Author Topic: DIRECT v2.0 - Thread 3  (Read 1123189 times)

Offline TrueBlueWitt

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Re: DIRECT v2.0 - Thread 3
« Reply #560 on: 01/22/2009 06:53 pm »
Have you heard any estimated costs for a space telescope that size? I keep thinking it might be $10bln, which seems like an awful lot of money to put on a single ride!

The JWST is $3.5B, and it's 6.5m, infrared, segmented, and will be at L2.  A visual scope, at 8.4m, non-segmented in LEO should be less, IMHO, even though it's larger.  The Large Binocular Telescope cost $120M, and it has two scopes with two of those 8.4m monolithic mirrors.

Interesting thought.. Would a Binocular(2x8.4m)  Telescope in LEO(or @L2) make more sense than trying to fabricate and fly a larger monolithic(or segmented) mirror? 

It seems there's enough throw mass available with J-232 or Ares-V to loft 2 8.4m mirrors.. Have two mirrors inline at launch and then rotate/translate out into position in orbit?  or would protecting the primary mirrors(extendable shields) be too dificult?
« Last Edit: 01/22/2009 06:56 pm by TrueBlueWitt »

Offline Lee Jay

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Re: DIRECT v2.0 - Thread 3
« Reply #561 on: 01/22/2009 07:01 pm »
I don't know if a J-232 could launch 2 scopes of that size in-line because of the length.  Even with an f2 primary, each scope would be more than 17 meters long.

I think if you were going to go to a large binocular scope in orbit, you'd use smaller scopes or more than one launch.  Perhaps the DIRECT team has thought about that and has other ideas.

Offline ballew

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Re: DIRECT v2.0 - Thread 3
« Reply #562 on: 01/22/2009 08:23 pm »
I don't know if a J-232 could launch 2 scopes of that size in-line because of the length.  Even with an f2 primary, each scope would be more than 17 meters long.


What is the maximum payload length for a J-23X?

Offline Kaputnik

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Re: DIRECT v2.0 - Thread 3
« Reply #563 on: 01/22/2009 09:14 pm »
Both groups are talking about only 40-50mT for an 8-10m diameter optical telescope as an upgrade to Hubble.   That sort of mass could probably be lifted on the J-120, let alone the J-232.

They couldn't care less that Ares-V has almost three times that mass capability or that Jupiter-232 has over twice that.   As long as it can lift up to 50mT, their only interest is getting that wide diameter PLF.   And they just can't get it via the EELV's, Space-X or Ares-I.

Ross.

Funnily enough, that sort of capability could keep the Mars lobby very happy too. To get to Mars realistically you need 10m or larger PLFs combined with c.40t throw mass, to accomodate the entry vehicles. Everything else can come up piecemeal.
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Offline kevin-rf

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Re: DIRECT v2.0 - Thread 3
« Reply #564 on: 01/22/2009 09:54 pm »

The JWST is $3.5B, and it's 6.5m, infrared, segmented, and will be at L2.  A visual scope, at 8.4m, non-segmented in LEO should be less, IMHO, even though it's larger.  The Large Binocular Telescope cost $120M, and it has two scopes with two of those 8.4m monolithic mirrors.

Why send it to LEO? The only reason HST went to LEO is because of the shuttle (and lack of a HLV that could toss it into a higher orbit). A monolithic would be better off in HEO or at an L-Spot. The thermal loads in LEO are killer, going in and out of earths shadow every 90 minutes. The tracking is worse, and you have this big blue marble you have to dodge every 90 minutes. Charge and discharging the batteries every 90 minutes. All the space junk wizzing by.

Just pay for the upper stage on the jupiter and send it into deep space. You can mostly stay out of the earths shadow, things track slowly across the sky, you can look at the same faint patch of light for days on end.
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Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #565 on: 01/22/2009 10:50 pm »
Have you heard any estimated costs for a space telescope that size? I keep thinking it might be $10bln, which seems like an awful lot of money to put on a single ride!

