jim@randvax.UUCP (Jim Gillogly) (01/18/86)
Columbia landed at Edwards this morning just before 6 AM, PST. In Topanga
(Santa Monica mtns above Malibu, CA) we only heard one sonic boom. For
each other Edwards landing we've heard two sonic booms, as discussed fully
here and in net.space. So, what's new with the shuttle and why didn't I
hear two this time?
--
Jim Gillogly
{decvax, vortex}!randvax!jim
jim@rand-unix.arpacushner@ttidcb.UUCP (Jeffrey Cushner) (01/22/86)
In article <2884@randvax.UUCP> jim@randvax.UUCP (Jim Gillogly) writes: >Columbia landed at Edwards this morning just before 6 AM, PST. In Topanga >(Santa Monica mtns above Malibu, CA) we only heard one sonic boom. For >each other Edwards landing we've heard two sonic booms, as discussed fully >here and in net.space. So, what's new with the shuttle and why didn't I >hear two this time? >-- > Jim Gillogly > {decvax, vortex}!randvax!jim > jim@rand-unix.arpa Sorry to disappoint you Jim, but I live in Simi Valley, closer by 15 miles than you and I heard, very distinctly the normal two booms. I must say that this time I wasn't expecting hearing them since I thought the weather would clear in Fla. but I was awake when it flew over. Perhaps the first one woke you up and you only heard the second one. -- ============================================================================== Jeff Cushner @ Citicorp-TTI Santa Monica CA 90405 (213) 450-9111 x2273 {randvax,trwrb,vortex,philabs}!ttidca!ttidcb!cushner ********************************************************************* ** The above comments do not necessarily reflect the opinions of ** ** Citicorp-TTI and if the corporation wants them to, they'll have ** ** to pay through the nose for the rights! ** *********************************************************************
bees@infoswx.UUCP (01/24/86)
There is nothing new with the shuttles that would effect the sonic booms. The shuttles still generate two booms. It is possible that you heard only one if: a) One was somehow muffled. b) They overlapped at your location. c) You can't hear. B-) Ray Davis Teknekron Infoswitch, Richardson, TX infoswx!bees, (214)644-0570
desj@brahms.BERKELEY.EDU (David desJardins) (01/25/86)
In article <639@ttidcb.UUCP> cushner@ttidcb.UUCP (Jeffrey Cushner) writes: >In article <2884@randvax.UUCP> jim@randvax.UUCP (Jim Gillogly) writes: >>Columbia landed at Edwards this morning just before 6 AM, PST. In Topanga >>(Santa Monica mtns above Malibu, CA) we only heard one sonic boom. For >>each other Edwards landing we've heard two sonic booms, as discussed fully >>here and in net.space. So, what's new with the shuttle and why didn't I >>hear two this time? > >Sorry to disappoint you Jim, but I live in Simi Valley, closer by 15 miles >than you and I heard, very distinctly the normal two booms. I must say >that this time I wasn't expecting hearing them since I thought the weather >would clear in Fla. but I was awake when it flew over. Perhaps the first >one woke you up and you only heard the second one. If the two sonic booms are generated nearly simultaneously by different parts of the spacecraft, as would seem likely, then the interval between hearing the two at the earth's surface would depend strongly on location. Ahead or behind of the shuttle the sounds would be well separated, but to the left or right of the flight path the sounds could arrive simultaneously... -- David desJardins
kwan@smeagol.UUCP (Richard Kwan) (01/25/86)
In article <2884@randvax.UUCP> jim@randvax.UUCP (Jim Gillogly) writes: >Columbia landed at Edwards this morning just before 6 AM, PST. In Topanga >(Santa Monica mtns above Malibu, CA) we only heard one sonic boom. In article <639@ttidcb.UUCP>, Jeff Cushner writes: > Sorry to disappoint you Jim, but I live in Simi Valley, closer by 15 miles > than you and I heard, very distinctly the normal two booms. I am not an aero/hydrodyamicist, so I can't speak with authority... If you look at a ship plowing through a body of water, the bow wave tends to be very distinct where it meets the bow. But it seems that the farther away you get, the more the body of the wave gets spread out across the surface of the water. (I think this is likewise for the stern of the ship.) After getting very far away from the ship you would expect the bow and stern waves to each become rather flattened and start to intersect. Going out a little further, you should only perceive one wave. Now, I'm guessing, because I haven't seen a ship on a sufficiently still body of water to see the intersection. In any case, you should be able to take whatever the two-dimensional hydrodynamic analogy is, and apply it to the aerodynamics of a shuttle landing with reasonable safety. Oh, yes. I live in the San Fernando Valley. I remember hearing two booms. Rick Kwan JPL P.S. Our system has only been on the net for a few months, so I can imagine someone may have already presented the above arguments. In that case, ignore me.