Author Topic: SpaceX Falcon 9 : Iridium NEXT Flight 4 : December 22/23, 2017 : Discussion  (Read 100814 times)

Offline old_sellsword

  • Full Member
  • ****
  • Posts: 632
  • Liked: 531
  • Likes Given: 463
A user on r/SpaceX is saying this core is flying expendable. Can anyone confirm this? And if its true, why? I know they are probably running out of room to store them but its still more data and more usable engines.

https://www.reddit.com/r/spacex/comments/7cgts7/iridium_next_constellation_mission_4_launch/drg64bk/

He said he got the info from a friend at Vandy. I'm still thinking it's unlikely to be going expendable, but this comment, even if the guy isn't proven reliable, might challenge that.

u/ASTRALsunder is very reliable, they’re the same user who first gave us Zuma’s name.

Offline ZachS09

Wasn't there something on the "General SpaceX Map", https://www.google.com/maps/d/viewer?mid=1wvgFIPuOmI8da9EIB88tHo9vamo&hl=en_US; that mentioned where JRTI was going to be located for Iridium-NEXT F4?

"Liftoff of Falcon 9: the world's first reflight of an orbital-class rocket."

Offline gongora

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 3366
  • US
  • Liked: 2722
  • Likes Given: 1639
Wasn't there something on the "General SpaceX Map", https://www.google.com/maps/d/viewer?mid=1wvgFIPuOmI8da9EIB88tHo9vamo&hl=en_US; that mentioned where JRTI was going to be located for Iridium-NEXT F4?

They have an FCC permit for ASDS communications.  Maybe the plan changed after they filed for that permit.

Offline FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 6211
  • UK
    • Plan 28
  • Liked: 5674
  • Likes Given: 1627
It could just be a matter of the barge not being available for some reason.

Yes, like not returning to port at Xmas? Ok I know lots of people do work at Xmas, but if SpaceX have no plans to reuse this booster again then they may decide recovery isn't worth the cost. They've stopped cleaning boosters between uses, which is surely cheaper than an ASDS return?

Online Formica

  • Rocket Boi
  • Member
  • Posts: 67
  • Richmond, CA
  • Liked: 61
  • Likes Given: 425
Assuming it is true, this would be the first time SpaceX has expended a flight proven booster, which has been a source of speculation for some time. I'm surprised they didn't pick a GTO mission to do so. (More value for the customer expending the booster for a higher supersync orbit, etc.) It will be interesting to hear the reasoning if they decide to share it with us.
« Last Edit: 12/19/2017 10:29 AM by Formica »
I'm just a space fan, please correct me if I'm wrong!

I think we are forgetting that SpaceX is entering a major transition time with Block 5 coming. They've engineered it for many reuses and fast turnaround. Maybe it won't be 24h from the beginning, but it seems like many dismiss the improvement by defaulting a pessimistic position, while imo it's safe to expect major impacts on the launch logistics starting Q2 2018, even if they don't even come close to the 24h turnaround.

An example: don't underestimate the possibility that the same core could launch many subsequent missions from a pad, with the refurbishment turnaround times matching the pad turnaround (skipping a few missions that fly on new cores every now and then).

The thing is, when block 5 flies and proves its refurbishment agility,  flying the previous versions no longer makes sense. Block 5 could very well be agile enough to cover every mission from the beginning, and the stock of older recovered cores would be useless. I think SpaceX is now rushing to fly every flight proven core they have and trying not to have to many <B5 cores in stock by the time B5 flies.
« Last Edit: 12/19/2017 11:51 AM by AbuSimbel »
Failure is not only an option, it's the only way to learn.
"Tradition is not the worship of ashes, but the custody of fire" - Gustav Mahler

Offline FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 6211
  • UK
    • Plan 28
  • Liked: 5674
  • Likes Given: 1627
Assuming it is true, this would be the first time SpaceX has expended a flight proven booster, which has been a source of speculation for some time. I'm surprised they didn't pick a GTO mission to do so. (More value for the customer expending the booster for a higher supersync orbit, etc.) It will be interesting to hear the reasoning if they decide to share it with us.

Iridium choose to go with reuse primarily to avoid further slips to their launch schedule. SpaceX have selected a booster that's available and acceptable to Iridium. If SpaceX have simply decided that the recovery cost isn't worth the benefit to them (eg no plans to reuse this booster again, with block 5 due soon) then I'm not sure the type of mission (not GTO) is particularly relevant to that decision?

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 7116
  • A spaceflight fan
  • London, UK
  • Liked: 641
  • Likes Given: 751
I suppose that it's possible that SpaceX have decided that, whilst good for launch, the condition of the condition of the booster is marginal for it to withstand EDL stresses so they've decided just not to bother.
"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 Raul

  • Full Member
  • **
  • Posts: 212
  • Ústí nad Orlicí, CZECH
  • Liked: 430
  • Likes Given: 30
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.

Online Galactic Penguin SST

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.

.....so why was the recovery position changed?
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Online Johnnyhinbos

  • Full Member
  • ****
  • Posts: 1344
  • Boston, MA
  • Liked: 1494
  • Likes Given: 212
I think people are missing an important aspect of SpaceX’s business plan, let alone corporate culture - that of reuse. I’ve posted this before.

Reuse.

I don’t see SpaceX tossing away a booster just because they don’t need it. That runs exactly opposite of the mindset they’re 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. I think SpaceX will only opt to throw away a core if it is absolutely the only option available.

