SpaceX Falcon Heavy Discussion (Thread 6)

[speedevil]

Given that there is talk of F9/H reentry tests, not a reusable S2, if an F9 or FH flight costs less than a BFS flight due to the amortization then BFR/BFS has failed to meet a large portion of its goals.

Paraphrasing:

I think in 2-3 years, we could be able to launch a fully reusable F9 for $6M

I think this was at the falcon heavy post-launch conference.
Clearly - FH can be similarly reusable if so.

I think this was the first mention they were actively considering actual full reuse, not it just being a research tool.
This would - if true - mean that Falcon Heavy could do nearly all the commercial launches BFR can do in the near term, for nearly the same cost per flight.

[Lar]

...because the cost to construct each vehicle will (at least initially) make it more expensive than any other vehicle on the market...

Depending on timing, I'd venture that an expendable BFS may be cheaper than a Delta IV Heavy

... If using up a F9 flight costs you less, then ...

Given that there is talk of F9/H reentry tests, not a reusable S2, if an F9 or FH flight costs less than a BFS flight due to the amortization then BFR/BFS has failed to meet a large portion of its goals.

... unless S2 production costs decline dramatically, OR unless the vehicle is being amortized over so many flights compared to a Marsbound BFS that the amortization is dramatically lower....

(not sure I see either as likely but they should be mentioned for completeness..... that said this is probably off topic as Gongora pointed out)

[su27k]

https://www.teslarati.com/spacex-executive-nobody-paid-us-to-make-falcon-heavy/

Seems that SpaceX refused government funding for FH, quite surprising:

Perhaps most intriguing of all Koenigsmann’s comments was an almost unprovoked segue into the US government’s involvement in Falcon Heavy development. According to the SpaceX executive, the company was actually approached by “the government”, with the unknown agency or agencies stating – in Hans’ words – that they wanted to be a part of the rocket’s development. According to Hans, SpaceX responded in an extremely unorthodox fashion: “we said, ‘Nope! We just wanna build it, you can buy it when it’s ready and we’ll charge you for the service.'” He noted in the next sentence that funding was the primary lever on the table:

“It’s a great position to do this, you gotta find the money, you gotta know people that have money and are willing to invest in your company, and [SpaceX has] been lucky enough to know some of those people.”

[woods170]

https://www.teslarati.com/spacex-executive-nobody-paid-us-to-make-falcon-heavy/

Seems that SpaceX refused government funding for FH, quite surprising:

Perhaps most intriguing of all Koenigsmann’s comments was an almost unprovoked segue into the US government’s involvement in Falcon Heavy development. According to the SpaceX executive, the company was actually approached by “the government”, with the unknown agency or agencies stating – in Hans’ words – that they wanted to be a part of the rocket’s development. According to Hans, SpaceX responded in an extremely unorthodox fashion: “we said, ‘Nope! We just wanna build it, you can buy it when it’s ready and we’ll charge you for the service.'” He noted in the next sentence that funding was the primary lever on the table:

“It’s a great position to do this, you gotta find the money, you gotta know people that have money and are willing to invest in your company, and [SpaceX has] been lucky enough to know some of those people.”

Emphasis mine.

It is not surprising. This way of doing things allowed SpaceX to do FH the way they envisioned it, without the government trying to change the design (like USAF did during early F9 qualification, until they were slapped on the hands by the Secretary of the AirForce).

Much the same approach is being used by SpaceX for BFR/BFS. At least, that is what SpaceX folks keep telling me.

So no, it is not surprising. People who have closely monitored SpaceX over the past 16 years know that SpaceX does things in an unorthodox fashion most of the time.

Also, it fits a SpaceX belief with regards to funding of launcher development: keep out direct government funding as much as possible. Examples:
- Falcon 1 development was fully funded with private money.
- Falcon 9 v1.0 saw some direct funding by the government (COTS), but most was again private funding.
- Falcon 9 v1.1 and Falcon 9 FT, all the way up to the current Block 5 have used only limited direct government funding (CCP). Most funding was again private.
- FH was completely funded with private money (like Falcon 1)
- BFR/BFS is being privately funded except for part of the development funding of the Raptor engine.

[ThePonjaX]

https://arstechnica.com/science/2018/10/spacexs-falcon-heavy-rocket-seems-to-be-a-hit-with-satellite-companies/

Seems the demo worked for more FH missions, which is great but I think Spacex has contract before with at least with Viasat.

