Mass of disposed items

"bob haller" wrote in message
...
my comments were that with a target as big as the pacific in a realitvely
lightweight vehicle with no heat shielding.. little but structural parts
probably survive reentry.

Totally ignoring that an uncontrollable Progress is likely to hit ISS before
it even gets a chance to perform the de-orbit burn. If the CG is out of
limits, you're screwed.

Jeff
--
Remove icky phrase from email address to get a valid address.

Sorry, but you fail Spacecraft Attitude Dynamics and Orbital Mechanics (both
500 level courses I took at Purdue many years ago). The prof used to work
for JPL and her classes were likely the hardest I took at Purdue (B.S. in
Aerospace Engineering).

If you can't control the spacecraft due to the CG being way off (i.e. the
attitude control system is simply unable to cope), your chances of backing
Progress away from ISS safely diminish.

Here's an early example. Weld a 100 foot beam horizontally on helicopter
(one end attached to the landing gear, the other placed 100 feet to the
right side) and put a sizable weight at the end of the beam. Even if the
weight of this contraption is within the helicopter's lifting limits, you've
surely exceeded the CG limits.

There is no way you could safely take off, you'd flip over on your right
side and not only destroy the helicopter, but would destroy anything else on
the ground that's nearby.

Essentially, that's what could happen with a Progress if the CG is out of
limits. It could flip end over end and hit ISS.

Jeff
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Thanks thats a great explnation and I greatly appreciate it. obviously it must
be done carefully.....

I stand corrected
HAVE A GREAT DAY!

(bob haller) wrote in message ...

has anyone studied what survives specifically a progress de orbit?

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

-Mark Martin

has anyone studied what survives specifically a progress de orbit?

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

-Mark Martin

thats true but certinally given its planned bath, deorbit speed etc, and the
mass of the vehicle and contents it must be possible to say.....

these paper products have no chance or survival while these gimbal bolts
probably will?

I assume the path is designed to drop the stuff in the center of the ocean
while burning up as much as possible?

did they ever recover skylabs film safe? it was predicted to survive. heavy
lead lined etc etc....
HAVE A GREAT DAY!

(bob haller) wrote in message ...

has anyone studied what survives specifically a progress de orbit?

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

-Mark Martin

thats true but certinally given its planned bath, deorbit speed etc, and the
mass of the vehicle and contents it must be possible to say.....

these paper products have no chance or survival while these gimbal bolts
probably will?

I assume the path is designed to drop the stuff in the center of the ocean
while burning up as much as possible?

Problem is collecting samples of the stuff that makes it all the
way down. It's deliberately dumped far away from people. And it all
falls within a pretty sizable landing ellipse. So where do you start
looking within that ellipse? The objects which immediately sink will
*never* be sampled, so the only things you'll ever find are the things
which float. But how large will they be? How much total will there be
of it? It'll be like scattering a few Hefty-Bags worth of trash onto
the churning ocean, and hoping to go back in a few days to find any of
it.

did they ever recover skylabs film safe? it was predicted to survive. heavy
lead lined etc etc....

Don't know. Don't think so. Everything recovered from Skylab
crashed onto western Australia. If the safe was so much more
mass-dense than the other stuff, its energy loss curve may have been
much more gradual. It might've landed way downrange of the other
things.

-Mark Martin

"Mark Martin" wrote in message
om...
(bob haller) wrote in message
...

has anyone studied what survives specifically a progress de orbit?

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

While this is true, I wouldn't be surprised if the Russians (initially
Soviets) didn't use radar to track at least the first few Progress vessels
as they destructively re-entered. A tracking ship or two could have done
this, at least to help characterize the size and speed of the pieces as they
fell into the ocean.

You'd surely have to ask the Russians, and they may not want to talk about
the details.



Jeff
--
Remove icky phrase from email address to get a valid address.

"Jeff Findley" wrote in message . ..

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

While this is true, I wouldn't be surprised if the Russians (initially
Soviets) didn't use radar to track at least the first few Progress vessels
as they destructively re-entered. A tracking ship or two could have done
this, at least to help characterize the size and speed of the pieces as they
fell into the ocean.

Yeah, you're probably right about that. For that matter, it
wouldn't surprise me if U.S. intelligence did the same to a lesser
degree. Classified trash.

-Mark Martin

Mark Martin wrote:

(bob haller) wrote in message ...

has anyone studied what survives specifically a progress de orbit?

How would they? By definition the re-entry path is engineered to
drop all leftovers into the ocean.

-Mark Martin

Damn, maybe we should get Bob in a boat at the drop zone.
He can take us some notes.

Sam

Damn, maybe we should get Bob in a boat at the drop zone.
He can take us some notes.

Sam


hey russia must know roughly what survives intact. At the time of the Mir
deorbit it was stated the following are expected to survive, and a list.

has anyone gone looking for Mir remants?
HAVE A GREAT DAY!