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According to the upcoming livestream of SpaceX CRS-14 (resupply of ISS):

SpaceX will not attempt to recover Falcon 9’s first stage after launch.

Why not? Wasn't that the whole point of (among others) the Falcon 9?

I'm not interested in unsourced speculation, so I'd like to see answers based on official sources.

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  • $\begingroup$ If preferred, one of the tags can be dropped for crs-14, but the tag didn't exist yet and I don't have tag-creation privileges. $\endgroup$ – Mast Apr 2 '18 at 12:51
  • $\begingroup$ See also Has SpaceX re-used a first stage twice yet? $\endgroup$ – uhoh Apr 2 '18 at 13:22
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    $\begingroup$ While not an answer, Ars Technica has an article about it for those that are interested. arstechnica.com/science/2018/04/… $\endgroup$ – MiniRagnarok Apr 3 '18 at 13:42
  • $\begingroup$ @MiniRagnarok Thanks, that link is a nice bonus. $\endgroup$ – Mast Apr 3 '18 at 20:21
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SpaceX designed the Falcon 9 for reuse. They have several iterations, starting with the 1.0 design (with the tic-tac-toe grid of engines).

The switch to the 1.1 design with the Octaweb, was distinctive and was finally able of landing.

The current model is Block 3, 4, or 5 (Block 3's have all been flown, and Block 5 is about to fly, end of April as I write this).

Experimentally, SpaceX determined that they could affordably refly a Block 3 or 4 models a maximum of 2 times. They took the lessons learned and rolled them into what they hope is their final version, Block 5.

Thus, when a booster is on its second flight, it is not going to be flown a third time. Thus the question is, what to do with second flight boosters?

The CRS-14 booster is on its second flight, it is core B1039 last flown as CRS-12.

Mostly they have been running landing experiments trying to see how efficiently they can land, with minimal fuel required.

They have tried to spin the stage up, and then recover from the spin, with minimal fuel usage on one of the Iridium flights which made a spectacular pattern in the sky.

What is interesting is that they are not trying to land at LZ-1, but likely because they want to try another exterme landing approach, and digging a hole in the Florida coast goes over poorly with the FAA, Air Force, and NASA.

A commentator noted that if what I answer is correct, why still mount the grid fins and legs on the boosters.

In the case of the Block 3/4 boosters, the fins are aluminium (The Titanium fins are a feature of the Block 5 booster design, that was tested on a couple of Block 3/4 missions (Like the Falcon Heavy demo flight side cores) and thus not needed for Block 5. The legs on Block 5 are different as well, so no need to stockpile older models). Finally, in order to really test the landing aerodynamics, you to test like you fly, so they mounted the landing equipment to make for a better, more accurate flight test.

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    $\begingroup$ See also Has SpaceX re-used a first stage twice yet? $\endgroup$ – uhoh Apr 2 '18 at 13:23
  • $\begingroup$ I was thinking this is probably a duplicate, or close to it. $\endgroup$ – geoffc Apr 2 '18 at 14:02
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    $\begingroup$ I don't think there's need to dupe it. There's no information about CRS-14 there, but it sounds like roughly every other launch is going to be re-used. So maybe you can make this answer as nice and thorough as possible and then every new "Why won't they recover the F9 from X?" question can be duped back here. $\endgroup$ – uhoh Apr 2 '18 at 15:20
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    $\begingroup$ "digging a hole in the Florida coast goes over poorly..." For the record, I've been driving through Florida recently, and it appears no one cares if you dig giant random holes in Florida. They're everywhere! $\endgroup$ – ceejayoz Apr 3 '18 at 2:35
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    $\begingroup$ @ceejayoz Those are NASA alligator traps. They were developed in the late 1960's to keep alligators from climbing on to the launch pad and eating the astronauts. By the 1970's they became very popular with the civilian population as well, as did other space-themed designs. Oh, it's not April 1st anymore, uhoh! $\endgroup$ – uhoh Apr 3 '18 at 6:11
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Earlier on Musk indicated it may be possible to fly a block 3/4 booster more than twice but it would depend on the missions flown, with LEO missions like this Commercial Cargo mission being easier than GTO missions. I suspect this booster and the previous one that did two cargo missions could be reused if SpaceX wanted to but they are choosing to move forward with block 5 so they are not bothering with recovery. Obviously they value whatever testing they are performing on this launch above whatever scrap value the rocket would have and whatever further information they would have learned from inspecting the landed booster.

Also keep in mind they do have a pretty specific reason to want to get block 5 going and get as many launches as they can on that: commercial crew. NASA requires 7-10 launches on a stable configuration before the crewed launches can occur. Block 5 also is supposed to have some changes to the blades in the turbo pump to address cracking which were requested by NASA so that stable config can't be block 3 or 4.

Reusing a pre-block 5 booster for a third flight would just end up delaying their block 5 flights needed for that certification and since they are aiming for the first crewed launch to be this year I don't think they want to skip any block 5 qualifying launches that they don't have to.

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  • $\begingroup$ That is a good perspective. I think if we knew the refurb cost of Block 3 and Block 4, it would make sense to decide if they are leaving money on the table to get to Block 5, or not. I expect, based on their decision that refurb on B3/B4 is high enough, and they expect B5 to be low enough, that it is a cost effective decision. $\endgroup$ – geoffc Apr 2 '18 at 17:41
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    $\begingroup$ Additionally, since they're not gonna refly a block <5 booster even if recovered, putting the drone ship out to sea or prepping the landing pad costs money and presents a nonzero chance of large scale property damage (ie droneship blows up) and returns minimal gains. They can instead "land" the falcon on the water to try new landing profiles in an experiment that'd otherwise be very expensive and risky for the droneship. $\endgroup$ – Dragongeek Apr 2 '18 at 18:10
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    $\begingroup$ IIRC they also ran out of (indoors) storage space for recovered cores. $\endgroup$ – Hobbes Apr 3 '18 at 8:31
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This answer deals more with the business-strategy issues rather than the techology-strategy. While reusability is a crucial part of Musk's strategy, reuse of early stage versions only makes sense when it furthers the objective of the achieving the more profitable long term certification of the Block 5. Now that Musk has credibly validated the concept of reuse with the early missions, it may be worth leaving some "change on the table" today, skipping reuse of this booster, in favor of getting speedier validation of the more advanced boosters where there are better commercial and NASA prospects. Plus, they are taking advantage of this non-recovered mission to gather important data on "pushing the recovery envelope" with this booster to aid future engineering.

In the current space race of commercial competitors "time is of the essence." Whichever US entity is first to validate to human launch capability for NASA, and heavy lift launch capability for the larger commercial and Govt market for really big payloads, will be the big leader in the long run, and get all the high margin early business. This represents the best bet for achieving real expansion of economical access to space for more commerce, and more "blue sky" projects (like a colony at L5, permanently occupied base on the Moon, colonization of Mars and more "blue sky" after that).

Musk is used to taking extraordinary risks. Let's hope he stays lucky.

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