So would you recommend something like a super-sized HL-20 being launched by the Saturn IB? Or perhaps a 70s-era mega-sized Cygnus equivalent? It seems like you're saying that the biggest problem for the Saturn IB wasn't the rocket but the Apollo CSM that launched atop it.
I don't know about half the mass of Skylab, Patchouli. That's one heck of a lot of mass (77,088 kg/2 = 38,544 kg). You would need to have a Saturn IB evolved to fling up some 83% more into orbit. That's going to require huge upgrades to the rocket. You would probably need an all-new core stage, preferably one with a single set of tanks and a common bulkhead. Going by chamber pressure, you'd need new H-1B engines with at least 1250 psi chamber pressure to pull it off (added efficiency would cut the thrust requirements). You'd also probably need to mount a second J-2S engine on a much enlarged upper stage. That sounds like a lot of expense, so maybe it would be better just to make modest changes, like upgrading to a J-2S engine up top or chopping the fins off the core stage?
Could cost per person to orbit be considered? Aside from pure cost of cargo to orbit discussions, comparison of STS to other systems is problematic IMO.
Quote from: Hyperion5 on 11/09/2014 02:04 amSo would you recommend something like a super-sized HL-20 being launched by the Saturn IB? Or perhaps a 70s-era mega-sized Cygnus equivalent? It seems like you're saying that the biggest problem for the Saturn IB wasn't the rocket but the Apollo CSM that launched atop it. Yes pretty much along those lines.
Quote from: Hyperion5 on 11/09/2014 02:04 amI don't know about half the mass of Skylab, Patchouli. That's one heck of a lot of mass (77,088 kg/2 = 38,544 kg). You would need to have a Saturn IB evolved to fling up some 83% more into orbit. That's going to require huge upgrades to the rocket. You would probably need an all-new core stage, preferably one with a single set of tanks and a common bulkhead. Going by chamber pressure, you'd need new H-1B engines with at least 1250 psi chamber pressure to pull it off (added efficiency would cut the thrust requirements). You'd also probably need to mount a second J-2S engine on a much enlarged upper stage. That sounds like a lot of expense, so maybe it would be better just to make modest changes, like upgrading to a J-2S engine up top or chopping the fins off the core stage? Actually it seems you don't need much in the way of modification to get more payload out of the Saturn IB.Add four Titian SRMs gets the payload up to 33,000kghttp://www.astronautix.com/lvs/satrnibd.htmThe same but with a tank stretch, and starting the H-1s in the IB stage at altitude and you can get 48,000 kg.http://www.astronautix.com/lvs/satint11.htm
Here is where the math doesn't favor larger station, the US infrastructure doesn't allow for spacecraft or payloads larger than the shuttle payload bay.
Quote from: Jim on 11/08/2014 12:28 amHere is where the math doesn't favor larger station, the US infrastructure doesn't allow for spacecraft or payloads larger than the shuttle payload bay.I wonder how Skylab arrived at the VAB from California, then.
I wonder how Skylab arrived at the VAB from California, then.
Quote from: Hyperion5 on 11/07/2014 08:29 pm Had NASA wanted to build the ISS with such a launcher, they would not have needed to design segments as small as the ISS Destiny module. You could have built the ISS with far fewer modules at less cost. Unsupported statements.Destiny is not small. The ISS is not for want of space.And it would not be cheaper.
Had NASA wanted to build the ISS with such a launcher, they would not have needed to design segments as small as the ISS Destiny module. You could have built the ISS with far fewer modules at less cost.
Quote from: Jim on 11/07/2014 08:50 pmQuote from: Hyperion5 on 11/07/2014 08:29 pm Had NASA wanted to build the ISS with such a launcher, they would not have needed to design segments as small as the ISS Destiny module. You could have built the ISS with far fewer modules at less cost. Unsupported statements.Destiny is not small. The ISS is not for want of space.And it would not be cheaper.The Saturn IB payload mass to a 370 km and 50° orbit is only 14.2 t, similar to the Space Shuttle. Thus, the modules would have been similar in size and mass to that carried in the Space Shuttle.
