
  • Likes Given: 3565
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #422 on: 05/01/2017 11:45 AM »
So glad I truncated my supermarket visit to just snatching a bag of carrots and potatoes, and got back for T-2:45; and then that footage!

Priorities, man!

I'm super impressed at the footage. A confluence of fortuitous events... no S2 coverage, improvements in process and procedures, and the weather cooperated to make it all visible

Yeah, cue the "SpaceX have been hogging awesome footage all along" conspiracy theorists HERE in 3, 2, 1 ... (you know who you are, you know I love you but I have to laugh)

---

Way more nitrogen thruster use than I thought, no wonder they ran out before introducing grid fins....
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online AncientU

  • Senior Member
  • *****
  • Posts: 4961
  • Liked: 2964
  • Likes Given: 4183
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #423 on: 05/01/2017 11:46 AM »
Very high apogee... only thrusters have control until reentry interface.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline Damon Hill

  • Veteran
  • Full Member
  • ****
  • Posts: 548
  • Auburn, WA
  • Liked: 71
  • Likes Given: 121
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #424 on: 05/01/2017 11:46 AM »
Wow and wow.  I'm going back to bed, but I doubt I'll sleep much.  Going to be some great video footage when it's all edited.

Offline chalz

  • Full Member
  • *
  • Posts: 168
  • Austrangia
  • Liked: 77
  • Likes Given: 1004
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #425 on: 05/01/2017 11:47 AM »
Was it me or was the re-entry burn vectored sharply off to one side during the middle phase? I wonder why they would have done  that; to give asymmetric braking?
It always does that, the elongated plume is visible from the onboard camera in many previous launches. It does look incredible from the outside though. I guess the supersonic airflow does strange things.

Offline cebri

  • Member
  • Posts: 69
  • Spain
  • Liked: 63
  • Likes Given: 53
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #426 on: 05/01/2017 11:47 AM »
Obligatory


Online Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6995
  • A spaceflight fan
  • London, UK
  • Liked: 553
  • Likes Given: 637
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #427 on: 05/01/2017 11:48 AM »
Did anyone really expect the ground tracking cameras of the booster in free autonomous flight mode to look so awesome? I certainly wasn't expecting the RCS/attitude control thruster plumes to be so visible.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline LouScheffer

  • Full Member
  • ****
  • Posts: 1555
  • Liked: 1756
  • Likes Given: 199
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #428 on: 05/01/2017 11:50 AM »
Looks like aerodynamic braking is pretty strong, as expected.  After the entry burn, it accelerated for a while in the thin air, then decelerated at about 2G.   Terminal velocity looked like about 300 m/s.  This is about as expected from something of that size, shape, and mass.

Offline envy887

  • Senior Member
  • *****
  • Posts: 2761
  • Liked: 1276
  • Likes Given: 801
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #429 on: 05/01/2017 11:50 AM »
Entry burn started at about Mach 3.6, landing burn at about Mach 0.9

Offline Moskit

  • Full Member
  • *
  • Posts: 111
  • Liked: 23
  • Likes Given: 7
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #430 on: 05/01/2017 11:50 AM »
Legs seemed to deploy just 3-4s before the touchdown, as opposed to 10s announced.
Given a higher apogee (+20%) is this more an indication of a new mission profile or operating closer to the limits?

Thrusters might have operated more frequently due to strong winds at high altitude (mentioned by Elon).
« Last Edit: 05/01/2017 11:51 AM by Moskit »

Offline hans_ober

  • Full Member
  • *
  • Posts: 100
  • Somewhere
  • Liked: 52
  • Likes Given: 1
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #431 on: 05/01/2017 11:51 AM »
It took only 12-14 secs from separation to start of boostback.

Well, the engines shut down.. but only briefly at MECO. While the centre engine isn't running, there is a continuous plume (from the turbopump, or is it venting LOX?). The center engine restarts first, probably to to keep the propellant from sloshing during the flip, and probably gimbals to speedup and stabilize the rates of rotation. The remaining 2 engines turn on soon after that.

Online AncientU

  • Senior Member
  • *****
  • Posts: 4961
  • Liked: 2964
  • Likes Given: 4183
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #432 on: 05/01/2017 11:52 AM »
Just wait until a 12m core does that RTLS.
Daily.
« Last Edit: 05/01/2017 11:53 AM by AncientU »
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8654
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5394
  • Likes Given: 3565
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #433 on: 05/01/2017 11:52 AM »
I wonder if fairing recovery was even attempted given the shroud[1] of secrecy

1 - yes I went there
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline yokem55

  • Full Member
  • ****
  • Posts: 443
  • Oregon (Ore-uh-gun dammit)
  • Liked: 247
  • Likes Given: 12
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #434 on: 05/01/2017 11:53 AM »
Wow and wow.  I'm going back to bed, but I doubt I'll sleep much.  Going to be some great video footage when it's all edited.
Same here... I'm t-minus 1.5 hrs til my normal Monday morning alarm. But that was worth it.

Offline spacekid

  • Member
  • Posts: 41
  • St. Petersburg, FL
  • Liked: 12
  • Likes Given: 25
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #435 on: 05/01/2017 11:55 AM »
Just wait until a 12m core does that RTLS.
Daily.
Just wait until first stage sep of a Falcon 9 Heavy with 3 stages coming back!

Offline Michael Baylor

  • Full Member
  • *
  • Posts: 196
  • Liked: 208
  • Likes Given: 115
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #436 on: 05/01/2017 11:59 AM »
The shot from the land based camera of reentry was...   8)

Offline M.E.T.

  • Full Member
  • ****
  • Posts: 445
  • Liked: 190
  • Likes Given: 12
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #437 on: 05/01/2017 11:59 AM »
Will there be a post launch press conference this time? Or is that not the norm for a spy satellite launch?

Online Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6995
  • A spaceflight fan
  • London, UK
  • Liked: 553
  • Likes Given: 637
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #438 on: 05/01/2017 12:03 PM »
They certainly won't have a joint presser with NRO or USAF but I wonder if SpaceX may issue a few press releases and answer a few Twitter queries on the launch vehicle's performance.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline rubtest

  • Member
  • Posts: 61
  • Liked: 17
  • Likes Given: 13
Re: SpaceX Falcon 9 - NROL-76 - May 1, 2017 - DISCUSSION
« Reply #439 on: 05/01/2017 12:14 PM »
what a landing , WOW and congrat to SpaceX NRO NASA Chrises especially about the most photogenic landing
seen till now
learned that:
1. First stage climbed after MECO from 66 km to 166 km in boost back scenario .
2. below 5 km air resistance slows quite fast the vehicle. Larger flaps in the future will probably enhance this effect.
3. releasing the landing legs almost before landing minimizes fire damage to them from the landing flames.

Space flight will not be the same again

Tags: