SpaceX v1.2 (FT) Core Discussion - Block 3, 4, and 5

[ecarfan]

In the Space Show radio program broadcast on 7/22/2017 at http://www.thespaceshow.com/file/7663/download?token=0hnS0L2y Gwynne Shotwell said that SpaceX is currently flying Falcon 9 Block 3, Block 4 coming soon, then 5 which will be the final iteration of the F9.

SpaceX is currently building F9s at a rate of 20/year. And it takes a little over a year to build a Falcon 9 from start to finish.

 

[RDoc]

Presumably at some point soon they'll have all the F9s they'll need as reuse becomes the norm. To be sure, they'll still need a few expendables for heavy payloads, but hopefully, they'll have some kind of heavier launcher done by the time they run out of cores.

 

[Grendal]

The Block 4 improvements will be more of a fluid change. The titanium grid fins that were on this last launch are a Block 4 improvement.

I liked how she mentioned that the current Merlin D's have been cranked up to 240K lbs of thrust (the first Merlin was 70K lbs of thrust) on the test stand. Block 5s are an improvement over that...

Presumably at some point soon they'll have all the F9s they'll need as reuse becomes the norm. To be sure, they'll still need a few expendables for heavy payloads, but hopefully, they'll have some kind of heavier launcher done by the time they run out of cores.

It's a bit off topic but it will be interesting to see how this will change production. If recovery becomes the norm and you have the Block 5 improvement and the stages can be reused 10 to 12 times before refurbishment then within a couple years you'll have a fleet of Falcon 9s and you won't be needing 20 of them a year. Falcon Heavy is even more rarely needed, for now. So I would guess at 2020 to 2021 that it could become an issue. Maybe they'll be focused on BFR/BFS by that time and only half the workforce will be needed for Falcon 9/H upkeep.

 

[Grendal]

There is speculation that SpaceX is currently building the first Block 5 booster. Reddit has two more Block 4 boosters pending and there may be any number of reuse flights to happen before this booster. The Block 5 booster is currently designated B1046. B1043 was Zuma, B1044 will likely be used for the very heavy HispaSat 30W-6 and is already in Florida, and B1045 is at MacGregor right now for testing with the expected payload to be TESS.

There is no confirmation that this is true, just speculation so far. SpaceX does need to get Block 5 launching ASAP.

 

[Cosmacelf]

Didn’t Elon say in his FH press conference, that they were only going to recover block 5 boosters from now on?

 

[ecarfan]

Didn’t Elon say in his FH press conference, that they were only going to recover block 5 boosters from now on?

I believe he said that from now on only Block 5 cores would be reflown. Not sure if he said specifically that from now on no Block 3/4 cores would be recovered. But I could be wrong.

 

[LCR1]

Whats the benefit with recovering after final flight and parting out vs just sending it off to burn up in the atmosphere

 

[ecarfan]

Whats the benefit with recovering after final flight and parting out vs just sending it off to burn up in the atmosphere

No one outside of SpaceX can answer your question with confidence. We don’t know how many parts in a Block 3/4 can be removed after recovery and used in a Block 5.

 

[Cosmacelf]

Actually, Elon did say that recovering the titanium grid fins was important. They are currently a production bottleneck and maybe expensive too.

 

[LCR1]

Actually, Elon did say that recovering the titanium grid fins was important. They are currently a production bottleneck and maybe expensive too.

If they had no plans to recover the rocket, I'm sure they would take them off before flight, same with the legs.

 

[Bobfitz1]

No one outside of SpaceX can answer your question with confidence. We don’t know how many parts in a Block 3/4 can be removed after recovery and used in a Block 5.

I've no idea how many air museums, air space museums, etc. might have space and the desire to showcase a recovered SpaceX booster.
But I think there must be a more than a few and NASA's space Disney World down at Johnson Space Center would surely take one.
Spreading better awareness of how SpaceX evolved from nothing to a key NASA partner and world's top commercial space company ought to be a worthwhile purpose for retiring previously flown boosters.

 

[Grendal]

First picture of a Block 5 booster by Chris R from Reddit:
B1046 headed through Yuma on its way to Texas for testing.

 

[Grendal]

For those asking about the differences, the details can be found here:

Falcon 9 Full Thrust - Wikipedia

 

[scaesare]

I liked how she mentioned that the current Merlin D's have been cranked up to 240K lbs of thrust (the first Merlin was 70K lbs of thrust) on the test stand. Block 5s are an improvement over that...

Are they detuned in use?

The Falcon 9 FT Wikipedia page you referred to earlier specifies 1,710,000 lbs of thrust,

 

[ccutrer]

Are they detuned in use?

The Falcon 9 FT Wikipedia page you referred to earlier specifies 1,710,000 lbs of thrust,

Multiply by nine, for nine engines per booster. The 1.71million number is actually a little low, if they’re up to 240k per engine.

 

[scaesare]

The 1.71million number is actually a little low

Hence my question. The post @Grendal made referenced 240K lbs thrust for "current" Merlin D's @ the Block 4 timeframe. That should equate to nearly 2.2mil lvs of thrust.

He was stating the Block 5's would be even greater, and the Wikipedia article said something like 7-8% more, which would put them over 2.3mil lbs. This puts the 1.71mil lbs a LOT low...

 

[Piney999]

Do we know when the Block 5 will have its maiden voyage?

 

[Grendal]

The picture on post #12 is thought to be the first Block 5 booster: B1046. It is on its way to McGregor, Texas for testing. It is speculated that it will used for the Bangabandu launch in late March/early April out of Florida. The booster will likely be confirmed as officially Block 5 when it is being tested in Texas. Some neighbor will manage to get a picture of it. This thread will give you details of the differences. Block 5 will be the design that freezes F9 and FH. Everyone expects that minor changes will continue to occur but the major overall design will stabilize so SpaceX can focus their efforts in other areas. The company might do something like stretch the second stage if a customer is willing to pay for that. That wouldn't be a change to the boosters though.

 

[Piney999]

Grendal, once again an abundance of SpaceX knowledge. Thank you!

 

[Electroman]

Amen. Thanks Grendal for all your postings.