Space shuttle variants - Options?

Aetius · 2004-02-01 09:09:58

I absolutely love the idea of using Delta IV for launching the CEV, and using Shuttle-C to launch everything else in large pieces.

All those shuttle missions and spacewalks made the ISS vastly more expensive than it needed to be.

Ad Astra · 2004-02-01 11:46:46

There's no doubt in anybody's mind that the space station SHOULD have been launched as a single, heavy module similar to Skylab. Try doing a search for ISS "Option C" to see how it would have been done. Of course, Option C would have made the shuttle orbiter and Russian Proton rockets irrelevant to the space station, so it could not be justified at the time.

Aetius · 2004-02-01 13:16:00

An awesome book about the troubled birth of Station Alpha is, "Island In The Sky", by Piers Bizony.

NASA may finally adopt Shuttle-C now, since the crisis caused by Columbia's loss has forced its various special interest groups to listen to common sense. It is twenty years late, but I say better late than never.

clark · 2004-04-19 08:55:29

Well, this is all about SDV... perhaps we might hear some counter claims to a recent bit by our favorite, Jeffery Bell.

[http://www.spacedaily.com/news/rocketscience-04k.html]http://www.spacedaily.com/news/rocketscience-04k.html
[http://www.spacedaily.com/news/rocketscience-04k.html]Shuttle-Derived Vehicle:

The space community finally seems to be coming to terms with the fact that the President's new space initiative requires the development of some kind of heavy-lift booster, one much more capable than the existing Delta 4H and Atlas 5H vehicles. But the question remains: what kind of booster?
A popular answer is: a Shuttle-Derived Vehicle (SDV), similar to the Shuttle-C and Shuttle-Z proposals of years gone by. This notion has a lot of superficial attractions -- especially to those people who earn their living by serving in the great army of Shuttle support personnel. But if you study it a little, it becomes clear that this idea has severe drawbacks.

While many times I must disagree with Bell, I find some of his points rather compelling. Perhaps a clean sheet approach to a HLLV is the best way to go, instead of inheriting the faults of the current Shuttle program.

John Creighton · 2004-04-19 09:19:55

Interesting read. I don’t know about a clean slate. It seems to be shuttle derived or EELV derived. Can booth paradigms potentially put the same mass in LEO? EELV seems to be cheaper and safer.

The result of this little exercise in back-of-the-envelope engineering shows the complete absurdity of a SDV. The only workable members of the family are SDV-5 or SDV-4, and these are not really "Shuttle-Derived Vehicles" because they no longer retain any element of the Shuttle.
These designs are really EELV-Derived Vehicles. The EELV program has provided NASA with a true second generation of chemical rocket technology, free of many of the bad features that earlier space boosters inherited from the military missiles of the 1950s

Rxke · 2004-04-19 11:47:03

Hmmm... When I read Bell's article, i couldn't help myself looking for flaws in his claims...
And i think i found some, he's opinionated, but it might b good to view shuttle C et all a bit more sceptical, before commiting to it.

Opinionated: he sais both disasters were due to 1)SRB's and 2) Flawed ET design.

Not true. Challenger was because of launching outside accepted temp. limits (wich does not mean the SRB's were not flawed, but it was just the weakest link that gave. )
Flawed ET: no. Flawed heat-shield COMBINATION with ET. If the leading edge were more sturdy they'd have survived, there would've been damage, but i think Colombia would've been able to at least crash-land... Side mounting... Shuttle-C wouldn't need that kind of re-entry heat-shields, so not a problem?

But if Bell's numbers are correct, it is crazy to build ET's at such a cost...

Bill White · 2004-04-19 12:22:38

Hmmm... When I read Bell's article, i couldn't help myself looking for flaws in his claims...
And i think i found some, he's opinionated, but it might b good to view shuttle C et all a bit more sceptical, before commiting to it.
Opinionated: he sais both disasters were due to 1)SRB's and 2) Flawed ET design.
Not true. Challenger was because of launching outside accepted temp. limits (wich does not mean the SRB's were not flawed, but it was just the weakest link that gave. )
Flawed ET: no. Flawed heat-shield COMBINATION with ET. If the leading edge were more sturdy they'd have survived, there would've been damage, but i think Colombia would've been able to at least crash-land... Side mounting... Shuttle-C wouldn't need that kind of re-entry heat-shields, so not a problem?
But if Bell's numbers are correct, it is crazy to build ET's at such a cost...

