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Old June 3 2012, 08:00 PM   #136
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Both of those refer to the type of fuel being stored. Hypergolic would be fuels like kerosene and other hydrocarbons while cryogenic would be primarily referring to liquid hydrogen.
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Old June 3 2012, 08:28 PM   #137
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Kerosene isn't a hypergolic--thats fuels like UDMH, MMH, "Aerozine," pentaborane, zip propellants. Anything that will combust upon touching an oxidant--like nitrogen tetroxide--that too is a hypergolic.

Now kerosene and HTP (pure H2O2 that blew the nose off the Kursk from a torpedo) are non cryogenic and storable at room temps like hypergolics are, but you still need the spark plug, if you will.

So while they are storable propellants, they are not hypergolic. Also there is a movement away from hypergolics due to toxicity.

Some of you might remember the recent satellite shoot-down where folks were worried about the threat of that one small craft's hypergolic fuel. Now, maybe that was just a fancy excuse for a test of the Standard Missile 3, and maybe it wasn't. At any rate, hypergolic depots are simply not on the table.


Hyperspace05 wrote: View Post
Anyone expressing "doubts about depots" is heavily invested in creating huge launch vehicles we cannot afford to operate. I would express huge doubts about their objectivity.
Actually it was the individual work worked for ULA and did work on the DTAL lander concept:
http://www.ulalaunch.com/site/docs/p...ty20067284.pdf
http://www.thespacereview.com/article/1447/1

An approach using propellant transfer appears to be more expensive than building some variety of heavy lift vehicle


In fact, it doesn't need to be either or
http://www.aviationweek.com/Article....-02-389517.xml
http://www.spacesafetymagazine.com/2...t-fuel-depots/

"Michael Gazarik, NASA’s space technology program director, says that CPST and the Space Launch System (SLS) heavy-lift rocket currently under development are complementary technologies. 'To explore deep space we need a heavy-lift vehicle — SLS — and we need this technology.'"

Still, the position of folks in the know is that depots are what we cannot afford now, in that "concerns about fuel boil-off in orbit remain. A paper presented by Patrick R. Chai and Alan W. Wilhite of the Georgia Institute of Technology at this year’s International Astronautical Congress estimates that depot tanks would lose about $12 million worth of propellant a month in low Earth orbit if protected only with passive insulation. But the state of the art in cryocoolers that would be needed to prevent boil-off falls short by 'an order of magnitude' and would require “significant research” to meet likely requirements."

More:
http://www.bautforum.com/showthread....41#post1957541
http://spacenews.com/commentaries/11...eavy-lift.html

The challenge for fuel depots is simply that the marginal specific cost of payload to orbit is generally lower for larger launch vehicles.

Lots of rancor remain:
http://news.yahoo.com/space-based-fu...214200266.html
http://www.bautforum.com/showthread....-Focus-of-NASA

The SLS and the Multi-Purpose Crew Vehicle (MPCV) are needed today. Fuel depots will be needed tomorrow, when a robust space operations infrastructure has been established and operations beyond LEO are common.

So, spaceflight is harder than popular culture has led on.
http://www.thespacereview.com/article/2069/1

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Old June 3 2012, 11:29 PM   #138
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

publiusr wrote: View Post
Kerosene isn't a hypergolic--thats fuels like UDMH, MMH, "Aerozine," pentaborane, zip propellants. Anything that will combust upon touching an oxidant--like nitrogen tetroxide--that too is a hypergolic.
You're right, my mistake.
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Old June 4 2012, 04:51 AM   #139
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

I'm personally of the opinion that the entire concept of an orbiting fuel depot is doomed to remain a power-point proposal until somebody develops a practical/non-toxic monopropellant for orbiting spacecraft. That will probably require some sort of propulsion system paradigm shift; either widespread adoption of NOFBX, or ion thrusters that can efficiently use more easily storable propellants.

Obligatory nod to Arthur C. Clarke; in Odyssey Three the most advanced ships in the solar system were all using water as a reactant mass for what was basically a nuclear-thermal rocket.
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Old June 4 2012, 06:12 AM   #140
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Yeah it just goes back to the problem that chemical engines aren't a good choice after you reach orbit.
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Old June 5 2012, 05:06 PM   #141
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Photos: Dragon capsule arrives at Port of Los Angeles

http://www.spaceflightnow.com/falcon9/003/120605port/
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Old June 12 2012, 12:26 AM   #142
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

There was an oxygen harvester called Profac: http://www.bisbos.com/rocketscience/...ac/profac.html

I'm not spooked by the nuclear fuel of this thing, which has to fly rather 'low' to harvest--maybe not as low as this satellite which feels enough drag to warrant fins: http://en.wikipedia.org/wiki/Gravity...ation_Explorer

My fear is a repeat of the disaster caused by the poor mans Centaur:
http://en.wikipedia.org/wiki/Briz-M http://www.satobs.org/seesat/Apr-2007/0199.html

I seem to remember that a Briz upper stage explosion caused more debris than the Chinese ASAT test and the recent American satellite shoot-down with a Standard missile 3 combined:
http://military.discovery.com/tv/sat...s/numbers.html

And that wasn't even trying to be a depot. Add hypergolics to the mix with a meteoroid, and you can imagine the rest. This is the real reason I favor HLLVs. Dump all you fuel off as thrust as quickly as you can and swap sloshing fuel for inertia that can't leak. Introduce docking and refueling to a zero g environment and you are asking for trouble.
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Old June 12 2012, 06:14 AM   #143
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Yep, it's been a BIG problem on ISS and MIR.

not.

Inertia from an HLLV can only get you so far. Eventually you need to develop refueling sources.
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Old June 12 2012, 06:23 PM   #144
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Most of the inertia from HLVs is wasted on the rocket itself. Ultimately, you're stacking an extra hundred tons of rocket just to get an extra ten tons of payload into orbit; it's not getting up there all that much faster, UNLESS you count some sort of huge Earth departure stage (which is cheating, by the way).

The only reason to use an HLV is if you don't have the patience to use cheaper EELVs to do the same job piecemeal. Thus America's first space station was built on the ground and tossed into orbit on top an HLV (Skylab on a Saturn-V). The Space Shuttle, arguably, was also an HLV if you count the mass of the orbiter as payload, but that still meant building the station piecemeal, and with the shuttle's lower payload it was essentially a highly expensive MLV.

In the end, we no longer use HLVs to launch space stations because we've discovered that we can build larger and more efficient structures using the tinkertoy approach. The same would be true of interplanetary missions for the same basic reason: you can build a larger spacecraft with much more propellant and much better equipment if you don't have to fit the whole thing onto a single rocket.
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Old June 16 2012, 08:39 PM   #145
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

That tinkertoy approach actually costs you more in the long run. Most missions we have now don't need assembly. It is just better to have all liquid handling done here on the ground. ISS modules are rather cramped--especially the Soviet versions. Remember, the American ISS parts werelaunched by shuttle so they are just cans--all propulsion was handled by orbiters which no longer fly.

A couple other folks on SLS--Carolyn Porco of the Cassini mission
http://forum.nasaspaceflight.com/ind...8485#msg848485

So, yes, the capability of the rocket DOES come before the mission design and the payload determination.

http://forum.nasaspaceflight.com/ind...8427#msg848427

John Grunsfeld
http://www.nature.com/news/an-astron...ientist-1.9835

The other is the size of the SLS. If down the road we wanted to launch a telescope that could, for instance, study the entire energy balance of Earth with pixel sizes smaller than clouds, it would take a big telescope. With a big rocket, you can think start to think about launching big optical systems. We think of the SLS as the human spaceflight programme, but it could be hugely enabling for science.
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Old June 16 2012, 11:48 PM   #146
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

publiusr wrote: View Post
That tinkertoy approach actually costs you more in the long run. Most missions we have now don't need assembly.
incorrect.

We don't have any missions now that require an HLV. In the long run it is cheaper to tinkertoy missions together. Economy of scale on MLV's out paces launching one or two HLV's per year pretty much any way you look at it.

Just for example, how much mass could you put in orbit aboard Atlas 5's or Falcon 9's compared to the cost of one launch of SLS? Assuming SLS ever gets built?

Carolyn goes on to say in the same post that "Planetary scientists want cheap rockets". Which completely conflicts with her assertion that she wants SLS sized missions.

Heck, your quote from John Grunsfeld contradicts her quote about rocket coming before the mission. He's designing a mission (this super resolution earth telescope) before having a vehicle to lift it on.

