Construction of NASA’s Space Launch System structural test stand at the Marshall Space Flight Center in Huntsville, Alabama was completed in late December 2016. Engineers are now installing the equipment needed to test the huge fuel tank needed to launch the SLS into its first unmanned flight later this year.
Construction of Test Stand 4693 began in May of 2014, according to Gizmodo. The structure stands 221 feet (67 meters) tall, and to commemorate the completion of the stand, NASA released a 60-second time-lapse video of it being built. The stand is a big deal for NASA because it is critical to the testing of the rocket’s biggest fuel tank.
Basically, Test Stand 4693 will subject the 537,000-gallon liquid hydrogen tank of the SLS’s massive core stage to the same stresses and pressures it must endure at launch and in flight. “There is no other facility that can handle something as big as the SLS hydrogen tank,” said Sam Stephens, an SLS engineer working on the tests.
After contractors and steelworkers handed over the stand to Marshall engineers, they began the process of installing networks of cables, pipes, valves, control systems, cameras, lighting and specially designed test equipment. The prototype fuel tank is so huge and heavy it will be delivered to the site on a barge.
The SLS liquid hydrogen prototype tank was built by Boeing at NASA’s Michoud Assembly Facility in New Orleans. The 149-foot-long (45.4 meters) test assembly consists of a liquid hydrogen tank with equipment attached on each end that will simulate other parts of the 212-foot-long (64.6 meters) core stage, the backbone of the rocket’s massive four-engine core stage.
Now check this out — with the liquid hydrogen tanks and the liquid oxygen tanks of the SLS working together, they will feed 733,000 gallons (nearly three million liters) of super-cooled propellant to four RS-25 engines. This combination will produce a total of two million pounds of thrust at the base of the core stage, according to NASA engineers.
A total of 38 hydraulic cylinders, ranging in weight from 500 to 3,200 pounds, will be positioned at points along the tank to simulate the thrust produced by the RS-25 engines. During testing, the cylinders, or “loadlines” will extend and retract, pushing and pulling in different combinations to expose the hydrogen tank to the conditions expected at launch, according to Nature World News.
While all this is happening over 3,500 individual measurements, including temperatures and pressures will be taken. There will be more than 30 different tests conducted, scheduled to take place over several months. One last thing – High-definition cameras are being installed on the stand, so once testing begins, we ought to be seeing some great videos.
