Author Topic: SpaceX Falcon 9 : Iridium NEXT Flight 4 : December 22/23, 2017 : Discussion  (Read 80953 times)

Offline cscott

  • Senior Member
  • *****
  • Posts: 2638
  • Liked: 1843
  • Likes Given: 658
It would be interesting if SpaceX reclaimed some of that extra margin by flying fairing recovery hardware.  Stripping the legs would free up some mass.  Trade expending the first stage for a good full-up fairing recovery test. 

I've got no info on this (other that the fairing recovery ship Mr. Steven is in Port of LA right now, isn't it? And its normal home is on the East Coast) --- but it seemed like an interesting trade one could make.

EDIT: see the new pictures of Mr. Steven at http://forum.nasaspaceflight.com/index.php?topic=37727.msg1761260.msg#1761260

Looks like my guess might be right?
« Last Edit: 12/19/2017 02:34 PM by cscott »

Offline JamesH65

  • Full Member
  • ****
  • Posts: 676
  • Liked: 406
  • Likes Given: 8
I donít see SpaceX tossing away a booster just because they donít need it. That runs exactly opposite of the mindset theyíre trying to establish. A few $100k to recover a core is absolutely nothing in the larger framework of mission cost - compare that to the value of underscoring the important of recovery and reuse to their customers.

If I understand you correctly, you're saying that SpaceX would spend a few 100k recovering a booster they don't need so that customers don't think they're going soft on re-use? After 20 previous successful recoveries, including the last 16 consecutive attempts? And on a flight using a flight proven booster?

I think we'll have to agree to disagree on that one.
Feel free. But I suppose with your mindset you see zero value in the returned booster. That's fine - but I see value in:

- Post flight examination of entire system
- Reuse of sub systems such as gimbal control system, hydraulic systems, grid fin actuators and the fins themselves (even if AL), engine control modules, Merlin components (at $1,000,000 for each M1D you say that getting parts off even a few engines won't cover the cost of recovery?)
- Maintaining the path that SpaceX has worked so hard to establish.


Again - disagree all you want, but I maintain it's fatally shortsighted...

Well, they have already examined many returned stages thoroughly, so I am not sure that is a valid argument.

If not reusing the whole booster, reuse of returned subsystems might have merit, if they are of use in block 5. If not, they are just so much scrap, that needs storage. Or do they just leave them out in the car park?

Maintain the path is irrelevant, Musk knows how to count and they already have an impressive track record. If the value return from bringing it back is less than dumping it, which do you think they will do?



Offline Comga

  • Senior Member
  • *****
  • Posts: 4012
  • Liked: 1342
  • Likes Given: 1088
According the original plans mentioned in FCC permit, planned booster recovery position should be so far on the south, that boostback burn would be completely skipped compare to previous flight of this booster with Iridium-2 or other IridiumNEXT missions. This also implies like no enough fuel margin for normal landing by some reason.
Change of plan to expedable booster would be comprehensible in this case.

SpaceXís track record and magic ingredient is to make progress, like developing first stage recovery, at extremely low marginal cost by piggybacking on paid launches. If they are forgoing the boostback or braking burn they will get an extremely energetic entry. A perfect opportunity to expand the envelope, from which they can best learn by recovering the first stage.

Wouldnít we expect to see titanium grid fins if they are planning on a high speed reentry?
Either way, we will know in a few days.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 9092
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5773
  • Likes Given: 3863
I think SpaceX are driven by cost, more than anything else. We don't have visibility to their cost numbers or the exact decision process (although maybe a tweet to Elon is in order?).

But whenever someone starts out with (in essence) "I think SpaceX made the wrong decision" I tend to start out disagreeing. Once in a while (AMOS-6) they flub. But not that often.

If this booster is not being recovered, there is surely a cost driven reason for it that made sense when they worked the trades. As AbuSimbel outlines.

These engines don't have the new impellers. That means they  may not be as valuable (it would be a big teardown to retrofit I would think) as some might suspect.
"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 Comga

  • Senior Member
  • *****
  • Posts: 4012
  • Liked: 1342
  • Likes Given: 1088
And then this from Twitter (via the UPDATES thread):

Quote
HŲchstErbaulich. @HochstErbaulich
Hey @IridiumBoss will the Falcon 9 core for Iridium-4 be recovered? There are rumors that the first stage has no recovery equipment installed.

