Author Topic: Alternative HLV Concepts  (Read 76078 times)

Offline M129K

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Re: Alternative HLV Concepts
« Reply #100 on: 12/14/2013 11:07 am »
I was under the impression that the Michoud vertical tooling could assemble components up to ten meters in diameter; is this not correct?
Not sure. I don't think it would be very easy to do so, but you could be right. I'll have to look that up.

Offline TomH

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Re: Alternative HLV Concepts
« Reply #101 on: 12/14/2013 05:30 pm »
I think it's fixed at 8.4 meters, but that should be wide enough for anything we'll need.

The ability to go smaller could actually be helpful in the event the tooling eventually might possibly be used to build a tri-core heavy (of something else) that would just fit through the VAB doors. I believe a tri-core of 8.4m each is too wide for the doorway.

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #102 on: 12/14/2013 06:43 pm »
I think it's fixed at 8.4 meters, but that should be wide enough for anything we'll need.

The ability to go smaller could actually be helpful in the event the tooling eventually might possibly be used to build a tri-core heavy (of something else) that would just fit through the VAB doors. I believe a tri-core of 8.4m each is too wide for the doorway.

Yea...I think a tri-core of around 6.5m wide each is about as wide as you can go...just barely without scraping the paint on the VAB doors.  ;-)

Put four RD-180's on each of those 6.5m cores and and upper stage powered by say four MB-60's...and I think you'd have something very capable right out of the gate...no boosters needed...no upgrades needed.

:-)

And all with the existing new SLS tooling and infrastructure...

Offline M129K

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Re: Alternative HLV Concepts
« Reply #103 on: 12/14/2013 07:07 pm »
I think it's fixed at 8.4 meters, but that should be wide enough for anything we'll need.

The ability to go smaller could actually be helpful in the event the tooling eventually might possibly be used to build a tri-core heavy (of something else) that would just fit through the VAB doors. I believe a tri-core of 8.4m each is too wide for the doorway.
Going with a penta-core Atlas Phase 2 seems like a much easier solution in that case though. The maximum a tri-core can do is about 6.6 meters, as the VAB doors can support 20 meters max (derived from 8.4m core+2 5.8 meter boosters maximum).

Offline davamanra

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Re: Alternative HLV Concepts
« Reply #104 on: 01/07/2014 03:02 pm »
It's been a while since I've been on this forum, and I've done a cursory search for this subject without success.  This thread SEEMS to be the appropriate for this subject, so here goes! 
 
   What about using 3 or more boosters on an SLS/HLV?  You could configure the boosters for a lower thrust, longer duration burn, as well as throttling back the main engines until booster burn out.

   The SLS Block II payload of 130mt is nice, but I would like to see a SHLV in the future for much more ambitious projects.
« Last Edit: 01/07/2014 03:59 pm by davamanra »
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Offline TomH

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Re: Alternative HLV Concepts
« Reply #105 on: 01/07/2014 04:40 pm »
It's been a while since I've been on this forum, and I've done a cursory search for this subject without success.  This thread SEEMS to be the appropriate for this subject, so here goes! 
 
   What about using 3 or more boosters on an SLS/HLV?  You could configure the boosters for a lower thrust, longer duration burn, as well as throttling back the main engines until booster burn out.

   The SLS Block II payload of 130mt is nice, but I would like to see a SHLV in the future for much more ambitious projects.

The following thread that I started discussed this concept. For numerous reasons, the short answer is no.

http://forum.nasaspaceflight.com/index.php?topic=27563.msg840654#msg840654

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #106 on: 01/07/2014 04:59 pm »
It's been a while since I've been on this forum, and I've done a cursory search for this subject without success.  This thread SEEMS to be the appropriate for this subject, so here goes! 
 
   What about using 3 or more boosters on an SLS/HLV?  You could configure the boosters for a lower thrust, longer duration burn, as well as throttling back the main engines until booster burn out.

   The SLS Block II payload of 130mt is nice, but I would like to see a SHLV in the future for much more ambitious projects.