How much of the ET cost is due to making foam that won't fall off? Even with a sidemount payload, if we avoid high tech carbon structures and ceramic tiles, we can just let the foam fall off during launch.

Foam hits on an expendable aluminum payload fairing is no big deal.

That said, I am all for finding ways to manufacture cheaper ETs - - why does that undermine the shuttle derived concept?

SRBs? Well, okay if this really is a problem (and after Challenger upgrades I am not so sure it is) then attach Russian kerosene engines rather than solid boosters.

No problem in principle, just how long (and how much) will all this take? If we scrap the shuttle infrastructure, we really are going back to the beginning with nothing to show for the past 25 years.

The shuttle standing army is getting paid one way or another.

How much would it really cost to stick some RS-68s on a cobbled together a shuttle C payload fairing and toss 50,000 kg of sand into the Indian Ocean as a test shot? I mean how much more than we taxpayers are paying right now anyways?

If all goes well, then start sending up ISS components.

On 2nd thought, how expensive is it to manufacture an ISS truss anyways? Skip the sand into the Indian Ocean, practice with ISS trusses sent to 51 degrees.

clark · 2004-04-19 13:34:26

All these modifications, for what? To save the "legacy" of the past 25 years... is it really worth saving? How much honor in defeat do we still need?

Every change to the exsisting Shuttle fleet to achieve some type of SDV is one more reason not to pursue the SDV. Instead of saying, "what's the best way to achieve the goal," we ask, "given what we have, what is the most we can achieve?"

So we don't have to worry about the foam, but that also means any SDV will not be man-rated. That leaves us in the position of having to man-rate the EELV- there is no other option, and SDV will only be used to launch large cargo bits. If we use the exsisting infrastructure, where do we save money? We largely agree that the Shuttle is ineffecient at best, so what's the point of retaining any of the ineffecient system to begin with? To have a sub-par SDV that is less than ideal? That's not a step forward, that's simply defering the hard decisions to a later date.

Why not simply go with man rating the EELV, look to improve it's launch capability to give us a more robust lunar program, and then develop a true HLLV without the inhereited problems of the SDV?

No matter how you cut it, we will need a HLLV for Mars, SDV will not cut it. Giving NASA two competing programs (a SDV and Constellation) may end up forcing concessions on either program (or both) to try and find parity, or to complete one.

Look at ISS or the Shuttle- how often are their individual budgets raided for other programs- or how often are other programs raided for ISS or Shuttle programs.

It seems if we give NASA something big to do, but not a lot of big things to do, we will all be better off.

SBird · 2004-04-19 15:12:28

Why do we necessarily need to have a man rated launcher right now? The Russians have a perfectly good one and are already doing the work to upgrade it up to a 6 person capacity. It's a lot cheaper to just buy space on the Soyuz/derivatives. Used the money saved and put it into the HLV program, Shuttle/EELV derived or de novo design.

Of course, we'll want to eventually wean outselves off of the dependence upon outside launchers but in the timeframe for plan Bush, I can't see a huge change in US - Russia relations and from a financial standpoint, it makes sense.

clark · 2004-04-19 15:27:25

Why do we necessarily need to have a man rated launcher right now?

It is wiser, in the long run, to not be dependant upon any other agency or nation to execute any space exploration plan. To give you an idea, the ESA and RSA are curtailed in their abilities to exploit the ISS as they see fit becuase of their dependance upon NASA to complete ISS.

We're in the drivers seat, so why give that up?

Besides, launching on Russian rockets is far from a certainty as long as their are laws against us providing funds to Russian companies (the Iran-non proliferation treaty). While the administration has hinted to its willingness to amend this treaty, it takes an Act of Congress to codify the neccessary changes. It could go either way.

It would make sense to purchase seats on a Russian Soyuz (modified or otherwise) from a financial point of view, but space exploration isn't just about finacial costs.

If SDv cannot be man rated, or it takes more time to man rate a SDV, we still have to man rate the EELV. That means we are doing the same work, twice. What's the point? Cut out SDV, go with man rating the EELV, work to improve on the EELV capabilities, save the money now, and develop a HLLV when we need it for Mars.

GCNRevenger · 2004-04-19 15:38:17

That Jeffy Bell guy needs to take his happy pills and stop re-running "The Mighty Saturns" DVD over and over again...

Alot of the money that goes into making Shuttle fly, which is about $1Bn a flight, goes into the manned spaceflight "department" (which doesn't fly Shuttle) and refurbishing the Orbiter for each flight.

One word that he uses many a time is the word "cheap;" who said that the HLLV has to be cheap to fly? If you aren't going to be flying it very often, and we'll be launching these big expensive componets, to be quite blunt it doesn't have to be inexpensive.

I'd like to reiterate past posts that the SRBs and ET are reliable enough, and at $60M a tank for the ETs are not so bad for a vehicle that will haul 100-120MT to orbit. And haul cargo it will, the CEV shouldn't ride on it, the old concept of mixing cargo and crew launch duties should be abandoned, since making the huge rocket man-rated for only a few MT of its capacity doesn't make alot of sense. A Delta IV Medium or Atlas V series would be a safer, cheaper, more reliable way to fly people or light cargo.

Next up, whatever SDV is built, it won't be flying to the ISS... the lack of last-mile guideance pretty much ensures that. Barring another Shuttle disaster, or Bell's conspiracy theory about the "walking dead" Shuttle, it will be used to finish ISS and US involvement terminated as much as is possible. If we need a space station, build a big TransHab one out of a few HLLV shots.

Shuttle-Z actually resembles a miniature version of some of the "Sons of Saturn" rockets... big SRBs, all cryogenic, big payload faring. I don't see the need to go clean-sheet, what we have now works well enough. Launch the Moon ship in one shot and the Mars ship in 2-4. Also like to note that I did some "back of envelope" math and the Shuttle-C payload bay could hold a TransHab big enough to equal the total completed internal volume of ISS in one shot. There's your space hotel...

Use the 5-segment SRBs, perhaps making them expendable, use a trio of RS-68 engines under the ET, and a side-mount mega upper stage with RL-10 or RL-60 engines to loft a giant payload faring for maximum volume. Optimize the KSC workforce for limited flight schedules that Moon/Mars missions will demand... say, 3-4 flights a year, maybe 5.

clark · 2004-04-19 15:46:46

If we're not going to be flying it all that often, why not look to a solution that allows us to routinely launch more rockets so as to perhaps realize a cost-saving on the number of launches (the basic underlying premise for the Shuttle- it will be cheap becuase we will fly alott). Plus, it gets NASA out of the launch industry, so it can foucs on research and exploration...

GCNRevenger · 2004-04-19 15:55:24

Because there isn't any reason to launch routinely... for the so called "private space explosion," the price of launch for unmanned and manned flights will have to drop by an order of magnetude, and the only type of vehicle that could pull that off is an RLV.

Making a true RLV, a good one unlike the "Refurbishable Launch Vehicle" the Shuttle turned out to be, would be quite expensive and take substantial time to perfect. Somthing like the DC-X/DC-I or the Shuttle-LSA would become a side-trip.

And, as with all practical RLVs, their payloads are pretty puny: even the production model of the DC-X would only haul about 10MT to orbit... less than half of what the Delta-IV HLV could. Making a giant RLV that carries more than 20-25MT isn't going to happen.

Exploring space in the near term with a reasonable budget will require some kind of heavy launcher. Using medium payloads we might mount a small Lunar expedition program, but for large flights to the Moon or ships to Mars, somthing bigger will be needed. Small lego-brick style construction of a large space vehicle is currently beyond our technology.

Or I should say, is currently beyond our technology to accomplish for a reasonable sum.

clark · 2004-04-19 16:02:15

Now we are coming back to where our hopes are informing our opinions...

Exploring space in the near term with a reasonable budget will require some kind of heavy launcher. Using medium payloads we might mount a small Lunar expedition program, but for large flights to the Moon or ships to Mars, somthing bigger will be needed. Small lego-brick style construction of a large space vehicle is currently beyond our technology.