Matt Desch @IridiumBoss
Replying to @HochstErbaulich
No, I understand it won't be

Interesting wording that supports the idea that the decision to recover or not is solely SpaceXís and even their customers sometimes donít know until right before launch.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Kansan52

  • Full Member
  • ****
  • Posts: 898
  • Hutchinson, KS
  • Liked: 276
  • Likes Given: 315
IMO, Job One is doing the customer's mission. Sounds like this was the way they could accomplish this for Iridium.

Offline pb2000

  • Full Member
  • *
  • Posts: 105
  • Calgary, AB/Mesquite, NV
  • Liked: 68
  • Likes Given: 39
With regards to reusability being a core part of SpaceX corporate culture; that really only works until they become too efficient and need to start laying off staff on the first stage production line. I'm sure the idea was to have BFR production needing staff before this became a problem, but who would have guessed the attempted recovery success would go to 100%?
Launches attended: Worldview-4 (Atlas V 401), Iridium NEXT Flight 1 (Falcon 9 FT)

Offline FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 4840
  • UK
    • Plan 28
  • Liked: 3498
  • Likes Given: 1130
Interesting wording that supports the idea that the decision to recover or not is solely SpaceXís and even their customers sometimes donít know until right before launch.

I agree the decision must be SpaceX's, but I think he does know for sure about recovery it's just that he's careful not to tread onSpaceX's toes and say anything definitive that relates to them rather than the mission.

BTW his response to being asked why no recovery on this mission is:

Quote
Can't answer that.

https://twitter.com/IridiumBoss/status/943161784994811904

Offline saliva_sweet

  • Full Member
  • ****
  • Posts: 508
  • Liked: 380
  • Likes Given: 1251
If this booster is not being recovered, there is surely a cost driven reason for it that made sense when they worked the trades.

In that case we can infer that the marginal cost of ASDS recovery is greater than the value of 20 tons of space grade metals and alloys.

Online woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 7486
  • IRAS fan
  • The Netherlands
  • Liked: 3270
  • Likes Given: 955
If this booster is not being recovered, there is surely a cost driven reason for it that made sense when they worked the trades.

In that case we can infer that the marginal cost of ASDS recovery is greater than the SCRAP-value of 20 tons of space grade metals and alloys.

There, fixed that for ya.

Offline cscott

  • Senior Member
  • *****
  • Posts: 2638
  • Liked: 1843
  • Likes Given: 658
Interesting wording that supports the idea that the decision to recover or not is solely SpaceXís and even their customers sometimes donít know until right before launch.

I agree the decision must be SpaceX's, but I think he does know for sure about recovery it's just that he's careful not to tread onSpaceX's toes and say anything definitive that relates to them rather than the mission.

BTW his response to being asked why no recovery on this mission is:

Quote
Can't answer that.

https://twitter.com/IridiumBoss/status/943161784994811904
My theory is that there is a significant fairing recovery experiment planned, and he is being careful not to step on SpaceX toes and let them announce that.  The reason for no S1 recovery is to enable the not-for-me-to-announce fairing recovery experiment.

Offline zubenelgenubi

  • Full Member
  • ****
  • Posts: 1266
  • Arc to Arcturus, then Spike to Spica
  • Commonwealth of Virginia
  • Liked: 280
  • Likes Given: 811
If this booster is not being recovered, there is surely a cost driven reason for it that made sense when they worked the trades.

In that case we can infer that the marginal cost of ASDS recovery is greater than the SCRAP-value of 20 tons of space grade metals and alloys.

There, fixed that for ya.

Or the value of another "rocket garden" artifact.  (Either for public display in a museum or such, or for private display in or near a SpaceX facility.)

(If there is discussion on SpaceX donating equipment for display, could someone point to it?)

On the flip side, Davy Jones gets a treasure for his locker that is becoming ever rarer--an expended Falcon 9 first stage! :D
« Last Edit: 12/19/2017 06:46 PM by zubenelgenubi »
Support your local planetarium!