That could certainly work, but it would require a complete redesign to SLS.  SLS is designed like STS, with two top-lifting boosters attached to an upper thrust beam.  So you can't add more than just the two.  To add more, you might need an upper thrust cross beam, and two more boosters, or come back to a traditional bottom lift booster system where you can add boosters around the core and attached them into the core's MPS. 

Or you could have two booster pairs on each side attached to a strongback which is then attached to the upper thrust beam.  That's probably the only way to could have more than two boosters without a complete redesign of the core. 

The "AJAX" concept by Downix would have used existing Atlas V CCB's and attached them around a shorter core than SLS, designed to take between 2 and 8 of them, whatever the mission requried.

I think one problem you have with multiple cryo boosters, is on the pad you need to get to them all, as well as the cryo core.  tri-core configurations are the easiest multi-core system, as the three are inline, and you can easily access them all from one side of the LV.  A tower arm or strongback on the one side can get to all three.  If you have a 4 booster system, then you'll have one booster on the opposite side.  So you need some way to tank and detank the propellants over there, and vent cryo gases, which I think complicate things on the pad.  The Soviets managed to do it with Energia, but they needed to towers, one on each side.  The RUssians will manage it with Angara, and that will use a type of dual tower gantry too.  So it's not a deal breaker, but it complicates things on the pad vs. multiple solids like Delta II or Atlas or Delta IV which don't need any service access on the pad.

I'm not sure how AJAX would have worked using the LC-39 hardware.  (Note, I'm a big fan of AJAX).  It might have needed a dual tower gantry built onto the pad that could access all of the boosters as well as the core.  And the LV itself could have rolled out to the pad without a tower like STS. 

However, even AJAX would have needed the design and development of a new core stage, not unlike SLS.  It just would use existing production boosters rather than 1-off big SRB's or new Advanced boosters.
This is where I think the -best- way for NASA to build a new rocket (if NASA -must- build their own rocket...which they probably shouldn't) then go with a narrower core, that can launch by itself, or as a tri-core heavy with identical cores.  A scaled up version of Atlas V-Heavy, Delta IV-Heavy, or Falcon Heavy.
That would allow a simgle tower on the MLP to access all three booster plus the upper stage, and probably be easier to use with the heritage hardware at KSC.

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #107 on: 01/07/2014 05:24 pm »
I think it's fixed at 8.4 meters, but that should be wide enough for anything we'll need.

The ability to go smaller could actually be helpful in the event the tooling eventually might possibly be used to build a tri-core heavy (of something else) that would just fit through the VAB doors. I believe a tri-core of 8.4m each is too wide for the doorway.
Going with a penta-core Atlas Phase 2 seems like a much easier solution in that case though. The maximum a tri-core can do is about 6.6 meters, as the VAB doors can support 20 meters max (derived from 8.4m core+2 5.8 meter boosters maximum).

See my previous post.  That's why I was thinking a tri-core, each about 6.5m wide, with four RD-180's on each.  That's 12 RD-180's, which would be two more than the 10 a penta-core Atlas Phase 2 would have with better mass fraction of fewer cores.  It would get away from needing some sort of dual tower setup at the pad to access all four boosters as well as the core.  A tri-core can access all cores plus the upper stage all from one side.  So just one tower which can be mounted on the mobile launcher.
A 6.5m booster would then allow for wider PLF options.  The upper stage could be core diameter so it'd all use the same tooling.  RL/MB-60's would be great upper stage engines for such an LV.  The upper stage could launch on a single core, with a partial propellent load, like the FH-sized upper stage does when launching on F9, and I think the 5m DCSS does when launching on D4-medium+.

A single and tri-core 6.5m, RD-180 powered LV I think would be the best of all worlds for a HLV that can most readily use KSC legacy hardware.  We could even call it an "Atlas 6" and an "Atlas 6 Heavy".
So why do this vs. the penta-core Atlas Phase 2?  A few reasons.

1)  A5P2 5m core, and A6 6.5m core are both new developments.  It would be different if A5P2 already existed, but it doesn't, nor are there any plans for other other than NASA.  NASA has to pay for either new core.
2)  A5P2 uses a 5m new common Centaur or ACES upper stage, which is good for EELV fleet standardization, but is also a new development which NASA would have to pay for whether they were building it at MAF, or ULA was building it in Decatur.  NASA's on the hook for the development cost either way.  There -could- be some cost sharing once it's in production however.
3)  The A5P2 penta-core would be underpowered with that 5m upper stage on it, as that upper stage is designed for use with the single core A5P2, which would be most of ULA's non-NASA launches.
4)  I think a tri-core would be easier to use with existing KSC hardware than a 5-core.  And a 6.5m tri-core plus a single core crew launcher would make a -very- capable 1.5 architecture.  Or a single launch on the heavy.  And for say just lofting Orion to the ISS?  Only install two RD-180's in the core, and two RL-60's in the upper stage, and short fuel them both.  Just design the MPS of both to take either 2 or four engines.  They'd still have symetry and all of the thrust loads would still be balanced.  Your upper stage would basically be a big ACES upper stage, with 2 or 4 RL-60's rather than 2 or 4 RL-10's.  And when launching with just two engines on each stage, it really wouldn't be any more costly than a single stick Atlas Phase 2.  same number of engines.  Just a little more aluminum alloy and some part empty tanks.
5)  Buiding cores and upper stages all with the same tooling at MAF.  Likely end up costing more than having ULA do it, but would be more politically palatable to keep more jobs where they are than if MAF were to close up entirely.  But...you could have ULA do it as an "Atlas 6" in Decatur.  I think the ship that transports Delta cores would transport Atlas 6 cores too.  Also, the Ares 1 upper stage tooling that had already been put in at MAF could probably have been used to create 6.5m cores.  I think it has adjustable diameter, although not sure what the upper limit is.  If it could do 6.3 to 6.5m diameter, that would work for this new LV.


Offline Lobo

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Re: Alternative HLV Concepts
« Reply #108 on: 01/07/2014 05:49 pm »
It's been a while since I've been on this forum, and I've done a cursory search for this subject without success.  This thread SEEMS to be the appropriate for this subject, so here goes! 
 
   What about using 3 or more boosters on an SLS/HLV?  You could configure the boosters for a lower thrust, longer duration burn, as well as throttling back the main engines until booster burn out.

   The SLS Block II payload of 130mt is nice, but I would like to see a SHLV in the future for much more ambitious projects.

The following thread that I started discussed this concept. For numerous reasons, the short answer is no.

http://forum.nasaspaceflight.com/index.php?topic=27563.msg840654#msg840654

Tom,

Re-reviewing your thread, I remember your post here:

http://forum.nasaspaceflight.com/index.php?topic=27563.msg858728#msg858728

And I think my post here about a tri-core "Atlas 6" would actually probably be better than AJAX, the more I think about it.  I like AJAX a lot, dont' get me wrong.  But AJAX needs a new core developed, which would fly at a relatively low rate.  Likely more than SLS. But still, it's a new core just as Direct would be, and SLS is.
And Jupiter, AJAX, or SLS all need a new upper stage.  Even if AJAX uses ACES-71...NASA would have to pay ULA to develop ACES as they don't seem to be building it on their own. 

So, if NASA is going to build a new core, build the 6.5m kerolox core, and a 6.5m upper stage using the exact same tooling, like F9 and Falcon upper stage.  Put four RD-180's on it so there's cost sharing with USAF, and put four RL/MB-60's on the upper stage, and then work with USAF to switch to it for EELV's once their existing stocks of RL-10's are used up.  (that was the purpose of RL-60 and MB-60 in the first place as I understand).  You need a new tooling set whether it's "Atlas 6" or AJAX.  This would get a higher production rate, as there are 3 cores plus an upper stage whenever the heavy launches.  And pad operations should be much easier with just a single tower on the mobile launcher like Saturn had and SLS will have.  Where I think AJAX would need some sort of double tower setup to access all of the cryo boosters.  (See Energia pad and Angara pad)

And they could make the MPS of the core and upper stage capable of mounting 2 or 4 engines each, like ACES would mount 2 or 4 engines and do partial propellant loads, to allow more flexibility.  In that config it'd probably put up performance similar to A5P2 or D4H.  With all four engines on the core, but just two engines on the upper stage and a partial upper stage prop load, you get optimal BLEO throw capacity in the Medium lift range (good for sending Orion to the ISS if needed).  Put all four engines in the upper stage, and you get LEO optimal capacity.  Or you add two CCB's as boosters with a full upper stage prop load, and you get maximum overall capacity.
That would allow for incremental felxibility from around 25mt to probably around 150mt.  And a 1.5 launch architecture in the 200mt range. 

And it can still mount quite a large PLF.  Using the Tital IV ratio of core size to PLF size, you could get in excess of a 10mt PLF.  It'd actually look very much like a scaled up FH with PLF.

And should be no more development cost than AJAX, but with a higher CCB production rate, and the ability to launch a single core version where AJAX needs at least two Atlas V's to get off the pad I think. 

So even though I'm a big AJAX homer, I think I like this "Atlas 6" concept better.


Offline TomH

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Re: Alternative HLV Concepts
« Reply #109 on: 01/07/2014 10:02 pm »
Lobo, for the past couple of days I had been thinking about a new thread re. something I've been pondering, but these last few posts here provide a good segue for the idea.

F9 v.1.1 just had a flawless countdown and launch. SpaceX is getting really good and FH is going to offer 2x the payload of DIVH @ 1/3 the price. That is a mind boggling 6x the cost efficiency for 53 mt to LEO. Musk may well come to dominate the market and his efficiencies of scale with all those cores and numerous engines, well...we've dreampt for so long of a line that is forever humming with production efficiency.

So what I have been pondering is this. Since DIV is supposedly capable of penta-core and septa-core configurations, could this be done with F9 v.1.1? I could even see eliminating the cross feed, putting 9 vacuum Merlins on the center core and don't even start it until you jetison the outer cores. The inner core becomes a powerful second stage, and the current US is the third stage. I know that's a lot of Merlins burning at 1 time, but heck, with the efficiency and proficiency Falcon is starting to demonstrate, I'm starting to think such an LV could outperform SLS at a much lower price. All the components already exist and are flying. It's just a matter of whether this (admittedly complicated) Lego rocketry could actually work.

Some of the challenges are engine cluster configurations-would the cores need to be offset a little? What does that do to aerodynamics. 54 Merlin 1st stage, 9 Merlin 2nd stage, 1 Merlin 3rd stage (EDS?) seems a reasonable thrust profile. To take advantage of the LV, cargo shroud would need to be wider than a core and/or longer than currently in use. Too wide of a shroud brings aerodynamic complexities, especially with 7-core cluster below it. So I admit to great complexities, but if they said DIV could do it, it makes me think that perhaps it is at least worth some studies.
« Last Edit: 01/07/2014 10:11 pm by TomH »

Offline Robotbeat

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Re: Alternative HLV Concepts
« Reply #110 on: 01/07/2014 10:05 pm »
Someone should count how many "n-core Falcon super-heavy" threads we've had in the past.
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Offline Lars_J

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Re: Alternative HLV Concepts
« Reply #111 on: 01/07/2014 10:06 pm »
So what I have been pondering is this. Since DIV is supposedly capable of penta-core and septa-core configurations, could this be done with F9 v.1.1? I could even see eliminating the cross feed, putting 9 vacuum Merlins on the center core and don't even start it until you jetison the outer cores.

Good luck fitting 9 vacuum Merlins on the core... You would need a core with 8m+ diameter for that.
« Last Edit: 01/07/2014 10:07 pm by Lars_J »

Offline ChrisWilson68

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Re: Alternative HLV Concepts
« Reply #112 on: 01/07/2014 10:11 pm »
So what I have been pondering is this. Since DIV is supposedly capable of penta-core and septa-core configurations, could this be done with F9 v.1.1? I could even see eliminating the cross feed, putting 9 vacuum Merlins on the center core and don't even start it until you jetison the outer cores.

Good luck fitting 9 vacuum Merlins on the core... You would need a core with 8m+ diameter for that.

Also, the standard Falcon Heavy would need a thrust-to-weight greater than 1.5 to be able to even lift off with a third of its core engine turned off.  But its thrust-to-weight is less than 1.3.
« Last Edit: 01/07/2014 10:12 pm by ChrisWilson68 »

Offline TomH

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Re: Alternative HLV Concepts
« Reply #113 on: 01/07/2014 10:13 pm »
O.K. so let me modify "vacuum Merlins" and just say "air started Merlins."
« Last Edit: 01/07/2014 10:15 pm by TomH »

Offline ChrisWilson68

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Re: Alternative HLV Concepts
« Reply #114 on: 01/08/2014 01:42 am »
O.K. so let me modify "vacuum Merlins" and just say "air started Merlins."

It still doesn't work because 18 M1Ds don't have enough thrust to lift a fully-loaded Falcon Heavy off the pad.  See my comment about the thrust-to-weight ratio of less than 1.5.

Offline mheney

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Re: Alternative HLV Concepts
« Reply #115 on: 01/08/2014 02:24 am »
Note that TomH referred to penta-core and hepta-core configurations.  With a T/W of 1.3, a 5-core version would (very slowly) get off the pad with the center core un-lit at launch; a 7-core would be pretty sprightly climbing out.

Offline ChrisWilson68

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Re: Alternative HLV Concepts
« Reply #116 on: 01/08/2014 02:30 am »
Note that TomH referred to penta-core and hepta-core configurations.  With a T/W of 1.3, a 5-core version would (very slowly) get off the pad with the center core un-lit at launch; a 7-core would be pretty sprightly climbing out.

Ah, thanks, I missed that.

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #117 on: 01/08/2014 05:05 pm »
Lobo, for the past couple of days I had been thinking about a new thread re. something I've been pondering, but these last few posts here provide a good segue for the idea.

F9 v.1.1 just had a flawless countdown and launch. SpaceX is getting really good and FH is going to offer 2x the payload of DIVH @ 1/3 the price. That is a mind boggling 6x the cost efficiency for 53 mt to LEO. Musk may well come to dominate the market and his efficiencies of scale with all those cores and numerous engines, well...we've dreampt for so long of a line that is forever humming with production efficiency.

So what I have been pondering is this. Since DIV is supposedly capable of penta-core and septa-core configurations, could this be done with F9 v.1.1? I could even see eliminating the cross feed, putting 9 vacuum Merlins on the center core and don't even start it until you jetison the outer cores. The inner core becomes a powerful second stage, and the current US is the third stage. I know that's a lot of Merlins burning at 1 time, but heck, with the efficiency and proficiency Falcon is starting to demonstrate, I'm starting to think such an LV could outperform SLS at a much lower price. All the components already exist and are flying. It's just a matter of whether this (admittedly complicated) Lego rocketry could actually work.

Some of the challenges are engine cluster configurations-would the cores need to be offset a little? What does that do to aerodynamics. 54 Merlin 1st stage, 9 Merlin 2nd stage, 1 Merlin 3rd stage (EDS?) seems a reasonable thrust profile. To take advantage of the LV, cargo shroud would need to be wider than a core and/or longer than currently in use. Too wide of a shroud brings aerodynamic complexities, especially with 7-core cluster below it. So I admit to great complexities, but if they said DIV could do it, it makes me think that perhaps it is at least worth some studies.

Tom,

As Robotbeat mentioned, mutli-core Falcon Super Heavies have been speculated a lot on on other threads.  Including a lot by myself!

It'd not like it can't be done, and I don't even thing that many separate engines is really as big of a problem as some thing, because once F9 v1.1 gets enough flights under it's belt to truely be considered "highly reliable" like Atlas V, I think you can start thinking of each core as it's own separate module.  Which can handle an engine out by throttling up the other engines to compensate. So a Falcon with 5 cores or 7 cores, might be able to be considered as having 5 or 7 engines almost, as each core is it's own proven unit.

However, from the various discussions, I think these are some problems with going this way:

1)  The upper stage, as I understand, is sized for FH tri-core.  a 5 or 7 core Falcon would either need a larger upper stage, or a lot of that booster capacity will be wasted unless you are only going to LEO.  Sort of like how the ICPS will cut SLS Block 1's BLEO capacity about in half.  SLS Block 1 will be a good example of a Falcon super heavy with the same upper stage.  So now there's another upper stage which reduces standardization, as it'd likely be just too darn big to fly on a single core F9 without a big performance hit.