The numbers I keep hearing are between $1bn and $2bn.   I personally would expect those to grow some, as all such projects seem to.   But grow by how much?   And for what reasons?


You have to realize that JWST is running massively over-budget because they're having to fight to get a hugely complex spacecraft within relatively tight mass and volume limitations.   The cost over-runs are currently 7 times the amount of the launcher.

If the designers had been given a lot more room and weight to work with, they could have avoided a good number (not all, but a lot) of the cost increases which have plagued that program.

The same is also try of Mars Science Laboratory too.   They're essentially trying to fit a probe three times heavier and four times larger into a very similar package that sent the MER's.   Weight saving is proving to be a very costly and time-consuming part of this business.

JIMO got canned because they couldn't make it affordable to fly on a single launcher.

And Mars Sample Return has had to absorb the very uncomfortable costs of needing two separate launches to support it.


For the telescopes though, what we've been talking to the researchers about are essentially "big dumb telescopes".   They aren't extraordinarily complex.   They don't have a million mirrors which need to be unfurled and adjusted all the time.   They don't have all the latest gimmicks and gizmo's.   They're essentially a really large mirror in a frame, a beefy power supply, an RCS system (hopefully based upon an existing set of hardware such as the Orion's to keep costs down), some on-board electronics for guidance, navigation and comms, and finally a set of 4-6 removable/replaceable science instruments.    More importantly, they aren't trying to squeeze 10lb of 'you know what' into a 5lb can, they can afford to weigh more than initially planned -- With something like just Jupiter-120 they could afford some growth and still not bust their cost profiles.

The best bit though, is that once the development costs are paid and the production line is built to make the first one, it is surprisingly cheap to build a second, third or tenth unit -- roughly 12-15% of the cost of the first.   And the ability to have a fleet of these high-power space telescopes all working at the same time - and potentially together -- would create a real banquet for the astronomical science community.

Ross.
« Last Edit: 01/22/2009 10:55 pm by kraisee »
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Offline bobthemonkey

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Re: DIRECT v2.0 - Thread 3
« Reply #566 on: 01/22/2009 11:20 pm »
I guess the limiting factor in establishing a fleet would be the rate at which you can produce the mirrors.

As I understand it, there are very few places that have that capacity. You have PerkinsElmer, Kodak and Steward University of Arizona. Steward is at maximum capacity for the foreseeable future for the Giant Magellan, and I have no idea if Kodak or PE would want to even bid for the work or be considered viable bidders respectively.

Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #567 on: 01/22/2009 11:38 pm »
It's just a point to be considered, not the definitive point to hang the whole argument either way on.

Just for the record, we've been speaking with a team at JPL and another at MIT about space telescopes.

Both groups are talking about only 40-50mT for an 8-10m diameter optical telescope as an upgrade to Hubble.   That sort of mass could probably be lifted on the J-120, let alone the J-232.

They couldn't care less that Ares-V has almost three times that mass capability or that Jupiter-232 has over twice that.   As long as it can lift up to 50mT, their only interest is getting that wide diameter PLF.   And they just can't get it via the EELV's, Space-X or Ares-I.

Ross.

Good to know Ross.  I'd mentioned telescopes and size limitation before, but hadn't had anyone address it.  And then I read that article on telescopes and the Ares V.  The first real info I saw addressing the issue.  And I didn't know how -wide- a payload the Jupter's could take up, which is obviously a huge constraint for telescopes.  The larger the mirror, the more powerful the telescope.   And that trying to assmeble one in space from multiple launches on smaller lifters would likely be highly undesireable.

I know the James Webb will be a multiple hex reflector, but hadn't been able to fine out much info on how that was deployed exactly, or the problems in that.  Obviously a large monolithic mirror has a greater chance of operational success because if just one of the hex's don't deploy and align -perfectly-, you have a multi-million dollar Yugo hanging out at L2 where we can't service it.
a nice wide payload fairing would allow the option of a monolithic mirror.  I'd assume (but I'd sure be interesed to know from the real brains you mentioned at MIT and JPL for sure) that given a choice, they'd prefer the monolithic mirror for that reason.  James Webb had to be segmented because of the EELV size lifters available when it was conceived.  Anything larger than another Hubble would need to be segmented.

Anyway, yea, that is good to know that the brains are thinking in their best nerdy wet dreams they only hope to have 40-50mt mass lifting capacity, and 10m dia width.
It's something I'd been wondering for awhile.  If we really want to try to find other habitable Earth class planets (which is really the holy grail of space exploration as a whole) then a new generation of large diameter telescopes are going to be what does it.  If we were to find one in the general neighborhood, then that would immediately set up the ultimate long-term exploration goal for mankind, just as traveling to the Moon did for mankind or hundreds of thousands of years prior to 1969.
And we need to not be handcuffed too badly as to the diameters that we can launch as we have been thus far.  And I wanted to know that DIRECT wouldn't do that.

Thanks again.

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #568 on: 01/22/2009 11:40 pm »
What is the maximum payload length for a J-23X?

I don't think we had ever checked.   Because you asked...

NOTE:   We are NOT actually proposing this.   But theoretically this is about as big as it could get -- although just 'eyeballing it', I'd say there would be some pretty interesting bending loads involved.

This is 12.0m (40ft) dia x 45.6m (150ft) long, with a 27.6m (90ft) long barrel section and would mass somewhere around 18.5mT.   Given that the PLF is jettisoned about 250-300 seconds into the launch, I estimate that would translate to something like 6mT lower performance to LEO than the baseline 10x10m PLF.

The same payload could also be used on Jupiter-120 too.   I would estimate it would still have over 30mT of lift capacity flying that, so there may be some potential uses.

Ross.
« Last Edit: 01/22/2009 11:54 pm by kraisee »
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Offline woyteck

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Re: DIRECT v2.0 - Thread 3
« Reply #569 on: 01/22/2009 11:48 pm »
Hello,

This might be a fresh voice here (as I just registered).

When I heard for the first time about Ares rockets (especially Ares-V), I thought 'cool, they will use some parts from the shuttle program', but then I found out that it's not like that... That NASA has to redesign almost everything.
It keeps me wonder, in history of space flight we can clearly see two ways of doing 'the stuff'.
One of them - to create a sucessful design, use it and then abandon it in favour of something different, built from scratch (Saturn V - the most obvious example).
The other one - to create a sucessful design of a rocket, and then use it for years, decades even, with only minor changes and upgrades to the original, but still using the most parts (and facilities) unchanged. The one with a motto 'If it's good, don't change it'. (Two good examples from Russia - R-7 derivatives with Soyuz being one of them and Proton as other).
I see it this way, and I can tell that, DIRECT will use more parts from shuttle program, and I believe that there will be an easy move from Space Shuttle to DIRECT, therefore it's better.

But I also have a question.
Was there any tests for Jupiter with four Shuttle SRBs attached?
I.e. in a cross configuraton, (or just any configuration, maybe Energia like)?
Would it give an additional capacity to match Ares-V ?
Woyteck

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Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #570 on: 01/22/2009 11:53 pm »
As another note, roughly speaking, how much percent cost of the J232 is the J120 expected to be? (omitting a second stage, just assume heavy lifting to LEO...so I guess that's really be a J230??)
Seems like the J120 is a J232/0 with one less cryo engine on it.  Is there any other expenses?  How do you get twice the lifting mass with the same SRB thrust and 33% more cryo thrust?

Are the tanks larger in the J232?  The core wall thickness?  Other costs?
Otherwise seems like the price of the J120 would be the same as the J232/0, less one RS-68 engine, which would be relatively nominal given the price of the rest of the launcher.

Just wondering...

Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #571 on: 01/23/2009 12:03 am »
Hello,

This might be a fresh voice here (as I just registered).