[noogie]

IIRC that this was an option being taken up and turned into a firm booking.
They lost an earlier Viasat launch to Ariane due to delays

[wannamoonbase]

IIRC that this was an option being taken up and turned into a firm booking.
They lost an earlier Viasat launch to Ariane due to delays

Still a FH flight.  It's nice to see it getting some traction.

The next couple of years with more (re)flights of FH and F9 it will be interesting to see if others opt for the increased FH capability or if operators select larger birds.

I've been following the space industry my whole life and this is the first time we have such a market disruption. It's all very exciting. (Edit: Maybe I'll see my moonbase yet)

[ThePonjaX]

IIRC that this was an option being taken up and turned into a firm booking.
They lost an earlier Viasat launch to Ariane due to delays

Still a FH flight.  It's nice to see it getting some traction.

The next couple of years with more (re)flights of FH and F9 it will be interesting to see if others opt for the increased FH capability or if operators select larger birds.

I've been following the space industry my whole life and this is the first time we have such a market disruption. It's all very exciting. (Edit: Maybe I'll see my moonbase yet)

Is OT but, you've the Elon promise:



https://twitter.com/elonmusk/status/1055350177941225473

[FutureSpaceTourist]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

[Alexphysics]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

It seems no one spent any real time trying to calculate the GEO numbers for F9 and FH so they could be put into that graphic...   

[Jcc]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

It seems no one spent any real time trying to calculate the GEO numbers for F9 and FH so they could be put into that graphic...   

F9/H have yet to perform a direct insertion, although with S2 coast time proven with the FH demo, it should certainly  be possible.

[Alexphysics]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

It seems no one spent any real time trying to calculate the GEO numbers for F9 and FH so they could be put into that graphic...   

F9/H have yet to perform a direct insertion, although with S2 coast time proven with the FH demo, it should certainly  be possible.

Has Vulcan done it too? No, right? Does it have to fly to calculate the theoretical performance of the rocket? No.

[MP99]

Seems to me... 
...a known satellite maker (like say SSL) could clean up in the planetary probe marketplace (such as it is) by designing a high capacity Hypergolic (not cryo) '3rd stage' that uses a SpaceX's dragon trunk perimeter mount to attach to a FH S2 (for lighter weight and efficient load transfer) and this new S3 "stage" is topped with a smaller Ruag fairing (as probes tend to be smaller anyway)...

SpaceX gets contracted to launch ~50 tonnes to LEO with Boosters to ASDS's and Core expended...
S2 saves enough prop to deorbit also... SpaceX gets $95mil plus for the trouble and expenses...

SSL has literally tonnes of prop margin to play with... to push the paying customers probe out to it's destination...

Bottom line is SpaceX likely does not want to get directly into high energy C3 launches, as they are few and far between.
But if someone like SSL wanted to finish the job and make FH the 'go to, lowest cost to way out there' C3 king...
Then yeah... 

Seems to me... 
...a known satellite maker (like say SSL) could clean up in the planetary probe marketplace (such as it is) by designing a high capacity Hypergolic (not cryo) '3rd stage' that uses a SpaceX's dragon trunk perimeter mount to attach to a FH S2 (for lighter weight and efficient load transfer) and this new S3 "stage" is topped with a smaller Ruag fairing (as probes tend to be smaller anyway)...

SpaceX gets contracted to launch ~50 tonnes to LEO with Boosters to ASDS's and Core expended...
S2 saves enough prop to deorbit also... SpaceX gets $95mil plus for the trouble and expenses...

SSL has literally tonnes of prop margin to play with... to push the paying customers probe out to it's destination...

Bottom line is SpaceX likely does not want to get directly into high energy C3 launches, as they are few and far between.
But if someone like SSL wanted to finish the job and make FH the 'go to, lowest cost to way out there' C3 king...
Then yeah... 

(Sorry for necro of an old post.)

ISTM that's the existing role for Star.

SpaceX have the S1 from Falcon 1, which could provide the basis for such a stage, if they wanted to go that way. Simple pressure fed engine, etc.

It would need to be modified to install under the PLF, and maybe stretched.

OTOH, you know SpaceX. It would be re-engineered, probably enhanced for subcooled kerolox, etc, etc. Would be quite a big project in the end.

But then it could be useful for high C3 missions from BFS, if they're willing to put that inside BFS.