Who here wants large flights to the Moon? Don't we want a small foot print, enough to "practice" Mars? I agree that a HLLV is neccessary for Mars, and the bigger, the better. However, Mars is the day after next, and I for one think we might all gain more by constraining our capability to do the Moon in a big way.

We also are forced to learn the on-orbit assembley and docking that is crucial for any Mars mission. I see that as a direct benefit of forgoing SDV development now.

Also, I agree that the cost to launch needs to come down by magnitudes for regular "space explosion" launches where private citizens get a chance to go. What is a better way to bring down the cost? With a SDV that can only launch cargo, or a government subsidized man rated EELV that brings down production costs through more routine launches?

Bill White · 2004-04-19 16:06:50

That Jeffy Bell guy needs to take his happy pills and stop re-running "The Mighty Saturns" DVD over and over again...
Alot of the money that goes into making Shuttle fly, which is about $1Bn a flight, goes into the manned spaceflight "department" (which doesn't fly Shuttle) and refurbishing the Orbiter for each flight.
One word that he uses many a time is the word "cheap;" who said that the HLLV has to be cheap to fly? If you aren't going to be flying it very often, and we'll be launching these big expensive componets, to be quite blunt it doesn't have to be inexpensive.
I'd like to reiterate past posts that the SRBs and ET are reliable enough, and at $60M a tank for the ETs are not so bad for a vehicle that will haul 100-120MT to orbit. And haul cargo it will, the CEV shouldn't ride on it, the old concept of mixing cargo and crew launch duties should be abandoned, since making the huge rocket man-rated for only a few MT of its capacity doesn't make alot of sense. A Delta IV Medium or Atlas V series would be a safer, cheaper, more reliable way to fly people or light cargo.
Next up, whatever SDV is built, it won't be flying to the ISS... the lack of last-mile guideance pretty much ensures that. Barring another Shuttle disaster, or Bell's conspiracy theory about the "walking dead" Shuttle, it will be used to finish ISS and US involvement terminated as much as is possible. If we need a space station, build a big TransHab one out of a few HLLV shots.
Shuttle-Z actually resembles a miniature version of some of the "Sons of Saturn" rockets... big SRBs, all cryogenic, big payload faring. I don't see the need to go clean-sheet, what we have now works well enough. Launch the Moon ship in one shot and the Mars ship in 2-4. Also like to note that I did some "back of envelope" math and the Shuttle-C payload bay could hold a TransHab big enough to equal the total completed internal volume of ISS in one shot. There's your space hotel...
Use the 5-segment SRBs, perhaps making them expendable, use a trio of RS-68 engines under the ET, and a side-mount mega upper stage with RL-10 or RL-60 engines to loft a giant payload faring for maximum volume. Optimize the KSC workforce for limited flight schedules that Moon/Mars missions will demand... say, 3-4 flights a year, maybe 5.

Okay, okay. .

I retract my previous comments and cheerfully say, "me too" I now agree with this guy. Well done GCNRevenger.

Jeffrey Bell, by the way, writes outrageous stuff to stir the pot and get people arguing, at least IMHO. Someday I might like to ask him what he really thinks about stuff.

Bill White · 2004-04-19 16:09:10

Also, I agree that the cost to launch needs to come down by magnitudes for regular "space explosion" launches where private citizens get a chance to go. What is a better way to bring down the cost? With a SDV that can only launch cargo, or a government subsidized man rated EELV that brings down production costs through more routine launches?

Government subsidies for Delta will not drive costs below Russian or Ukrainian costs, hence NO private sector demand for EELV. Even Elon Musk would have no viable business model without US AirForce interest.

Zenit is just too damn cheap.

= = =

PS - we Americans aren't in the drivers seat, at least IMHO. We spend billions yet have surprisingly little space capability.

GCNRevenger · 2004-04-19 16:21:29

Or Jeffy "Ding Dong" Bell has an axe to grind with Nasa... haven't heard one nice thing about the agency from him yet.

America isn't far out ahead because we haven't needed to be, and it was far more effective way to keep Nasa engineers employed for long periods by spinning our wheels, not going someplace where they wouldn't be needed anymore.