When I heard for the first time about Ares rockets (especially Ares-V), I thought 'cool, they will use some parts from the shuttle program', but then I found out that it's not like that... That NASA has to redesign almost everything.
It keeps me wonder, in history of space flight we can clearly see two ways of doing 'the stuff'.
One of them - to create a sucessful design, use it and then abandon it in favour of something different, built from scratch (Saturn V - the most obvious example).
The other one - to create a sucessful design of a rocket, and then use it for years, decades even, with only minor changes and upgrades to the original, but still using the most parts (and facilities) unchanged. The one with a motto 'If it's good, don't change it'. (Two good examples from Russia - R-7 derivatives with Soyuz being one of them and Proton as other).
I see it this way, and I can tell that, DIRECT will use more parts from shuttle program, and I believe that there will be an easy move from Space Shuttle to DIRECT, therefore it's better.

But I also have a question.
Was there any tests for Jupiter with four Shuttle SRBs attached?
I.e. in a cross configuraton, (or just any configuration, maybe Energia like)?
Would it give an additional capacity to match Ares-V ?


Ross or one of the other guys who are the guru's on it will give you a better answer than this, but as I understand it, the problems with the two extra boosters (I asked this same questions before) is you have to change the internal structure of the core to give it two more "hardpoints" to attach the extra SRB's.
Also, the SRB are rolled out to the pad fully fuelled and are extraordinarily heavy compared to the empty ET, which is fuelled at the pad.
So the added weight would overload the crawler, and necessitate a complete pad overhaul.  All are added costs that the DIRECT team is arguing Ares V needs but they -don't- need.

They do have some conceptuatl designs of larger vehicals using a new core, then basically adding two Shuttle ET/SRB assembly's to either side of it (except the ET's would have engine cores under them like the Jupiter's, but have the pointy nose like the Shuttle's ET).  (I think there's a pic in the "Direct Derived Vehicle" thread)

So you're core would have boosters that have boosters.  Slick idea really, as the Shuttle ET is already design to be attached to the shuttle on one side.  Those attachment points and releases are already there.  You are just attaching them to a common core rather than to a shuttle.
So you have SRB separation, then later drop your two ET's, then I imagine drop you main core.  It'd have some ungodly lifting capacity in excess of Ares V.  A good future growth option, but it'd require a massive crawler and major redesign of one of the Complex 39 pads. 

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #572 on: 01/23/2009 12:19 am »
But I also have a question.
Was there any tests for Jupiter with four Shuttle SRBs attached?
I.e. in a cross configuraton, (or just any configuration, maybe Energia like)?
Would it give an additional capacity to match Ares-V ?

Firstly, welcome to the site!

I initially liked that exact idea -- until I looked into it more a few years ago.   The problem is that unlike liquid stages, the SRB's are fully fueled when they are stacked in the VAB.   Each segment weighs about 150mT (metric tonnes).   To put that into its correct perspective the gigantic Core Stage of the Ares-V, dry, doesn't weigh as much as a single SRB segment.   The entire Upper Stage and Payload on top of Ares-V together don't weigh as much as a single segment does.   The Shuttle Orbiter and External Tank together don't weigh as much as a single SRB segment either.

So while the SRB segments look small, they are most definitely the heaviest bits during the roll-out.

Now, the Crawler Transporters have an upper limit of what they can safely carry to the Pad.   The Pad itself also has structural limits for what it can support.

Right now Shuttle is comfortably below those limits with 8 SRB segments.

But the Ares-V currently has three extra segments (~450mT) plus the huge 400ft tall Launch Tower (~800mT) on top of the Mobile Launcher.   Together those parts are already pushing beyond the limits of the Crawler, the Crawlerway and the Pad structure.

