 Why are these men rocking a Saturn V with their feet? I'm Amy Scheer title and this week on Vintage Space we're talking about the Saturn 500F Shake Test. Building a rocket to go to the moon is a little more involved than just building a rocket and launching it to the moon. In the case of the Saturn V every piece of the rocket was built by a contractor in a different location and it was up to NASA to assemble the vehicle at the Kennedy Space Flight Center. That meant technicians at the Cape also needed the facilities to lift up the rocket stages to mate them, check out that they were all talking to each other and then move the finished rocket from the vehicle assembly building onto the launch pad with the crawler way. Checking that all this pre-launch hardware was working demanded a separate round of tests and for this NASA didn't use a flight-ready vehicle. The agency used a dummy Saturn V, in this case of the Saturn 500F for facilities integration tests. It was used to make sure that it fit the service platforms that worked with the crawler transporter to get between the VAB and the launch pad and that all the connections to the mobile launcher and support equipment worked. Midway during its active lifetime at the Cape in 1966 Hurricane Alma swept through and the vehicle was hastily moved from the launch pad back into the VAB for shelter. Perhaps inspired by this brush with a hurricane because Florida can get some pretty nasty winds engineers decided to run a very simple shake test with the rocket. Technicians on the bottom pushed with their legs while men on top pulled with a rope attached to the spacecraft. Shaking the mammoth rocket in an attempt to get it to reveal its natural frequency. Something that would in turn give engineers an indication of its structural mechanics. The manual shake test actually knocked the launch escape system right off the top of the rocket. But luckily it didn't land on anybody when it fell. In an era before computer modeling was common enough to solve all the problems technicians came up with some pretty interesting workarounds, eh? Leave your questions and comments below and for more on the Saturn 500F shake test check out the latest article on vintage space over at Popular Science. You can grab me on Twitter for daily old timey space content as AST Vintage Space and for weekly vintage space video updates don't forget to subscribe.