REDSTONE ARSENAL, Ala. - The first of five rounds of SLS structural tests are underway at Marshall Space Flight Center at Redstone Arsenal. This needs to happen in order to qualify the rocket stages for flight.
"It's essential. You don't fly, period, without structurally testing the rocket," explained Mike Roberts, structural test team lead.
Teams have been working on Integrated Structural Tests since February, and expect to wrap in May. Then other portions of the SLS will be tested.
For the tests, crews construct test articles that simulate actual portions of the SLS. The test articles are built, then stacked just as they would be on the rocket. The engineers then apply up to half a million pounds of force to see how they stand up to the forces in flight.
The scientists collect data for compression, tension, bending, torsion and shear. Instead of fuel, they use liquid nitrogen because it's inert. The rocket doesn't have to fly, for them to observe how it would do in flight.
"Every conceivable force you could have on the rocket during flight, we mimic here on the ground.So when you launch you have the thrust pushing up, and you have the atmosphere pushing down. A lot of that is compression and bending, torsion and shear. We have to replicate all those forces here on the ground," said Roberts.
It's a lot of work. The integrated structural test articles will undergo 55 rounds of testing before it's through.
Roberts loves numbers, and he loves seeing how parts stand up to the tests. He said so far, it's looking good at this point.
And that's a good thing. It took years of work to get here, and there's a lot at stake.
"You've certainly got the seriousness of our job, but you have to understand it goes through design, development and analysis," said Keith Higginbotham, Integrated Structural Test team lead. "A lot of this is verifying all the prior work we've done and once we test it, we will verify that our models and everything were correct. And then it gives us confidence that it's good to go," he explained.
History is being made with each test.
"It's going to be the most powerful rocket ever built, and so the one thing that's nice about NASA is we've been able to build on our past experience," said Higginbotham. "There's been a lot of good work done before us. We're able to build on that, but the fact of what its capability will be is really awesome."
For more about the SLS, click here.