NASA Engineers recently fired the rockets of a scaled down model of the future Space Launch System (SLS), measuring the acoustic impact that liftoff could have on the launch pad and rocket.

The impact of sound doesn't sound like it could do much to a massive launch pad made of high-strength alloys, coolant, and concrete, but NASA's Jeremy Kenney, acoustics engineer at NASA's Marshall Space Flight Center (MSFC), says not to be fooled. High and low frequency sound waves from the SLS solid rocket motors can bounce off the pad, potentially damaging the launch site and even the spacecraft itself.

"The noise the engines and boosters generate is so great that it can impact the rocket, and the crew, during liftoff. We have to ensure we have the proper suppression system to basically turn that noise down to a safe level," he explained in a recent statement.

Of course, NASA isn't going to fire extremely expensive rocket motors intended for a deep space mission over and over just to test sound waves.

To achieve this, NASA's team of engineers built a scaled-down exact replica of the SLS, which they are testing at the Marshal Space Flight Center in Huntsville, Alabama.

This mini-model has been equipped with more than 200 sensors, and each individual piece was crafted to the most finite details of the real SLS using a 3D printing technique called selective laser melting (SLM) - a process where individual parts can be crafted out of a single block of material.

Sandy Elam Green said that this process has allowed her team to bypass a lot of machining that would normally take much longer, and the resulting parts have actually even surpassed the performance of traditionally welded parts.

"When you're building the largest rocket in the world, you have to take everything into consideration," said SLS Chief Engineer Garry Lyles.

According to Lyles, with this acoustic testing helping engineers determine how to "dull" the rocket-noise, NASA is one step closer to the deep space rocket's first flight.


[Credit: NASA/MSFC/SLS]