And neither of them seem to understand that SLS will leave no money to develop those missions they want.
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Old June 17 2012, 09:02 AM   #147
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

publiusr wrote: View Post
That tinkertoy approach actually costs you more in the long run. Most missions we have now don't need assembly. It is just better to have all liquid handling done here on the ground. ISS modules are rather cramped--especially the Soviet versions. Remember, the American ISS parts werelaunched by shuttle so they are just cans--all propulsion was handled by orbiters which no longer fly.
All of the Salyut space stations as well as the Mir were assembled in orbit without the aid of an orbiter. China's space station concept is similar to the Mir and calls for assembly the same way. And if you consider that Skylab required some major repairs in orbit before it could be made operational, this means that ISS is the only space station ever constructed that "required" the space shuttle orbiter for construction; all of the others employed old fashioned autonomous rendezvous using either disposable space tugs or a minimum amount of self-propulsion.

As for the "rather cramped" ISS modules... nothing is more cramped than a non-existent module, which is exactly what NASA will have if it has to depend on HLVs just to service the station, let alone send up a crew. China and Russia both understand this, which is why China has no long-term plans to develop HLV capability and Russia wisely gave up after the N1 fiasco and has been using the Soyuz ever since.

So, yes, the capability of the rocket DOES come before the mission design and the payload determination.
As far as NASA is concerned, this is true. Not because it's SUPPOSED to be this way, but because the U.S. Senate has gotten used to using space exploration has a pork barrel public works project: the rocket is designed to maximize participation by selected aerospace contractors, not with any particular mission or capability in mind.

Really, it's like handing a car designer a set of specifications that say "It must use a GM transmission, a Ford engine and alternator, computers and electronics installed by either HP or Intel, a Sirius Satellite Radio, Eddie Bauer seats, an aluminum frame, and it must be really really big."

The other is the size of the SLS. If down the road we wanted to launch a telescope that could, for instance, study the entire energy balance of Earth with pixel sizes smaller than clouds, it would take a big telescope.
We already have telescopes that can do that. The NRO has been using them for decades (in fact they have so many of them that they're giving them away) None of them require HLVs to put them into orbit.

With a big rocket, you can think start to think about launching big optical systems.
The Hubble telescope doesn't qualify as a "big optical system" to you? Because it does to most people, and the entire system only weighs about 12 tons, about what you could launch on an Ariane 5 or a Proton.

The really funny thing is, if you docked those optical systems together in an array -- say, a huge fan of smaller mirror/receptors in steerable grids -- then you wouldn't have to launch the whole thing on a single rocket, you could send them a few at a time and then dock them together into an increasingly large telescope platform; the array could literally be as large as you want it to be. 12 tons or 120 tons, perfectly scalable, in addition to being much easier to repair and service. Most importantly, not requiring a $20 billion HLV to put it into orbit means it doesn't have to work perfectly the first time you put it up there, nor do you only have to settle for ONE of them.
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Old June 18 2012, 08:26 PM   #148
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

Well the HLV isn't going to cost 20 billion. Thats a figure floated by its enemies within NASA. Also EELV launched modules will be even more cramped than Shuttle launched modules--where the shuttle did all the lofting, docking etc. HLV advocates were around long before it became pork. Selling lots of EELVs is pork too, especially if you are constantly launching say, 36 D-IV heavies or 24 F-9 heavies to do what one or two HLLVs can do. Five of them and ISS would have been finished with most of its useful life ahead of it, not behind it.

Ares V was going to be used for a piecemeal optical system: http://up-ship.com/blog/?p=9363

SLS can launch a goodly sized scope on one shot as well
http://www.stsci.edu/institute/atlast/
http://event.arc.nasa.gov/aresv/
http://www.futureinspaceoperations.c...20Ares%20V.pdf
http://www.nasa.gov/mission_pages/co...elescopes.html
http://trs-new.jpl.nasa.gov/dspace/b...%2008-03_A.pdf

Ms Porco from Cassini knows her stuff. Proton was a manned station launcher before placing a rover on the moon. As far as NRO giving those spysats away, you might want to look at the post of this JPL man:
http://www.bautforum.com/showthread....41#post2028241

More http://www.thespacereview.com/article/150/1

This examination shows there is no significant cost savings by pursuing the use of numbers of medium-lift vehicles when compared to the development of a new, shuttle-derived heavy lift booster.

