The Myth of Heavy Lift - (Let the fight begin...)

GCNRevenger · 2005-02-18 00:21:21

No, no you can't.

This is one of those times that it makes sense to wait so you can afford to develop the more capable hardware.

If you haven't noticed, MarsDirect calls for a launch vehicle with about six times the lift as Ariane-V ECB, 3-4 times the lift as a hypothetical "mega Ariane-V+" that doesn't exsist, and don't forget that you have to include several tons of your TMI mass for the aerobrake shield and lander (with enough fuel for late-term course adjustments).

Even if you drop the need to carry hydrogen in the hyperinsulated tanks for the ISRU system, and you send the ERV seperatly (which is a bad idea, since if you miss the landing then fueling it is a hazardou question mark), you still aren't anywhere near the lift capacity of any of the Ariane models. You would still need to carry a nuclear reactor (which weighs more then Zubrin estimates I think) AND a water drilling/purifying/storage rig.

The reason that Ariane can't be used to assemble a Mars ship in orbit any more then Delta-IV can is due to one big problem: too many pieces: splitting up the LOX/TMI, LH2 fuel tanks & solar pannels, the manned ship, the lander/aerobrake shield, perhaps a flight for assembly/checkout/supply, and finally the Mars crew would be alot of trouble... and still might have pieces too far beyond the throw weight of any Ariane-V varient

Also Hydrogen boiloff is an issue: That unless the Hydrogen fuel is used promptly, preferably within a month, you will lose alot of it. This places some pretty heavy scheduling concerns and would be

Ariane-V would need radical improvements, aproximatly doubling its LEO performance, before it would be able to launch a Mars ship in a reasonable number of pieces. Even then, this option would require nontrivial on-orbit assembly (particularly fuel tank integration) and would add substantially to the cost and risk of the mission. A bigger rocket would be more appropriate, like Ariane-M.

Zubrin thinks Mars can be done for $25Bn I thought... and I think this number too low by a multiple to get to Mars safely, and about one third the cost to go to Mars "well" with options for more then exploration.

dickbill · 2005-02-18 08:46:53

No, no you can't.
This is one of those times that it makes sense to wait so you can afford to develop the more capable hardware.
If you haven't noticed, MarsDirect calls for a launch vehicle with about six times the lift as Ariane-V ECB, 3-4 times the lift as a hypothetical "mega Ariane-V+" that doesn't exsist, and don't forget that you have to include several tons of your TMI mass for the aerobrake shield and lander (with enough fuel for late-term course adjustments).
.

GCN, then maybe the Mars direct or semidirect must be re-designed for LEO assembly, a shorter "stay" on the floor of mars, with less people, but with a faster trip, at least for the crew vehicle, because a compact nuclear reactor would allow it.
Very likely, France will be choosen soon to harbor the "International" thermonuclear Reactor facility (ITER) at Cadarache, because of its expertise in nuclear research. France and UK also have an expertise in nuclear submarine reactors. Then can probably design a nuclear reactor that would fit in the 5-6 tons range for a space ship.

The reason that Ariane can't be used to assemble a Mars ship in orbit any more then Delta-IV can is due to one big problem: too many pieces: splitting up the LOX/TMI, LH2 fuel tanks & solar pannels, the manned ship, the lander/aerobrake shield,

well, poeple could have say that of the ISS, and still, the ISS has been assembled. Maybe the ISS could be used as a Martian space ship assembling dock as well.

Also Hydrogen boiloff is an issue: That unless the Hydrogen fuel is used promptly, preferably within a month, you will lose alot of it. This places some pretty heavy scheduling concerns and would be

You mean for the in situ propellant reactor on MArs ? no H2 needs to be kept in huge amount for a long time sinec it has to be recombined to make Ch4 and O2. Pressured Ch4 liquid would be stable on Mars.

Even if you drop the need to carry hydrogen in the hyperinsulated tanks for the ISRU system, and you send the ERV seperatly (which is a bad idea, since if you miss the landing then fueling it is a hazardou question mark),

Apparently NASA showed an excellent precision in their landing. But I agree that some work must be done here to improve the landing target area to a walkable range.

Zubrin thinks Mars can be done for $25Bn I thought... and I think this ****** too low by a multiple to get to Mars safely, and about one third the cost to go to Mars "well" with options for more then exploration.

i agree, probably 100-400 billion dollars is more reallistic because of cost of development organization redundancy etc.
Just a fraction of the cost of the war in Iraq anyway.

GCNRevenger · 2005-02-18 11:22:42

I think it is safe to say that the ISS is the perfect textbook example of why extensive orbital assembly is to be avoided. If you can't launch your Mars ship in three pieces or less, then you are going to get into quite a bit of trouble. The ISS is also in the wrong orbit, which makes it unfavorable for Lunar/Mars ships, and it is not well suited as any sort of construction yard due its symmetric structure (required for gyros) and populated truss segments.

You also can't stay on Mars for a shorter window then ~500 days, because that is how long it takes for the planets to allign for a favorable transit time.

You can't get there any faster with chemical engines easily either, since the amount of fuel you would need to shorten the trip would increase exponentially.

As far as LH2 boiloff, I mean about using it for the TMI burn to push the initial Mars ship out of Earth orbit. MarsDirect already assumes a 25% boiloff, and thats for hyperinsulated tanks for the ISRU. A larger light weight fuel tank, like you would need for the TMI stage, would lose its fuel pretty rapidly while waiting for the ship to be assembled and readied for departure.

RobS · 2005-02-18 21:32:39

With the development of slush hydrogen technology, I wonder whether the hydrogen launched to Mars for ISRU could be in a slush state, with enough extra tank volume to accommodate it when it all liquifies. Zubrin says hydrogen boiloff can be kept to 1% per month. But if the hydrogen started as slush, it could take a year or more before the hydrogen completely reaches a liquid state.

-- RobS

GCNRevenger · 2005-02-18 23:32:17

Its not quite that easy Rob, that the solid hydrogen can sublimate and become a gas directly without having pass through the liquid state.

Also, slush hydrogen is even colder then regular liquid hydrogen, so storing it would be even harder. The extra tank volume you would need would also be signifigant, since slush hydrogen is 20-30% denser then liquid.

publiusr · 2005-02-24 16:44:19

Thank you very much for championing the cause of Heavy-Lift here. I wrote Heavy Lift Is Needed, Cut The Umbilical, and EELV's Are A Bad Deal

The lack of Engine-Out in the Delta IV--which must rise 1,000 feet straight up and can subject crews to 25 g during abort is all the reason to avoid the lemon that is the Delta IV.

That and its undershooting its orbit by 10,000 miles. It isn't a bad sensor. I am hearing that a vortex baffle set up a flow that failed to keep the sensor wet.

Its painful raise from the pad set up extensive charring as well.

See below:

http://www.thespacereview.com/article/1 … icle/185/1
"The Aldridge Commission suggested that a heavy-lift vehicle was necessary, calling it an “enabling technology” for implementing the vision, yet also suggested that heavy-lift vehicles might be developed commercially..."

http://www.spacedaily.com/news/oped-05z … -05za.html
http://www.space.com/spacenews/business … 40412.html

Michael Griffin, NASA’s associate administrator for exploration from 1991-1993, says the most logical approach, all things considered, is to spend the $3 billion or $4 billion it would cost to build a shuttle-derived heavy lifter and forget about EELV-driven approaches.

http://www.thespacereview.com/article/1 … icle/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. The development of such a heavy-lift booster supports the President’s space vision by providing the capability of lofting heavy payloads to the Moon in support of the construction of a lunar base as well as providing the capability to conduct other missions. I believe the development of a heavy booster in conjunction with the appropriate use of medium-lift boosters and modular spacecraft represents the most effective strategy for the US manned space program."

Log onto http://www.starshipmodeler.net]http://www.starshipmodeler.net
and look at the real-space forum for some space links--and nice models

http://www.k26.com/buran]http://www.k26.com/buran

John Creighton · 2005-02-25 09:38:30

publiusr writes:

More radical approaches involving the EELV, Sackheim said, could include new and fatter core stages for the Atlas and Delta to yield as much as 40 to 60 metric tons of lift.

I don’t know if you links are dated or the research in the articles wasn’t that good at the time. But IIRC the fatter delta could lift 40-60 without the solid rocket boosters and could lift 80 with the solid rocket boosters. It is interesting that the word radical is used. It doesn’t sound like an objective word but anti-boien propaganda. Anyway, I thought the current delta IV heavy could lift 40 MT with its heaviest configuration using solid rocket boosters.
http://aviationnow.ecnext.com/free-scri … ...2215top

Boeing says even modest upgrades could double the Delta Heavy's Earth orbit capability to more than 50 metric tons, including being able to fire up to 20 metric tons on escape trajectories to Mars.

Delta IV Heavy upgrade options can be mixed and matched to various exploration mission architectures. The options that can use the existing pad infrastructure include:
*New upper stages: Depending upon the upper-stage cryogenic propellant load desired, the current Heavy uses either a 4- or 5-meter-dia. upper stage with a 25,000-lb.-thrust Pratt & Whitney RL10B-2 engine.
For larger payloads, however, Pratt is well into testing its new RL60 upper-stage engine that, when mated with the Delta Heavy, can begin to push the Earth orbit capability to more than 40 metric tons.
Likewise, Boeing and Mitsubishi are examining a U.S./Japanese MB-60 with about 60,000 lb. thrust. The RS-68 first-stage engine could also be used as a translunar-stage engine, under some Boeing studies.
*Solid rocket booster additions: The addition of four ATK Thiokol GEM-60 solid rocket motors, two on either side of the core, would boost Heavy unmanned Earth orbit payload performance to more than 30 metric tons and escape payloads to 12 metric tons.
Boeing has examined other Heavy unmanned cargo options using six solids to achieve in excess of 50 metric tons to orbit. Each GEM-60 has 191,000 lb. of liftoff thrust and, by mounting them all on the same side, the vehicle can still use Pad 37 without changes.

Boeing has also looked at other IV Heavy derivatives that would cluster 5-7 common cores with 5-7 RS-68 first-stage engines for 85-metric-ton Earth orbit payloads and 36-ton capability to Mars.
And it has considered increasing the diameter of the clustered cores from 16.1 ft. to 23 ft. for more propellant, giving the vehicle a payload capability comparable to the 7.5-million-lb.-thrust Saturn V. But the concepts with the multiple or enlarged cores would require new pad infrastructure and are not likely for any near-term mission options.

With regard to cost and complexity:

But Boeing notes the Delta Heavy's 650,000-lb.-thrust RS-68s use higher energy oxygen/hydrogen propellants, are relatively simple and could also be used as an upper-stage engine for a translunar stage in exploration architectures. The RS-68 is the first new large rocket engine built in the U.S. in 25 years, and has 80% fewer parts than an SSME.

GCNRevenger · 2005-02-25 09:59:48

"The lack of Engine-Out in the Delta IV--which must rise 1,000 feet straight up and can subject crews to 25 g during abort is all the reason to avoid the lemon that is the Delta IV."

This is not true

The 25G seperation is a scare-tactic lie with no basis in reality. The Delta-IV simply cannot generate loads that high in any configuration.

"It isn't a bad sensor. I am hearing that a vortex baffle set up a flow that failed to keep the sensor wet."

More unsubstantiated rumor-mongering. The USAF doesn't seem terribly concernd and intends to use the HLV to launch an extremely expensive and vital spy satelite in the middle of this year. The single-core Delta-IV flights have all performed flawlessly.

It wouldn't really surprise me if these lies came from disgruntled NASA/United Space employees working at KSC who may become "surplussed" without a heavy lift rocket based from there.

Engine-out capability is also not that important, and only one vehicle in history (Saturn-V) has had true engine-out capability. It needed it too, since it had eleven engines (twelve counting the Apollo SM).

If the objective is to simply ensure the crew survives a launch a high percentage of the time, then a small number of reliable engines is sufficent versus a larger cluster of engines with engine-out. There is the lovely chance that if your engine-out rocket had a failure, that the failed engine would take out the other engines or the whole stage. Multiengine designs makes it more likly you can achieve orbit, but it also increases the chance of catastrophic failure.

The model of Delta-IV that I am most interested in is the upgraded 40MT version of the current Delta-IV HLV, which will be able to acend from the pad much faster with its improved engines and lighter construction.

If you take one of the cores from this vehicle, it should have high enough performance on its own with no solid rockets at all, to launch a LEO CEV for crew flights. Only two engines total, an RS-68 and an ML-60.

As far as EELV+ versus Heavy Lift, there are two big advantages:

1: Better known costs, that the EELVs are more-or-less a known quantity and are flight proven, while a clean-sheet or SDV rocket have the potential for costs to balloon out of control... especially with the SDV and the accursed Shuttle Army. If whatever option costs more then ~$500M per sortie to place a payload into Lunar orbit, then VSE is doomed.

2: Flexibility, that if you want to only launch 40MT at a time, you are out of luck with SDV. A clean-sheet "light" HLLV could do this, but its development costs are sure to be fairly high.

Going with "Delta-IV+" will also save having to develop two rockets.

publiusr · 2005-02-25 16:31:21

The lack of Engine-Out in the Delta IV--which must rise 1,000 feet straight up and can subject crews to 25 g during abort is all the reason to avoid the lemon that is the Delta IV.

"This is not true. The 25G seperation is a scare-tactic lie with no basis in reality."

It most certainly is true. That is Boeing hype that tells you it isn't.

"More unsubstantiated rumor-mongering."

Take a look at the other HLLV thread--for a picture of Delta IV surrounded by fire.

Or is that a scare tactic too?

Or Johnson's not taking a shine to it?

"The USAF doesn't seem terribly concernd"
The Air Farce is run by retards.

"It wouldn't really surprise me if these lies came from disgruntled NASA/United Space employees working at KSC who may become "surplussed" without a heavy lift rocket based from there."

It wouldn't surprise me if Boeing's lies about Delta IV are to unload that dog on us taxpayers now that it has been withdrawn from the commercial market--with its Zenit Sea Launch vehicle taking those--Zenit, the Energiya HLLV strap-on.

Two words: Darleen Druyen.

"Engine-out capability is also not that important."

:laugh: :laugh: :laugh:

"The model of Delta-IV that I am most interested in is the upgraded 40MT version of the current Delta-IV HLV, which will be able to acend from the pad much faster with its improved engines and lighter construction."

--throwing away five RS-68s to do it, where shuttle-derived can do it with three and have engine out.

"Going with "Delta-IV+" will also save having to develop two rockets."

We already have two tax supported EELVs as it is. We need one EELV and one HLLV. Not duplication of effort.

GCNRevenger · 2005-02-25 17:39:03

It most certainly is true. That is Boeing hype that tells you it isn't.

Fine, tell me how any model of the Delta-IV could subject the CEV to 25G loads. The maximum acceleration that the booster can achieve is no where near that great, even if it were pointed straight down. In fact, no other launch vehicle or even military missile in the world can produce those kinds of loadings, past or present. That figure is so high as to defy credibility, both the person who make the claim as well as yours publiusr.

If you mean 25G's from the escape system to ensure crew surviveability in a booster failure, that is equally nonsense. Thikol estimated that putting CEV on top of a modified Shuttle SRB in their "Shuttle derived" vehicle would have only exposed the crew to 8Gs.

And the engine out thing? You know those Russian Zenit and Energia rockets that you blindly worship? Guess what? Russia's new Klipper manned spacecraft, the replacement for the allmighty Soyuz... will ride on Zenit. No engine out capability there, and it doesn't seem to bother the Russians. The statistics are all that matters, not your wannabe-engineers' "intuition."

"--throwing away five RS-68s to do it, where shuttle-derived can do it with three and have engine out."

Actually, each one would come equipped with only three booster cores, and only three RS-68's each. Also, it is not possible to mount a trio of RS-68 engines on the Shuttle-C basic design because they are bigger then SSMEs, so you would have to do what Marshall SFS wants to do and place the payload on top and the engines on the bottom of the tank, Magnum style.

It would also probobly help your future attempts at crazy Boeing-hate/Russia-worshiping rumor mongering if you knew that each Shuttle SRB costs almost as much to recycle as to buy two RS-68 engines.

PS: Oh, and about that Delta-IV fireball... did you know that Aluminum does not burn? And that the Delta-IV happens to made of this wonderous metal. Wow, how handy is that?

publiusr · 2005-03-02 17:17:21

revenger wrote:
"Fine, tell me how any model of the Delta-IV could subject the CEV to 25G loads."

Abort profiles. I find the folks at Thiokol more credible than Boeing . Read last weeks av week about the Delta IV's problems--and how the astronauts don't like EELV.

"If you mean 25G's from the escape system to ensure crew surviveability in a booster failure, that is equally nonsense. Thikol estimated that putting CEV on top of a modified Shuttle SRB in their "Shuttle derived" vehicle would have only exposed the crew to 8Gs. "

Their vehicle--less than Boeing's. Talk to Chuck Jensen there at ATK.

"Guess what? Russia's new Klipper manned spacecraft, the replacement for the allmighty Soyuz... will ride on Zenit. "

Actually, Kliper was an excuse to convince the Euro's to give the R-7 pad there a hydrogen upper stage handling capability to double its payload and turn it into an Ariane killer by sneak.

Don't even try to talk down engine out. It is more than a nice thing to have. I doubt kliper will ever see service.

"No engine out capability there, and it doesn't seem to bother the Russians. The statistics are all that matters, not your wannabe-engineers' "intuition."

That is friendly talk from you. I guess the engineers who do appreciate engine-out aren't as smart as you. Or maybe you are just a smart-ass.

You sound like one.

"--throwing away five RS-68s to do it, where shuttle-derived can do it with three and have engine out."

Actually, each one would come equipped with only three booster cores, and only three RS-68's each.

Yeah three each--for five Delta IVs to do what one three RS-68 HLLV can do with the engine-out which saved at least one Saturn V mission--remember?

http://www.space.com/spacenews/pdf/zubr … zubrin.pdf

Read it and weep.

On to other matters then...

Ariane V may actually be phased out. The Zenit is Ukrainian--not Russian--in design, and the R-7 is what the Russians want upgraded, because with a hydrogen upper stage, it will take a bit more to LEO than even Zenit can--unless it gets the same work.

If the Euros go along with a hydrogen upper stage, they may try to build a larger launcher for their Aurora plans.

Energiya M would have been better than Ariane V anyway.

GCNRevenger · 2005-03-02 19:19:19

Overall, it doesn't look like you are really listening to me Publiusr, which kind of defeats the purpose of me spending any time to talk to (at?) you.

Your insistance that engine-out is some kind of panacea of launch technology and thoughtless dismissal of its drawbacks is eblematic of the fact that you really aren't concerned with why its better, only that it is counter to whatever NASA or I am saying... which doesn't really seem like the characterisitc of a person debating, only trolling.

You obviously don't know what you are talking about anyway, or at least just bleating what old and angry Apollo-era engineers (which we see our share of, remember JimM?) have told you about the magical wonders of engine-out and how reality & statistics don't matter... casually forgetting that you have more engines that can blow up on the bottom of your rocket too.

Anyway...

-Nothing to back up the 25G rumor or anything like it, and it is an absurd number given that no rocket can produce such accelerations.
-Pointing at the Aviation Week column, which you don't detail anything out of it, and their story is just that... a story. Embelished for dramatic effect very likly, willing to cite "sources" and such.
-Astronauts are not aerospace engineers, and the risk of launch casualty is a fairly small risk compared to what VSE will entail. Even the stock EELVs with health monitoring and robust escape systems should be minimally safe enough for an orbital capsule.
-Soyuz doesn't have engine out either, its upper stage only has a single engine, and the service modules' engines are too small to achieve orbit on their own.
-"...the R-7 is what the Russians want upgraded, because with a hydrogen upper stage" Nice conspiracy theory about the Russians... Russia doesn't intend to modify R-7 (Soyuz rocket) with a cryogenic upper stage, they are not doing it actually, they are going to fly it from Zenit from Baikanour or Plestek.
-By "smart-ass" you mean "actually considers the real risk probability of casualty and not in nameless engineers' hunches" then yes, I am.
-Three RS-68's per launch vehicle obviously. Each of which costs half of a SRB recovery/refurbishing. An improved version of the three-core Delta-IV could lift 40MT, perhaps even 50MT. Two launches, not five, to reach mass parity to HLLV.

Again, Saturn needed engine out, it had three stages and eleven engines of questionable reliability. Today we can make a heavy lift rocket with only five or six engines with an almost perfect reccord over dozens of uses and only two stages... engine out isn't nessesarry. Zubrin's rocket only has engine out because it uses the $50M SSMEs, and only on the "main" stage... if the upper stage or the boosters fail, your hosed anyway. Duh.

And speaking of Zubrin...

"It is a well known feature of launch vehicle economics that larger boosters are more economic than smaller boosters"

Except that it isn't nessesarrily true, a SDV may be more expensive per pound because of the buracracy and manpower requirements of the STS system.

"In fact, in just a few weeks we would need to accomplish four MLV launches,"

Also not true, as long as you use the EDS stages within a month or two of launch, then it doesn't matter when you launch anything. The Lunar module could loiter in Lunar orbit for months before it would need to be used. Zubrin here is either ignorant or a liar (again) because he is biased in favor of a rocket for MarsDirect, and is not interested in the best option for VSE.

Zubrin also compares all the "medium launch" rockets, and not any particular rocket line. For instance, the Delta series are extremely reliable, and the Atlas-III line has never failed. Averaging the lousy reliability of the Titan rockets skews the data and is another scare tactic... besides, those rockets aren't designed with enhanced reliability because it was more important that they be cheap.

Zubrin's numbers just aren't very credible anyway, he waves his hands and assumes a fairly large failure rate for a simple operation when he has no idea how reliable the actual production componets will be and just arbitrarily assigns a number so that it gives him the "scarry" result he wants.

Sure there will be missions failures, but there are plenty of abort modes which will radically reduce the chance of crew casulty below Zubrin's figures, and is the true benchmark.

For my opinion of the Earth-orbit-rendevous scheme, I deffer to a higher authority then the reactor-engineer-by-trade Zubrin, the patron saint of rocket scientists, Verner Von Braun... who advocated EOR and was opposed to Saturn-V.

Comparing Energia to Ariane-V? You really are a the (Rocket Scientist)^-1

John Creighton · 2005-03-02 19:50:19

“Overall, it doesn't look like you are really listening to me Publiusr, which kind of defeats the purpose of me spending any time to talk to (at?) you.” I’m listening though. Keep up the good work.

publiusr · 2005-03-03 16:23:25

I loved Revengers smack against "Angry Apollo era engineers."

How thoughtless.

Zubrin is not the only one who understands the need for SDV HLLV:

http://www.starbooster.com/aquila.htm]h … aquila.htm
http://www.starbooster.com/TALAYPanel3F … 3FINAL.pdf
http://www.nsschapters.org/ny....ied.pd … ...ied.pdf
http://www.thespacereview.com/article/1 … icle/150/1

And you're right and they are all wrong. But Mr. Revenger has never been wrong about anything, has he?

GCNRevenger · 2005-03-03 17:46:16

Why do you say that I am against HLLV? Did I say that "heavy lift is a stupid idea" or something to that effect? You might have noticed that I was rather specific in my condemnation and that I have supported heavy lift over and over in various threads... I don't like any Shuttle Derived heavy lift option, because of its poor flexibility and likly very high manpower requirements, nor was it designed as a heavy lift vehicle to begin with, and it would have to be re-man-rated if you were to fly people on it.

I do think that we should seperate the carriage of people and cargo, which means that we will need a small man-rated rocket with decent performance, high inherint & proven reliability, and relativly low development and operational costs. The EELVs happen to fit this bill, and given the fact that NASA does not have a great deal of money to spend on development nor should NASA risk the possibility of a ruinously expensive SDV, then upgrading the EELVs for both manned and initial VSE work makes sense. An upgraded EELV won't even be a medium lifter anymore, as it would have double the average "heavy" lift performance and we happen to know with good accuracy how much they will cost.

The uprated EELVs also have superior flexibility for payloads too large for older rockets, but too small for heavy lifters... supply flights to LEO or the Moon, large space probes to Mars or the other planets, and heavier military orbital payloads.

They are no where near powerful enough for a Mars program or building anything big, no arguments there, but they are big enough for a Lunar program. The Saturn-IV EOR concept would have used a rocket of similar performance.

The Starbooster folks are almost as bad as the insane Space Island maniacs (or con men, as the case may be)... and the Space Review willfully discounts the reality that the EELVs ("E" is for Evolved) today are not the end of the line, and can themselves be improved to virtually double the performance and reach aproximate price parity with SDV. Thanks to the Rocket Equation, small changes in vehicle efficency with lighter tanks and improved engines yeild large payload dividends.

Also, the article takes the low cost of the Ares and Shuttle-C vehicles on faith without batting a lash at about $280M each, even though the parts alone for Ares would cost about $380M each, and a bit over $280M for Shuttle-C. You'll have to do better then that.

Tank ~$60M
2X five-segment SRBs ~$60M
5X SSME (Ares) ~$225M (perhaps 6X for LEO version)
3X SSME (Shuttle-C) ~$135M

80MT of payload by Delta-IV+ "SHLV" ~$400M, fly away

publiusr · 2005-03-04 15:31:06

Clean-sheet is not an option now. That has nothing to do with me.

You have just let STS bashing go to your head. I for one do not accept your cost estimates, and even if they were true, a billion a shot was already the case for some Titan IV launches at 1/4-1/5 the payload. that $400 million cost for Delta IV heavy is itself a guess, and there is nothing keeping Boeing from gouging if there is an EELV downselect.

If we could afford Titan IV, (and this stupid war) we can damn sure afford Shuttle-derived.

It's the only game in town now.

Either support it or don't.

Ad Astra · 2005-03-04 22:31:00

Every plan to recover liquid fuel rockets from the ocean has involved a retractable metal shield that would deploy over the engine bells. This would add some weight and some complexity to the recoverable engine pod, but it's not an insurmountable challenge.

IF they build an SDV, I was thinking about the idea of recovering the avionics. It's been said that over 90% of the cost of a military aircraft is its avionics. While a rocket has higher non-avionics costs and less sophisticated avionics than combat aircraft do, the cost benefits of recovering the avionics might be justified.

GCNRevenger · 2005-03-04 22:41:25

Retractable metal shield? I don't think I like the sound of that... If the whole recovery option adds much mass or complexity, then you might as well stick with throw-aways... The nessesity to seperate at the proper time, avionics and communications, attitude sensors and control, heat shield with fuel line/mounting/control penitrations, parachutes, floatation gear, and now a fancy metal clamshell (none of which can interfere with the aerodynamics much during supersonic acent)... I think that its pretty clear that it would be more trouble then its worth. If we built Magnum, probobly the more realistic compromise design, it would only be saving a pair of RS-68s.

Also, since seperation comes so late in the acent, where would the engine pod fall? It sure wouldn't be falling near shore like the SRBs for easy pickup.

Recovering the avionics would be nice, but I don't think thats practical or that bennefical either for the above reasons and the large non-avionics costs. Improved computer technology could also reduce how much the avionics cost.

RobertDyck · 2005-03-05 01:23:15

Um, no. I described the configuration several times so I surprised I have to go into detail again. Use the same engines: 3 SSME. Use the same engine thrust support structure with attachment to the ET. Same gimbals with the same auxiliary power units to power them. Same helium tanks...well they increased the number of helium tanks, a new pod could simplify that with a smaller number of larger tanks. Replace the 5 old computers (4 main computers and 1 backup) with a Commercial-Off-The-Shelf (COTS) Single-Board-Computer (SBC). I know a manufacturer who makes one; it isn't as fast as a modern PC but faster than all the current computers on Shuttle put together. They used to make a couple models, but now sell only the fastest. It's as big as a PC mother board and masses 1.5kg. Software can be adapted from the current Shuttle. Remember I am a computer programmer, I know what's involved with software development. A change that big would cost millions, but single digits of millions, not billions.

Heat shield? Remember I said to use an ablative heat shield that can be replaced as a single piece, just by unbolting the old one and bolting on a replacement. Tiles are too fragile; take too much work to maintain. Just put thermal blankets on the side of the pod and ablative heat shield on top. It would re-enter up-side-down with engines pointing up. Then use the same parafoil that was developed for X-38, and take it's landing software. The X-38 landed abruptly on skids, so protect the engines from impact with air bags.

Remember to include the complete OMS pods. They're used for orbital circularization as well as any change of orbit. The RCS thrusters on the OMS pods are used for fine manoeuvres, like stabilizing cargo while the shuttle orbiter or a tug picks pieces off for completion of ISS. Remember I said one Shuttle-C launched from one of the pads at LC39 and the orbiter from the other pad could complete 1 year worth of construction in a single mission. Or Shuttle-C could lift a giant space telescope, or lunar base modules, or of course a Mars spacecraft. Fine manoeuvring with the RCS thrusters gives it a lot of options, such as delivering modules for an on-orbit assembled Mars vehicle.

With an ablative heat shield you don't need the flap (retractable metal shield) over the engine bells. Parafoil and airbag eliminates an ocean landing so you don't expose the engines to salt water. Recovery is by a flatbed truck with dual rear axle and a truck crane. There are a couple truck manufacturers that build that as a stock item. You might want to include the existing shuttle service truck that drains OMS propellant. Operationally, truck recovery from the salt flats should be much cheaper than sea recovery. Just drive it back to KSC.

You'd need a payload adapter to connect to the engine thrust support structure around the heat shield. You'd also need some sort of structural member connecting the top of the engine pod to the ET due to torsion. Sit payload on the engine pod, not the tank. When I calculated payload mass of 104.7 tonnes to 185km orbit I included everything except the payload adapter and torsion structural member. I even included the composite payload fairing for commercial flights of Titan IV. It turns out that fairing is the Contraves fairing also used by Ariane 5 and Atlas V. I based that calculation on the assumption that an engine pod the same as the engine section of the shuttle, and a payload fairing the same diameter as the nose & fuselage of the orbiter will have very close to the same aerodynamic forces. So I assume the total of orbiter + cargo will be the same as engine pod + fairing + cargo.

