Before any of NASA's rockets can fly up to space, there's a lot of testing to be done. Marshall Space Flight Center's Building 4619 houses the structural testing, but to accommodate NASA's upcoming Space Launch System, it needed a few upgrades. Space Launch System is the rocket that will propel astronauts in the Orion capsule up into space. Before any rocket can take off, NASA has to conduct some tests, and some of those involve crushing and pulling all the important components.
To do so, custom housings have been built for the engine sections and the fuel tanks. That's no simple matter — the tank and engine are 19 and 15m tall, respectively, and enclosures had to be built to test each. Once the housings were built, hydraulic cylinders were attached to exert force on the test engines, and now NASA will crush, pull, push and twist the Space Launch System until it breaks, using millions of kilograms of force.
This may all seem like overkill, until you consider that this is the rocket that's supposed to take mankind to Mars, and no-one has experience testing a rocket quite this powerful. After all, you don't want Matt Damon to get stranded again.