Saturn V: Interstage

The job of the Interstage in the Saturn V was to act as a kind of “spacer” between the first and the second stage.

The second stage of the Saturn V has five J-2 engines that could collide with the first stage upon separation. This “spacer ring” acts as a kind of buffer between the two sections. It is the section that is most often seen in the iconic separation of the first and second stages and is the image I used at the top of this page

First the first stage separates from the Interstage, by detonating a series of explosive bolts. It’s important that they all detonate at the same time for otherwise, the consequences could be disastrous. Then a few second later, the Interstage separates from the second stage and the second stage engines ignite. The interstage must separate from the second stage to prevent the engines from overheating.

So, all in all, what looks like a simple even, is actually quite complex.

There’s only one pic so far because I’ve been toying with the idea of printing the superstructure rings on my 3D printer instead of cutting them from paper, but in modelling them, I’ve hit a bit of a snag.