GCNRevenger · 2005-03-05 09:48:15

Risk a billion-dollar rocket launch on such a puny un-robust computer not failing? Iiii don't think you are really being realistic Robert, not at all. The reason why computers cost so much for rockets today is that they must not fail. The cost of making a new and robust control computer will be expensive.

Ablative heat shield would add to the per-flight costs, and add to the refurbishment costs per-flight. It is probobly the only real option, but that isn't saying much since the shield must be so large... multiple meters wide, much bigger then any in history (probobly at least 7m), plus it must be structurally heavy to resist the hypersonic reentry loadings. I bet it would cost 1/3rd as much as a brand new RS-68 would.

"Then use the same parafoil that was developed for X-38, and take it's landing software. The X-38 landed abruptly on skids, so protect the engines from impact with air bags."

The engine pod, with everything it would need, is going to definatly weigh lots more then the little X-38 would. Heck, the SSMEs themselves will weigh more then it did. You can't use the same parachutes, they are too smal... And where do you intend to land it?

The extra mass of the fuel tank, SSMEs, and recovery hardware for same is so heavy that the little OMS engines probobly can't perform orbital insertion if they have to push all that mass and the payload. The tank and engines themselves will weigh about as much as the payload will, and carrying enough OMS fuel will cut into your payload mass signifigantly... So, the tank will never reach orbit. Since it will never reach orbit, then that tank is going to come down again somewhere over the middle of the Atlantic ocean, so a water landing in the middle of the sea is unavoidable. You can't land it on dry ground... and frankly, I don't trust air bags to protect $200M worth of space ship engines.

"You'd need a payload adapter to connect to the engine thrust support structure around the heat shield. You'd also need some sort of structural member connecting the top of the engine pod to the ET due to torsion. Sit payload on the engine pod, not the tank."

I think that this structural member will be much heavier then you think if it must go around the heat shield. As such, the vast thrust from the engines will bend this mounting if it were very light weight, so its going to cut into your payload considerably no doubt about it. The only other option is to cut holes in the heat shield... Oh, and the fuel lines/umbilicals will have to go around the shield too, how will that work?

Putting the payload between the engines and the tank is also absolutely out of the question, since an alteration that radical to the design would be fatal to the design costs for SDV. It would also nessesitate that you lug the engine pod all the way to orbit, which will knock about too much off your payload. Ain't gonna happen.

The whole idea of recovering the engines just doesn't make any sense if it is only saving $30M worth of the RS-68's.

RobertDyck · 2005-03-05 12:55:00

Actually, the computers currently on Shuttle were an IBM Off-The-Shelf model at the time it was developed. They just connected 4 computers together with some fancy connection circuitry to make a redundant system. The computer I'm talking about is already space rated, it complies with several military specifications and radiation tolerance >300 years without an uncorrected upset. The added circuitry for redundancy actually increases the chance of a fault, the point is to ensure it continues to operate anyway. That multiple redundancy is very expensive but absolutely necessary for a manned vehicle. The chance of failure of a single computer like this is so slim that it's more cost effective for an unmanned launch vehicle. This is one of the reasons for separating cargo from crew.

Cost of repairing lost tiles before every flight is so high that it defeats the point of a reusable heat shield. A capsule operates so hot that thermal stress on the hull leaves it unusable for a second flight, but that's because they don't protect the sides. I'm saying to use Advanced Flexible Reusable Surface Insulation (AFRSI) blankets on the sides. The coating on AFRSI should seal out re-precipitated ablative material, if not then use DurAFRSI which has an inconel foil skin. The point is to reduce labour necessary to turn around the pod for another flight. Bolting and unbolting a single component is quick and easy. Compare the cost of an ablative heat shield with the labour cost to change it out vs. the cost of replacement tiles and labour cost to apply them. I think you'll find the disposable ablative heat shield has the lowest total cost. Yea, I know, I'm mixing disposable and reusable here. The point is to find the most practical and cost effective solution.

X-38 has a variety of configurations, weight ranged from 6.8 to 11 tonnes. The engine pod I calculated would be 14.4 tonnes empty. The parafoil would be a little bigger but same technology.

Extra mass? Remember I said the total of engine pod + fairing + cargo will exactly equal the current shuttle's orbiter + cargo. That means the total mass the OMS pods have to push is exactly the same. In fact, after you discard the fairing the mass will go down a little. Also remember the SRBs drop off while still in the atmosphere, they don't have a heat shield. The ET drops off just after leaving the atmosphere, but before orbital insertion. The tank follows a suborbital trajectory and burns up on re-entry. The OMS pods just push the orbiter + cargo, not the tank. Same with Shuttle-C, but the fairing will discard at the same time as the ET.