I've heard that you can work in ISS all day and not see anyone! So, yes there is plenty of space on ISS.The average Space Shuttle launch (not including development) was about $500M. Each Saturn IB had a production cost of $46.7M around 1966. That is $343M today using normal inflation. Adding in launch operations and that would easily cost $500M a launch total.However, instead of designing and building the Space Shuttle in the 1970's, NASA could have designed and built a Space Station instead. It wouldn't have been any cheaper or larger than ISS, but it would have been available 20 years earlier.
We're going to be building a joint space station with the USSR in the 1970s in this scenario? I think that's unlikely, Steven, especially considering how bad US-Soviet relations got after 1979. Could you re-do the orbits and assume a more benign, Cape Canaveral-friendly orbit?
Skylab flew at 50°. I'm not sure why they chose that inclination, but it does allow the Space Station to fly over all of the US states except Alaska as well being a better platform for Earth observation.
Quote from: RyanC on 11/09/2014 11:49 pmI wonder how Skylab arrived at the VAB from California, then. They used the Super Guppy to carry it.
Granted, the Titan IIIC could not lift as much as the Saturn IB at the start, but by the time we got to the ISS era, the Titan IV had nearly the same size and payload capabilities as the shuttle. With automated docking, we could have relatively easily assembled at least the core of ISS.
I'm not really sure which would have been better. I think now the economics of the combined use by NASA and USAF would have driven the cost of Titan down, even gives the need to change facilities to accommodate Titan. But, as I speculate, an expenditure od existing Saturn and Apollo hardware would have covered the gap and allowed the cost to be spread over a period of years.
I was comparing the ISS with a theoretical 1970s-era station based around Skylabs (but suitably modified). We're talking about 2-3 years of sustaining the Saturn V's assembly lines, not 20 or more. Given that short extension period, I'm willing to bet that six Saturn V launches and 1 Titan IIIE launch would have led to a station dramatically cheaper (inflation-adjusted) than the ISS.
So, I can"guarantee" that the "math" favors shuttle size payloads.
Here is where the math doesn't favor larger station, the US infrastructure doesn't allow for spacecraft or payloads larger than the shuttle payload bay. None of the major US spacecraft producers are near navigable bodies of water. You would have to build a dedicated facility some where on the US waterways to produce such a space station. Also, you would have to greatly upgrade in the facilities at KSC to handle such modules.
Quote from: Jim on 11/08/2014 02:42 amBesides, who said anything about the 1990s? I was comparing the ISS with a theoretical 1970s-era station based around Skylabs The comparison has to be for the same timeframe. There was no money for such a station in the 1970s. So your point fails
Besides, who said anything about the 1990s? I was comparing the ISS with a theoretical 1970s-era station based around Skylabs
Uhm, by that "logic" Jim the Saturn=-V could never have been built and nothing could be flown on the Saturn-1 as it would be "impossible" to get the payload to the Cape Upgrading KSC is a given (it happened for the Shuttle) and some upgrades of transportation is to be expected as well. (You actually shoot this idea out of the water later {pun intended} becasue they can and did ship the Skylab OWS section of the S-IVB stage by water from California to the Cape. So the capability already was in place to support such operations )
Quote from: Hyperion5 on 11/08/2014 04:23 pmQuote from: Hyperion5 on 11/08/2014 04:23 pmQuote from: edkyle99 on 11/08/2014 02:33 pmNow why on Earth would NASA keep flying the Saturn IB? Well for one the infrastructure was all there, unlike with the actual Shuttle (in terms of pad infrastructure). It would have been vastly cheaper to have kept flying the Apollo CSM atop the Saturn IB than to modify any other rocket to do the task. The problem is that NASA did not have the money. It had to cancel both Saturns in 1967-68, thanks to Vietnam and LBJ's Great Society. Later it did not even have enough funds to fly the Saturns that it had already built. Two Saturn V and two complete Saturn IB rockets (along with first stages for three more) were never flown. Any scenario that keeps Saturn IB alive has to include lots of money that wasn't there.I don't know, Ed. I was under the impression that the Shuttle itself wasn't exactly a a champion of cheap development. If we were to compare the yearly costs of Shuttle development with the cost of a Saturn IB w/Apollo CSM launch, what kind of ratio do we get? According to the following calculations, Apollo 7 cost about $920 million in today's dollars, assuming CPI inflation. The real number would likely be higher. NASA could probably only do two or three such missions on an annual STS budget. For that they would only get crew, and not the payload that Shuttle also provided.http://www.asi.org/adb/m/02/07/apollo-cost.htmlOn the other hand, NASA would have avoided the $14 billion then-year dollar cost of Shuttle development.
