A launch INSIDE a rocket? #history #shorts

This is just too cool not to share. This is the view inside the liquid hydrogen tank on the S4B stage of Apollo Saturn 203, which launched on July 5th of 1966. This was an unmanned Apollo mission designed in large part to test the behavior of super cold liquid hydrogen fuel in the S4B stage. There was going to be a slightly modified version of this stage on the Saturn V that would take Apollo astronauts to the moon, and it had one incredibly important job to do. It had to relight in orbit. Crews going to the moon actually stopped in Earth orbit for a while before doing what was called the translunar injection burn. This meant that the S4B stage is going to be off and then have to relight, and engineers had to make sure that the fuel would be able to get up against the feed lines to feed into that engine so it would burn safely and properly for this all-important burn. They also needed to see how the super cold liquid hydrogen would interact with things in the fuel tank, like baffles and screens, so they put a camera in the tank. Unlike the camera that took the staging videos on this mission, this one couldn't be recovered after orbit, so they actually got a video downlink during the mission. They saw the fuel sloshing around during the burn, which was exactly what they expected to see, and then they also saw it settle at the bottom of the tank while they were venting gases. The venting gas is providing just enough force to move that fuel to the back of the tank so it could burn cleanly. Basically everything showed that the fuel was behaving exactly like their model said it would. This is such a unique shot with so much cool engineering value, but it's also just fascinating to see.