Falcon Heavy - General Discussion

[Ulmo]

Wow, I had never thought of that. When looking at those beautiful images of those seemingly peaceful deployments, you don't realize how big and heavy those satellites might be. Not that it matters once they are in orbit, but still, they look tiny on the video.

I agree with respect to peacefulness aspect of it vs. how they would be to handle in person at 1G.

To help conceive of it, I think of a one ton pallet, something I transported during my cargo truck driving warehouse part of my employment. But those pallets were heavy! They always bumped up on the max the truck could carry, and I had to position the pallets properly and drive differently with them on; such pallets were not graceful to move around like those satellites looked in space videos.

Indidentally, this is one case where one ton and one megagram (1Mg) are both approximately similar measurements, and one of the rare cases where I think the Metric system isn't as bad as it is in other areas (temperature, length measurements, etc.). But, Metric being a piece of crap as always, I look it up and find out that "megagram" isn't supposed to be used, and instead, some inconsistent anti-math atrocity is mandated by the Metric System. Ok, so Metric sucks as always! Screw them. I extend the most benign of peace offerings to the Metric System, and it comes back and bites me like a rabid dog. Damn it to hell!

 

[Ulmo]

That was my point. I don't think it can. I think the 10 Iridiums are stuffed into the current fairing as it is. FH and F9 fairings are the same size. I'm almost certain that they can't be made any larger either. Anything larger would cause an unacceptable level of instability in F9 and FH. So that leaves redesigning F9 and FH or leaving them alone and focusing on BFR. SpaceX and Elon have said they will focus on BFR.

Please, Elon, go for it! If BFR is better because you realize the fallacy of sunken costs, then by all means, jump ship! I am so heartened whenever I hear of this push for BFR. It's a slight bit of a letdown from the original ITS, but BFR's usefulness, timeliness, and affordability stature are all fantastic in comparison to ITS and FH.


Glossary:

BFR= Big #&(&!^@ Rocket:

ITS= Interplanetary Transport System:

FH= Falcon Heavy:

; Falcon Heavy Static Fire Test.

F9= Falcon 9:
SpaceX on YouTube (almost every recent launch to date (Feb 4, 2018) & not one of the above vids)

SpaceX= "Space Exploration Technologies Corp.": SpaceX


When going through the glossary, it's nice to see the typical evolution: FH a "youthful" too-crazy and too-small ambition set to rambunctious rock music (but they're going to do it a little bit anyway; oops!); ITS a more mature upward correction with an attempt at professional big thinking that is too large and too crass (literally at the ending during the Q&A, hopefully edited out of the above vid); and then BFR growing up to an adult realistic right-sizing, way bigger thinking than the original youthful thoughts, yet smaller than the super upward correction (which turned out to be over-sized for best early time & cost efficiency), way more useful, getting all the goals, but much less crazy.

Addendum:

Here's a pic that was easy to generate with this posting that shows the comparison between the payload capability between BFR and ITS:

 

[Grendal]

Is there public price tag for Falcon Heavy reusable vs Falcon 9 FT expendable?

Expendable prices; "$62 million price tag on a modern Falcon 9 rocket --And the Falcon Heavy price is now $90 million"

Forget the Falcon Heavy’s payload and focus on where the rocket will go

SpaceX hasn't yet posted pricing for using reusable boosters. I believe SpaceX has just negotiated with each vendor individually. In most cases, for now, there are no discounts but the vendor gets priority on a launch date. I'm pretty sure that happened with Iridium. If there is a discount, I'd bet it's less than 10%. I expect that FH will always be flown only in recoverable mode unless someone big and powerful (like the military, government, or NASA) shells out even larger bucks for SpaceX to throw away 3 boosters for some critical launch that exceeds the recoverable numbers. Once Block 5 happens, as I mentioned before, you won't see any more expendable F9 launches either. Unless the vendor wants to use one of the previously flown boosters still laying around.

That is a smart move for SpaceX. Hold these older boosters for expendable launches.

 

[ccutrer]

SpaceX hasn't yet posted pricing for using reusable boosters. I believe SpaceX has just negotiated with each vendor individually. In most cases, for now, there are no discounts but the vendor gets priority on a launch date. I'm pretty sure that happened with Iridium. If there is a discount, I'd bet it's less than 10%. I expect that FH will always be flown only in recoverable mode unless someone big and powerful (like the military, government, or NASA) shells out even larger bucks for SpaceX to throw away 3 boosters for some critical launch that exceeds the recoverable numbers. Once Block 5 happens, as I mentioned before, you won't see any more expendable F9 launches either. Unless the vendor wants to use one of the previously flown boosters still laying around.

That is a smart move for SpaceX. Hold these older boosters for expendable launches.

Is it possible for Falcon Heavy to fly in different configurations of “expendable”? I.e. recover side boosters, but not center core, or vice versa. Just thinking of trying to match launc requirements of something like that to the most amount of recoverability.

 

[e-FTW]

I also loved that article, and came here to post it. As always, real life and work prevent me from doing that in a timely fashion. ;-)
Fantastic analysis folks. And yes, Eric wrote a great piece!