sojourner wrote: View Post
And neither of them seem to understand that SLS will leave no money to develop those missions they want.
SLS will not always be in the development phase. Remember, we sustained over 100 STS missions that were HLVs in their own right It was just 90 to 100 tons of that was the orbiter. Now it will be all payload--payloads no one thought to ask for before the capability. People want to raid SLS budgets so they can keep launching Delta II sounding rockets and are being small minded and petty. That is what Carolyn refered to. delta II launches are like lollypops an alcoholic father gives to kinds every five minutes to keep their traps shut. Better to spend that money on a filling meal at the end of the day--even if that means listening to their squawks

http://www.wired.com/politics/law/ma...16-10/sl_porco

Now imagine if we had flown 100 Saturn or SLS missions instead of shuttle missions-- and imagine at what we might have up there now--maybe even something like this: http://up-ship.com/blog/?p=15169

Nice fictional model of a shuttle:
http://www.starshipmodeler.co/galler...snshuttle.html

Last edited by publiusr; June 18 2012 at 08:56 PM.
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Old June 18 2012, 09:31 PM   #149
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

publiusr wrote: View Post
Well the HLV isn't going to cost 20 billion. Thats a figure floated by its enemies within NASA. Also EELV launched modules will be even more cramped than Shuttle launched modules-
incorrect all current ISS components could have been launched on existing vehicles.
-where the shuttle did all the lofting, docking etc. HLV advocates were around long before it became pork. Selling lots of EELVs is pork too, especially if you are constantly launching say, 36 D-IV heavies or 24 F-9 heavies to do what one or two HLLVs can do.
24 f9H's for one or two HLLV's? The F9H will be capable of 53,000 kilograms. The SLS in it's final form will carry about 127,000kilograms. Do the math again and tell me which is cheaper per Kilo?
Five of them and ISS would have been finished with most of its useful life ahead of it, not behind it.

Ares V was going to be used for a piecemeal optical system: http://up-ship.com/blog/?p=9363

SLS can launch a goodly sized scope on one shot as well
http://www.stsci.edu/institute/atlast/
http://event.arc.nasa.gov/aresv/
http://www.futureinspaceoperations.c...20Ares%20V.pdf
http://www.nasa.gov/mission_pages/co...elescopes.html
http://trs-new.jpl.nasa.gov/dspace/b...%2008-03_A.pdf

Ms Porco from Cassini knows her stuff. Proton was a manned station launcher before placing a rover on the moon. As far as NRO giving those spysats away, you might want to look at the post of this JPL man:
http://www.bautforum.com/showthread....41#post2028241

More http://www.thespacereview.com/article/150/1

This examination shows there is no significant cost savings by pursuing the use of numbers of medium-lift vehicles when compared to the development of a new, shuttle-derived heavy lift booster.

sojourner wrote: View Post
And neither of them seem to understand that SLS will leave no money to develop those missions they want.
SLS will not always be in the development phase.
Yeah, actually, it will pretty much. remind us again when the first flight of block one is? and block 2?
Remember, we sustained over 100 STS missions that were HLVs in their own right It was just 90 to 100 tons of that was the orbiter. Now it will be all payload--payloads no one thought to ask for before the capability. People want to raid SLS budgets so they can keep launching Delta II sounding rockets and are being small minded and petty. That is what Carolyn refered to. delta II launches are like lollypops an alcoholic father gives to kinds every five minutes to keep their traps shut. Better to spend that money on a filling meal at the end of the day--even if that means listening to their squawks

http://www.wired.com/politics/law/ma...16-10/sl_porco

Now imagine if we had flown 100 Saturn or SLS missions instead of shuttle missions-- and imagine at what we might have up there now--maybe even something like this: http://up-ship.com/blog/?p=15169

Nice fictional model of a shuttle:
http://www.starshipmodeler.co/galler...snshuttle.html
Now imagine what we could have built with 1000's of cheaper launches. something like this perhaps:
http://www.nss.org/settlement/space/oneillcylinder.htm
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Old June 19 2012, 06:58 PM   #150
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Re: SpaceX is a go for April 30th: 1st commercial launch to space stat

publiusr wrote: View Post
Well the HLV isn't going to cost 20 billion. Thats a figure floated by its enemies within NASA.
It's less than the space shuttle ended up costing, even in 2012 dollars. And the space shuttle was developed with a number of specific missions in mind, its specifications developed around those missions even though half of them never materialized. The Senate Launch System is being designed with NO specific mission in mind and thus its specifications are highly nebulous and subject to random, arbitrary changes.

