To prevent heat, dust, and moisture from getting inside a booster before it ignites, engineers install a foam plug at the nozzle. It’s designed to fall apart during ignition, and NASA scientists want to know how their latest, more denser, foam design is working out.


During this successful two-minute test of the SLS, temperatures reached nearly 6,000 degrees Fahrenheit. Following the test, some bits of foam were found as far as 1,500 to 2,000 feet away from the nozzle. The smoky ring that you see coming off the booster is condensed water vapor generated by the pressure difference between the motor gas and normal air.

Should all go well, NASA plans to send an uncrewed flight of the SLS with the Orion spacecraft some time in 2018. We can’t wait.