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#1 2004-08-14 16:32:12

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: Cheap heavy launcher - can it be done at all

This a question that has been hinted at in other threads but not for a long time taken square on.

What would be the cheapest Heavy launcher( ie minimum of 100 tons to LEO) and how would you build it and how much would it cost?

One way is to combine a whole load of other engines like a bundle of pencils and use that to put a cargo up, But is that the best way.

Or is it the Sea dragon way, make your rocket in a shipyard and "crack" your fuel from the sea and up you go.

Or is a super nuclear rocket the way to go?


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#2 2004-08-14 17:08:53

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

That depends on what you call "cheap," among other things...

Lowest development dollars?
Lowest cost per launch?
Lowest cost per pound?
How often do you need to launch it?
Does it have to be built with only American money? ESA/RSA money?

Shuttle Derived would probobly be the cheapest way to go as far as development, would have decent flight rates, and would be "all-American." Launch costs might be fairly high. Limited payloads to around 100-120MT tops without serious modification.

Energia would probobly be the cheapest re-development wise since Russians work for peanuts, and would have decent launch costs. Payloads of up to ~120MT with upper stage, 100MT or so without. Flight rate is "iffy," and would require doing alot of work in Russia for any mission.

Clean-sheet EELV derived HLLV, probobly powerd by RD-180 strapon boosters or Shuttle SRBs combined with RS-68 cryogenic core and RL-60 upper stage. High development costs, modest to low flight costs, but probobly would offer higher payloads (150-200MT) and flight rates (EELV factories used).

SeaDragon... a pretty esoteric concept to say the least... extreme payloads, so large that you'd be hard pressed to make a payload that would use all of it. Development costs would probobly be fairly low, but launch costs are anybodies' guess. The sheer size and need for water handling will incur signifigant cost and limit the flight rate without expensive parallel operations. Very little utility beyond launching ultra-huge payloads, not scalable or modular at all, and not in any fasion suited for human launch.

A rocket with a fission powerd first stage is definatly out, and using an NTR engine for an upper stage is of limited bennefit considering that the reactor is going to come back down without boosting to an 800km orbit or firing until escape velocity is reached.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#3 2004-08-14 17:25:28

Martian Republic
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From: Haltom City- Dallas/Fort Worth
Registered: 2004-06-13
Posts: 855

Re: Cheap heavy launcher - can it be done at all

This a question that has been hinted at in other threads but not for a long time taken square on.

What would be the cheapest Heavy launcher( ie minimum of 100 tons to LEO) and how would you build it and how much would it cost?

One way is to combine a whole load of other engines like a bundle of pencils and use that to put a cargo up, But is that the best way.

Or is it the Sea dragon way, make your rocket in a shipyard and "crack" your fuel from the sea and up you go.

Or is a super nuclear rocket the way to go?


It all depend on the amount you want to spend to develop it or if your going to use technology off the shelf and eliminate most of the development cost.

But, assuming that we want as little development cost as possible, our choices are relatively limited as to what we could choose.

We could go with C Shuttle design.

A two piece cargo shuttle design like space ship one, but of cargo launcher instead of people.

Or we could go back to a three piece rocket design.

That would be basically it.

But, if we are going invest so where between 20 to 30 billion for development cost, then there are other possibilities of heavy launcher like.

Scram/Ram jet designs cargoes with rocket being used right at the top of the atmosphere, but the development cost will be very high to bring them on line, but would be cheaper operate than with present technology is for building heavy launcher.

Fission heavy launcher are out not because they can't do the job better at a cheaper price than the other technology mentioned so far, but because of the radiation they emit during it use or if one of them ever crashes, it would be a pollution problem. So it would be out of the running even though it would be the best technology mentioned so far.

Fusion heavy launcher would be even more efficient that fission heavy launcher are and would not have the problem of pollution during use or if they crashed either. But that technology is currently not available so it out of the running for the present time.

I'm sure other people have other opinion or have more information, but that as I see it.

Larry,

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#4 2004-08-14 17:35:43

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

If development must be held to within $5-6Bn, Shuttle-Derived or Energia are probobly the only vehicles that can be afforded for sure. For $10Bn, you can start thinking about a clean-sheet EELV-derived vehicle.

Air launch for an HLLV is definatly out, no airplane can carry a vehicle that heavy. Airbreathing launch vehicles are also going to be limited in size, so I don't think a 100MT payload from them is practical either. Nuclear powerd rockets are basicly out, except for Fission upper stages for escape-velocity trajectories.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#5 2004-08-14 19:09:03

Euler
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From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: Cheap heavy launcher - can it be done at all

Another question you have to ask is where you want to launch payloads to.  If you just want to send them to LEO, you would end up with a different optimum design than if you want to launch payloads to a higher orbit or directly to Mars.

One way is to combine a whole load of other engines like a bundle of pencils and use that to put a cargo up, But is that the best way.

Generally, one big engine will perform better than a bunch of smaller engines.  However, no engines of the size that we want exist, meaning that if you want 1 big engine you will have to have higher development costs to create one.

Clean-sheet EELV derived HLLV, probobly powerd by RD-180 strapon boosters or Shuttle SRBs combined with RS-68 cryogenic core and RL-60 upper stage. High development costs, modest to low flight costs, but probobly would offer higher payloads (150-200MT) and flight rates (EELV factories used).

If you just want to go to LEO, I think that a big Atlas makes more sense than a big delta.  However, I don't think it is very realistic to make either of them into a 100 MT+ vehicle, you would need way too many of those "little" engines to lift such a vehicle.

If you just want to get cargo to LEO and weren't too concerned with trying to use parts that are already available, then I think you would probably end up with a high performance LH2/LOX core with an optional number to strap-on boosters (using either RP-1 or solid) and no upper stage.  If you want a clean sheet vehicle to send cargo directly to Mars, I think you would end up with a big RP-1 bottom stage and 1 or 2 LH2 upper stages (like Saturn V).

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#6 2004-08-14 20:02:23

prometheusunbound
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From: ohio
Registered: 2003-07-02
Posts: 209
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Re: Cheap heavy launcher - can it be done at all

I've heard that the government has destroyed all the blueprints to the Saturn Five after the program was finished.  Is this true?  Can blueprints still be found?  Can the Sat. 5 be used as a heavy lifter?


"I am the spritual son of Abraham, I fear no man and no man controls my destiny"

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#7 2004-08-14 20:16:39

Euler
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From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: Cheap heavy launcher - can it be done at all

I've heard that the government has destroyed all the blueprints to the Saturn Five after the program was finished.  Is this true?  Can blueprints still be found?  Can the Sat. 5 be used as a heavy lifter?

They did not destroy the blueprints, but that does not mean that bringing back Saturn V is a reasonable option.  Most of the equipment used to manufacture the Saturn V is gone and it would cost a considerable amount to bring back that infrastructure.  Even if Saturn could be brought back cheaply, that does not mean that we would want to do so.  There have been some advances in technology since then and we could probably build a modernized version that is significantly cheaper.

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#8 2004-08-14 22:17:37

GCNRevenger
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From: Earth
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Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

The Saturn-V cost nearly $2.5-3.0Bn a pop in today's dollars, not counting development(!), definatly not an option even if a few hundred million could be knocked off...

Hmmm yeah, the RD-180 is a little puny for such a big rocket, but the RD-170 used on Zenit and Energia is actually more powerful than the Saturn's F-1 engine at around 800K kilograms of thrust, and has higher specific impulse. The reigning champion by far though is the Shuttle SRBs, with the 4-segment version coming in at 1.175M kilos and the 5-segment around 1.500M kilos.

I am wondering if the missions for medium-heavy launch (40-80MT), large launch to LEO (>80MT), and Earth-escape/superheavy missions can be served by different versions of the same vehicle, taking a page from Energia... A large cryogenic core with multiple RS-68 engines (say three?) and 2X booster stages for medium payloads, for larger ones use either 4X or 6X booster stages with no upper stage for max pounds-per-dollars, and a Earth-escape version of the six-pack with a large upper stage powerd by multiple RL-60 engines, a single vacuum-optimized RS-68, OR small NTR engines.

