SpaceX Falcon Heavy Discussion (Thread 6)

[Jim]

The advantage of the triple booster is largely to lower the cost of an interim payload size growth in the market.

The disadvantage is that it can amplify costs, as it does for DIVH.

not true.  Atlas V Heavy would not have had the same issues. 
DIVH issues stem from under performance of the basic core and hence the 5 to 6 core versions needed to meet EELV requirements.

[Jim]

So can anyone share a little bit about the development of Delta IV Heavy?

One thing we know about Delta IV is that it has, IIRC, four different versions of core:  single-stick medium core, heavy core, left booster core and right booster core.  That makes it more expensive than it ought to be.  The plan was for just three cores, with the heavy core flying as the medium core, but performance shortfalls meant that the medium core had to be lightened, making it a separate variant.  It sounds like the Falcon family has at most three cores, because the left and right heavy boosters are identical.

For Delta IV Heavy, even Left and Right booster are not the same?

mirror images of each other.
Atlas V would have just had one core for all vehicles, even heavy

[Space Ghost 1962]

The disadvantage is that it can amplify costs, as it does for DIVH.

not true.  Atlas V Heavy would not have had the same issues.

Atlas V Heavy had other issues. Similar to F9H as a paper rocket, both used singular designed cores. You're overselling here.

 
DIVH issues stem from under performance of the basic core and hence the 5 to 6 core versions needed to meet EELV requirements.

True that RS68 way underperformed, overcosted, ... They didn't want to wait for meeting spec, chose "good enough ".

True that booster structure/ mass also missed spec. Same reason.

Hundreds of other issues make both clustered EELV's fiscally infeasible and "doomed".

You are cherry picking to save EELV "face".

Reuse, flight frequency, and low cost architecture outcompetes them, judged on the same scale/execution.

Nothing new here.

[Jim]

Atlas V Heavy had other issues. Similar to F9H as a paper rocket, both used singular designed cores. You're overselling here.

Not true at all.  Atlas V Heavy has no "issues", just needed time.   The core as it can handle 0-5 SRBs.  Heavy loads would be less.

[Jim]

Hundreds of other issues make both clustered EELV's fiscally infeasible and "doomed".

Wrong again.  If designed right, it is cheaper than two different vehicles (F9 and mini ITS)

[Space Ghost 1962]

Atlas V Heavy had other issues. Similar to F9H as a paper rocket, both used singular designed cores. You're overselling here.

Not true at all.  Atlas V Heavy has no "issues", just needed time.   The core as it can handle 0-5 SRBs.  Heavy loads would be less.

Rebuild of VIF - barely enough room for SRBs/GSE. Rebuild of launch table. lssues with MLP. Upscaleing props loading.

Atlas V skipped heavy bc LM did minimal bid /work bc didn't know if it (EELV) would ever pay back investment, which was smart.

[Space Ghost 1962]

Hundreds of other issues make both clustered EELV's fiscally infeasible and "doomed".

Wrong again.  If designed right, it is cheaper than two different vehicles (F9 and mini ITS)

Don't drag ITS into it.

Reuse of side boosters alone means EELV heavies doomed.

You were the one years back who said who could hav known they could have made such a cheap kerolox architecture. You were right then. Same is true now, even if you evade to avoid an uncomfortable truth.

[Jim]

Atlas V Heavy had other issues. Similar to F9H as a paper rocket, both used singular designed cores. You're overselling here.

Not true at all.  Atlas V Heavy has no "issues", just needed time.   The core as it can handle 0-5 SRBs.  Heavy loads would be less.

Rebuild of VIF - barely enough room for SRBs/GSE. Rebuild of launch table. lssues with MLP. Upscaleing props loading.

Atlas V skipped heavy bc LM did minimal bid /work bc didn't know if it (EELV) would ever pay back investment, which was smart.

Wrong, LM did more than minimal work.  The CCB was structurally designed for it.  The VIF as is can support it. It was designed from the beginning for the Heavy.  The platform cutouts for side boosters exist.  The MLP required no rebuild.  It was designed from the beginning for the Heavy.  The openings for the side boosters is what the current SRBs are mounted over. The MLP just needed to be outfitted for the side boosters (holddowns, LOX TSMs, and avionics umbilical).

