SpaceX Falcon Heavy Discussion (Thread 6)

[pippin]

(F9 booster refurb likely is ALREADY cheaper than 1/3 of the cost of a new booster).

Only if you don’t consider depreciation.
Current F9 cores can only be reused once so overall even with zero additional work they would be at least at half the price of a new stage.

[hkultala]

In the current situation FH will only be needed for heavy weight / medium weight, high energy missions. On the other hand when second stage reuse has been implemented, FH will maybe be needed for nearly all missions due to the second stage additional mass penalty. Since the whole system will be reusable in that case, the extra cost due to needing the FH will be much less. Additionally, being able to reuse the second stage on nearly every mission will give them a lot of orbital reentry data that is possibly relevant to BFR.

There will be no second stage reuse for falcon 9 family. It's much more clear now than it has ever been.

[georgegassaway]

There will be no second stage reuse for falcon 9 family. It's much more clear now than it has ever been.

Hmmm. Even if they didn't do it for operational reasons, I'd be surprise if they didn't at least modify some F9 2nd stages to reflect BFR 2nd stage technology, at least for re-entry and aerodynamic flip-around purposes.  (Note I am not talking re-use here, but R&D).

Maybe not necessarily propulsive landings for re-use, but all they can up to (or down to) that point. 

I know Shotwell said they were going to try something next year, perhaps along those lines, perhaps not.

I myself am curious as to regards the aerodynamic and flight control stability of the high AOA re-entry (much like the orbiter) with just two small stubby delta wings, and how that will transition to descend thru the atmosphere tail-first with the kind of PRECISION as now provided by the deployable grid fins, before the landing burn begins.

Almost like the punchline to an old joke, about some incredibly complex thing that a scientist has "solved", a solution which he called "ATAFMH". When asked what that word / acronym was, he replied:

"And Then a [F-word]ing Miracle Happens"

I think they need to flight test that long before a BFR does, to whatever extents are practical.

Though the existing F9 booster may not be suitable aerodynamically (or structurally) due to the change of the CP of the whole stack if a 2nd stage had such stubby wings added, without adding some fin area to the booster.  And the aerodynamically induced bending loads in the booster, particularly the tankage below the interstage, might require structural reinforcement.  If so,  not simple but not unsurmountable.

[macpacheco]

(F9 booster refurb likely is ALREADY cheaper than 1/3 of the cost of a new booster).

Only if you don’t consider depreciation.
Current F9 cores can only be reused once so overall even with zero additional work they would be at least at half the price of a new stage.

The fact that SpaceX haven't yet flown the same core 3x doesn't mean it can't be done safely.
It just means there aren't enough customers that signed the dotted line so far.
Much like saying F9 boosters that landed from GTO trajectories can't be relaunched. The fact is Block III boosters don't have much performance left from a GTO launch for a thermally nice re-entry, but that will change with Block V on regular missions (after SpaceX direct F9 expendable launches to FH reusable ones).
There's way too much premature conclusions.
SpaceX is in the early stages of migrating towards routine booster reuse.
Customers are still digesting the technical and financial (savings vs risk) of going with reuse. Some more edgy customers have already signed on the dotted line, but most aren't ready to do that yet. They want more successes first. Its a chicken egg problem that will begin to go away after the sixth successful booster relaunch.

Current reuse customers have the luxury of being able to select which booster to fly on. It will take at least a dozen reflights before customers free SpaceX to choose which booster to refly. This is specially a concern after the AMOS incident (not the explosion itself per se, but the lack of wisdom to do static fires with the payload attached).

[pippin]

(F9 booster refurb likely is ALREADY cheaper than 1/3 of the cost of a new booster).

Only if you don’t consider depreciation.
Current F9 cores can only be reused once so overall even with zero additional work they would be at least at half the price of a new stage.

The fact that SpaceX haven't yet flown the same core 3x doesn't mean it can't be done safely.

SpaceX have said that they can reuse the current core only once. No pages full of speculation needed.
They will do multiple reflys only with Block 5 cores.

