# Why no sonic boom during launch? **URL:** \ **Category:** Factual Questions\ **Created:** [May 29, 2007, 1:38pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905 "2007-05-29T13:38:23Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [May 29, 2007, 1:38pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/1 "2007-05-29T13:38:23Z")
I’ve heard planes hit the sound barrier before and have been around when the space shuttle re-enters the atmosphere and heard the thunderous BOOM when it occurs. So why is there no BOOM when the Space Shuttle launches? I think it hits Mach1 soon after takeoff. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [May 29, 2007, 1:50pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/2 "2007-05-29T13:50:04Z")
[QUOTE=Hampshire] I’ve heard planes hit the sound barrier before and have been around when the space shuttle re-enters the atmosphere and heard the thunderous BOOM when it occurs. So why is there no BOOM when the Space Shuttle launches? I think it hits Mach1 soon after takeoff. [/QUOTE] My WAG is that the booster engines are so loud that they cover up all other sound. ---
**Author:** ![anson2995](https://avatars.discourse-cdn.com/v4/letter/a/c77e96/32.png) [@anson2995](https://boards.straightdope.com/u/anson2995)\ **Post date:** [May 29, 2007, 1:51pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/3 "2007-05-29T13:51:33Z")
By the time it reaches that speed, it’s too high for the sonic boom to be heard on the ground. Per NASA: > [@](#): > > Why isn’t there a sonic boom when the shuttle reaches the speed of sound after lift-off? > > Sound moves out and away from you in a circle, like a ripple in a pond from a stone, at a rate of about 700 mph. So if you fly 700 mph, all the noise you make builds up as a wave that moves along with you. During launch, we are going straight up, so that wave is travelling with us up. By the time we turn to parallel the Earth’s surface, we’re so high that there’s no air to carry the sound. If you were in an a balloon at about 20,000 feet at the Cape, you would hear the Boom as the Shuttle climbed by. But the folks on the ground are all behind the Shuttle, so they never hear it. ---
**Author:** ![Dr.Lao](https://avatars.discourse-cdn.com/v4/letter/d/2bfe46/32.png) [@Dr.Lao](https://boards.straightdope.com/u/Dr.Lao)\ **Post date:** [May 29, 2007, 1:55pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/4 "2007-05-29T13:55:21Z")
According to [this](http://www.aerospaceweb.org/question/spacecraft/q0183.shtml) the space shuttle reaches mach 1 approximately 45 seconds after liftoff. [Here’s a picture](http://www.unexplained-mysteries.com/gallery/displayimage.php?album=25&pos=21). As to why you didn’t hear it, I am not sure. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [May 29, 2007, 2:09pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/5 "2007-05-29T14:09:34Z")
Check out this cool annotated shuttle launch video that shows speed, altitude, and downrange distance all the way into orbit. It mentions passing through the sound barrier as well. [![](https://img.youtube.com/vi/VgfavsFKjlE/hqdefault.jpg "Discover Shuttle Launch - 7.4.06") ](https://www.youtube.com/watch?v=VgfavsFKjlE) ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [May 29, 2007, 2:14pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/6 "2007-05-29T14:14:20Z")
because it is all a hoax, done in a studio. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [May 29, 2007, 2:22pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/7 "2007-05-29T14:22:15Z")
[QUOTE=Sapo] because it is all a hoax, done in a studio. [/QUOTE] Agreed, but why couldn’t they hire some guy with a gong to make the whole thing more realistic. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [May 29, 2007, 3:04pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/8 "2007-05-29T15:04:02Z")
As noted in the quote from NASA, the main reason is that the shuttle is traveling away from ground observers. From above, the boom would be easily heard. ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [May 29, 2007, 3:22pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/9 "2007-05-29T15:22:33Z")
[QUOTE=Shagnasty] Agreed, but why couldn’t they hire some guy with a gong to make the whole thing more realistic. [/QUOTE] Because everybody would expect a boom. Not having one, confounds expectations and makes it more realistic. ---
**Author:** ![happywaffle](https://avatars.discourse-cdn.com/v4/letter/h/ee59a6/32.png) [@happywaffle](https://boards.straightdope.com/u/happywaffle)\ **Post date:** [May 29, 2007, 9:30pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/10 "2007-05-29T21:30:21Z")
[QUOTE=Shagnasty] Check out this cool annotated shuttle launch video that shows speed, altitude, and downrange distance all the way into orbit. It mentions passing through the sound barrier as well. [![](https://i.ytimg.com/vi/VgfavsFKjlE/hqdefault.jpg "Discover Shuttle Launch - 7.4.06") ](https://www.youtube.com/watch?v=VgfavsFKjlE) [/QUOTE] Can someone help me out with this video? Its downrange number seems to be increasing at a faster rate than its altitude rate. I thought downrange was the horizontal distance from the launch point to the point directly below the shuttle. But that would mean the shuttle is shooting out at a 45 degree angle which obviously ain’t happening. EDIT: Figured it out the instant I clicked “Post.” It’s the linear distance from launch to shuttle. Right? ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [May 29, 2007, 11:48pm UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/11 "2007-05-29T23:48:04Z")
[QUOTE=happywaffle] Can someone help me out with this video? Its downrange number seems to be increasing at a faster rate than its altitude rate. I thought downrange was the horizontal distance from the launch point to the point directly below the shuttle. But that would mean the shuttle is shooting out at a 45 degree angle which obviously ain’t happening. EDIT: Figured it out the instant I clicked “Post.” It’s the linear distance from launch to shuttle. Right? [/QUOTE] No. You had it right the first time. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [May 30, 2007, 12:01am UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/12 "2007-05-30T00:01:47Z")
[QUOTE=happywaffle] But that would mean the shuttle is shooting out at a 45 degree angle which obviously ain’t happening. [/QUOTE] No, but soon after launch it begins to curve away from perfectly vertical, and follows a curved path that becomes more horizontal with every passing second. Not a straight line though. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [May 30, 2007, 12:53am UTC](https://boards.straightdope.com/t/why-no-sonic-boom-during-launch/405905/13 "2007-05-30T00:53:29Z")
[QUOTE=Shagnasty] Check out this cool annotated shuttle launch video that shows speed, altitude, and downrange distance all the way into orbit. It mentions passing through the sound barrier as well. [![](https://i.ytimg.com/vi/VgfavsFKjlE/hqdefault.jpg "Discover Shuttle Launch - 7.4.06") ](https://www.youtube.com/watch?v=VgfavsFKjlE) [/QUOTE] [Obscure factoid]:The linked flight was wacky Lisa Nowak’s one and only shuttle flight – she of the cross country Pampers express. [/Obscure factoid]