Even Zenit isn't cheap enough for large-scale development of space I don't think, especially since it lacks inherint last-mile guideance, can't fly all that often, nor is it man-rated. Elon Musk I think is awfully optimistic about the future of plain-jane expendable/refurbishable rockets.

It would be nice to make a new HLLV launcher for whatever purpose, but even when we are ready to go to Mars, we won't be needing anything much bigger than 120MT, and we won't be using the HLLV for much else on a regular basis (save maybe Moon flights). I still don't see a justification for building a new megalauncher, which would run in the tens of billions easy and not be alot cheaper to fly than SDV.

clark · 2004-04-19 17:08:22

I still don't see a justification for building a new megalauncher, which would run in the tens of billions easy and not be alot cheaper to fly than SDV.

Once again (sorry), if a SDv will run tens of billions (if not more, as you hint at), why do we need it now? Why do we need to inherit the limitations that comes with a SDV based on Shuttle architecure?

Either way we look at it, a HLLV/SDV will cost a lot, right? With a pursuit towards EELV now, we might just gain a few more capabilities, and at the least, not hamstring our future endeavours with an architecure designed in the 60's for a different purpose.

SDV will not reduce launch costs at all. EELV on a more routine production line just might. I think we have more to gain than we lose by going EELV. (And I agree, Bell rants, but I'm trying to look at some of the legitimate points he makes)

GCNRevenger · 2004-04-19 17:45:12

Ah but an SDV won't cost >$10Bn's because it won't be all new... some estimates put it at $3-5Bn from the exploration cheif back in Goldin's early days for the C-model. A brand new rocket based on EELV technology (RD-170/180 plus RS-68 plus RD-60) will easily cost much more. Even making the dinky Delta and Atlas rockets cost billions... making a GIANT one will be quite expensive.

The thing of it is, launch costs aren't a limiting factor to space exploration, the launching of larger vehicles by mass and volume is. Assembly in small pieces isn't practical now and it won't be for a while. An HLLV is not an optional thing for Mars missions, we will make one or we won't go.

I also reject the notion that the SDV is such a bad idea... Fundimental rocket technology is today limited by the efficency of the fuel really, which reached its zenith in the 60's with the introduction of liquid hydrogen, rocket technology hasn't improved substantially nor will it for the time being. Did I mention the SDV would be primarily a liquid hydrogen rocket?

Cookie-Cutter assembly of EELVs doesn't make a large amount of fiscal sense either. Rocket parts and launch pads and engineering staffs have largely inelastic costs, that is, they don't get alot cheaper by buying in bulk. Also, having to launch so many engines for such a small payload doesn't make much sense. There is also the flight computers and gyros and such that have to be duplicated for each small launch.

SDV: 8 engines for 120MT to LEO (two SRB three RS68 three RL60)
Delta IV HLV: 4-5 engines for 25MT (3 RS68 1-2 RL10)

clark · 2004-04-20 08:17:32

Ah but an SDV won't cost >$10Bn's because it won't be all new... some estimates put it at $3-5Bn from the exploration cheif back in Goldin's early days for the C-model.

I agree, SDV will be cheaper if we use as much of the exsisting Shuttle Architecture as we can. Yet that merely means we continue the same problems we have today. In order to make anything better, we have to pour more resources into the design of the system. We have to alter the architecture. With every change comes an increase in the final cost, with no real proof that the result will be any better.

What do we need a SDV for, today, or even while going to the Moon?

The current EELV's can just about do what we did with Apollo. Yes, they need to be improved, and I believe they can. You say they will cost more, but I'm more inclined to believe that it will either cost the same, or less. Going the EELV route also means NASA dosen't have to manage any new special porjects. It means they become a purchaser of launches instead of a producer.

If we spend the money on a giant bird that flies every few times, we're still getting hit on the human-labor/infrastruture side for all the stuff we have to support when the giant bird isn't flying. It's ineffecient at best, a waste at worse, and shows we aren't learning to do anything new.

I agree that HLLV is not optional for Mars, but we're not going to Mars yet. NASA is looking at two current architectures for SDV/HLLV development. One is to build a SDV now, with a clean sheet HLLV at a later date, the other is to build a clean sheet HLLV when we're ready for Mars, and use exsisting EELV now.