2)  The central core will need to be beefed up, making another unique core.  Again, that works again standardization.  With just 1 core and 3-core LV's, you can find a compromise core that's not too heavy for the single core performance, but strong enoguh for the needs of the 3-core.  The central core on a 5 or 7 core Falcon would be too heavy to use for a single core, and it would hurt FH's performance likely...although to a lesser degree.  So in addition to the boosters being different from the core, there's be two cores.  You can start getting into the Delta IV situation where you had a whole host of different unique cores and upper stages.

3)  It makes pad ops more difficult, as I mentioned, a tri-core, everything can be accessed from one side.  With more boosters than that, you can't do that.  Angara will do it, but they have a very different pad configuration than Falcon.  (Although they do have horizontal integration with it, so it's possible SpaceX could retain that for like a 5-core Falcon)

4)  There are concepts of Delta IV and Atlas V with multiple core configurations, but as I understand, that would involve new upper stages, and different cores.  I think per Jim, Atlas V could only have done a tri-core heavy with it's current core.  To go more than that it would need new cores, not to mention completely new pads and integration facilities.  Delta already had 5 different cores.  3 different ones for D4H, and then one for D4-medium, and another for D4-Medium+.  I think that's been trimmed to 4 now, with the elimination of the D4-Medium core.  D4 has some problems that A5 and F9 wont' have with their hydrolox cores needing top tank vents (or something to that effect) so that each booster and core needs to be different so all of the vents are on the same side.  That's not required for kerolox boosters.
RAC-3 looked at various multi-core Atlas and Delta LV's, but they were nightmares of interfaces as I understand.  So I think you'd get that with a 5 or 7 core Falcon too.
Now, maybe that's still cheaper to develop and produce than a whole new rocket.  I'm just saying that the costs do really start to shoot up even though you are keeping the same narrow diameter core size.  I think those concepts were mainly just a ULA proposition on what is "possible" to NASA as alternatives to SDHLV that were Delta and Atlas derived.  Like Atlas Phase 2 variants.  With no actualy plans to build any of that with their existing hardware unless NASA paid them to build them for them.

5)  Musk already has plans for a larger rocket, so there's not much need to expand Falcon.  If that wasn't the case, then maybe there could be a case for another evolution of Falcon to a 5 core, with the boosters arranged in two pairs on each side, similar to Energia or the four booster Angara.   They could have a stretched Falcon upper stage that might not be too big of a performance hit for F9 single core.  Or they could just have two upper stages.
But then again, what's the market for a 5-core Falcon?  FH should handle all the current or near future commercial and government payloads.  But a 5-core Falcon would probably still be smaller than NASA really wants for it's HSF program.  I think they want something CxP/SLS class.  (regardless of if they really -need- a single rocket that large or not).  So if NASA were to use an Alternative HLV to SLS that had anything to do with SpaceX, it'd be that methalox BFR likely.  If SpaceX had started about 10 years before it did, it might have had such a HLV in the works during CxP or SLS, and I think even with a thumb on the scale of the ESAS report, that would have been a hard option to overlook in favor of CxP.




« Last Edit: 01/08/2014 05:07 pm by Lobo »

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #118 on: 01/08/2014 06:58 pm »

And I think my post here about a tri-core "Atlas 6" would actually probably be better than AJAX, the more I think about it.  I like AJAX a lot, dont' get me wrong.  But AJAX needs a new core developed, which would fly at a relatively low rate.  Likely more than SLS. But still, it's a new core just as Direct would be, and SLS is.
And Jupiter, AJAX, or SLS all need a new upper stage.  Even if AJAX uses ACES-71...NASA would have to pay ULA to develop ACES as they don't seem to be building it on their own. 


