The SLS rocket launch during NASA’s Artemis I Moon mission produced noise levels greater than that of a siren from an ambulance at a distance of 5 kilometers.
(Video: Bob Jacobs)
According to a new study published in the journal JASA Express Letters, the launch of the Space Launch System (SLS) rocket and the Orion spacecraft during NASA’s Artemis I Moon mission generated significantly more sound than expected, Space reported on February 18. A team of experts measured noise levels from five microphones installed at distances ranging from 1.5 to 5.2 kilometers from Launch Pad 39B at Kennedy Space Center in Florida. The noise at each microphone exceeded predicted levels.
The rocket engines produced a crackling sound due to shock waves generated from strong sound pressure thresholds. According to co-author Whitney Coyle, the noise from Artemis I at 5 kilometers was approximately 40 million times louder than a bowl of Rice Krispies. At this distance, the noise level reached 129 dB – louder than an ambulance siren or a chainsaw, sufficient to cause hearing damage.
Noise levels above 85 dB can lead to permanent hearing loss with prolonged exposure, according to the Advanced Hearing Center of the U.S. Department of Defense. The Artemis I launch lasted only a few minutes, and the next SLS launch will not occur for at least another year.
One reason the Artemis I launch was so loud is the extreme thrust produced by the SLS – the most powerful rocket ever launched. This 98-meter tall rocket features two solid rocket boosters, combined with a core stage that generates approximately 4,000 tons of thrust at liftoff.
The noise from the Artemis I launch at a distance of about 5 kilometers.
NASA engineers anticipated that the SLS launch would be very loud, so they poured 1.7 million liters of water onto the launch pad to reduce sound levels. However, the SLS still produced noise exceeding NASA’s earlier predictions. The noise measured about 20 dB higher than expected at a distance of 5 kilometers from the launch site.
“This study is an important step, but we still have a long way to go to understand everything about how rocket noise is generated, propagates, and is perceived,” said physicist Kent Gee from Brigham Young University, the lead author of the study.