In this case, it isn't a question of whether the rocket will overrun its budget by a small or huge amount. Given the political realities faced by NASA, it's a question of whether or not it will ever fly at all.

Also EELV launched modules will be even more cramped than Shuttle launched modules
And this makes a difference WHY? The Russians built SEVERAL space stations this way, and the Chinese are reusing that technique for Tiangong-2.

Ironically, Skylab remains the only space station that was ever launched, fully assembled, with an HLV. This is ironic, because NASA's reliance on HLVs (the Saturn-V) and derivative technology left their space program with a gaping performance gap through which Skylab eventually crashed. And now that we are returning to HLVs for future exploration, the exact same thing is happening to the ISS: a bigger space station with a bigger performance hole, SSDD. The only difference is we now HAVE a fallback position in a fleet of proven and reliable EELVs that wouldn't take much to man-rate, plus the Falcon 9 system which has ALREADY proven its ability to send payloads to the space station. It would be cheaper and easier to evolve that existing capability to support the space station and build NEW space stations than embrace a technological pipe dream that has already proven not to work very well.

HLV advocates were around long before it became pork. Selling lots of EELVs is pork too, especially if you are constantly launching say, 36 D-IV heavies or 24 F-9 heavies to do what one or two HLLVs can do.
First of all, you don't seem to understand what "pork" means, since in this case there aren't a lot of politicians slumming for ULA or SpaceX just to give them something to do. The EELVs actually have a lot of important work to do for the NRO and the JPL, as does SpaceX -- now -- have a lot of work to do for NASA. That's like saying the auto industry is pork just because the government gave them a loan.

Second of all, your math is a little funny on this, considering 24 F9 Heavies would be worth TEN HLVs, not just one or two. If you want a better comparison, it's really more like comparing a single SLS rocket -- at its ultimate capacity of 120 tons -- to the standard Falcon 9. The SLS puts that payload into orbit for $2 billion (space shuttle pricing). The Falcon 9 puts that into orbit over ten launches for a little over $1 billion. In the end, the smaller rockets do the same job at a lower cost, with less concentration of risk for the entire payload. Moreover, splitting the payload into ten launches lets you benefit from economies of scale and you actually wind up spending LESS than the full billion when it's all said and done.

Five of them and ISS would have been finished with most of its useful life ahead of it, not behind it.
With EELVS and replacement modules, the ISS's useful life is STILL very much ahead of it. The only reason there's any talk of retiring it is because NASA doesn't have the means to send replacement modules, nor the budget to build them, nor the political leverage to ask for more money to do so. The reason for three of these is that they have been ordered by congress to spend all of their money on an HLV that will not be operational for more than a decade.

Ms Porco from Cassini knows her stuff. Proton was a manned station launcher before placing a rover on the moon.
You're blurring the lines between EELVs and HLVs, then, considering Proton's capabilities are similar to the Delta-IV Heavy but less than predicted for the Falcon 9H. If THAT'S what you mean by HLVs, then we're already having two different conversations altogether.

OTOH, by that definition all the "normal" HLVs currently in use would still have to build orbiting structures piecemeal, just using slightly bigger modules.

People want to raid SLS budgets so they can keep launching Delta II sounding rockets
No, they want to raid SLS budgets so they can fund SpaceX and Sierra Nevadas development of rockets and spacecraft that already exist and are far more likely to be useful in space exploration. It's the same people who crunched the numbers and figured out that the same money that is being spent on the DEVELOPMENT of the Senate Launch System could just as easily find a hundred LAUNCHES of useful payloads on the rockets we already have.

Think of it like a family argument. Dad wants to buy a Ford-F250 Heavy Duty with a Hemi engine and customized suspension because he wants to be able to haul three months worth of groceries in a U-haul trailer (which he will ALSO have to pay for). Everyone else in the family tells him they already have a sedan and a perfectly good minivan to shop with and the money he wants to spend on a new truck could be spent elsewhere.

It's a silly argument, because at the end of the day the only reason to buy the truck is "because it's cool!"

Now imagine if we had flown 100 Saturn or SLS missions instead of shuttle missions
For that same money you could get 1000 EELVs or Falcon-9Hs. If you're using it for building space stations or long-haul interplanetary vessels, the former is going to be a LOT more efficient in the long run, especially since an EELV can launch every 6 months from any SINGLE launch pad (and can use multiple locations without a lot of overhead) and an HLV can barely manage it once a year and can only launch from Kennedy.
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