While reading it though, I kept being annoyed at the comparisons between FH and SLS. But I think it makes sense when you look at the potential market for FH, vs the priorities that Congress has set. And how SLS locks Congress into some long term plans that FH may not be able to break into.
I do appreciate that SLS can be a better fit for human missions to Mars and science to the outer solar system because of speed and power (especially second stage). But that wholly ignores the fact that BFR is being planned to address just that.
And as @Grendal pointed out, everyone needs to reset their interpretation of “they'll only build two Falcon Heavy” to mean SpaceX will be doubling their capability with a re-usable rocket. This does not mean two launches and call it a day, like some other system we know of...

 

[dhanson865]

Is it possible for Falcon Heavy to fly in different configurations of “expendable”? I.e. recover side boosters, but not center core, or vice versa. Just thinking of trying to match launch requirements of something like that to the most amount of recoverability.

FH has multiple recoverability options

* all 3 cores Return to landing site (RTLS) - lowest payload capacity
* 2 side cores RTLS, center core lands on an Autonomous Spaceport Drone Ship (ASDS) - next higher capacity

both of the first two options will see use for varying cargo loads and destinations.

* all 3 cores expendable - not likely cost would be prohibitive, but it would give maximum capacity

somebody might pay for this, but it'll be rare and expensive, may not happen, but definitely part of the advertised price list.

Those are known guaranteed options, now the possible what could they do?

* 2 side cores land on ASDS - center core expendable - not likely would require more drone ships and would slow launch cadence and increase cost
* 2 side cores expendable - center core lands on ASDS - not much gain in cargo capacity vs the RTLS option, not worth the cost difference?

The 2 side cores expendable could be a way to use up old block 4 first stages since they have so many but I'd assume they would rather have those as insurance (falcon 9 production stops at some point and they need a stock pile of usable boosters for contract missions while switching over to BFR/ITS production. So maybe they just keep a few in reserve in case the transition lasts longer than they expect).

I think you'll only see the top two RTLS options covering 90% of the flights, none of the expendable variations are likely but if they go there I'd say it'd be for an all out everything goes launch. You either get 3 cores back or you send 3 cores out never to come back, nothing in between.

 

[jkn]

That was my point. I don't think it can. I think the 10 Iridiums are stuffed into the current fairing as it is. FH and F9 fairings are the same size. I'm almost certain that they can't be made any larger either. Anything larger would cause an unacceptable level of instability in F9 and FH. So that leaves redesigning F9 and FH or leaving them alone and focusing on BFR. SpaceX and Elon have said they will focus on BFR.

Lack of cargo space limits FH capacity to low orbit. For high orbits, Moon and planets it has enough cargo space.

SpaceX has not yet saved significantly with reuse. (If it can be used only twice, it needs lot of service between flights.) Block 5 will change that.

I look it up and find out that "megagram" isn't supposed to be used,

There is nothing wrong with Mg. Who says it should not be used?

 

[bxr140]

Lack of cargo space limits FH capacity to low orbit.

...and specifically the diameter, hence BFR (and new Glenn). A wider base is necessary to keep heavier loads stable.

 

[e-FTW]

Also, from the Ars article, we are reminded of how the location in Hawthorne forced SpaceX into designing FH with Falcon 9 cores.
They need to build BFR elsewhere to be able to move it out of the factory and to a launchpad.

 

[KarenRei]

* all 3 cores expendable - not likely cost would be prohibitive, but it would give maximum capacity

somebody might pay for this, but it'll be rare and expensive, may not happen, but definitely part of the advertised price list.

I can't imagine commercial launches ever needing anything that large, but I can readily picture NASA taking advantage of that for flagship missions. Possibly some large military sats as well. It's really not that expensive, so you might as well up your spacecraft capabilities (and consequently mass). One thing that SpaceX's low prices are also doing (and will keep doing moreso in the future) is making it so that you don't have to spend a fortune to try to shave tiny bits off your spacecraft masses.

 

[Ulmo]

Published on Apr 5, 2011

Elon Musk introduces the world's most powerful rocket from SpaceX.

 

[RDoc]

...and specifically the diameter, hence BFR (and new Glenn). A wider base is necessary to keep heavier loads stable.

I'd like to see a source for that statement because it makes very little sense to me. The stability of an object has a lot more to do with the center of mass location and its stiffness than the width of the base. There have been several launches where satellites were stacked into a pretty tall package.

AFAIK, larger diameter fairings are being worked on because they may be attractive for future missions that use physically larger payloads.

 

[bxr140]

The stability of an object has a lot more to do with the center of mass location and its stiffness...

Lol. That’s exactly what I said.

Since both stiffness and CG have more or less been optimized already, the only practical solution for larger payloads (size or mass or both) is a wider structure. A taller payload of the same mass or a heavier payload of the same size are both going to have a higher CG and be more flimsy.

There have been several launches where satellites were stacked into a pretty tall package.