If you want to add 8 more segments by doubling the number of 4-segment boosters, you're actually talking about adding ~1,200mT of extra weight during the roll-out.   That's going to totally breach the limits.   In order to support it you would have to replace both Pads, the Crawlers, the Crawlerway and the MLP's entirely.   By all accounts even the floor of the VAB couldn't support that weight either, so you'd need a new VAB too.

While it could be done, we're talking about some serious money to replace all that.   And the money just isn't in the budget.


BTW, if you did add an extra pair of SRB's, you'd actually only get about 15-18mT of additional performance to LEO.   There are much cheaper alternatives which could buy that sort of increase -- for example a barrel stretch of ~412" to the Jupiter Core Stage would buy you roughly 25mT more performance.

Ross.
« Last Edit: 01/23/2009 12:24 am by kraisee »
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Offline kevin-rf

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Re: DIRECT v2.0 - Thread 3
« Reply #573 on: 01/23/2009 12:28 am »
Obviously a large monolithic mirror has a greater chance of operational success because if just one of the hex's don't deploy and align -perfectly-

Other than you have to keep the large mirror at a uniform temperature and properly mounted which is no small trick. Of course you could plan in advance to use adaptive optics to counter any distortions in the optical system.
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Offline woyteck

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Re: DIRECT v2.0 - Thread 3
« Reply #574 on: 01/23/2009 12:48 am »
Thank you for detailed explanation.

AFAIK crawlers are in use since Saturn-V missions.
What is the maximum weight they can carry?
Also what's the maximum weight supported by the launchpad?

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Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #575 on: 01/23/2009 12:54 am »
As another note, roughly speaking, how much percent cost of the J232 is the J120 expected to be? (omitting a second stage, just assume heavy lifting to LEO...so I guess that's really be a J230??)

Not sure what you're asking.   Could you clarify, please?


Quote
Seems like the J120 is a J232/0 with one less cryo engine on it.  Is there any other expenses?  How do you get twice the lifting mass with the same SRB thrust and 33% more cryo thrust?

No.   The Upper Stage is used to complete the ascent, not just perform the TLI burn in space.

The J-120 configuration is designed to burn the ~728mT of Core Stage propellant in about 8 minutes to reach orbit.   The SRB's assist the Core Stage to get up to around 2,400m/s velocity and about 30nmi altitude.   The Core then finishes the remaining work.

The J-232 configuration works differently:   The SRB's still help to get the vehicle up to 2,300m/s and around 22nmi altitude.   But the Core Stage is burning its fuel 50% quicker and is producing 50% more thrust too.   It's job is to lift the Upper Stage to a velocity of around 5,450m/s at around 71nmi altitude at MECO.   That's most definitely sub-orbital still.   The extra thrust of the Core helps lift a larger Upper Stage to that point, where it takes over and completes the ascent.   The Upper Stage then ignites and burns for about 5 more minutes.   It adds about 3,700m/s to the velocity and raises the altitude to the intended circular insertion point before SECO.

The Upper Stage (when flying the EDS profile, anyway) then has about 110mT of additional fuel left inside after reaching orbit.   After the LSAM/CEV dock to the EDS, that fuel is then used to perform the TLI burn and send the mission to the moon.

For non-EDS use, the Upper Stage is only partially filled (~62%) before launch.


Quote
Are the tanks larger in the J232?  The core wall thickness?  Other costs?

No.   Absolutely not.

The Core Stages are intended to be Common Core Designs.   They will be built identically and can be swapped between J-120/J-232 flights by adding/removing the central engine.   The intention being that this is a field operation which can be performed at MAF or at KSC in less than 48 hours.

The design is optimized for the J-232's Lunar performance, and is simply flown "as is" for J-120 LEO missions.   Sure, J-120 is not optimized as highly as it could be, but even un-optimized its still got roughly twice as much performance as we actually need to lift Orion -- so who cares?

The intent of making a single Common Core which will do both jobs,  is to save as much development time and money as possible.   We prefer to develop one $15bn vehicle and use it twice.   Not develop two $15bn vehicles and use each one once -- that's a FAR more expensive approach and is one of the biggest bones of contention which we have with Ares.