Cheers, Martin

Sent from my GT-N5120 using Tapatalk

[docmordrid]

Why bother arapting a Merlin when they're developing methane thrusters for BFR based on the Raptor chamber design?  Or, evolve a new member of the Draco family. Still pressure fed, add the appropriate nozzle.

[LouScheffer]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

It seems no one spent any real time trying to calculate the GEO numbers for F9 and FH so they could be put into that graphic...   

OK, here are some guesses.  For F9 expendable, we know Intelsat-35 put 6700 kg into a 42000 km apogee.  This is about 100 m/s more than a GEO apogee.  So if we save that 100 m/s for apogee, we need 1700 m/s more for direct injection.  Using the more or less usual assumptions (ISP=348, fuel = 111.5t, empty mass = 4.5t) then must reduce the payload mass to 2.2t to get the extra performance needed.

Another way to estimate F9 is to know it could put 7000 kg into a GEO apogee (based on Intelsat 6700 kg to 42000 km).  Now they need 1800 m/s to circularize.  At an ISP of 348, that's a mass ratio of 1.7 .  With a 4.5t empty stage, the initial mass is 7000 + 4500 = 11500, the final mass 6.8t, and the payload 2.3t.   So it's consistent.

For the FH, from the graph it can put 26t into GTO.  If the empty mass is 5t (maybe it needs to be stronger) then the stack mass in GTO is 31t.  Using the mass ratio of 1.7, at the end of the burn stack masses 18t.  Subtract the 5t empty mass to get a 13t payload.

[speedevil]

For the FH, from the graph it can put 26t into GTO.  If the empty mass is 5t (maybe it needs to be stronger) then the stack mass in GTO is 31t.  Using the mass ratio of 1.7, at the end of the burn stack masses 18t.  Subtract the 5t empty mass to get a 13t payload.

Exactly what the other penalties are is an interesting question.
If you vent the tanks (as was apparently done for the demo mission), you can greatly reduce heat conduction in them, and this, and proper use of ullage and surface tension may let you stick the propellant to the appropriate ends so you don't get the liquid oxygen trying to freeze the kerosene. Or allow you to place the liquid oxygen in a shadowed portion of the tank.

This of course means you need more helium to repressurise them.
(Of course, the intertank insulation may in fact be good enough this is not an issue)
If the kerosene freezing was not in fact driving the desire to vent the tanks, the oxygen heating up and overpressurising the tank could be - that could be mitigated by pointing the vehicle at the sun post GTO burn, and appropriate use of ullage.

A minimum number could be gotten by estimating the tesla mission performance, but from memory, there were areas where the profile seemed considerably sandbagged, making it hard to determine what reality is.

[lrk]

If you vent the tanks (as was apparently done for the demo mission)

Source on this?  Keep in mind F9/FH use hot helium, pre-heated by the turbopump exhaust, to pressurize the tanks.  My (possibly incorrect) understanding is that the long coast allowed the helium in the tanks to cool, requiring extra helium for repressurization after the coast.  Also the engine requires helium for spin-starting the turbopump, and the FH demo did 3 burns instead of 2 like on most missions. 

[Herb Schaltegger]

Elon Musk’s big Falcon Heavy rocket might find a market after all
By Tim Fernholz1 hour ago

https://qz.com/1439557/spacex-is-building-a-market-for-falcon-heavy/

Graphic from article attached

It seems no one spent any real time trying to calculate the GEO numbers for F9 and FH so they could be put into that graphic...   

F9/H have yet to perform a direct insertion, although with S2 coast time proven with the FH demo, it should certainly  be possible.

Has Vulcan done it too? No, right?

Vulcan-Centaur hasn't, but [FIRST STAGE OF CHOICE] + Centaur has many times, and that's not nothing.

(Just playing Devil's advocate here; I'm well aware SpaceX has done a number of S2 long-coast experiments and tests in the last couple years).

[Lars-J]

F9/H have yet to perform a direct insertion, although with S2 coast time proven with the FH demo, it should certainly  be possible.

Has Vulcan done it too? No, right?

Vulcan-Centaur hasn't, but [FIRST STAGE OF CHOICE] + Centaur has many times, and that's not nothing.

(Just playing Devil's advocate here; I'm well aware SpaceX has done a number of S2 long-coast experiments and tests in the last couple years).

Yes, but the Centaur stage flying on Vulcan will be a new design. Many components will be the same or similar, but the tank structure has never flown, so it really does count as a new upper stage. No matter what ULA will say.

[Lar]

Let's not go too far down the Vulcan Centaur road...