Your argument was discarding the ET requires an ocean landing to avoid debris hitting populated areas, and jump to the conclusion this dictates an engine pod sea landing. Does the current shuttle splash down? I don't think so. There's no difference between flight profile of the engine pod of Shuttle-C vs. the orbiter of the current Shuttle. The orbiter can land in Spain, or Nevada, or Florida. Likewise a Shuttle-C engine pod can land at the same salt flats in Nevada. Your assertion that it has to be a sea landing is not credible. X-38 was designed to land on ground with a parachute, a engine pod can as well.

Putting the payload between the engines and the tank is also absolutely out of the question

Huh!? Where do you get this stuff? I said to mount the cargo on top of the engine pod the same as you mount payload on an axial configuration expendable rocket. The cargo goes where the orbiter cargo bay used to be.

By the way, I'm not talking about RS-68 engines. Changing main engines changes the complete flight profile. With the same ET, SRBs, payload location, fuselage profile, and main engines, this vehicle will have the same flight profile as the current shuttle. RS-68 requires a large engineering effort, and does increase per-launch cost by the price you quoted.

GCNRevenger · 2005-03-05 21:08:45

NASA DRM-III estimates the heat shield mass at about 8MT. How much would a cargo faring weigh?

Ad Astra · 2005-03-05 22:23:25

RS-68 is cheaper; I don't know the cost of RD-0120 but I imagine they're also cheaper. They're expendable and Russia tends to make good stuff at a lower price.

I assume that RD-0120 is even cheaper than RS-68 because the labor and certain raw materials (like titanium) are cheaper in Russia.

The two factors which would make the RD-0120 more expensive are the cooling jacket (which adds complexity, versus the simple ablative RS-68) and the cost of resuming production and refurbishing the tooling and assembly lines. I have heard that the Energia plant is now used to make items like syringes and baby strollers. They'll have to either find a new plant or kick the strollers and needles out. Most likely, they'd sign an agreement with Pratt & Whitney to build the engines in the US (which negates the inherent cost advantages of doing business in Russia.)

RobertDyck · 2005-03-05 23:19:49

Energia manufactures prosthetic limbs, not syringes or strollers. They produced the complete launch vehicle, not the engine. KBKhA still produces rocket engines.

Ad Astra · 2005-03-06 01:00:17

My bad on messing up the details. Still, it's important to know if the RD-0120 manufacturer has started producing mundane consumer and medical products like Energia has. I haven't seriously considered the RD-0120 before, but I will compare it with the SSME and RS-68 in my SDV paper study.

New Mars Forums

Announcement

#51 2005-02-18 00:21:21

Re: The Myth of Heavy Lift - (Let the fight begin...)

#52 2005-02-18 08:46:53

Re: The Myth of Heavy Lift - (Let the fight begin...)

#53 2005-02-18 11:22:42

Re: The Myth of Heavy Lift - (Let the fight begin...)

#54 2005-02-18 21:32:39

Re: The Myth of Heavy Lift - (Let the fight begin...)

#55 2005-02-18 23:32:17

Re: The Myth of Heavy Lift - (Let the fight begin...)

#56 2005-02-24 16:44:19

Re: The Myth of Heavy Lift - (Let the fight begin...)

#57 2005-02-25 09:38:30

Re: The Myth of Heavy Lift - (Let the fight begin...)

#58 2005-02-25 09:59:48

Re: The Myth of Heavy Lift - (Let the fight begin...)

#59 2005-02-25 16:31:21

Re: The Myth of Heavy Lift - (Let the fight begin...)

#60 2005-02-25 17:39:03

Re: The Myth of Heavy Lift - (Let the fight begin...)

#61 2005-03-02 17:17:21

Re: The Myth of Heavy Lift - (Let the fight begin...)

#62 2005-03-02 19:19:19

Re: The Myth of Heavy Lift - (Let the fight begin...)

#63 2005-03-02 19:50:19

Re: The Myth of Heavy Lift - (Let the fight begin...)

#64 2005-03-03 16:23:25

Re: The Myth of Heavy Lift - (Let the fight begin...)

#65 2005-03-03 17:46:16

Re: The Myth of Heavy Lift - (Let the fight begin...)

#66 2005-03-04 15:31:06

Re: The Myth of Heavy Lift - (Let the fight begin...)

#67 2005-03-04 22:31:00

Re: The Myth of Heavy Lift - (Let the fight begin...)

#68 2005-03-04 22:41:25

Re: The Myth of Heavy Lift - (Let the fight begin...)

#69 2005-03-05 01:23:15

Re: The Myth of Heavy Lift - (Let the fight begin...)

#70 2005-03-05 09:48:15

Re: The Myth of Heavy Lift - (Let the fight begin...)

#71 2005-03-05 12:55:00

Re: The Myth of Heavy Lift - (Let the fight begin...)

#72 2005-03-05 21:08:45

Re: The Myth of Heavy Lift - (Let the fight begin...)

#73 2005-03-05 22:23:25

Re: The Myth of Heavy Lift - (Let the fight begin...)

#74 2005-03-05 23:19:49

Re: The Myth of Heavy Lift - (Let the fight begin...)

#75 2005-03-06 01:00:17

Re: The Myth of Heavy Lift - (Let the fight begin...)

Board footer