Author Topic: Saturn I: A right rocket at the wrong time?  (Read 20083 times)

Offline Archibald

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Re: Saturn I: A right rocket at the wrong time?
« Reply #20 on: 02/21/2011 06:18 am »
How central did the NASA consider the shuttle to be to the agency's post-Apollo future?

Initially, not very. In the circa-1969 documents, the Space Shuttle is really only ever mentioned as an afterthought, with a ~7 tonne payload. The big push was to a post-Skylab "Space Base" with a reusable "Nuclear Shuttle" for ferrying stuff to/from GEO and lunar orbit (and as a basis for the Mars vehicle).

Without DoD support for Shuttle, NASA may very well have followed a path closer to the Soviet's strategy of the era, with LEO space station(s) and capsules. One (of many) ways to do that would be to fly Skylab as was historically done, but with a fourth mission that reboosts it in 1977-78. Then, in the 1980s, modules are added Mir-style (launched on Saturn IC/Fs). So, by the end of the Cold War, the US has a large (6-person) but aging space station serviced by capsules. In other words, precisely the situation that we'll have in four years' time. :)
I like this. What you describe is the core of my alt-space-history. The shuttle dies of natural causes in the fall of 1971, and NASA switch plans: the space station in 1972, the shuttle in 1984. But nothing happens as planned of course.
Han shot first and Gwynne Shotwell !

Offline Archibald

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Re: Saturn I: A right rocket at the wrong time?
« Reply #21 on: 02/21/2011 06:30 am »
1x J-2 on 1x F-1 would have been an excellent TSTO. Of course you'd want a monolithic 6.6m tankset on the first stage.

But for either of these concepts to have flown, it would have required NASA deciding to make its post-Apollo direction be in large space stations, not Shuttle.

I'm still confused about this part NASA history even after watching the Dale Myers presentation on MIT OpenCourseware.

I know that George Mueller and Tom Paine wanted a large space station in LEO as the next step toward Mars, I know that he'd hoped the post-Apollo budget would leave room for both a large space station launched on Saturn Vs and a reusable "space shuttle" for crew and provisions, and I get the sense that they were envisioning a considerably smaller shuttle than the DoD requested.

But in alternative history mode: once Myers comes in and the budget cuts come down and it becomes clear that they won't be able to afford a space station along with the DoD-spec shuttle even if they cancel Saturn V and launch the station on the shuttle, would it have been unthinkable for NASA to prioritize the station over the shuttle?

After all, the station was the desired end, and the shuttle was just one arguably ambitious means to that end. If they'd scrapped the shuttle and pursued the station instead, the Saturn family would remain relevant, and I think that the DoD would have been happy to see the shuttle fall by the wayside.

How central did the NASA consider the shuttle to be to the agency's post-Apollo future? Were they operating in the hope that the budget cuts were temporary and that they'd have more funding in the future to get their space station?

It's a long, tortuous story. Nixon first asks a Nobel Prize, Charles Townes, to advise its campaign staff late 1968.
Early 1969 Townes recommend more lunar exploration. Meanwhile, Webb has left, and has been replaced by Tom Paine. Paine lobby against Townes, and instead the Space Task Group is born, in February 1969.
The Space Task Group report to Nixon in September 1969; Mueller Integrated Space Program Plan consists of four major elements
- the space shuttle
- the space station (to evolve into a huge space base)
- Saturn INT-21 (two stage Saturn V)
- NERVA nuclear shuttle (to go everywhere, to the Moon or Mars)

Nixon spent six months without answering, then on March 7, 1970 cautiously endorse the space station + the space shuttle (and nothing else: goodbye NERVA, goodbye Saturn V).

Then Paine resigns (September 1970) and acting administrator George Low clearly understand that budget cuts only allow the shuttle OR the space station.
NASA chose the shuttle before the space station, since the shuttle is seen as the natural, low cost vehicle that will make a space station cheap to build and access.
Then all over the year 1971 NASA has to battle Nixon varied advisors (PSAC and OMB) to obtain funding for the shuttle. Nixon finally endorse a compromised shuttle early 1972.
Han shot first and Gwynne Shotwell !

Offline edkyle99

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Re: Saturn I: A right rocket at the wrong time?
« Reply #22 on: 02/21/2011 06:12 pm »
Keep in mind F9 does achieve it's payload with a hydrocarbon upper stage.
With a hydrogen upper stage it likely would be similar to Atlas V still smaller but over all it is a more flexible system due to the fact it is a modular LV.

A modular vehicle like F9 can do both Titian IIs and the IB's jobs depending on its configuration.

I remain skeptical of the "modular" approach to space launch, at least as it has been developed with EELV.  Delta 4 Heavy hasn't turned out to be as modular as one might think, due to differences required in the CBCs for Heavy versus Medium configurations.  Russia doesn't seem to be terribly excited about modular Angara either. 

Quote

As for growth potential the only way I can think of to really increase the IB's payload past something easily reached by F9-H or even existing EELV variants such as the Delta IV-H would be a complete redesign the first stage to use monolithic tanks.
I'm not sure if SRBs or even multi cores were an option with the cluster tank.
No provisions for attachment etc....