[SmallKing]

There was a rumor in Reddit about FH inaugurating from SLC-40 rather than 39A. But considering the size of 40s HIF, it won't be realistic I thought.
https://www.reddit.com/r/spacex/comments/73h3ky/unconfirmed_rumor_regarding_slc40/

[gongora]

There was a rumor in Reddit about FH inaugurating from SLC-40 rather than 39A. But considering the size of 40s HIF, it won't be realistic I thought.
https://www.reddit.com/r/spacex/comments/73h3ky/unconfirmed_rumor_regarding_slc40/

That is nonsense.

[Comga]

There was a rumor in Reddit about FH inaugurating from SLC-40 rather than 39A. But considering the size of 40s HIF, it won't be realistic I thought.
https://www.reddit.com/r/spacex/comments/73h3ky/unconfirmed_rumor_regarding_slc40/

That is nonsense.

Agreed. Nonsense. It is impossible.
We went over this many times over several years.
Let's not do it again.

[guckyfan]

SpaceX have said that they can reuse the current core only once. No pages full of speculation needed.
They will do multiple reflys only with Block 5 cores.

Have they? I am pretty sure they only have said at best that they won't, not that they can't.

[pippin]

SpaceX have said that they can reuse the current core only once. No pages full of speculation needed.
They will do multiple reflys only with Block 5 cores.

Have they? I am pretty sure they only have said at best that they won't, not that they can't.

Not that this makes any difference for the cost structure we are talking about here.
Even if it’s because they feel the goblins told them to, flying the core only twice means each flight of an F9 expends at least half a core and flying FH means expending 1 1/2 - except that IIRC the FH center core will already be block 5, or do I remember that wrongly?

[Semmel]

Source for claim that payloads over 11t require a new fairing? A new PAF is considerably simpler than a fairing.

There are images on this very site where the encapsulated payload with PAF and fairing is lifted by slings around the fairing in order to mate it with the second stage. I cant find the link (looked for it 30 minutes now, I give up) but I have seen it not that long ago. For a heavier payload, they not only need to provide a new PAF but also fairings that can handle a higher load for integration.

[alang]

How about a BFS scale model as a FH demo dummy payload.
It would be expensive as it would need to be able to do a controlled reentry, but can anyone see SpaceX doing this rather than just relying on simulations and S2 reuse attempts?

[Req]

How about a BFS scale model as a FH demo dummy payload.
It would be expensive as it would need to be able to do a controlled reentry, but can anyone see SpaceX doing this rather than just relying on simulations and S2 reuse attempts?

This would take a couple years to prepare, so I'd call that option pretty unlikely unless they have not only been lying about having not selected a payload yet fairly recently, but also managed to keep the test article completely secret during all that time.

[Ronsmytheiii]

imagery from an airplane passing over LZ-1 , looks like the pad concrete pour is almost done on the second landing pad:

https://www.instagram.com/p/BaCPZEWl253/

[Ronsmytheiii]

Concrete pad almost done for the north pad, looks like the south area has been cleared for the new Dragon building construction:

https://www.planet.com/explorer

[SPITexas]

The Falcon Heavy is still planned to launch in late December right?

[ZachS09]

The Falcon Heavy is still planned to launch in late December right?

As of right now, yes.

But it could slip into next January.

[wannamoonbase]

The Falcon Heavy is still planned to launch in late December right?

As of right now, yes.

But it could slip into next January.

With just over 2 months left in the year, if they have it assembled and laying on the TEL before 12/31 that would be pretty amazing.

Who knows, from the time it's assembled till the time it flies may only be a few weeks.  Dare to dream.

[SPITexas]

The Falcon Heavy is still planned to launch in late December right?

As of right now, yes.

But it could slip into next January.

I doubt it will be January, even tho it’s already considered of being pushed back again.  They still want to launch it before the end of the year hopefully.  There nearly done finishing the LZ for the stages.

[M.E.T.]

I just had a thought and I'm not sure if it has been discussed or even raised before.

I have no idea if it is possible, but has anyone ever calculated what Falcon Heavy would be capable of lfiting to orbit and beyond if it had not just two side boosters next to the core stage, but say 4 or even 6 side boosters attached on all sides of the core, similar to how some of the Russian rockets have a whole bunch of boosters surrounding some of their heavy lift rocket cores.

Is such a configuration even feasible, and if so, what kind of capabilities would this open up for Falcon Heavy?