Space Rocket History #146 – Saturn: S-II Stage Part 1: Common Bulkheads, Gores, & Honeycomb Sandwiches

The structural efficiency of the S-II stage, in terms of the weight and pressures taken by its extra-thin walls, was comparable only to the capacity of one of nature’s most refined examples of structural efficiency, the egg.

Saturn S-II Stage Diagram

Saturn S-II Stage Exploded View

Saturn S-II Cut-Away Drawing

5 thoughts on “Space Rocket History #146 – Saturn: S-II Stage Part 1: Common Bulkheads, Gores, & Honeycomb Sandwiches”

Michael, Listening to your podcast is a high point of my week. Keep up the great work! I had a question after listening to #146. Was there an advantage to having LH2 storage on TOP of LOX in the S-II instead of the other way around? When liquified there is probably not a weight difference per unit volume, but maybe there is some, so perhaps the was a center-of-gravity issue? I believe LH2 is colder, was that the rationale? Anyway just interested to know. Thanks again from just across those snow covered mountains.

spac9750 on January 29, 2016 at 9:55 am said:

I can’t say with certainty. I have read that to prevent freezing in the lines you should run your colder line LH2 past the warmer LOX tank. The balance of the heat transfer is then likely to keep your cold lines slightly warm, and your warm tank slightly cold, and thus propellant flow is not restricted. Additionally the colder tank is further from the rocket exhaust. There could also have been a structural load reason for putting the lighter hydrogen propellant on top.

Hi Michael,

I’m a bit behind on the podcasts and just listened to this one… and really enjoyed hearing about all the manufacturing processes that went into the SII. You made it really easy to picture what was going on. But I’d love to learn more. Could you share your sources for this specific podcast?

Keep up the great work!

Christophe M.