Growth options were available, and were contemplated in theory, but would have required money.  One approach would have been to replace S-IVB with a heavier second stage powered by a cluster of J-2 engines.  This, combined with either short-loading or shrinking the first stage could have resulted in 27 tonnes to LEO.  Another approach could have been to replace the four center H-1 engines with a single F-1, increasing first stage thrust by more than 40%. 

The first stage wasn't as mass-efficient as a single-tank structure, but a lot of that weight was due to conservative design rather than the cluster-tank structure.  The total propellant mass fraction of a Saturn I Block II first stage was 0.90 (Liftoff mass 435.3 tonnes, dry mass 40.8 tonnes).  The usuable propellant mass fraction was 0.886.  The structure accounted for a 0.064 fraction.  The engines accounted for 0.023.  A lot of weight could have been gradually taken out of that stage even without changing the tank setup if it had been flown for a few decades.   

 - Ed Kyle

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Re: Saturn I: A right rocket at the wrong time?
« Reply #23 on: 02/21/2011 06:15 pm »
Delta 4 Heavy hasn't turned out to be as modular as one might think, due to differences required in the CBCs for Heavy versus Medium configurations.

Of course, you realize that has nothing to do with the viability of the concept, but more to do with engine performance shortcomings and the design decision to go with one mirrored booster.

Offline Jim

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Re: Saturn I: A right rocket at the wrong time?
« Reply #24 on: 02/21/2011 06:20 pm »
the design decision to go with one mirrored booster.

which is due to the pad design and the way the vehicle erected on the pad.

Offline edkyle99

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Re: Saturn I: A right rocket at the wrong time?
« Reply #25 on: 02/21/2011 06:30 pm »

Part of the reason that the original S-I stage was so heavy was that it had to support the huge bending loads that would have been imposed on it when launching the winged Dyna-Soar (I've never understood how the more slender Titan III-C was going to cope with those loads). 

When Dyna-Soar was looking for a launch vehicle, Martin proposed something called "Titan C" (not "IIIC").  At the time Titan was only what we know today as "Titan I" (Martin did not get a contract for Titan II until 1960, a couple of years after the Titan versus Saturn consideration was underway).  "Titan C" would have been a fat Titan powered by four Titan I LOX/RP engines, topped by a fat second stage powered by a pair of the same engines, with longer nozzles.  See http://history.nasa.gov/SP-4404/ch12-3.htm for details.

 - Ed Kyle

Offline edkyle99

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Re: Saturn I: A right rocket at the wrong time?
« Reply #26 on: 02/21/2011 06:44 pm »
Delta 4 Heavy hasn't turned out to be as modular as one might think, due to differences required in the CBCs for Heavy versus Medium configurations.

Of course, you realize that has nothing to do with the viability of the concept, but more to do with engine performance shortcomings and the design decision to go with one mirrored booster.

I'm not so sure.  Delta 4 is, to my knowledge, the first launch vehicle ever deployed using this modular first stage idea, wherein the first stage is flow either singularly or in triplet.  It works, yes, but the flight rate compared to Atlas 5 is telling.  A more successful approach proven in service has been to add smaller strap-on "modules" to a larger core based on payload needs, as with Ariane 4 or China's very successful Chang Zheng series.

 - Ed Kyle
« Last Edit: 02/21/2011 06:47 pm by edkyle99 »

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Re: Saturn I: A right rocket at the wrong time?
« Reply #27 on: 02/21/2011 06:49 pm »
Are you suggesting the cost of Atlas would jump through the roof as well if the Heavy was fielded?

Offline edkyle99

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Re: Saturn I: A right rocket at the wrong time?
« Reply #28 on: 02/21/2011 07:37 pm »
Are you suggesting the cost of Atlas would jump through the roof as well if the Heavy was fielded?

*That* is a very good question!  ;)

 - Ed Kyle

Offline Jim

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Re: Saturn I: A right rocket at the wrong time?
« Reply #29 on: 02/21/2011 07:49 pm »
Are you suggesting the cost of Atlas would jump through the roof as well if the Heavy was fielded?

*That* is a very good question!  ;)

 - Ed Kyle

Atlas would not have to modified the cores for a heavy. 

Offline alexw

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Re: Saturn I: A right rocket at the wrong time?
« Reply #30 on: 02/21/2011 08:37 pm »
Are you suggesting the cost of Atlas would jump through the roof as well if the Heavy was fielded?
*That* is a very good question!  ;)
    Why would it? The cores themselves, MLP, pad, and VIF are (supposedly) ready to go, except for (IIRC Jim has observed) adding the other tail service masts -- which hardly seems like a major engineering challenge. I ran across a quote from ULA that at least 95% of the hardware has already flown.
     In the absence of other information, would not one assume that the costs to bring the last elements from CDR to flight would be borne by the first customer ordering the minor variant, as for example happened with Atlas V 551 and New Horizons, no?
    What would the additional ongoing costs to keep the Heavy in service, borne (perhaps) by all A-V customers?
    -Alex


