Author Topic: 5 core (4 booster) variant of FH  (Read 22629 times)

Offline moralec

5 core (4 booster) variant of FH
« on: 01/27/2015 09:56 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?



Offline meekGee

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Re: 5 core (4 booster) variant of FH
« Reply #1 on: 01/27/2015 10:10 pm »
I think you want more pads than cores.  Otherwise it is too easy to run out of pads if something is not nominal.

I think this is actually a 4 pad system.  The center pad is the crash pad, and the cores normally divert to the side pads, so you have 4 active pads, and one extra pad in case you're otherwise full.

So if for whatever reason you're launching FHs fast, you don't absolutely have to get the cores out of the way before the next one comes in.
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Offline nadreck

Re: 5 core (4 booster) variant of FH
« Reply #2 on: 01/27/2015 10:17 pm »
hmm, what about a 5 booster single core where the core reaches orbit? I think that technically could work, the cross feed would be quite tricky and all boosters have to drop at the same time (a 4 booster one could have a complicated cross feed and drop two and then another two for greater efficiency but probably would not yield as useful a payload).

I think the 1 technical advantage would be to deliver something with a larger volume as well as weight to LEO, without the existing 2nd stage you could make a wider, longer fairing and support it's weight better with the single core.

 However let me suggest that SpaceX starts painting them orange  8) (ducks and covers)
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Offline Lars-J

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Re: 5 core (4 booster) variant of FH
« Reply #3 on: 01/27/2015 10:47 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

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Offline macpacheco

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Re: 5 core (4 booster) variant of FH
« Reply #4 on: 01/27/2015 11:07 pm »
Falcon Heavy with cross feeding, side boosters RTLS center booster barge landing offer massive payload, very few missions would require sacrificing the center booster, then why an even bigger FH ? They need the advantages of Raptor to go full reusability and have a single first stage booster instead.
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Offline CJ

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Re: 5 core (4 booster) variant of FH
« Reply #5 on: 01/27/2015 11:19 pm »
Hrmmm....

Okay, 5 pads, one larger than the others. That's intriguing, but, we also should bear in mind that landing pads like these are cheap - easier and cheaper to built what you might need all at once. 

The larger pad is interesting. I'm going to hazard a wild guess that it could be for Dragon?

IMHO, the first thing we ought to look at regarding a hypothetical 5 core FH is, is it possible? That IMHO depends on how the hard attach points are designed; if designed so that a stage structural redesign is needed for 5 cores, it ain't happening. Second issue, cost; is there a financial reason to go 5 core? If not, it ain't happening.

On the flip side, if a future FH variant with 5 cores is even being considered, it'd make financial sense to pour all 5 pads at once. 




Offline Damon Hill

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Re: 5 core (4 booster) variant of FH
« Reply #6 on: 01/27/2015 11:21 pm »
Requires launch pad/transporter/erector/assembly building to handle this configuration.

Launches on four boosters, core ignites at altitude or shuts down after liftoff and restarts at separation (in-flight shutdown/restarts have been demonstrated multiple times).  No crossfeed needed, core could run on five engines with expanded nozzles (will octoweb support this?).  Excessive energy means no core recovery.  Presumed higher payload could require semi-custom core with strengthening.

Serious high energy upper stage needed?  Could boosters separate as pairs and return un-separated?

Not really seeing this; this is what BFR is for.  But fun to speculate if BFR is delayed and an interim solution might be needed for some heavy/high energy mission.

Don't know how to do the math, so little idea of potential payloads/missions a hypothetical F9DoubleH could meet.
« Last Edit: 01/27/2015 11:23 pm by Damon Hill »

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #7 on: 01/28/2015 12:00 am »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

Wrong assumption.  There is no such thing.  This is the second time you posted this nonsense.

Offline moralec

Re: 5 core (4 booster) variant of FH
« Reply #8 on: 01/28/2015 12:17 am »

The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

Wrong assumption.  There is no such thing.  This is the second time you posted this nonsense.

Three comments about this
1) I was not the one that originally came with the hypothesis.: I just opened the thread for the fun of speculation.
2) Nether you and me have enough evidence to either confirm and discard this. That means that, even if minor, is a possibility.  Rewind 5 months: You were attacking me in a similar way saying we will never see a falcon booster landing on a barge.... and then, here we  are....
3) Even is Space X is not planing to do this it is very entertaining to speculate about these sort of things.

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #9 on: 01/28/2015 12:40 am »

2) Nether you and me have enough evidence to either confirm and discard this. That means that, even if minor, is a possibility.  ..
3) Even is Space X is not planing to do this it is very entertaining to speculate about these sort of things.

2.  yes, it is very easy to discard this.  There is no need, they have the MCT

3. No, it isn't.  It dilutes the speculation of things that are really going happen.  There is still a lot of FH to look into vs a vehicle that is not going to exist.  There is even the MCT to speculate about.

Offline Karlman

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Re: 5 core (4 booster) variant of FH
« Reply #10 on: 01/28/2015 01:03 am »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

I'd guess a more likely possibility is returning boosters from both a F9 and a FH on the same day or something like that.. that would be 4 boosters..leaving 1 spare pad.
They will soon have 2 launch pads that could utilize the landing area.
(assuming things like return to land is approved, and other issues that currently keep launches separated by a couple of days are also changed).


Offline Ohsin

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Re: 5 core (4 booster) variant of FH
« Reply #11 on: 01/28/2015 05:02 am »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

May be UAE can have some answers for you.
http://forum.nasaspaceflight.com/index.php?topic=35195.msg1228389#msg1228389
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Offline moralec

5 core (4 booster) variant of FH
« Reply #12 on: 01/28/2015 11:55 am »
What a crazy video!

Any possibility that the HF transporter/erector/assembly building could support one extra booster? Or new ground infrastructure would still be needed?
« Last Edit: 01/28/2015 11:59 am by moralec »

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #13 on: 01/28/2015 12:01 pm »
What a crazy video!

¿Any possibility that the HF transporter/erector/assembly building could support one extra booster? Or new ground infrastructure would still be needed?


It would require new hangar, new GSE, new erector and new pad.  nothing that currently exists or is in design for FH can be used for this concept
« Last Edit: 01/28/2015 12:01 pm by Jim »

Offline moralec

Re: 5 core (4 booster) variant of FH
« Reply #14 on: 01/28/2015 12:07 pm »

What a crazy video!

¿Any possibility that the HF transporter/erector/assembly building could support one extra booster? Or new ground infrastructure would still be needed?


It would require new hangar, new GSE, new erector and new pad.  nothing that currently exists or is in design for FH can be used for this concept

It's a no go then, just like the 4 booster version. Thanks Jim.

Offline AncientU

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Re: 5 core (4 booster) variant of FH
« Reply #15 on: 01/28/2015 02:17 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

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Offline GreenShrike

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Re: 5 core (4 booster) variant of FH
« Reply #16 on: 01/28/2015 05:23 pm »
I'd guess a more likely possibility is returning boosters from both a F9 and a FH on the same day or something like that.. that would be 4 boosters..leaving 1 spare pad.

Having five pads would be useful for a twin Falcon Heavy mission, with one launching the payload and the other launching an EDS or fuel tanker or something. The lighter FH could do a 3-core return, and the heavier a 2-core with downrange recovery of the center core on the Reader or other spaceport drone ship.

I'd guess that splitting up a mission so that a pair of FHs can fly it from LC-39A and 40 with an in-orbit rendezvous would be a hell of a lot cheaper than the dev and construction costs necessary to launch a 5-core Falcon.
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Offline JasonAW3

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Re: 5 core (4 booster) variant of FH
« Reply #17 on: 01/28/2015 07:06 pm »
I think you want more pads than cores.  Otherwise it is too easy to run out of pads if something is not nominal.

I think this is actually a 4 pad system.  The center pad is the crash pad, and the cores normally divert to the side pads, so you have 4 active pads, and one extra pad in case you're otherwise full.

So if for whatever reason you're launching FHs fast, you don't absolutely have to get the cores out of the way before the next one comes in.

Another guess?

Launching a Dragon on a 3 core launch, recovering all 3 cores, the second stage and Dragon from a previoust mission.  But as was told before, the main pad is just that, a main pad.  the other four are, at present, divert pads in case of problems.

Personally, I like the idea of a 5 core beast, as this should be able to boost 200 tons plus, although as far as I know, we don't have any payloads just yet, that would need that much oomph!
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Offline meekGee

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Re: 5 core (4 booster) variant of FH
« Reply #18 on: 01/28/2015 07:40 pm »
I wouldn't go with any concept that requires 100% utilization of the pads.