Offline cppetrie

  • Full Member
  • ****
  • Posts: 448
  • Liked: 236
  • Likes Given: 3
I can totally understand the economical reasons for foregoing booster recovery along with not wanting to add to the stockpile of 'old' block boosters. I'm honestly more disappointed from an environmental standpoint. Given the ability to recover, it seems a bit irresponsible to just throw the trash into the sea so to speak. I don't really know what hazards might be on board when it goes in the drink, so maybe it's just mostly stuff that doesn't matter/polute. Can they purge/consume any liquid contaminants prior to impact with the water?

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 9092
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5773
  • Likes Given: 3863
I can totally understand the economical reasons for foregoing booster recovery along with not wanting to add to the stockpile of 'old' block boosters. I'm honestly more disappointed from an environmental standpoint. Given the ability to recover, it seems a bit irresponsible to just throw the trash into the sea so to speak. I don't really know what hazards might be on board when it goes in the drink, so maybe it's just mostly stuff that doesn't matter/polute. Can they purge/consume any liquid contaminants prior to impact with the water?

What kind of wastrel throws a perfectly good rocket in the drink... :)

As for your questions, I can give you Tory Bruno's twitter ID, you can ask him what ULA is doing to mitigate this....  more seriously, purging contaminants? wouldn't those just end up in exactly the same place anyway? (or in the atmosphere)
"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 edkyle99

  • Expert
  • Senior Member
  • *****
  • Posts: 12957
    • Space Launch Report
  • Liked: 3710
  • Likes Given: 634
Expend the booster to save money.  Hmmmm. 

 - Ed Kyle

Offline cppetrie

  • Full Member
  • ****
  • Posts: 448
  • Liked: 236
  • Likes Given: 3
I can totally understand the economical reasons for foregoing booster recovery along with not wanting to add to the stockpile of 'old' block boosters. I'm honestly more disappointed from an environmental standpoint. Given the ability to recover, it seems a bit irresponsible to just throw the trash into the sea so to speak. I don't really know what hazards might be on board when it goes in the drink, so maybe it's just mostly stuff that doesn't matter/polute. Can they purge/consume any liquid contaminants prior to impact with the water?

What kind of wastrel throws a perfectly good rocket in the drink... :)

As for your questions, I can give you Tory Bruno's twitter ID, you can ask him what ULA is doing to mitigate this....  more seriously, purging contaminants? wouldn't those just end up in exactly the same place anyway? (or in the atmosphere)
I was specifically thinking of TEA/TEB. By purging them together they ignite and burn off rather than leaking individually into the water. I donít know what else is on the booster. Residual helium, N2 and LOx donít really matter. Theyíre inert and/or naturally occurring. The kerosene isnít great. You could burn it to empty before impact? Any other hazardous materials onboard? Probably some heavy metals in the electronics but the amount compared to volume of ocean probably makes inconsequential. Thatís likely the argument any of the launch providers use. Tiny amounts in huge oceans...therefore doesnít matter. Probably true but that logic has been used before to justify doing things that eventually turned out to be problems.

Online kevinof

  • Full Member
  • ****
  • Posts: 492
  • Dublin/London
  • Liked: 248
  • Likes Given: 319
There is another side to the decision - they don't need the stage, they probably won't reuse it and therefore it has little or no value. However in trying to recover it, there is always a risk that the landing will fail, do a lot of damage to the barge and cost Space X a lot of money and time to repair.

If there's a risk (however small)  vs the zero value of the stage then splash it?

Offline Wolfram66

There is another side to the decision - they don't need the stage, they probably won't reuse it and therefore it has little or no value. However in trying to recover it, there is always a risk that the landing will fail, do a lot of damage to the barge and cost Space X a lot of money and time to repair.

If there's a risk (however small)  vs the zero value of the stage then splash it?

Or possibly testing the FH Side booster engine gimbal separation sequence? IDK... throwing stuff at the wall here

Offline Greg Hullender

  • Member
  • Posts: 54
  • Seattle
    • Rocket Stack Rank
  • Liked: 57
  • Likes Given: 69
I would guess that they learn a lot from each recovered stage. Information that could help them further reduce the cost of reuse, for example, or give them a better idea of how many times they can refly the same stage.

Offline whatever11235

  • Member
  • Posts: 29
  • Liked: 5
  • Likes Given: 23
I would guess that they learn a lot from each recovered stage. Information that could help them further reduce the cost of reuse, for example, or give them a better idea of how many times they can refly the same stage.

After 20 times I think they learned all they could.

Tags: