Why the rocket launch sound could kill you? - sciencenerds

Sound waves created during Rockets launches can get so loud that could knock down a close-by building 

we can't see sound, doesn't mean it's not something physical it is and the loudest sounds ever created like the sound of a rocket launching it can be powerful and damaging, sound needs to travel through something like the air we can hear the sound because it vibrates the air molecules as it travels but that also means that the air has to pass out the way permitting sound to travel making a pressure wave.

The pressure wave is proportional to the intensity of a sound it's measured in decibels and as the intensity of a sound wave increases so does the waves pressure sound is mechanical so the waves are moving the air to make higher and lower densities of air molecules essentially an explosion pushes the air out of the way vibrating it at a high frequency with a lot of mechanical energy now think of rockets they're generating so much sound that the decibel levels are huge a typical conversation registers at about decibels and things can't get much louder before we start to damage our hearing sounds between and decibels like a subway train feet away from you is the level where you start to have hearing loss from sustained exposure a loud rock concert which could cause actual hearing damage is around decibels that's louder than a motorcycle or a power saw physical pain starts at around a hundred twenty-five decibels think standing a few feet away from a pneumatic Riveterouch anything above certain decibels like a jet engine roaring a from a hundred feet away can cause damage to your tissues in your ear irreversibly in a very short time.

One of the highest sound power levels ever recorded was, when NASA was testing these super cool awesome first stage of the Saturn rocket this stage used five engines to generate 1 million pounds of thrust and one test registered about decibels modern rockets are a little quieter coming in at about decibels I went to see that last shuttle launch STS  and even on the opposite side of the tidal pond from the platform the sound was really extremely noisy however it took a short time to get some which were really cool sound doesn't just threaten our hearing the energy stored in sound can create strong enough pressure waves that can damage physical structures in cool putting the rocket that's making the sound it doesn't seem like a good idea.

With  Merlin engines firing to produce and a half million pounds of thrust, it's fair to say, it’s pretty loud. For rockets with this much power, the sound energy produced by the engines can actually be very damaging to the rocket itself as well as the surrounding buildings.

In this article, we’re going to look at the method that NASA uses to reduce some of the sound damage. We’re also going to look at the unique way that the Russian’s deal with this problem.

 Incredible heat energy emerging out from the engines includes sound energy when the rocket lifts off from the launchpad.

According to NASA, the Saturn delivered a sound degree of around decibels during lift-off. If you were close enough to the engines, it wouldn’t just destroy your eardrums, leading to death. During the launch of the first Space Shuttle flight STS-, the sound energy produced by the engines was powerful enough to damage some of the protective thermal tiles on the Shuttle's hull. Although NASA used sound suppression frameworks before, the danger of harming the rocket or placing the team in danger was higher for the shuttle due to its unique shape and sensitive heat shield.

To avoid damaging the vehicle or putting the crew in danger, NASA solved this problem by implementing a more effective sound suppression system. This consists of a large water tower at the launch site which dumps over 1 million lbs of water onto the launch pad in just 40 seconds.

As the sound waves meet the water, they are absorbed by bubbles of air that contract and heat up, turning the sound energy into heat energy. Along with this enormous spray of water, NASA also used “water bags” at the base of the SRB’s to further dampen the shock waves. These were large nylon bags - each about one foot wide and one foot deep - filled with water and stretched across the SRB flame holes. Together, these two frameworks had the option to diminish the sound degree of the Space Shuttle from decibels to a progressively good, the likeness a fly taking off.

Although it can be difficult to see the water deluge system in action, it’s during a sound suppression test that we really get a sense of just how much water is used. Dumping this much water onto the launch pad not only protects the rocket and nearby buildings from intense shock waves, but it also stops any fires that might be caused by the exhaust of the rocket. NASA still uses a very same water deluge system at it's all main launch sites. whereas Russians using a different approach.

Since a lot of the Russian Soyuz rockets launch from Baikonur in Kazakhstan, where the temperatures can be as low as - degrees in the winter, a water deluge system would freeze up instantly, making it completely useless.

Their solution is to simply suspend the rocket over a much larger flame trench. This means that it is very little in the way for the shock waves to damage or reflect back onto the rocket. So although rocket science deals with some of the most complex engineering challenges, it’s interesting to see that some problems can be solved with very simple solutions.

~sciencefreak