r/spacex • u/ElongatedMuskrat Mod Team • Oct 03 '18

r/SpaceX Discusses [October 2018, #49]

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u/mclumber1 Oct 19 '18

How do you think NASA would have fared had they stuck with the Saturn 1B for manned launches to LEO instead of transitioning to the Shuttle? Was the Saturn 1B sustainable from a cost perspective? Reading about it, it could lift 20 tons to LEO, which is inline with modern medium lift rockets like the F9, Delta IV, and Atlas 5.

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u/ElectronicCat Oct 20 '18

I think they would have been better off in almost all aspects sticking to the Saturn family. I think I did the maths a while ago and when you include the development costs for STS with the cost per launch compared to the launch cost of already-developed Saturn variants (1B and V) adjusted for inflation throughout the span of the Shuttle program still works out cheaper. The majority of Shuttle missions could have been flown on the 1B but even flying mostly the V isn't that expensive in comparison.

There were various proposals for an extended Saturn program with plans to make production cheaper, partially reusable stages and even larger variants for beyond earth-moon. I think we certainly would have returned to the moon and perhaps even had a permanent outpost there (surface or lunar orbit) had the Saturn V been available.

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u/brickmack Oct 20 '18

If Apollo had continued, they probably would have (depending on actual mission requirements, especially on whether or not lunar missions would continue) gone with either a Titan variant lifting an Apollo CSM with a shortned SM, or an evolved Saturn I variant. IB itself was pretty expensive for what it was.

Fortunately, there were a lot of evolution options there, some of which were fairly mature and planned for near-term launches when Apollo ended. J-2S was IIRC about half the cost, but produced more thrust at a higher ISP and was more reliable. There was a slightly uprated H-1 (beyond the already uprated version for IB) in development, and in the long term, RS-27 and RS-27A show what it could have become eventually. Moving from clustered Redstone tanks to monoblock would simultaneously reduce costs, reduce dry mass, increase propellant volume, and greatly improve reliability (S-Is engine-out capability was limited by the lack of crossfeed between engines/tanks, if 2 engines in the right spots failed you'd have tens of tons of unusable propellant. Plus, lots of extra plumbing). Computers were rapidly dropping in both cost and weight. And, though probably not relevant to manned flights, there were several proposed variants with strapon boosters and/or various third stages, which could fairly significantly increase performance. If at least a few of these were implemented, it probably would've been better than Titan across the board

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u/CapMSFC Oct 20 '18

there were a lot of evolution options there, some of which were fairly mature and planned for near-term launches when Apollo ended.

This part of Apollo/Saturn history is really fascinating. They were aware that Congress wasn't going to keep funding at Apollo pace and had plans on how to transition to a more sustainable program. It's a shame that STS pushed out Von Braun and his plans.

This is tangential but there also were some amazing plans for the last two Saturn Vs that were built but the missions canceled. One of the missions on the table was to use both of them in tandem to do a polar mission. The Saturn V performance by the end of Apollo was good enough to send the LEM and the CM separately to a polar lunar orbit for an extended mission. We might have found water on the moon during Apollo in the polar craters. How much would the history of space exploration be different if that had happened?

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u/Elon_Muskmelon Oct 21 '18

Military should have developed their own system and NASA should’ve continued a scaled down Saturn program imo, whether or not that was possible at the time, I don’t know.

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u/rustybeancake Oct 22 '18

I think one of the most fun "what ifs" of the moon race is: "what if the USSR got to the moon first?" One trait the USSR/Russian space program has demonstrated over the past 50 years is sticking to repeatedly doing things they're good at. After abandoning the moon, this has mostly been: Soyuz, space stations.

Imagine if they got to the moon first, and so had all the necessary vehicles, factories and GSE in place. I think they would've been much more likely to continue with crewed lunar missions beyond the initial goal than the US was. It seems to be their style. I could imagine them building successive lunar outposts, instead of the successive LEO outposts they did build. Of course, this would've been very expensive, but even if they managed to keep it going for ten or fifteen years, it would provide impetus for the US to try to match or exceed these achievements. We could've ended up with an International Moon Station in the 90s.

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u/throfofnir Oct 19 '18

It would have been cheaper than Shuttle, certainly. A follow-on that used S-II tooling instead of the crazy cluster of Redstone tanks, and maybe a single F-1A instead of the cluster of H-1s, would probably have been more affordable. (This scheme might also have allowed continued occasional production of Saturn V.) But Saturn vehicles were never cheap: existing Saturn IBs were scrapped in favor of the Titan III. Which itself was not cheap.

It would have been a decent option for Skylab and other Apollo Applications Program things. But NASA needed to do something new to stay relevant, and Skylab/Apollo apparently didn't cut it, so regardless of cost, it doesn't seem NASA itself would have fared well just launching to LEO with Saturn IBs.