In the CAD-based movie, everything is smooth and nice.  In reality, one pad may be undergoing re-surfacing, on pad may be closed down long-term because who knows what, and it takes forever to get permits, so if I was planning on returning only 2 cores at a time, I'd get a minimum of 4 pads built.  Just for kicks.  It's hardly more expensive.

Then the center pad, which is large and has a gravel "sump" around it, serves as the aim-to pad and can take a crash with less effect on the environment, and the 4 surrounding pads are for touchdowns.  The center pad can also be used for touchdowns, but as long as there's something on it, the entire complex is on "hold", so I think it will be used as little as possible.
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Offline Lobo

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Re: 5 core (4 booster) variant of FH
« Reply #19 on: 01/28/2015 11:36 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

Well, I do love building paper rockets, as my posts have shown over time.  :-)

But, when you have more than 2 outboard boosters, you can't put all of the cores inline any more like you can with 3.  Which means you cannot access umbilicals to all the boosters from one side, like you can with just 3.  You'll need a little more complex mast/ubilican arrangement.  So pad modifications to all of your pads that are launching 3-core FH.

But more importantly, SpaceX is building a fully reusable BFR.  There won't be any paylaods that a fully expendable FH cannot handle for quite some time I reckon. Once BFR is flying, any payload that a 3-core FH can't handle would be a great candidate to get some more flight rate on BFR.  As BFR will be fully reusable, it's not overly costly to put a 60mt payload on an LV that can handle 100mt or 150mt or whatever it's block 1  turns out to be.  And that gets it's flight rate up from whatever SpaceX will start out using it for.  Tt won't immediately be taking thousands of colonists to Mars.  There'll be a period that it'll be flying but MCT won't be ready for Mars yet, and they'll want to get it flying whatever they can on it.
That's where a 5-core FH payload would go.  So I just don't see a need for it.

Offline Zed_Noir

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Re: 5 core (4 booster) variant of FH
« Reply #20 on: 01/29/2015 12:42 am »
Well what @jim & @Lobo said seem to be not much chance for the 5-core Quin-Falcon to be realize.  :(

However in theory the future BFR infrastructure possibly located at Florida could be jiggle to support a Quin-Falcon launch. Of course it is really not very sensible.

Offline BobHk

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Re: 5 core (4 booster) variant of FH
« Reply #21 on: 01/29/2015 04:13 am »
Theres a master plan pic around here that shows three launch pads with by two five pad landing pad areas ...

if all three launch pads launch a FH they'd need 9 spots for booster landings, the plan has ten.

Solved?

on this page http://forum.nasaspaceflight.com/index.php?topic=35425.400


Offline Silmfeanor

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Re: 5 core (4 booster) variant of FH
« Reply #22 on: 01/29/2015 07:04 am »
Theres a master plan pic around here that shows three launch pads with by two five pad landing pad areas ...

if all three launch pads launch a FH they'd need 9 spots for booster landings, the plan has ten.

Solved?

on this page http://forum.nasaspaceflight.com/index.php?topic=35425.400


That plan was imagined by a member here. it is not made by spacex, and thus you should not base any arguments on it.

Offline Jimmy Murdok

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Re: 5 core (4 booster) variant of FH
« Reply #23 on: 01/29/2015 01:42 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

I already proposed a BFR not as huge as some envision here + 4 boosters based on Falcon9, something symilar to Energya rocket. That would fit perfect with the four small pads + the big central one. This modular BFR could be configured for loads between 80 to 200 tons to LEO depending on the nº of boosters.
That architecture don't require to build a monster while they reuse the reliable infrastructure and knowledge of Falcon boosters. In the event of landing and then launching form Mars, you don't need boosters and your rocket is already well sized for that task.

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #24 on: 01/29/2015 02:01 pm »
There isn't any existing "reliable infrastructure" for such a vehicle

Offline Jimmy Murdok

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Re: 5 core (4 booster) variant of FH
« Reply #25 on: 01/29/2015 02:33 pm »
There isn't any existing "reliable infrastructure" for such a vehicle
Sure, it isn't now, but in the time frame of 5-7 years all the F9+FH infrastructure including RTLS of first stages & boosters should by then be quite reliable and well tested.

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #26 on: 01/29/2015 03:10 pm »
Quite wrong.  There is no infrastructure (pad, erector and hangar) planned for such a vehicle (5 body) and hence it can't be termed reliable.  Concrete pads don't really matter as reliable infrastructure.  And a new core also doesn't qualify as reliable
« Last Edit: 01/29/2015 03:15 pm by Jim »

Offline JasonAW3

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Re: 5 core (4 booster) variant of FH
« Reply #27 on: 01/29/2015 03:12 pm »
Well what @jim & @Lobo said seem to be not much chance for the 5-core Quin-Falcon to be realize.  :(

However in theory the future BFR infrastructure possibly located at Florida could be jiggle to support a Quin-Falcon launch. Of course it is really not very sensible.

Don't really think that a 5 core beast will launch from Florida, but from the size or the new flame trench, shown in the latest video, SpaceX is either thinking of something truely ginormous or is trying to make sure that it can accomidate pretty much anything launchable in the next few decades!

The trench under the pad looks big enough to handle two launch platfors side by side!

Maybe this is for accoustics, but I get the impression SOMEONE is dreaming REALLY big!
« Last Edit: 01/29/2015 03:12 pm by JasonAW3 »
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Offline JasonAW3

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Re: 5 core (4 booster) variant of FH
« Reply #28 on: 01/29/2015 03:14 pm »
Quite wrong.  There is no infrastructure (pad and hangar) planned for such a vehicle (5 body) and hence it can't be

I kind of suspect anything like a 5 core beast would likely have to be suspended over the flame trench like the Russians do with their rockets.
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Offline docmordrid

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Re: 5 core (4 booster) variant of FH
« Reply #29 on: 01/29/2015 04:12 pm »
Why build a massively complex kerolox launcher like this when a BFR single stick using better for reusability  methane is already in the pipeline? Makes no sense.
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Offline moralec

Re: 5 core (4 booster) variant of FH
« Reply #30 on: 01/29/2015 04:22 pm »
Quite wrong.  There is no infrastructure (pad, erector and hangar) planned for such a vehicle (5 body) and hence it can't be termed reliable.  Concrete pads don't really matter as reliable infrastructure.  And a new core also doesn't qualify as reliable

The lack of infrastructure (or plans to develop it) is really the killer evidence against this variant... Honeslty, I don't think will ever see this bird flying.

However something (very unlikely) that may occur is that if the development of the BFR gets very delayed SpaceX may consider to develop this vehicle as a heavier alternative in the interim....

I know that this is 100% speculation, but any thoughts on this?  Any chance that the BFR infrastructure (to be developed) could be flexible enough to support a vehicle like this for a period of time until the definitive rocket is ready?



Offline RocketmanUS

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Re: 5 core (4 booster) variant of FH
« Reply #31 on: 01/29/2015 04:45 pm »
Quite wrong.  There is no infrastructure (pad, erector and hangar) planned for such a vehicle (5 body) and hence it can't be termed reliable.  Concrete pads don't really matter as reliable infrastructure.  And a new core also doesn't qualify as reliable

The lack of infrastructure (or plans to develop it) is really the killer evidence against this variant... Honeslty, I don't think will ever see this bird flying.

However something (very unlikely) that may occur is that if the development of the BFR gets very delayed SpaceX may consider to develop this vehicle as a heavier alternative in the interim....

I know that this is 100% speculation, but any thoughts on this?  Any chance that the BFR infrastructure (to be developed) could be flexible enough to support a vehicle like this for a period of time until the definitive rocket is ready?
There has already been threads on FH with more than two boosters. They all end up with it won't happen.

FH could just launch pieces to be assemble in LEO, it is possible fora Mars exploration type of mission. So no need for the added cost and risks of adding more boosters to FH. It might not even be possible with all those engines.

No rush for the BFR unless there is a paying customer for it.

Offline beb

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Re: 5 core (4 booster) variant of FH
« Reply #32 on: 01/29/2015 04:52 pm »
I am just kind of interested why US rockets only use two common core boosters while Russian rockets (Soyuz, Angara) are perfectly happy using four boosters. Are US rockets large enough that they don't need the extra thrust of four boosters, is there some practical reason why three cores is good but 5 is not? I'm not asking if SpaceX or ULA should go to five core rockets because obviously they aren't. I'm just curious why a five core rocket was never considered?