Indeed. Ariane 5 does that all the time...and the Sylda is a super wide, super stiff structure that completely envelopes the lower payload and barely fits in the fairing. The upper payload is not connected in any way to the lower payload, because if it was the lower payload would have to be ridiculously overbuilt. Most of the big names in the commercial industry are trying to overcome that problem, since the Sylda is effectively wasted mass that you could theoretically put on the satellites themselves [as more capability], but to date its been a tough one to crack without actually sacrificing mission capability.

AFAIK, larger diameter fairings are being worked on because they may be attractive for future missions that use physically larger payloads.

Of course necessarily wider payloads is one reason--you can cram a wider telescope or antenna in a fatter fairing, for instance. That said, if you look at fairing volume vs payload volume for pretty much any launch, there's a lot of unused space above the payloads, not to mention some amount of unused launch mass capacity. The reason is because impractical to fill that space with payload because to do so you need to create an inherently less stable object that will start to break the CLA.

 

[dhanson865]

Published on Apr 5, 2011

Elon Musk introduces the world's most powerful rocket from SpaceX.

Some things that have changed since the 2011 reveal

In the video he expected FH launch in Dec 2012, looks to actually happen in Feb 2018 (5 years and a few weeks later)

* First launch in FL not CA (SpaceX didn't have access to 39A in 2011)
* Propellant cross feed feature removed.
* Max LEO Payload increased from 117,000 pounds to 140,660 pounds (fully expendable launch)
* Payload to Mars increased from ~30,000 pounds to 37,040 pounds (fully expendable launch)
* $1,000 per pound target has inflated to about $1,400 per pound on fully expendable (using $90m price, 5 years of inflation + a slight miss on price)

We don't have fully reusable cargo weight and any price difference between reusable or expendable so that price per pound might be higher or lower depending on your target weight and what the price difference is.

 

[jkn]

The approved unit is Tonne.

Replies to Discussion of Numerical Punctuation

Mg is official SI unit: International System of Units - Wikipedia
versions of ton are not.

My translation of local law as I understand it (not a lawyer):
"SI units must be used when measurement is required by law or has economic value or has effect on safety or health."

Another cargo on a rocket test launch: Home

 

[Grendal]

Here is an article from the LA Times about FH. It includes some info on a press conference Elon gave today concerning the rocket. It has a slightly provocative title but the content is pretty accurate.

SpaceX nears launch of Falcon Heavy, facing a changing market for heavy-lift rockets

Ars Technica article that covers the presentation and questions:

Elon Musk says the Falcon Heavy has a 50-50 chance of success

 

[e-FTW]

Here is an article from the LA Times about FH. It includes some info on a press conference Elon gave today concerning the rocket. It has a slightly provocative title but the content is pretty accurate.

SpaceX nears launch of Falcon Heavy, facing a changing market for heavy-lift rockets

Ars Technica article that covers the presentation and questions:

Elon Musk says the Falcon Heavy has a 50-50 chance of success

Good reads there. Especially the Ars interview. I love Ars.

 

[Nikxice]

Might be premature, but still fascinating to hear Elon at Monday's short news conference theorizing about the possibility of a Falcon Super Heavy. Quoting from 'The Verge', "Musk was asked whether SpaceX can increase the Falcon Heavy’s performance over time, much like it has with the Falcon 9. That’s when the CEO suggested the possibility of a Falcon Super Heavy — a Falcon Heavy with extra boosters. “We could really dial it up to as much performance as anyone could ever want. If we wanted to we could actually add two more side boosters and make it Falcon Super Heavy,” Musk said. This five-rocket Falcon Super Heavy would have around 9 million pounds of thrust, Musk said, nearly doubling the rocket’s current capability, and putting it in line with the Saturn V as the most powerful rocket ever built." .....Perhaps adding another stepping stone prior to building the BFR?

 

[Grendal]

Both Jeff Bezos and Tony Bruno tweeted Good Luck to Elon. Very cool.

 

[dhanson865]

Might be premature, but still fascinating to hear Elon at Monday's short news conference theorizing about the possibility of a Falcon Super Heavy. Quoting from 'The Verge', "Musk was asked whether SpaceX can increase the Falcon Heavy’s performance over time, much like it has with the Falcon 9. That’s when the CEO suggested the possibility of a Falcon Super Heavy — a Falcon Heavy with extra boosters. “We could really dial it up to as much performance as anyone could ever want. If we wanted to we could actually add two more side boosters and make it Falcon Super Heavy,” Musk said. This five-rocket Falcon Super Heavy would have around 9 million pounds of thrust, Musk said, nearly doubling the rocket’s current capability, and putting it in line with the Saturn V as the most powerful rocket ever built." .....Perhaps adding another stepping stone prior to building the BFR?

Interesting but I'd take exception to calling it "This five-rocket" rocket. It has that that quality of saying something like VIN Number or PIN Number with the added bit of imprecise terminology added to the redundancy.

I know you didn't write this and I'm sure Elon didn't use that exact phrase but if the person that did wanted to avoid terminology issues they could have gone with "This 5 core Falcon Super Heavy" which gets the point across while ignoring the 2nd stage or maybe "This Falcon Super Heavy would have 45 first stage engines" to avoid talking about what the 5 things are standing side by side.