The booster would either be a Shuttle SRB or a recoverable module packing a pair of RD-170 engines... the whole thing, idealy, would be able to loft 150MT at least, perhaps the capacity to do 200MT (with NTR engines, maybe more?) in the escape version with upper stage... One of the reasons that the NOVA rockets to suceed Saturn were axed was because SRB augmented Saturn-derivitive rockets were almost as powerful, some able to loft >360MT.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#9 2004-08-16 06:27:12

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

The case for shuttle-derived heavy lift
http://www.thespacereview.com/article/208/1

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#10 2004-08-16 07:11:11

Grypd
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From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: Cheap heavy launcher - can it be done at all

What I should have asked is
For space to be opened up it is essential for a heavy launcher to be able to put the infrastructure into space. It then becomes the question what would be best develop a new class of heavy launcher using modern materials which would be "cheaper" to use over and over again or redevelop the shuttle infrastructure which would be cheaper to do but flies more expensive flights due to its design.

Personally with the current spaceflight climate I would go for a shuttle C type operation. Not that im enamoured of the Shuttles high overhead costs. But it would start going in the right direction and this would mean it would be harder to cancel a program if it has a lot of infrastructure up in space. Also im sure that a shuttle C would lead to pressure to develop a new "cheap" Heavy launcher. I am also sure that if we wait to develop a new launcher it will become very at risk of cancellation or severe distortion similar to what happened to the shuttle. I am also sure that the "new" heavy launcher would be constantly in time and cost overuns if it does not have something urgent to replace.

This may be a cynical belief but with the way things have gone before I believe it to be very apt.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#11 2004-08-16 07:51:53

SpaceNut
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From: New Hampshire
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Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

The intent of my other thread, Rocket Business model for shuttle delta IV atlasV, and others good or bad was to give a cost based analysis as to what should be the avenue of choice. What should be the cheaper heavy lift launcher developement and manufacturing cost to create infrastructure for the future. Based on the current rockets as models for what not to do.

Large protoype design cost and over runs

Cost over runs to solidly consistant manufacturing of expendable rocket designs

Cost over runs for refurbishment of re-usable craft designs

Operations launch cost

Workfare when staff is not really working but is idle

Questions for those that know more about the Lockheed and of Boeing rockets.
Does either launch there own rockets for profit?
What is there work staff base for carrying on these facets of infrastruture?

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#12 2004-08-16 08:35:37

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

From earlier in the thread using the RD-170 versus the F1 of the Saturn is a good choice for a first stage engine.

This sort of sound like a Saturn 1 or V re-du derivative only modernized for a business model using what is a close match for the old specification.

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#13 2004-08-16 10:07:09

SpaceNut
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From: New Hampshire
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Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

sat1gen.gif

To take a page out of what the Russians continued to do with their soyuz space craft. They made continued changes and enhancemens as need to keep there rockets flying and are still doing so today.

While america kept changing the rocket platform in large jumps or into other design concepts each time.

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#14 2004-08-16 10:49:37

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

The trouble with just making Saturn-V redux is that its still going to cost a bundle, since you'd be throwing away alot of engines (5X RD-170, 2X-3X RS-68, multiple RL-60) for every flight ($$$) and the arcitecture really isn't very scaleable. You can't really make a "Saturn-V mini" for lighter loads without basicly building a new rocket, and the Saturn design is best suited for escape-velocity shots and not LEO delivery. The Skylab version of Saturn-V took a big payload hit with the changed upper stage.

I like the idea of going more with the Energia concept, with a varying number, say 2-6, of SRBs (big 5-segment Shuttle SRBs) or large reuseable liquid fueled stages (perhaps an Atlas-V mod with RD-170 engines or even Zenit-II cores) around a cryogenic core. Said core, powerd by RS-68 engines and built by Boeing, would have an optional upper stage for superheavy or escape velocity missions.

"To take a page out of what the Russians continued to do with their soyuz space craft. They made continued changes and enhancemens as need to keep there rockets flying and are still doing so today.
While america kept changing the rocket platform in large jumps or into other design concepts each time."

This is kinda simplistic... The Soyuz-TMA riding on the old R-7 really hasn't changed all that much from the earlier models. The R-7 is still a similar rocket to the same one built almost 50 years ago, and the basic Soyuz vehicle design hasn't changed much either. Landing rockets, new electronics, modifications here and there... but still the same chassis, same engines, same corrosive fuels, same reentry vehicle, same lousy payload capacity.

And as the saying goes, "if it ain't broke, don't fix it" still applies to rockets too, that there is no good reason to incrimentaly improve our rockets if they do what is needed. In fact, the development cost for modifications can make the whole proposition more expensive. Building a new rocket only when you have to makes some sense. And today, our rockets are pretty good, operating at >80% of what is theoreticly possible from our fuels, we're using the lightest practical/reliable materials, and using most every trick in the book to save on weight (Atlas-V pressure stable tankage).


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#15 2004-08-16 11:51:00

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

I could not help but notice the simularities to the Space Launch Initiative's vehicle and this one.
sts70lc.jpg

rlv-starbooster-orbit-bg.jpg

SLI Explores Flyback Booster Possibilities

http://www.spacedaily.com/news/rocketscience-02u.html

It is to bad that some programs have been cancelled that could have been the solution to the delma that we are in.

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#16 2004-08-16 12:03:00

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

Here is the other one that I had seen from the Next generation or SLI work that has been recently canned. It seems like most of the Nasa links are now gone to this info.

sli_generic_lead_01.jpg

NASA Working with Contractors to Explore Shuttle Successor
http://dev.space.com/missionlaunches/fl_021030a.html

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#17 2004-08-16 12:29:55

Euler
Member
From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: Cheap heavy launcher - can it be done at all

The trouble with just making Saturn-V redux is that its still going to cost a bundle, since you'd be throwing away alot of engines (5X RD-170, 2X-3X RS-68, multiple RL-60) for every flight ($$$)

You could use an RS-68 as the top stage engine as well (like Saturn V did with the J-2), and save money on engines.  However, the Saturn V redux would still be pretty expensive, and the concept of a big three stage rocket may be obsolete.

I like the idea of going more with the Energia concept, with a varying number, say 2-6, of SRBs (big 5-segment Shuttle SRBs) or large reuseable liquid fueled stages (perhaps an Atlas-V mod with RD-170 engines or even Zenit-II cores) around a cryogenic core. Said core, powerd by RS-68 engines and built by Boeing, would have an optional upper stage for superheavy or escape velocity missions.

I agree.  It would be nice if the RS-68 had a bit higher ISP for applications like this, but sometimes it is best to work with what you've got rather then developing something new.  It seems that the Chinese also agree, as their next generation Long March rockets have a layout very similar to this.

To take a page out of what the Russians continued to do with their soyuz space craft. They made continued changes and enhancemens as need to keep there rockets flying and are still doing so today.
While america kept changing the rocket platform in large jumps or into other design concepts each time."

This is kinda simplistic... The Soyuz-TMA riding on the old R-7 really hasn't changed all that much from the earlier models. The R-7 is still a similar rocket to the same one built almost 50 years ago, and the basic Soyuz vehicle design hasn't changed much either. Landing rockets, new electronics, modifications here and there... but still the same chassis, same engines, same corrosive fuels, same reentry vehicle, same lousy payload capacity.

A better example would be the Ariane V.  It first flew in 1996, but it has already received substantial upgrades to the cryogenic core and SRBs.  In 2006 another new version will fly, with an improved upper stage.  In just 10 years, the Ariane V will have nearly doubled its payload capacity to GTO just by these incremental upgrades.

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#18 2004-08-16 13:05:33

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

Hmmm some of the heavier concept versions for Energia, ones not built of course, had 6X single RD-170 Zenit boosters around the cryogenic core with 4X RD-0120 and a single RD-0120 cryogenic upper stage. How much it could lift though, remains kind of unclear, possibly around 120MT.

...A clean-sheet vehicle, with a large cryogenic core built at the old Delta-IV plant (instead of it being shut down... eliminate Michoud) that is a little bigger than Energia's core or Shuttle's ET. Equiped with 3X RS-68 engines giving a little more thrust but less Isp than Energia's core, ringed by 2-6X Shuttle SRBs which would not be modified and would be recoverd between flights, or 2-6X boosters based on Atlas-V or "Atlas-VI" with RD-170 instead of RD-180 and would be likewise recoverable. The optional upper stage would be powerd by 3X RL-60 engines of 25,000Kg thrust each with 460sec Isp. Target development price of no more than $8Bn USD with a launch cost of around $500M per flight not counting booster purchase. RD-180 engines are being manufactured in the US for the air force, so it is not a stretch for the US to buy design rights to the RD-170 as well so the vehicle would meet any "US only" requirements.

Rocket rundown:
Shuttle SRB (4-segment)
Thrust: 1,175MT
Isp: 269sec
Weight: 589MT wet/86MT dry

RS-68 (Boeing Delta-IV derived)
Thrust: 300MT
Isp: 430sec

hypothetical stage weight dry 8m wide and 60M tall cylinder @ 69.5kg/m^2 with three RS-68 engines: 67.124MT, which would hold around 900MT of fuel, in theory. Rough figures.

RD-170/171 booster engine (Zenit-II derived)
Thrust: 800MT
Isp: 309sec

Hypothetical "Atlas-VI" 5M wide stage powerd by RD-170 for booster role, same construction as launch vehicle with 1MT for recovery hardware, dry weight of 34.24MT and holding ~611MT of fuel.

RL-60 (hypothetical)
Thrust: 25MT
Isp: 460sec

Stage dry weight likly to only be ~5MT plus ~2-3MT for interstage

Anybody know how to roughly figure atmospheric drag penalties into a Delta-V for easy figuring into the staged rocket equation? ...Small payloads launched by the Core + 2 boosters, heavy payloads by Core + 4-6 boosters, superheavy or escape payloads by 4-6 boosters + upper stage. How much it would cost is sketchy... SRBs cost about $30-35M each per flight, the core would probobly be around $150-200M, and the upper who knows.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#19 2004-08-16 13:16:39

ANTIcarrot.
Member
From: Herts, UK
Registered: 2004-04-27
Posts: 170

Re: Cheap heavy launcher - can it be done at all

Define 'heavy'. You say around 100tons per launch, but where's it going? Is the idea to put up lots of ISS size stations? Send huge 60mt probes off to mars et all? Build something *really* big, like an SSPS? Or just put a huge amount of fuel or small parts/people into orbit?

For the first two, some kind of SDV like Zeus, Shuttle-C or Shuttle-II (space island group) would be good. For the last, something on the scale of DH-1 or a mass produced zenit (literally launch them as they roll off the production line) might be better and cheaper to operate. For the third, something like SeaDragon really is the way to go; especially for projects in the 10,000ton plus range. wink

It all depends on how much you want to put up and how quickly. Just remember that the more you put up and the more often you launch the cheaper it all becomes.

ANTIcarrot

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#20 2004-08-16 13:35:53

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

I consider the breakdown to be somthing like this...
Light: 5-15MT
Medium-light: 15-25MT
Medium: 25MT-40MT
Medium-heavy: 40MT-80MT
Heavy: 80-120MT
Superheavy: 120+

All versions without the upper stage would be headed to LEO most likly, with some superheavy LEO payloads using the upper stage for extra kick. Escape velocity payloads would all use the upper stage and would probobly use the max number of boosters, but you could do fewer if you want to send smaller objects (probes) direct to their destination.

The whole idea of going clean-sheet is to do away with Shuttle. Do away with everything that has anything to do with Shuttle that you can... no more Michoud, no more Pad-39, no more old VAB/crawler, no more of KSC than you absolutely need... An enlarged Delta-IV launch complex at the Cape' would handle the launch. Ultimatly, this is to reduce the manpower needed for each flight signifigantly compared to Shuttle or Shuttle-derived. Shuttle derived will probobly be cheaper to develop, but if the launch costs cannot be kept under control (like $400-$500M a shot for HLLV) then it doesn't matter... we're better off starting over.

The idea of light payloads launched by reuseable vehicles or assembly-line supercheap rockets is folley... the assembly cost for the payload on orbit would be so high and the efficency of launching dozens of little bits would so bad, that it would definatly doom the whole enterprise. Its been tried before, supercheap all-solid rockets, but they keep on blowing up too often. A rocket that doesn't blow up but hauls payload is going to be too pricey to defeat scaling up of current rockets. A small reuseable vehicle will also have very high development costs (somthing to the tune of $7Bn for DC-I) and would have to have a very high degree of reliability with fast turn around to be competitive with loss amoratization versus small numbers of launches by large expendables.

SeaDragon is a pretty crazy concept... I don't think it could be done in such a fasion that it would be practical, since the thing simply isn't going to turn around fast, mostly because of the trouble of building and handling and assembling somthing that big, and it is so big that it has very limited utility with its lack of granularity. Much higher risk of dooming the whole project if there is a launch failure too if you launch your whole ship in only 1-2 shots.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#21 2004-08-16 13:46:03

Euler
Member
From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: Cheap heavy launcher - can it be done at all

RD-170/171 booster engine (Zenit-II derived)
Thrust: 800MT
Isp: 309sec
Hypothetical "Atlas-VI" 5M wide stage powerd by RD-170 for booster role, same construction as launch vehicle with 1MT for recovery hardware, dry weight of 34.24MT and holding ~611MT of fuel.

Don't make the boosters carry too much fuel.  The idea of strapon boosters is that they provide a high amount of thrust for a relatively short amount of time, in order to increase the vehicle's T/W ratio and limit gravitational losses.  For example, the Energia stapons that used RD-170 engines only carried 320 MT of fuel.

Anybody know how to roughly figure atmospheric drag penalties into a Delta-V for easy figuring into the staged rocket equation?

According to The Rocket Company, the total Delta V for an orbital launch vehicle(including gravitation losses, atmospheric drag, etc.) is generally between 30000-31000ft/s (9150-9450m/s).  Since our vehicle is so big, it should have fewer losses due to atmospheric drag and be closer to the lower estimate

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#22 2004-08-16 13:52:07

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Cheap heavy launcher - can it be done at all

If the full-size Atlas-VI boosters were used though, how much payload could the thing carry I wonder? If 200MT payloads could be achieved merely using bigger fuel tanks on the boosters, that would be really nice. Oh, and I picked the RL-60's because of their light weight. Only like 200kg each if its RL-10 sized.

Anyway, I mentioned the Atlas-VI because it would be a great vehicle to launch the CEV on, liquid fueled top to bottom, only two engines (RD-170 or 180 + RL-60), and with enough payload to launch the LEO version of CEV with no SRMs at all. A version with smaller fuel tanks could probobly be built for booster applications without much trouble.

Another item to note, I don't know if the the giant SeaDragon is very well suited for escape velocity missions without an additional stage on top, which would make it more closely resemble the configuration of the Saturn-V rockets. SeaDragon is so big, that the trouble of handling, integrating, checking, and water-sealing additional stages would really start to eat into the launch rate and rack up higher launch costs.

Using 6X big 5M wide boosters on an 8M core might be problematic just to get them all to fit though... perhaps an 9M wide, shorter core would be better and would have less tank mass.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#23 2004-08-16 13:53:55

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

Last I knew aerodynamics has to due with surface area and angles relative to direction. Hence the more surface area the more drag.

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#24 2004-08-16 14:04:24

Euler
Member
From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: Cheap heavy launcher - can it be done at all

Last I knew aerodynamics has to due with surface area and angles relative to direction. Hence the more surface area the more drag.

Yes, but as you make the vehicle larger, the volume and mass of the vehicle increase faster than the surface area.  This is why aerodynamics is less of a factor for big vehicles than for small vehicles.

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#25 2004-08-16 14:24:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Cheap heavy launcher - can it be done at all

We have talked about every thing but the manned portion of the rocket. As every one has noted it is fairly easy to design something to lift materials or other items to almost anywhere that we would want.
Man is the problem that still needs a real solution when it comes to space flight.
We could say use a capsule like; Big gemini or apollo, a small lifting body as in lockheeds concept art or from some of the x series vehicles and some would continue to say a plane format is the way to go.
We need this part of the solution today in order to retire the shuttle to only cargo mode and completion of the ISS.
I still believe that the wieght of this issue needs to be resolved by Nasa's current rocket vendors and not be issueing more contracts for what is already known to be of need.

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