Offline guckyfan

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Re: 5 core (4 booster) variant of FH
« Reply #33 on: 01/29/2015 05:03 pm »
Angara is limited by transport. They cannot make the boosters larger because of train transport and they need the capacity. So they have no choice but use 5 cores.


Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #34 on: 01/29/2015 05:58 pm »
I am just kind of interested why US rockets only use two common core boosters while Russian rockets (Soyuz, Angara) are perfectly happy using four boosters. Are US rockets large enough that they don't need the extra thrust of four boosters, is there some practical reason why three cores is good but 5 is not? I'm not asking if SpaceX or ULA should go to five core rockets because obviously they aren't. I'm just curious why a five core rocket was never considered?

It is less complex to make a larger core and use water transportation vs road, rail or air.
« Last Edit: 01/29/2015 05:59 pm by Jim »

Offline Lobo

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Re: 5 core (4 booster) variant of FH
« Reply #35 on: 01/29/2015 06:14 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

I already proposed a BFR not as huge as some envision here + 4 boosters based on Falcon9, something symilar to Energya rocket. That would fit perfect with the four small pads + the big central one. This modular BFR could be configured for loads between 80 to 200 tons to LEO depending on the nº of boosters.
That architecture don't require to build a monster while they reuse the reliable infrastructure and knowledge of Falcon boosters. In the event of landing and then launching form Mars, you don't need boosters and your rocket is already well sized for that task.

They could do that.  But again, why?

Why have outboard F9 boosters?  Why not just make the booster core as powerful as you want it?  Then you are landing just one core back at the launch site, rather than it plus a bunch of F9 boosters?

The only reason you might want to do that would be if BFR already existed and was flying, but SpaceX decided they wanted more capacity.  Then it might be cheaper to modify the existing core to mount outboard boosters than to build a larger, more powerful core.

But, BFR doesn't exist and they can just make it the capacity they want it.

Besides, if they did want some sort of modular design, or a shorter stack with parallel boosters, it's make more sense to make BFR a mult-core LV.  They have to build a new core anyway, so this would get their produciton up, and keep all pad ops the same (same cores, engines, and propellants).  Rather than having different sized cores with different propellants.
But even then, the only reason to go with a multi-methalox core configuration is if they wanted to fly a single methalox core for some reason.  The reason FH is tri-core, is because SpaceX wants the single core, so a multi-core is a cheaper way to upgrade than building a whole new class of LV.  Same with D4/D4H, and Angara.   If you are -only- going to fly the multi core version, then it's cheaper/easier/more effient to just make a single larger core.  And if you are going to fly just one core of a tri-core, for what payloads would you use it?  What payloads are out there that FH won't be able to handle?  And even if there are some, if your BFR is reusable, why can't you just fly it on the full BFR?  The stages aren't expended so there's not really much more cost involved in that.  If everything was expended then it might make sense for BFR to be a tri-core where each single core could cover a payload class above FH.  That single smaller core would be cheaper than a larger BFR flying well below it's capacity.  But with reusabilty, that paradigm changes.  It can become more cost effective to have just one really large LV and use it for various medium-heavy class payloads that are well below what it could handle, than to have intermediate sized LV's for those payloads.

Offline moralec

Re: 5 core (4 booster) variant of FH
« Reply #36 on: 01/29/2015 06:24 pm »
The Falcon Heavy flight and booster recovery Video shows 5 landing pads. This may be an indication that Space X is working on a 5 core (4 booster) variant.

- What would be the capacity of this booster?
- Would it make sense from a technical perspective (rocket equation)?
- Would this be a reasonable thing to do from a Business Perspective?

What do you think?

I already proposed a BFR not as huge as some envision here + 4 boosters based on Falcon9, something symilar to Energya rocket. That would fit perfect with the four small pads + the big central one. This modular BFR could be configured for loads between 80 to 200 tons to LEO depending on the nº of boosters.
That architecture don't require to build a monster while they reuse the reliable infrastructure and knowledge of Falcon boosters. In the event of landing and then launching form Mars, you don't need boosters and your rocket is already well sized for that task.

They could do that.  But again, why?

Why have outboard F9 boosters?  Why not just make the booster core as powerful as you want it?  Then you are landing just one core back at the launch site, rather than it plus a bunch of F9 boosters?


Economies of scale?