In this same vein, Depending on what SpaceX has in mind for their new HLV, it could be similar to this "Atlas 6" Concept.  Just that they'd design their own new SC methalox engine rather than using an existing SC kerolox engine in RD-180.
Not unlike what Hyperion shared on another thread.

http://forum.nasaspaceflight.com/index.php?topic=33494.msg1144208#msg1144208

Although I think the cores could be thinner and taller and still fit 9 raptors under them in the same style (depending on if the engine diameter in that graphic is close to what the real Raptor would be or not).  Obviously F9 is much taller vs. it's diameter.  I wonder where such a powerful LV could launch from though?  I don't know that pads 39A or B could handle that much, or if the sound would be too great for the launch control building and VAB (would they be damaged by it's sound, being about twice as powerful as Saturn V?)

Would the Boca Chica site be too close to structures or people to launch something like this there?
Would the Shiloh site be too close to populations for that much thrust?

Could pad 39A or B work if it's stacked at the pad, lengthwise with the trench?  With a 30m wide flame divider, designed to handle that much thrust?  Can the rest of the trench itself handle that much thrust?
If the concrete trench itself could handle it, and a new flame divider could be designed to withstand it, and the sound didn't damage the buildings at KSC, then perhaps 39A could be used for this monster, if it were redesigned form Falcon operations, or if it were designed for it from the start.
I'd imagine the cores could be brought into the turn basin at KSC andd transported horizontally to the pad by a "Dragon Wagon", or "Draggin Wagon" or whatever that was called that transported the 10m S-1C around.    Taken up the ramp, and then there maybe being a mobile gantry that would come and lift the core to vertical, and then move it over to it's mount on the pad over the trench.  Repeat for all 3 cores.  Then the same with the upper stage, and then the same for MCT (if it were carring MCT).   There'd obviously need to be a big fixed tower with arms to access the various parts of the stack and MCT (or other payload), so that'd probably mean an entirely new and purpose build tower where the FSS is. 
A big crane could work and be off to the side so it wouldn't have to straddle the flame trench during launch, which may cause damage to the gantry.  But a trade off of the two could be evaluated.  I'm thinking like the big moble gantries Like at ship yards. (see below).  Although it looks like they have ones on wheels rather than rails.  If one could be made like that at 39A or B, which could travel down the ramp without tipping over, then it could be stowed in a safe place for launch.  If designed right, it might be able to actually pick each core up, and then take them up the ramp and place them on each launch mount. 

Anyway, I doubt the cores would be skinny enough to get down to 6.5m wide, which makes using the VAB and CT's and ML's would be about impossible, so this would all have to be done at the pad.  But if SpaceX were launching such a thing from 39A while SLS is launching from 39B...question could start to be asked about the need for continuing SLS when a more capable HLV is launching right from KSC. 

All things considered, that's probably the most likely "Alternate HLV" there might be.  Although I'd still fun to go back and rethink better options for CxP and SLS in threads like this.  ;-)

PS:  If SpaceX's HLV were to be something like Hyperion's graphic, but say, 7 Raptors on each core rather than 9.  Then that -might- be skinnied down to 6.5m wide per core.  (I know Shotwell has already said "at least 7m wide...but 6.5 or 6.6m wide is pretty close to that)  They could still do boost back and landing like F9, it'd just be 6 engines in a circle with a central 7th engine.  Then this could actually be stacked in the VAB and rolled out to a pad using the CT.  That'd allow F9/FH operations to continue at 39A, and this launching from 39B's clean pad.  That'd still be almost 13Mlbs of thrust at sea level at lift off.
Obviously if the HLV were a really big single core, then there wouldn't be any issues with VAB door width or flame trench width.
In such a scenario, maybe SpaceX would then lease the VAB, crawlerway, CT's, and pad 39B lock, stock, and barrel.  So they'd have full control over all of those elements, and not get conflicts with NASA and USA. 
It could be a cheaper way to go with such a huge LV, and KSC may be one of the few places in the US that could launch such a beast from sound level constraints. 
NASA would just be a customer for any launches they may want to buy on the BFR, subject to SpaceX's schedule and manifest. 

Offline TomH

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Re: Alternative HLV Concepts
« Reply #119 on: 01/09/2014 03:21 am »
Any thoughts on an AJAX core, but instead of AV boosters, use Falcon 9 V1.1, using either 6 or 8 boosters and air starting the core at booster jettison?

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