PurduesUSAFguy · 2004-04-20 09:51:10

After witnessing that last Soyuz launch, which went off without a hitch as usual, my slant on LEO activities right now, and into the foreseeable future (ten years, say) would be to add as many docking ports as can be to the ISS and launch Soyuz ships with "Astrocosmonauts," "Mission Specialists" and "Paying Passengers" enough to carry out work (as well as maintainence) as desired. That way, there'd always be enough "lifeboat" capacity to get 'em all back if worst comes to worse. I'd even adapt a Soyuz refueling means, for taking the Hubble refurbishment hardware up to its orbit, and then return it to the ISS. I'd develop the six-passenger Soyuz, and launcher for it, to enable the multi-TMA dockings to be reduced gradually and simultaneously increase the capacity of the Progress ships to handle the increased cargo and waste disposal quantities. The Chinese, with their fresh approach could be phased in or operate in parallel. The remaining Space Shuttle craft and infrastructure could then be superceded with "next generation" space transportation development, my grandchildren might use, because that ain't gonna happen in my lifetime. It'd work, and it's do-able right now. God, I'm sick of war priorities lousing up maybe the last chance for my (and your) generation to get into space . . . for (?) time. . . .

I think it's really an odd statement to say that the war or defense spending is the reason we "can't afford" an advanced space program or national lab projects like our own large scale tokomak. NASA gets about 0.7% of the federal budget, the national labs get about 0.67%. That's small change compared to the vast majority of worthless and pork barrle social programs that are in the budget (53% last time I looked) or the militaries budget of about 45%. (although one could argue that at least the USAF/Navy side of that house is driving towards the space goal as it was the military that developed the EELV and is working on some really advanced systems, both for launch and power. A 200 kilowatt fission reactor developed to power space based rail guns and lasers for the SDIO and later STRATCOM would come in pretty handy for H2M if it got declassifed. Of we won't know specifics of the systems for many year until they are declassified but they are out there.

Point being there is more then enough room in the budget for defense and space, and in many cases they go hand in hand. Space is the new ocean, and like the ocean going powers of the previous century whoever controls the ocean controls what goes on in the world. That's why space control, acess, and strike (SCAS) is the biggest priority now of USSTRATCOM and DARPA.

Ad Astra · 2004-04-20 14:06:10

I just read the Jeffrey Bell article and I must say that I disagree with almost everything he said.

I will not pretend that the shuttle stack is very reliable by any measure (certainly not as reliable as the amazing Atlas II and Delta II,) but with a record of one launch failure in 113 launches, it will probably be good enough for unmanned lunar-Mars launches. The post-Challenger redesign of the SRB will probably reduce this statstical failure rate further. The falling foam problem is being fixed as we speak, and even with the pre-Columbia foam shedding, it poses less of a risk for a narrow, side-mounted cargo pod than it does for an orbiter with a large wingspan.

Launching crew and cargo on separate rockets is the way to go. Humans need a small, reliable booster with robust escape capabilities. Cargo needs a large booster without the escape systems. Launching humans on an EELV and cargo on SDV makes sense. Ask the Caltech people who designed their Mars reference mission. The crew was launched by Soyuz while cargo was carried on the Energia-derived Janus.

I'm not a fan of SRB's either, but using them allows you to keep the unmodified shuttle launch pad. Jeffrey Bell suggests liquid boosters using the RD-180 engine. Well, Lockheed studied this option. It meant redesigining the shuttle launch pad, and the boosters had an ungainly cluster of four RD-180 engines on the back end. One solution would be a cluster of RD-191 engines (the single-chamber version of RD-170 and RD-180.) Separate combustion chambers means you have engine-out redundancy.

The liquid-fuel booster problem is the reason behind the RS-84 program. Whereas the RD-180 was desgned for 20 uses, the RS-84 was a clean-sheet engine designed for 100 uses. It also produced more thrust. However, NASA short-sightedly pulled the plug on this remarkable engine, and now we probably won't get our liquid-fuel booster.

dicktice · 2004-04-20 14:58:25

PurduesUSAFguy: Perhaps I was unclear when I wrote "I'm sick of war priorities "lousing up" maybe the last chance for my (and your) generation to get into space," when I should have written . . . "sidetracking" . . . since fulltime engineering effort is needed (forgetting budget for a moment) to get these capabiilitiess not only developed but routinely utilized as the Russians (bless 'em) seem able to in spite of every impediment.