Some people in this forum are so completely stuck in an unbendable formulaic mentality. Sometimes it’s important to step back and think about the entire thing and realize there’s also value in perception and forward thinking. 
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 6211
  • UK
    • Plan 28
  • Liked: 5674
  • Likes Given: 1627
I don’t see SpaceX tossing away a booster just because they don’t need it. That runs exactly opposite of the mindset they’re 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.

Online Johnnyhinbos

  • Full Member
  • ****
  • Posts: 1344
  • Boston, MA
  • Liked: 1494
  • Likes Given: 212
I don’t see SpaceX tossing away a booster just because they don’t need it. That runs exactly opposite of the mindset they’re 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...
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline rsdavis9

I thought that the block 5 adds nothing to engine reuse? The engines are already at the pretty much maximum for reuse. Maybe the turbines are better in block 5? So 9 engines at 1M a piece seems well worth it to recover.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Offline ATPTourFan

  • Member
  • Posts: 45
  • Liked: 26
  • Likes Given: 409
When we first learned about the position of JRTI back in October, I suspected SpaceX and Iridium compromising on the use of a flight proven booster to facilitate on on-time launch. Part of that agreement is additional margin. Now SpaceX feels recovery of this block 3 booster is just not worth it and removing legs/fins provides Iridium even greater margin for success.

Quote
My first thought was that SpaceX is giving Iridium as much margin as possible to get their payload to the proper orbit. Iridium and SpaceX worked out the arrangement to utilize the flight-proven core to help schedule this launch, but SpaceX really doesn't need to be gentle to this core as much as they MUST get Iridium-4 payload where it needs to go - maximum margins to make customer happy.

Offline wannamoonbase

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 3017
  • Denver, CO
    • U.S. Metric Association
  • Liked: 696
  • Likes Given: 1154
When we first learned about the position of JRTI back in October, I suspected SpaceX and Iridium compromising on the use of a flight proven booster to facilitate on on-time launch. Part of that agreement is additional margin. Now SpaceX feels recovery of this block 3 booster is just not worth it and removing legs/fins provides Iridium even greater margin for success.

I think we can expect to see Block 3's and 4's refly once but that the final flight may in fact be expendable.

They've tested hot recoveries, they've collect reflown Block 3/4.  Maybe they don't need any more boosters that won't fly again.

In conclusion, All hail the mighty Block 5!!
« Last Edit: 12/19/2017 01:47 PM by wannamoonbase »
SpaceX, just a few things planned for 2018: FH, Starlink Prototypes, Block 5, Dragon 2, Increased launch rate.

Offline envy887

  • Senior Member
  • *****
  • Posts: 4105
  • Liked: 2123
  • Likes Given: 1269
When we first learned about the position of JRTI back in October, I suspected SpaceX and Iridium compromising on the use of a flight proven booster to facilitate on on-time launch. Part of that agreement is additional margin. Now SpaceX feels recovery of this block 3 booster is just not worth it and removing legs/fins provides Iridium even greater margin for success.

I think we can expect to see Block 3's and 4's refly once but that the final flight may in fact be expendable.

They've tested hot recoveries, they've collect reflown Block 3/4.  Maybe they don't need any more boosters that won't fly again.

In conclusion, All hail the mighty Block 5!!

I think that parts reuse and the scrap value of the raw materials in a F9 booster are probably worth the cost of recovery. But they may not be worth the lost margin if an engine or two goes out on the way up.

I don’t see SpaceX tossing away a booster just because they don’t need it. That runs exactly opposite of the mindset they’re 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...

The fact is that SpaceX already has too many flight proven cores in storage that they have to use before block 5 flies or they become useless. 
We will see very few old cores missions after B5's maiden flight, SX will want to literally jump to B5 as fast as humanly possible.
NASA wants Block 5 flight history for Commercial Crew, SpaceX wants to fly as many B5 as they can to acquire flight history and because it's cheaper to reuse. After Block 5, flying anything but B5 essentially becomes a pain in the ass to them, they may do it for 1-2 missions but only because logistically forced. Formosat, NROL-76, OTV-5, CRS-12, Iridium-3, Koreasat (+Zuma after it lands) all have to fly before block 5. This means flying them on these possible missions: GovSat, Paz, CRS-14, Iridium-5, maybe Hispasat. After those, reusing Block 5 is much more convenient because it's easier, faster, cheaper, necessary for NASA and for SX's own reuse program.
 
They do have:
Plenty of cores already that could be stripped off the components you listed (and I haven't seen evidence it would be useful to do so, we know about engines getting swapped between cores but I don't think they're frankentseining them too much with other systems). Plenty of data on reflown boosters. Enough used cores to refly for the very few missions that require them before block 5.

What do they lack?
Storage space.
« Last Edit: 12/19/2017 02:32 PM by AbuSimbel »
Failure is not only an option, it's the only way to learn.
"Tradition is not the worship of ashes, but the custody of fire" - Gustav Mahler

Offline jgoldader

  • Full Member
  • ****
  • Posts: 710
  • Liked: 253
  • Likes Given: 154
I think that parts reuse and the scrap value of the raw materials in a F9 booster are probably worth the cost of recovery. But they may not be worth the lost margin if an engine or two goes out on the way up.

That seems like an awfully good point.  Aside from SpX and their customers, I doubt many know details of the trade space (performance/recoverability/margin) involved in the negotiations.  The mass of the recovery hardware obviously impacts both margin and recovery.
« Last Edit: 12/19/2017 02:04 PM by jgoldader »
Recovering astronomer

Offline cscott

  • Senior Member
  • *****
  • Posts: 2896
  • Liked: 2016
  • Likes Given: 664
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 »

Tags: