AW: [meteorite-list] Spaceflight and Meteoroids

From: <>
Date: Mon Jul 5 12:17:35 2004
Message-ID: <>

Walter and J?rn,

Nice passage and back of the envelope comparisons.

Just a comment on each from the Mexican jalape?o gallery in the grandstands,
while the US has stood tall these days, I don't think Nolan Ryan could even
throw a 200 mph fastball. The world record is close to 100 mph, so your
calculation needs to be adjusted by a factor of 4, the "baseball" now calculates to
900 grams.

An official baseball weighs 145 grams plus or minus 4 grams.

So make that the energy of over six Nolan Ryan pitches in one for your .01g

And a comment to Walter on terminology, of course you gracefully excused
Cooper's over use of the word meteorite, but in the case you mentioned "being hit
by "meteorites" on his Gemini flight"... if cows and dogs and planets and
comets and other meteoroids are hit by meteorites, why not a space ship orbiting

Saludos, Doug

Hello Walter and list,
This is a nice report by this Gemini astronaut. I have never heard about it
or any other report alike.
Interesting is the comparison of this meteoroid impact with a baseball
fastball. As a non-American, I am not at all an expert in baseball but if I assume
a fastball has 200 miles per hour at its best and the mass of the meteoroid
grain was 10 mg, the energy of this object would be comparable to a baseball of
225 grams in weight!
m1*v1^2 = m2*v2^2
where m1 = mass of meteoroid 0.01 grams,
m2= weight of baeball (I don't know!!!),
v1 = velocity of meteoroid (30,000 miles / hour),
v2 = velocity of baseball (200 miles/hour),
m2 = 0.01g * 30,000^2 / 200^2 = 225 grams
Considering this mass, it is not so surprising that such tiny meteoroid
particle caused so much sound on impact.
Joern Koblitz
MetBase Editor
The MetBase Library of Meteoritics and Planetary Sciences
Benquestrasse 27
D-28209 Bremen, Germany
phone: +49 421 24 100 24
fax: +49 421 168 2799
email: info at

-----Urspr?ngliche Nachricht-----
Von: branchw at [mailto:branchw at]
Gesendet: Montag, 5. Juli 2004 14:47
An: Meteorite List
Betreff: [meteorite-list] Spaceflight and Meteoroids

Hello Everyone,
I am an enthusiast of the US space program and I finally got around to
reading Gordon Cooper's book Leap of Faith. Cooper was the pilot of Faith 7, the
last Mercury flight and the command pilot of Gemini 5. On pages 125-126, he
talks about being hit by "meteorites" on his Gemini flight. I think his
description is interesting (overlookling innaccurate terminology). Does anyone else
know of any more reports by astronauts or cosmonauts of their spacecraft being
hit by meteoroids while in flight.
Here is the text:
We were told by astronomers to expect front-row seats for a regular meteorite
shower that occurs in the latter part of every August. It would be the frist
one to be observed by man from space. The first night of the shower was a
sight to behold - thousands of meteorites passing under our spacecraft as they
entered the Earth's atmosphere and burned up like falling stars.
We knew there was a chance that a meteorite might strike our spacecraft but
there was nothing we could do to prevent it and only hoped that if it happend
it would be a small one. We carried a patch kit with rubber plugs to repair
any tiny puncture holes (tiny was the operative word) to try to keep from losing
our cabin pressure. But we were not prepared for what it sounded like when
one actually hit.
A hard metallic BANG!
Pete and I both jumped.
It sounded like a major-league fastball hurled against the side of our
pacecraft, but we knew it was no bigger than a grain of sand. If the meteorite had
been anywhere near the size of a baseball, it would have gone right through
the side of the spacecraft - ending, in a nanosecond, oor mission and our lives.
Over the course of the next couple of days, we were struck four or five
times. When the spacecraft was dismantled upon it's return to the Cape - every
returning spacecraft was taken apart piece by piece as part of a total
engineering report to assess how it handled the stresses of flight - impresions were
found on the outside wall, as if someone had driven home an ice pick with a
hammer. The meteorites had actually reshaped the outer titanium wall of the
spacecraft, pushnig in the toughest metal known to man as much as a quarter -inch.
(Titanium takes more heat with less damage than any metal on Earth.) It
seemed unbelievable that such a mall particle had so much energy and caused so much
sound, but these cosmic fastballs were a bit faster than any Hall of Fame
pitcher's - a speed gun would have clocked them in the range of thirty thousand
miles per hour.

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