GCNRevenger · 2004-04-20 16:08:55

I would like to ask, what problems with the Shuttle stack? Or the government operating a launch vehicle?

The government is the only customer anyway, and with only two companies that like to team up, there isn't much competition. The flight rate is pretty low, so there isn't much streamlining to be done there. Why is it a good thing to turn over development to Boeing/LHM and fire a bunch of Nasa engineers again?

And i'm not aware of any serious problems or massive inefficencies concerning the part of the system proper. Drop everything to do with the Orbiter, man rating, and high flight rate and it isn't that expensive. The SRBs are as good as they get, with the about the same Isp as the F-1A kerosene engine slated to power "Son of Saturn" and even more thrust. Whats wrong with the Shuttle stack?

Since rocket performance is largely a measure of fuel efficency, I don't see how making a new clean-sheet vehicle will be loads better... large solid rocket boosters with a large cryogenic first stage and a small upper stage are about as good as it gets. The Shuttle ET is really not alot different then all rocket tankage either, its just bigger than most and still built in an older way.

It is possible to make a Moon flight based soley on EELV or modestly upgraded EELV rockets, but why bother? We'll need a big rocket eventually, we can make one in fairly short order for a reasonable cost, and you can pull off the Moon mission easier.

Bill White · 2004-04-20 16:16:09

I just went back and re-read what I wrote on January 28th to open this thread. I am now prepared to drop the man-rated SDV (for now, doing Ares later can be discussed later) yet everything else still seems true to me.

I believe I am open to changing my mind yet I see no reason to change my mind on this issue.

A brand new HLLV, which requires new launch infrastructure and a total re-build of Pad 39, just doesn't seem appropriate or prudent.

= = =

Isn't foam only a problem for the delicate and mission critical ceramic tiles and the carbon leading edge of the wing? Foam strikes on standard spacecraft aluminum should merely bounce off harmlessly, correct?

New Mars Forums

Announcement

#26 2004-02-01 09:09:58

Re: Space shuttle variants - Options?

#27 2004-02-01 11:46:46

Re: Space shuttle variants - Options?

#28 2004-02-01 13:16:00

Re: Space shuttle variants - Options?

#29 2004-04-19 08:55:29

Re: Space shuttle variants - Options?

#30 2004-04-19 09:19:55

Re: Space shuttle variants - Options?

#31 2004-04-19 11:47:03

Re: Space shuttle variants - Options?

#32 2004-04-19 12:22:38

Re: Space shuttle variants - Options?

#33 2004-04-19 13:34:26

Re: Space shuttle variants - Options?

#34 2004-04-19 15:12:28

Re: Space shuttle variants - Options?

#35 2004-04-19 15:27:25

Re: Space shuttle variants - Options?

#36 2004-04-19 15:38:17

Re: Space shuttle variants - Options?

#37 2004-04-19 15:46:46

Re: Space shuttle variants - Options?

#38 2004-04-19 15:55:24

Re: Space shuttle variants - Options?

#39 2004-04-19 16:02:15

Re: Space shuttle variants - Options?

#40 2004-04-19 16:06:50

Re: Space shuttle variants - Options?

#41 2004-04-19 16:09:10

Re: Space shuttle variants - Options?

#42 2004-04-19 16:21:29

Re: Space shuttle variants - Options?

#43 2004-04-19 17:08:22

Re: Space shuttle variants - Options?

#44 2004-04-19 17:45:12

Re: Space shuttle variants - Options?

#45 2004-04-20 08:17:32

Re: Space shuttle variants - Options?

#46 2004-04-20 09:51:10

Re: Space shuttle variants - Options?

#47 2004-04-20 14:06:10

Re: Space shuttle variants - Options?

#48 2004-04-20 14:58:25

Re: Space shuttle variants - Options?

#49 2004-04-20 16:08:55

Re: Space shuttle variants - Options?

#50 2004-04-20 16:16:09

Re: Space shuttle variants - Options?

Board footer