Quote from: Hyperion5 on 11/08/2014 04:23 pmQuote from: edkyle99 on 11/08/2014 02:33 pmNow why on Earth would NASA keep flying the Saturn IB? Well for one the infrastructure was all there, unlike with the actual Shuttle (in terms of pad infrastructure). It would have been vastly cheaper to have kept flying the Apollo CSM atop the Saturn IB than to modify any other rocket to do the task. The problem is that NASA did not have the money. It had to cancel both Saturns in 1967-68, thanks to Vietnam and LBJ's Great Society. Later it did not even have enough funds to fly the Saturns that it had already built. Two Saturn V and two complete Saturn IB rockets (along with first stages for three more) were never flown. Any scenario that keeps Saturn IB alive has to include lots of money that wasn't there.I don't know, Ed. I was under the impression that the Shuttle itself wasn't exactly a a champion of cheap development. If we were to compare the yearly costs of Shuttle development with the cost of a Saturn IB w/Apollo CSM launch, what kind of ratio do we get?
Quote from: edkyle99 on 11/08/2014 02:33 pmNow why on Earth would NASA keep flying the Saturn IB? Well for one the infrastructure was all there, unlike with the actual Shuttle (in terms of pad infrastructure). It would have been vastly cheaper to have kept flying the Apollo CSM atop the Saturn IB than to modify any other rocket to do the task. The problem is that NASA did not have the money. It had to cancel both Saturns in 1967-68, thanks to Vietnam and LBJ's Great Society. Later it did not even have enough funds to fly the Saturns that it had already built. Two Saturn V and two complete Saturn IB rockets (along with first stages for three more) were never flown. Any scenario that keeps Saturn IB alive has to include lots of money that wasn't there.
Now why on Earth would NASA keep flying the Saturn IB? Well for one the infrastructure was all there, unlike with the actual Shuttle (in terms of pad infrastructure). It would have been vastly cheaper to have kept flying the Apollo CSM atop the Saturn IB than to modify any other rocket to do the task.
Quote from: RanulfC on 11/10/2014 06:39 pmUhm, by that "logic" Jim the Saturn=-V could never have been built and nothing could be flown on the Saturn-1 as it would be "impossible" to get the payload to the Cape Upgrading KSC is a given (it happened for the Shuttle) and some upgrades of transportation is to be expected as well. (You actually shoot this idea out of the water later {pun intended} becasue they can and did ship the Skylab OWS section of the S-IVB stage by water from California to the Cape. So the capability already was in place to support such operations )Wrong. As I said, there are no spacecraft companies near waterways, only booster companies. No real payloads were flown on Saturn I.KSC was not "upgraded" for shuttle. Existing facilities were used for payloads. The only new facility came online after Challenger, PHSF, and its first use was a Titan IV payload. The USAF had the SPIF, it was only "new" facility.
1. JPL could never have transported a "large" probe to Los Angles harbor correct, Boeing couldn't find an oulet to the sea nearby? Huges had no access to any port? Need I go on? 2. And that all of course assumes that no one thinks to build "modular" satellites that are assembled at the Cape for launch. Which is pretty silly considering ALL the aforementioned companies DID consider doing so should larger satellite and spacecraft be required.3. Far fewer "changes" would have been required to be done to fit the already existing Saturn LVs than had to be re-done to fit and service the Shuttle stacks Jim so saying that KSC was not "upgraded" to fit the Shuttle is like saying, well that nothing at KSC was even CHANGED to fit the Shuttle and its operations which is obviously un-true.4. Finally your trying to point out that "no real payloads" were flown on the Saturn-1/B is pretty silly. The Apollo-CM wasn't a 'real' payload? Nor the LM? The Skylab crews were "not-real" either then?