SpaceX Starship's Sonic Boom Creates Risk of Structural Damage, Test Finds

Rockets do make sonic booms on launch when they go supersonic but the shockwave travels forward and out. Generally unless something has gone very very wrong most rockets are launched upwards so generally people behind the rocket won't hear a sonic boom.

> Terracon found a peak sound pressure level of 144.6 decibels as the rocket descended, which is also higher than Port Isabel expected, said the city manager, Jared Hockema

That's loud. NIOSH recommended exposure limits are 8 hours at 85 dB(A), and for every 3-dB over that cut the time limit in half. For 144.6 dB (assuming it is dB(A)...the article just says decibels) the exposure limit would be 30 ms.

It's not clear though if that halving the time per 3-dB increase rule is applicable at the point. 144 dB looks like it might be above the threshold were there is instant hearing damage.

Anyway, how can they mitigate this? Since the problem is the returning booster could they change the flight profile so that after the booster separates it slows down to subsonic speed before it starts coming down?

“Notably, a supersonic Concorde flying at an altitude of 18 km produced a sonic boom with a PL of ∼105 dB at the ground. With a difference of 5 dB, one approximation for a Starship flyback boom at 20 km is a ∼50% increase in loudness over the Concorde boom (where 9 dB represents a loudness doubling; see Stevens, 1972).”