Mass of disposed items

When they load a Progress with rubbish, do the crewmembers have to calculate
total waste mass to allow ground people to calculate re-entry parameters ?

Or do they just load the puppy up to the brim, and once undocked, the ground
controllers fire an engine for a set number of seconds and then calaculate
mass based on acceleration telemetry ?

If the crew must calculate mass of items loaded into Progress, how is this
done ? Just estimates ? Would it require such precision that even human waste
bags would need to have their mass measured ? Or would they have general
statistical mass numbers that are used for regularly dumped waste, alleviating
the need to measure each item ?

John Doe wrote in message ...
When they load a Progress with rubbish, do the crewmembers have to calculate
total waste mass to allow ground people to calculate re-entry parameters ?

From previous status reports, it sounds like there are quite detailed
plans sent up from the ground. My understanding is that this is to
ensure the CG is where the flight control system expects it to be.
They most likely also try to make maximum use of the available volume.

So the ground has a list of things that need to be tossed, works out
where they should be, and sends that up to the crew.

I can't find it ATM, but I recall one of the previous crewmembers who
made public 'letters home' describing it in some detail.

On 16 Aug 2004 15:24:32 -0700, (hop) wrote:

John Doe wrote in message ...
When they load a Progress with rubbish, do the crewmembers have to calculate
total waste mass to allow ground people to calculate re-entry parameters ?

p.s. The Crew loads the Progress while folks on the ground runs all
the numbers... ;-)

Andy

From previous status reports, it sounds like there are quite detailed
plans sent up from the ground. My understanding is that this is to
ensure the CG is where the flight control system expects it to be.
They most likely also try to make maximum use of the available volume.

So the ground has a list of things that need to be tossed, works out
where they should be, and sends that up to the crew.

I can't find it ATM, but I recall one of the previous crewmembers who
made public 'letters home' describing it in some detail.

Mass of disposed items
From:

given their target is so large I doubt its a real exact number.

anywhere in this section of the pacific will be fine, and besides most stuff
burns up anyway
HAVE A GREAT DAY!

"bob haller" wrote in message
...
Mass of disposed items
From:

given their target is so large I doubt its a real exact number.

anywhere in this section of the pacific will be fine, and besides most
stuff
burns up anyway

They have to have some idea of the mass and the distribution, otherwise the
CG of the Progress can be way off and that makes it difficult to control.
The Russians don't want to be responsible for another out of control
Progress damaging a space station, so I'd expect they keep a close eye on
this issue.

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

They have to have some idea of the mass and the distribution, otherwise the
CG of the Progress can be way off and that makes it difficult to control.
The Russians don't want to be responsible for another out of control
Progress damaging a space station, so I'd expect they keep a close eye on
this issue.

Jeff

Wellon its last trip away from the station it probably isnt a big concern since
its on the way to the pacific and thats a big gaerbage can//
HAVE A GREAT DAY!

(bob haller) wrote in
:

They have to have some idea of the mass and the distribution,
otherwise the CG of the Progress can be way off and that makes it
difficult to control. The Russians don't want to be responsible for
another out of control Progress damaging a space station, so I'd
expect they keep a close eye on this issue.

Jeff

Wellon its last trip away from the station it probably isnt a big
concern since its on the way to the pacific and thats a big gaerbage

Typical "foam logic" from hallerb. The Progress isn't on its way to the
Pacific until after the deorbit burn. The deorbit burn must be performed in
the correct attitude. Progress can't maneuver to the correct attitude
unless its CG is within limits.

It's a good thing you don't have to work on a machine more complex than a
copy machine, Bob.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

For one that is constantly goes on about SAFETY FIRST (or is that SW#AFety
FurSTe) I would expect you to take a more conservative attitude (pun
intended). Now, what does it take to ensure that the craft is stable in all
axes? Are there requirements for that? If so, do you propose waiving or
ignoring such requirements? Are there mass limits to ensure that it can be
put down in footprint where it's guaranteed to be safe? What if they can't
guarantee that, it crashes through someone's roof and deposits "waste" on
someone dinner table?


anywhere in this section of the pacific will be fine, and besides most
stuff burns up anyway

Is that the correct attitude from one who is so safety concious? I shall
point you to the events of February 1, 2003, and do note that a good amount
of
the Orbiter did in fact make it to the ground. Indeed, videotapes could be
played, data tapes contained important flight data, as examples of items that

survived the descent. And wasn't it you who rants constantly about the
danger
of killing people from debris?

I find your attitude of arm waving and ignoring safety to be just one more
example of your hypocrisy and moral bankruptcy.


HAVE A GREAT DAY!

--
rk, Just an OldEngineer

The data tapes and parts of columbia rthat survived would never have done so
except the columbia protected them for a good bit of their descent.

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.

has anyone studued that?



HAVE A GREAT DAY!

earth [1]. It is estimated that between 10% and
40% of a spacecraft will survive reentry.

"THE REENTRY BREAKUP RECORDER: A “BLACK BOX� FOR SPACE HARDWARE"
V. Kapoor and W. Ailor
Paper SSC03-VIII-3
17th Annual AIAA/USC Conference on Small Satellites

Now, my self-contradicting intellecutally dishonest friend, from what I know
about spacecraft, I can't think of the 10% to 40% that I would want to get on

the head with. After all, Professor, look at what a little piece of foam can


foam on launch is one thing, very different on reentry

has anyone studied what survives specifically a progress de orbit?

HAVE A GREAT DAY!

"bob haller" wrote in message
...


They have to have some idea of the mass and the distribution, otherwise
the
CG of the Progress can be way off and that makes it difficult to control.
The Russians don't want to be responsible for another out of control
Progress damaging a space station, so I'd expect they keep a close eye on
this issue.

Wellon its last trip away from the station it probably isnt a big concern
since
its on the way to the pacific and thats a big gaerbage can//

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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