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Possible Challenger To Sputnik, manhole first manmade object in space?
Bob Shaw
post Jan 3 2006, 06:40 PM
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QUOTE (tty @ Jan 3 2006, 06:50 PM)
Actually, if You throw a rock into the air by hand it also goes into an elliptic orbit around the Earth with the perigee (way) under ground level.

tty
*


Yes, very true - and a great classroom demonstration - it's easy to see, cheap to perform, and you have a fairly profound aspect of the universe right in front of you!

Bob Shaw


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Remember: Time Flies like the wind - but Fruit Flies like bananas!
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Guest_BruceMoomaw_*
post Jan 3 2006, 07:36 PM
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I first read about the manhole cover years ago in a letter to "Smithsonian Air & Space Magazine". Since it weighed several hundred km, there's an excellent chance that some of it survived its trip through the atmosphere -- and while it certainly was not "the first object to enter space" (the best claim for that honor probably goes to the Aerobee second stage on that 1949 Bumber-WAC launch from White Sands), it would have been both the first man-made object to escape from Earth and the first one to hit solar escape velocity.

Moreover, in (I believe) Nov. 1957, a small suborbital research rocket was launched to detonate, at high altitude, a grenade stuffed with little metal pellets to simulate micrometeoroids entering the atmosphere; and photos indicated that at least two of them went upwards at more than escape velocity, and that some portion of them likely survived the air friction.
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tty
post Jan 3 2006, 10:27 PM
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QUOTE (BruceMoomaw @ Jan 3 2006, 09:36 PM)
I first read about the manhole cover years ago in a letter to "Smithsonian Air & Space Magazine".  Since it weighed several hundred km, there's an excellent chance that some of it survived its trip through the atmosphere -- and while it certainly was not "the first object to enter space" (the best claim for that honor probably goes to the Aerobee second stage on that 1949 Bumer-WAC launch from White Sands), it would have been both the first man-made object to escape from Earth and the first one to hit solar escape velocity.
*


The second stage of the Bumper WAC was a WAC Corporal - not an Aerobee. The Bumper WAC is often claimed as the first two stage rocket but it wasn't, since the original WAC Corporal itself was actually two-stage with a Tiny Tim solid booster. And in any case the german 1944 Rheinbote artillery rocket was four stage! As a matter of fact it had a somewhat higher top speed than the A4 (V 2) and if the germans ever launched one straight up it was probably the first thing to reach space.

tty
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dvandorn
post Jan 3 2006, 11:28 PM
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QUOTE (Bob Shaw @ Jan 3 2006, 07:40 AM)
...Shuttle ETs have gone into orbit several times, but following an orbit which has a perigee below the surface of the Earth (that's why the OMS fires after ET Sep, to circularise the orbit of the shuttle itself).
*

That used to be the case. But over the past several years of Shuttle flight operations, more and more of the launches are "SSME direct-to-orbit", in which the entire stack -- orbiter *and* ET -- are placed into a stable (albeit somewhat low) orbit. No OMS burns required during the first orbit to maintain a safe orbit.

This started when the Shuttle needed to get the maximum cargo possible up into the ISS orbit. Adding some SSME delta-V made it possible to get those big components, like Destiny and the solar arrays, up to ISS.

-the other Doug


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“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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ljk4-1
post Jan 4 2006, 03:20 AM
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QUOTE (tty @ Jan 3 2006, 05:27 PM)
The second stage of the Bumper WAC was a WAC Corporal - not an Aerobee. The Bumper WAC is often claimed as the first two stage rocket but it wasn't, since the original WAC Corporal itself was actually two-stage with a Tiny Tim solid booster. And in any case the german 1944 Rheinbote artillery rocket was four stage! As a matter of fact it had a somewhat higher top speed than the A4 (V 2) and if the germans ever launched one straight up it was probably the first thing to reach space.

tty
*


Correct me if this is apocryphyl, but didn't von Braun say "Today the spaceship was born" after the first successful V-2 launch in 1942?


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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DDAVIS
post Jan 4 2006, 03:34 AM
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[quote=ljk4-1,Jan 4 2006, 03:20 AM]
Correct me if this is apocryphyl, but didn't von Braun say "Today the spaceship was born" after the first successful V-2 launch in 1942?

It was said by Dornberger:

http://www.donaldedavis.com/PARTS/V-2.html

Don
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tasp
post Jan 4 2006, 03:54 AM
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I probably won't field any questions as to how I know this, but near the earth's surface where the atmosphere is densest, a 'typical' manhole cover, dropped edge on from a height of roughly 100 feet is aerodynamically stable till impact with a cement sidewalk.

Upon emerging from the hole, if the cover can be shown to have been edge on to the oncoming slipstream, might there be hope that a significant fraction of it survived to 200 km?

rolleyes.gif
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tty
post Jan 4 2006, 07:13 AM
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What is the stagnation temperature in front of a generic manhole cover moving at 60 kms-1 through a standard atmosphere? The answer doesn't seem to be in the literature. Do we have a good aerodynamicist among the members? A ballpark guess would be well over 10,000 K. blink.gif

tty
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edstrick
post Jan 4 2006, 10:06 AM
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"What can you say about chocolate-coated manhole covers?"

<grin>

What's that line from?
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dvandorn
post Jan 4 2006, 05:39 PM
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Ed, that's a Larry Niven short story, called (IIRC) "What Can You Say About Chocolate-Covered Manhole Covers?"

-the other Doug


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“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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tty
post Jan 4 2006, 05:57 PM
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QUOTE (edstrick @ Jan 4 2006, 12:06 PM)
"What can you say about chocolate-coated manhole covers?"


"It's the only thing on this world that we know we can eat" smile.gif

tty
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nprev
post Jan 5 2006, 08:14 AM
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QUOTE (tty @ Jan 4 2006, 10:57 AM)
"It's the only thing on this world that we know we can eat" smile.gif

tty
*


"That one fell pretty flat. What can you say about chocolate covered manhole covers?" tongue.gif


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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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edstrick
post Jan 5 2006, 08:28 AM
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DVandorn wins the keg of Geritol Beer for getting the answer., and without checking the text (20+ years since I read it), I believe that's the last or one of the last lines in the story that TTY posted. <grin>
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ljk4-1
post Jan 26 2006, 05:28 AM
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Sputnik-3, its flight and radio systems

http://www.svengrahn.pp.se/radioind/Sput3r.../Sput3radio.htm


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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ljk4-1
post Feb 9 2006, 02:00 PM
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Includes discussion of the fact that no one actually said "Goldstone has the bird!" in regards to the launch of Explorer 1 in 1958.


Apocrypha now: no go for seven orbits
---

One of the commonly-accepted "truths" of the history of the American
space program is that a potential heat shield problem caused John
Glenn's historic Mercury flight to be cut from seven orbits to
three. Dwayne Day digs into the historical record to expose that
myth and show that Glenn's flight was intended to be three orbits all
along.

http://www.thespacereview.com/article/550/1


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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