Offline Jim

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Re: 5 core (4 booster) variant of FH
« Reply #37 on: 01/29/2015 06:49 pm »

Economies of scale?

don't work when the core is different


Offline Darkseraph

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Re: 5 core (4 booster) variant of FH
« Reply #38 on: 01/29/2015 07:07 pm »
Hey, why stop at only 5!?   ;D

Seriously though, I have my doubts about even the Falcon Heavy being reliable with 27 separate engines (not just multiple chambers like Russian rockets). The last rocket to have so many engines exploded quite a lot, and although I think Falcon can be more reliable than that, it's still a little too many for comfort. In many ways, it's not the rocket they would have liked to have designed, but its the one they could make with their experience with smaller kerolox engines. It's not even that rocket will necessarily blow up, but think of the amount of scrubs and delays they have had with single core rockets so far, and then add two more cores with lots of fun things that can be found to be wrong enough to delay the launch.

I wouldn't be incredibly surprised if Falcon Heavy gets phased out for a simpler 5-meter methalox reusable vehicle that is suited to heavier GSO payloads, but has manned spaceflight uses too. In fact, it seems a bit of saner stepping stone than building your 100 colonist mars rocket right off that bat. If they don't do that, there will be more hydrogen upper stage options available at the end of the decade that would be a far better idea than 5 cores with 45 engines under them. :/ 
« Last Edit: 01/29/2015 07:10 pm by Darkseraph »
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." R.P.Feynman

Offline Lobo

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Re: 5 core (4 booster) variant of FH
« Reply #39 on: 01/30/2015 12:23 am »
Hey, why stop at only 5!?   ;D

Seriously though, I have my doubts about even the Falcon Heavy being reliable with 27 separate engines (not just multiple chambers like Russian rockets). The last rocket to have so many engines exploded quite a lot, and although I think Falcon can be more reliable than that, it's still a little too many for comfort. In many ways, it's not the rocket they would have liked to have designed, but its the one they could make with their experience with smaller kerolox engines. It's not even that rocket will necessarily blow up, but think of the amount of scrubs and delays they have had with single core rockets so far, and then add two more cores with lots of fun things that can be found to be wrong enough to delay the launch.

I wouldn't be incredibly surprised if Falcon Heavy gets phased out for a simpler 5-meter methalox reusable vehicle that is suited to heavier GSO payloads, but has manned spaceflight uses too. In fact, it seems a bit of saner stepping stone than building your 100 colonist mars rocket right off that bat. If they don't do that, there will be more hydrogen upper stage options available at the end of the decade that would be a far better idea than 5 cores with 45 engines under them. :/

There's a whole speculation thread about such an interim BFR.  "SFR" if you will.

http://forum.nasaspaceflight.com/index.php?topic=36508.0

Myself, I don't think FH would get "phased out".  But if they build a shorter and/or less powerful "Block 1" BFR as an SFR, they could move possible payloads over to it that would require expending FH cores to accomodate.  It could be cheaper to launch than a fully expendable FH, and get some revenue and flight history logged before they'd go to the full size/full power BFR.
But any type of interim LV would require a lot of pad pods to SLC-4W, LC-40, and Boca Chica to accomodate, as well as completely new infrastruture because pretty much anything larger than a F9 core can't be road transported.  If some sort of Block 1 BFR/SFR were to ever possibly happen, it would be launching from 39A only.  The other 3 SpaceX pads would continue to launch F9 and FH.

I would expect SpaceX to develop a methalox version of Merlin and modify F9 cores to proper fuel/oxidizer tank ratios before I'd expect SpaceX to actually replace FH.  While the core couldn't hold as much mass of methalox as it does kerolox, the engines should be a little more efficient to help compensate for the difference, and the upper stage could be stretched a little bit too.  A vacuum methalox Merlin's increased efficiency with some additional propellant might get back to roughly F9 performance.   And the cores should be easier to reuse with the much cleaner methalox. 
I don't think they'll do that, but I'd see it before they'd replace Falcon with something else.  Too much investment into F9 and FH.

Offline Zed_Noir

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Re: 5 core (4 booster) variant of FH
« Reply #40 on: 01/30/2015 12:50 am »
Hey, why stop at only 5!?   ;D

...


Because SpaceX is only planning on 5 landing pads at the landing site.