[CyndyC]

So we had to redesign the whole center-core airframe on the Falcon 9 because it’s going to take so much load.

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously? 

[old_sellsword]

So we had to redesign the whole center-core airframe on the Falcon 9 because it’s going to take so much load.

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously?

The “airframe” of a Falcon consists of the octaweb, aft skirt, tank walls, and interstage. We know for a fact that the octaweb, aft skirt, and interstage are more structurally reinforced than a normal F9/FH side booster, but I’m not sure if the FH center core will have thicker tank walls.

[Jim]

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously? 

All rockets are made that way since the V-2

[CyndyC]

So we had to redesign the whole center-core airframe on the Falcon 9 because it’s going to take so much load.

The “airframe” of a Falcon consists of the octaweb, aft skirt, tank walls, and interstage. We know for a fact that the octaweb, aft skirt, and interstage are more structurally reinforced than a normal F9/FH side booster, but I’m not sure if the FH center core will have thicker tank walls.

Thanks!

[pippin]

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously? 

All rockets are made that way since the V-2

Over-generalization. See N1

[Jim]

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously? 

All rockets are made that way since the V-2

Over-generalization. See N1

N-1 just used over sized interstages ;-)

[envy887]

Excuse me, if I may, clustered or not, I believe Jim or someone else once confirmed the walls of the LOX & RP-1 tanks and the walls of the rocket are one & the same, so what is the airframe? Is this the first this particular upgrade has been made public, or has it been discussed previously? 

All rockets are made that way since the V-2

Over-generalization. See N1

N-1 just used over sized interstages ;-)

Everyone seems to be forgetting the intertanks most rockets use... Definitely rocket wall but not tank wall.

[matthewkantar]

Didn't the V-2 have an outer load carrying shell? I remember a video of a tech stuffing the space between the shell and the skin with insulation.

Matthew

[Space Ghost 1962]

Atlas V Heavy had other issues. Similar to F9H as a paper rocket, both used singular designed cores. You're overselling here.

Not true at all.  Atlas V Heavy has no "issues", just needed time.   The core as it can handle 0-5 SRBs.  Heavy loads would be less.

Rebuild of VIF - barely enough room for SRBs/GSE. Rebuild of launch table. lssues with MLP. Upscaleing props loading.

Atlas V skipped heavy bc LM did minimal bid /work bc didn't know if it (EELV) would ever pay back investment, which was smart.

Wrong, LM did more than minimal work.  The CCB was structurally designed for it.  The VIF as is can support it. It was designed from the beginning for the Heavy.  The platform cutouts for side boosters exist.  The MLP required no rebuild.  It was designed from the beginning for the Heavy.  The openings for the side boosters is what the current SRBs are mounted over. The MLP just needed to be outfitted for the side boosters (holddowns, LOX TSMs, and avionics umbilical).

Atlas V Heavy made it to CDR, but Delta IV Heavy won a launch and thus made it to flight. (If DIVH failed along the way, then all the details we're back/forth over would have been dealt with more time and budget.) Can't think of what otherwise would have paid for a rational AVH.

There was no reason/customer for Atlas V Heavy (likewise FH) since DIVH got there first.

(Still maintain that LM got the better of the deal over Boeing, who didn't have to do so much "new" propulsion/pad/structural/avionics/engine/other. And it shows in AV accumulated flight history/performance.)

Note that cost doesn't/didn't play a factor in choice of "heavy" - you just need the occasional utility of such. One is enough. Nor for that matter flight frequency.

But an essential for national security.

[Jim Davis]

Soyuz is clustered, Proton is not.

I'm pretty sure the Proton first stage consists of a cluster of tanks, 6 fuel tanks surrounding a larger oxidizer tank.

And Soyuz does not use identical 'cores', the center one is very different.

And why is that a disqualification for being considered clustered?

[gongora]

"Clustered" as it is being used here is putting together several similar boosters as the first stage.  Soyuz and Proton aren't even close to that.  Soyuz has four strap on boosters that are a different design from the core.  Proton doesn't even use additional boosters on the first stage.

[Proponent]

There was no reason/customer for Atlas V Heavy (likewise FH) since DIVH got there first.

Boeing broke the law at some stage in its competition with LM, and I think it was in connection with the heavy variant.  Boeing was punished by losing some launches.