Discovery

[GordMay]

The headline reads: “NASA May Bend Safety Rules for Shuttle Launch”
With a fuel gauge problem still unexplained, NASA said it will bend its long-standing safety rules to launch Space Shuttle Discovery on Tuesday.

Nasa seems to be ignoring two important rules, that most cruisers follow:
~ There is NO schedule, merely a mild preference.
~ Accept NO unexplained mysteries, that could hurt you.

Good Luck to Commander Eileen Collins, Pilot James Kelly, Mission Specialist Andy Thomas, MS Charles Camarda, MS Wendy Lawrence, MS Soichi Noguchi, MS Steve Robinson

I hope I've posted in the wrong thread ...

IMHO,
Gord

[Rick]

Touche!

[GordMay]

‘Discovery’ safely launched at 10:39 a.m. The fuel-gauge problem that thwarted a launch attempt two weeks ago did not resurface before liftoff. NASA did not immediately say how the sensors behaved during the climb to orbit, but everything appeared to go well.
God watches over fools and drunks. I know, for I've been both.

[boredinthecity]

So .........


dose this mean


that if i learn more i will have to drink more so that god will watchover me

ill drink to your religion any day (or night)

now thats a real incentive to learn

[GordMay]

This means I join the ranks of prognosticators such as Bill (640K ought to be enough for anybody) Gates, and Lord William (Radio has no future - X-Rays will prove to be a hoax) Kelvin.

Notwithstanding ...
I stand by the axioms.

[Alan Wheeler]

Ummm, hope this isn't bad, but as the main fuel tank fell away, NASA noticed some object flash past the camera mounted on the shuttle hull. They don't know what it is yet. Personally, I don't think Ducks fly at 10miles up, so I dobt it was one of those. Maybe the captain was looking out the window and is cap blew off, err, I dunno. Maybe I ain't knowledgable enough to speculate.
I hope all goes well.
OH for a little trivia. If anyone has ever personally watched a lift off, they will note the loud crackle in the roar fo the engines. You easily hear it on TV and many viewers (if they think about it) just presume it's bad sound recording. Actually it is distortion, but it is natural distortion of sound in our atmosphere. It's basicaly like this(without getting to nerdy and over anybodies heads) Sound comes to you in waves of energy. The waves, just like an AC voltage sine wave, has a negagtive and positive swing. The positive is the pressure wave and this can be of infinite pressure, but the negative is a vacume and a vacume is finite. So what happens is the sound arrives to the listener in a very distorted form which is what you hear as a crackle. This happens when sound reaches about 188dB. The exact depends on altitude, humidity and temperature. But what ever, it's damn loud.
As I am a sound engineer, I have made freinds with sound guy's all over the world. And one close freind of mine, used to work for NASA in the early days of the shuttle. He designed and built equimpent that would shake the snot out of sattelites using 150dB of sound pressure to ensure the payload could withstand the noise vibration inside the payload compartment.

[BC Mike]

I experienced the crackle last Friday night. Went to a Robert Zimmerman ( Bob Dylan ) concert, and Bob sounded like Daffy Duck barking. Could not understand a word he tried to sing. I asked the guy next to me if he could understand what he was saying / singing and he said " Govori li Bob engleski "
The other time I heard the crackle was when Lenny went by in his Hondo hull with a big block Ford at 7500 revs. He had dry pipes, zero mufflers.
Michael

[Alan Wheeler]

ehrrrrrrr, that's just how Bob sounds ain't it???
Ummm, however, both accounts are compleately different types of sound distortion.

[Rick]

According to my calculations that sound test at 150 dB is over 6,000 times LESS power of sound level than the 188 dB of the rocket sound and 150 dB has one million times more power level than that which is the threshold of pain in human hearing. Wow!

[Alan Wheeler]

Yeeeup! But Rick, you have waaay to much time on your hands then.
As another story from my mate, NASA had a problem in the very early days of the Shuttle saga. On re-entry, the sonic boom would tend to wake up the nieghbourhood by shattering windows. So they looked at what frequencies where involved and how it affected things and how they could change portions on the shuttle to change the boom if they could. So Tom designed this "speaker" not as you imagine a speaker, that would reproduce the sonic boom. They could reproduce 3Hz at 150dB. You can't hear 3Hz, but the felling at 150dB makes you feel very sick. Anyway's, they placed it beside a two storey house as a test and turned up the volume. The stopped the test when they heard a very loud "Crack". It moved this two storey building 6" off it's foundations.
His NASA carrier pretty much ended when the first shuttle blew up and everything kinda closed down. But as a hoby, he was playing with Sound transducer designs and he went on to do that as a job. He now produces some of the most famouse Bass reproducing bins in the commercial sound industry today as well as some very cool and clever top boxes.
Arrr, but this is all waaaay of topic. I better stop now.

[Rick]

I wanna hear more!

[Alan Wheeler]

Well I'll have a think of some other stories. Sound has been a huge part of my life and there are lots of stories.

But for now, here's another bit of sound trivia, did ya know a whale can produce a sound as loud as 180dB under water. It's interesting that some of the sonar guy's on subs have reported that they could hear a pod of Whales comminicating with other whales thousands of miles apart.

[Alan Wheeler]

OK Rick. I have been thinking for a few day's of what I could post on sound and still keep a topic of boating. Well here's another story.
A young bright spark fellow came up through the ranks of BOSE. While playing with some idea's, he stumbled on something very cool. He thought about the idea of using two Ultra sonic transducers, not unlike the sort you would use on a depth sounder, and used the HF signal as a carrier wave. He modulated another signal into that HF carrier wave. Follow me so far?? Now, the ultra sonic trnasducers would have a very very narrow beam width and could be projected along distance. If the two transducers where seperated as a "stereo pair" and aimed at a point, the two waves would interact and an audible sound would be demodulated out of the sonic combination. OK, so that all sounds rather complicated and you may not be following. So in plain english, this meant sound could be projected some distance and if anyone's ears were within the point of the combined signal, they could hear an audible sound. No one outside of that point would hear it. It's pretty cool. Unfortunately, the US Navey brought the patent and rights to all testing and knowlege of it. No one seems to know what they are doing or intending to do with the idea. Another company has been playing with a similar idea, I don't know how they get around the patents etc, but so far, only a limited frequency range has been reproduced. The idea is to one day have people listening to concerts without the nieghbour hood hearing the noise.