Feb 04

Space Rocket History #147 – Saturn: S-II Stage Part 2: Trials and Tribulations

“The S-II stage was a nightmare the minute it was conceived, and it only got worse from there. During the course of its creation, it would grind up people and careers the way the transcontinental railway devoured laborers.  Though the methods and materials used to build the S-II were reasonably well known, nobody had ever tried to apply them on such a titanic scale.  Originally, it was to be somewhere around 8 stores tall with a diameter of 22 feet, but the width ballooned from there to 27 feet before the contract was  even signed, then to 30, and finally to 33 feet.  And all the while as the size of thing increased, NASA was trimming the allowable weight.”  Harrison Storms of NAA.

Test firing of S-II Stage in Mississippi

Test firing of S-II Stage in Mississippi

Saturn V S-II Second Stage

Saturn V S-II Second Stage

Saturn S-II Assembly Building at Seal Beach.

Saturn S-II Assembly Bldg at Seal Beach.

S-II during stacking operations in the VAB

S-II during stacking operations in the VAB

S-II Inboard Profile in 1963

S-II Inboard Profile in 1963

S-II Cut-away with callouts

S-II Cut-away with callouts

Jan 28

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 Diagram

Saturn S-II Stage Exploded View

Saturn S-II Stage Exploded View

Saturn S-II Cut-Away Drawing

Saturn S-II Cut-Away Drawing

Jul 09

Space Rocket History #120 – Apollo: Stages S-IV and S-IVB

The key to high-energy stages was to use liquid hydrogen as the fuel.  Liquid hydrogen fuel appealed to rocket designers because of its high specific impulse, which is a basic measure of rocket performance. Specific Impulse is the impulse delivered per unit of propellant consumed.  You might think of it as the efficiency of the rocket.  Compared to an RP-1 (kerosene) fueled engine of similar size, liquid hydrogen fuel could increase the specific impulse or efficiency of an engine by 40 percent.  The combination of hydrogen and oxygen for propellants made the moon shot feasible.

S-IV Rocket Stage

S-IV Rocket Stage

S-IV & S-IVB Stage Position

S-IV & S-IVB Stage Position

S-IV Stage in Saturn IB and V

S-IV Stage in Saturn IB and V

S-IVB Differences Between Saturn IB and V

S-IVB Differences Between Saturn IB and V