Quote
Otherwise seems like the price of the J120 would be the same as the J232/0, less one RS-68 engine, which would be relatively nominal given the price of the rest of the launcher.

Just wondering...


The way we do it, is we only count the number of cryo stages and engines used *during the launch* to make the Jupiter-xyz numbering scheme.

x = Number of Cryogenic Stage (SRB's are simply assumed).
y = Number of Main Engines on the Core Stage.
z = Number of Engines on the Upper Stage.


For any configurations which fly an Upper Stage which won't be used until making orbit, those are considered part of the in-space payload, not the launch vehicle.   For example, the Lunar Flyby mission will use a Jupiter-120 to launch a Delta-IV Heavy Upper Stage and an Orion spacecraft to an orbital insertion point, where the payload will take the mission around the moon.   That stage is therefore *not* strictly part of the Jupiter.

But if that same stage, on the same Jupiter-120, were to need to be used to complete the ascent, it would make the vehicle a "Jupiter-221 (DIVH)" configuration and would then be considered part of the launcher.


It's a particularly complicated distinction we're making, but the code identifies the launch vehicle elements *alone* in order to explicitly differentiate what elements are payload and which are launcher.

Ross.
« Last Edit: 01/23/2009 01:02 am by kraisee »
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Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #576 on: 01/23/2009 01:04 am »
Thank you for detailed explanation.

AFAIK crawlers are in use since Saturn-V missions.
What is the maximum weight they can carry?
Also what's the maximum weight supported by the launchpad?

I'd have to look the precise figures up, but off the top of my head I think it's about 12.6 million pounds or so.   Shuttle is somewhere around 10-11m lb IIRC.   Ares-V is somewhere between 13-15m lb depending on which specific configuration you're talking about.

Ross.
« Last Edit: 01/23/2009 01:09 am by kraisee »
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Offline Lancer525

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Re: DIRECT v2.0 - Thread 3
« Reply #577 on: 01/23/2009 03:16 am »

This is 12.0m (40ft) dia x 45.6m (150ft) long, with a 27.6m (90ft) long barrel section and would mass somewhere around 18.5mT.   

Jiminy-creepers! I may just have to model this one too!

I am just gobsmacked at how good this launcher looks.

Ross, how about a  set of dimensions for this one, just like you did for the others? All I'll need is everything above the Core.  ;D
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Offline A_M_Swallow

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Re: DIRECT v2.0 - Thread 3
« Reply #578 on: 01/23/2009 03:16 am »

This is 12.0m (40ft) dia x 45.6m (150ft) long, with a 27.6m (90ft) long barrel section and would mass somewhere around 18.5mT.   Given that the PLF is jettisoned about 250-300 seconds into the launch, I estimate that would translate to something like 6mT lower performance to LEO than the baseline 10x10m PLF.

The same payload could also be used on Jupiter-120 too.   I would estimate it would still have over 30mT of lift capacity flying that, so there may be some potential uses.

Ross.

The 150 ft length would allow a fair sized space station, possibly split into two 19 ft high sections.

Possibly a fuel tank for a Mars transfer vehicle
(ruff inside dimensions)
volume of cylinder = pi r2h = pi * 5.52 * 45 = 4276 m3
or 4 276 000 litres or 1 130 000 US gallons

Offline Lampyridae

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Re: DIRECT v2.0 - Thread 3
« Reply #579 on: 01/23/2009 03:44 am »
15m is enormous. It's as wide as the largest ISS modules are long. Even 12m is perfectly good. Seriously, short of the core of a space colony, I don't see anything need that big a PLF. Most big telescopes this days are made up of multiple element arrays and you could assemble truly huge ones in space with a modest effort towards in-space assembly.

Also, if you stage your lunar ops at L2, you have the perfect chance to service and repair your telescopes.
« Last Edit: 01/23/2009 03:47 am by Lampyridae »

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