Offline Jimmy Murdok

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Re: 5 core (4 booster) variant of FH
« Reply #41 on: 01/30/2015 03:14 pm »
They could do that.  But again, why?

Why have outboard F9 boosters?  Why not just make the booster core as powerful as you want it?  Then you are landing just one core back at the launch site, rather than it plus a bunch of F9 boosters?

The only reason you might want to do that would be if BFR already existed and was flying, but SpaceX decided they wanted more capacity.  Then it might be cheaper to modify the existing core to mount outboard boosters than to build a larger, more powerful core.

But, BFR doesn't exist and they can just make it the capacity they want it.

Besides, if they did want some sort of modular design, or a shorter stack with parallel boosters, it's make more sense to make BFR a mult-core LV.  They have to build a new core anyway, so this would get their produciton up, and keep all pad ops the same (same cores, engines, and propellants).  Rather than having different sized cores with different propellants.
But even then, the only reason to go with a multi-methalox core configuration is if they wanted to fly a single methalox core for some reason.  The reason FH is tri-core, is because SpaceX wants the single core, so a multi-core is a cheaper way to upgrade than building a whole new class of LV.  Same with D4/D4H, and Angara.   If you are -only- going to fly the multi core version, then it's cheaper/easier/more effient to just make a single larger core.  And if you are going to fly just one core of a tri-core, for what payloads would you use it?  What payloads are out there that FH won't be able to handle?  And even if there are some, if your BFR is reusable, why can't you just fly it on the full BFR?  The stages aren't expended so there's not really much more cost involved in that.  If everything was expended then it might make sense for BFR to be a tri-core where each single core could cover a payload class above FH.  That single smaller core would be cheaper than a larger BFR flying well below it's capacity.  But with reusabilty, that paradigm changes.  It can become more cost effective to have just one really large LV and use it for various medium-heavy class payloads that are well below what it could handle, than to have intermediate sized LV's for those payloads.

You have strong arguments :D and you and Jim are probably right, but I think it all depends on the BFR Mars architecture strategy.

If the BFR main raptor stage is supposed to be refueled in space and later land on mars, with the mono core strategy I think is a really oversized rocket to fly from mars, and I'm not sure how the structural integrity of a huge rocket will survive to land (does the scaling up of a rocket have symilar integrity issues like an elephant vs a mouse?). In that case I think it fit to have some boosters to help leave the earth gravity and keep a smaller main stage .

If the first stage of the mono core is supposed to just boost a second stage (the MCT) to space and land inmediately back to earth and physically is not a big deal to be landed back, then I agree with you and my hypothesis makes no sense. I suspect something that massive will be really fragile to land back to earth, but to be honest I don't know how the scaling up of a rocket really affect it's integrity when landing to earth.

Following the speculation, F9 boosters would be like Ford's model T and Raptor BFR stages like a Rolls Royce with few units.

So if I'm wrong, the question is still open, why so many landing pads with a big spot in the middle?  ::)

Offline RanulfC

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Re: 5 core (4 booster) variant of FH
« Reply #42 on: 02/09/2015 09:06 pm »
Wandering the web I found someone who took my "F9Advanced" concept and put some pretty pictures with it here:
http://richspacetech.blogspot.com/2013/09/the-falcon-shuttle-reusable-launch.html

12 F9-stages and 10 F9US all wrapped up in a fully reusable launch and no "raptor's" needed... SERIOUSLY doubt this would even enter SpaceX's or Elon's thinking... You never know though :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Lars-J

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Re: 5 core (4 booster) variant of FH
« Reply #43 on: 02/09/2015 09:55 pm »
Wandering the web I found someone who took my "F9Advanced" concept and put some pretty pictures with it here:
http://richspacetech.blogspot.com/2013/09/the-falcon-shuttle-reusable-launch.html

12 F9-stages and 10 F9US all wrapped up in a fully reusable launch and no "raptor's" needed... SERIOUSLY doubt this would even enter SpaceX's or Elon's thinking... You never know though :)

Randy

Well... I certainly is out of the box thinking in some ways (not always good), but otherwise terribly stuck in the past (Mars architecture Apollo style). I think a Raptor powered BFR might just be a better vehicle by ANY metric. :)

162 Merlin engines on the 1st stage of the Mars ship.  ;D ;D Nice drawings, though!
« Last Edit: 02/09/2015 09:56 pm by Lars-J »

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