Offline edkyle99

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Re: Saturn I: A right rocket at the wrong time?
« Reply #31 on: 02/22/2011 12:09 am »
Are you suggesting the cost of Atlas would jump through the roof as well if the Heavy was fielded?
*That* is a very good question!  ;)
    Why would it? The cores themselves, MLP, pad, and VIF are (supposedly) ready to go, except for (IIRC Jim has observed) adding the other tail service masts -- which hardly seems like a major engineering challenge. I ran across a quote from ULA that at least 95% of the hardware has already flown.
     In the absence of other information, would not one assume that the costs to bring the last elements from CDR to flight would be borne by the first customer ordering the minor variant, as for example happened with Atlas V 551 and New Horizons, no?
    What would the additional ongoing costs to keep the Heavy in service, borne (perhaps) by all A-V customers?
    -Alex

Complex 37B's Delta 4 record shows that the average time between a prior launch and a Heavy launch is more than twice the time for a Medium.  That implies a more than doubling of launch processing costs for a Heavy.  Launch campaigns of such significantly different durations (Medium versus Heavy) reduce program efficiency and drive up costs.  Using just Mediums (or just Heavies) allows for a more cost effective launch tempo.

Someone said that building and launching a Heavy is almost as involved as building and launching three Mediums!  Each Heavy has, rather than one first stage, three first stages, each with separate propulsion, hydraulics, pressurization systems, propellant systems, avionics, and structures.  Clearly, Heavy hardware costs more than twice as much as for a Medium.

The Heavy is needed, but what I wonder is if it is worth driving up the cost of the Medium to make it "modular".  Could the total cost of both programs be less if they were separate (i.e., Medium Atlas and Heavy Delta, only)?

Tying this back into this thread, look at the Saturn I launch tempo from 37B.  Pretty steady-rate, every 4 months at first for Block II, sped up to nearly every 2 months at the end.  No stopping to process smaller rockets on the same pad!

 - Ed Kyle
« Last Edit: 02/22/2011 03:04 am by edkyle99 »

Offline Proponent

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Re: Saturn I: A right rocket at the wrong time?
« Reply #32 on: 02/22/2011 03:21 am »
Atlas would not have to modified the cores for a heavy. 

Why does Atlas not have to modify its cores for the heavy version, whereas Delta does?

Offline Proponent

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Re: Saturn I: A right rocket at the wrong time?
« Reply #33 on: 02/22/2011 03:28 am »
When Dyna-Soar was looking for a launch vehicle, Martin proposed something called "Titan C" (not "IIIC").  At the time Titan was only what we know today as "Titan I" (Martin did not get a contract for Titan II until 1960, a couple of years after the Titan versus Saturn consideration was underway).  "Titan C" would have been a fat Titan powered by four Titan I LOX/RP engines, topped by a fat second stage powered by a pair of the same engines, with longer nozzles.  See http://history.nasa.gov/SP-4404/ch12-3.htm for details.

Early on Titan C certainly was the launch vehicle proposed for Dyna-Soar, but I'm pretty darn sure that as of the time of Dyna-Soar's cancellation, Titan III-C was the horse to be used.

Offline Proponent

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Re: Saturn I: A right rocket at the wrong time?
« Reply #34 on: 02/22/2011 03:40 am »
I'm not sure if SRBs or even multi cores were an option with the cluster tank.
No provisions for attachment etc.

There were lots of proposals for adding solid strap-ons to the IB.  Astronautix.com lists some.

EDIT:  Spelling.
« Last Edit: 02/22/2011 04:20 am by Proponent »

Offline Downix

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Re: Saturn I: A right rocket at the wrong time?
« Reply #35 on: 02/22/2011 04:15 am »
Atlas would not have to modified the cores for a heavy. 

Why does Atlas not have to modify its cores for the heavy version, whereas Delta does?
RS-68 failed to meet performance goals.
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Offline Jim

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Re: Saturn I: A right rocket at the wrong time?
« Reply #36 on: 02/22/2011 12:19 pm »
Atlas would not have to modified the cores for a heavy. 

Why does Atlas not have to modify its cores for the heavy version, whereas Delta does?

Because it designed the pad GSE not to require a mirror booster.

Offline Downix

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Re: Saturn I: A right rocket at the wrong time?
« Reply #37 on: 03/18/2011 11:36 pm »
Getting this back on-track.  I studied various options that could have been done for the clustering off the shelf components, rather than tying the tanks to the core as was done.

Instead of welding them together, my thought: Take a Jupiter-C tankage, stretch it to double the length (more than doable studying it's design), mount an F-1 on the bottom. Adding to it, up to four Thor's as is with H-1's on the bottom.

Would give a far more capable initial launcher, which could then grow into what was needed later.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline simonbp

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Re: Saturn I: A right rocket at the wrong time?
« Reply #38 on: 03/19/2011 04:12 am »
Isn't the nozzle of an F-1 wider than the tank on Redstone?!?

Offline Downix

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Re: Saturn I: A right rocket at the wrong time?
« Reply #39 on: 03/19/2011 05:59 am »
Isn't the nozzle of an F-1 wider than the tank on Redstone?!?
Doh!  Didn't mean Jupiter-C, I meant Jupiter MRBM.

Redstone is a good meter narrower than Jupiter.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

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