As I predicted, space X to get military contracts:)

In article 0afe038b-ae0a-40b0-9647-152f44bf3f13
@f19g2000vbv.googlegroups.com, says...
such a large object in orbit wll almost certinally tumble without
station keeping. the solar panel drag will cause tumbling
eventually....

Depends. Ever heard of gravity gradient stabilization? If not, try
taking a 500 level Spacecraft Attitude Dynamics class at an aerospace
engineering college and get back to us when you finally get a clue.

heck even skylab tumbled. in skylabs case once controllers got it back
under nominal control, they stoped the tumble to get it in as log a
drag position as possible to try and direct it to a water impact, and
only ordered it to tumble just before decay....

One data point proves nothing.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"Jeff Findley" wrote in message
...

In article 0afe038b-ae0a-40b0-9647-152f44bf3f13
, says...
such a large object in orbit wll almost certinally tumble without
station keeping. the solar panel drag will cause tumbling
eventually....

Depends. Ever heard of gravity gradient stabilization? If not, try
taking a 500 level Spacecraft Attitude Dynamics class at an aerospace
engineering college and get back to us when you finally get a clue.

heck even skylab tumbled. in skylabs case once controllers got it back
under nominal control, they stoped the tumble to get it in as log a
drag position as possible to try and direct it to a water impact, and
only ordered it to tumble just before decay....

One data point proves nothing.


To be fair, Salyut 7 also tumbled.

But, Bob might be surprised to learn that this didn't prevent cosmonauts
from docking.

Seriously, Bob, the sky is falling. Go hide in a cave. Oh wait, please
don't do that. I don't want to run into you there on my next caving trip.


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

heck even skylab tumbled. in skylabs case once controllers got it back
under nominal control, they stoped the tumble to get it in as log a
drag position as possible to try and direct it to a water impact, and
only ordered it to tumble just before decay....

Things don't just start tumbling on their own, Bobbert. *Jesus, I wish
you'd bloody learn something about physics if you're going to continue
to expound here. *I'd think even a high school level course would
prevent you from saying some of the stupider things you've emitted
over the years.


Skyl;ab tumbled, at first because there weas no control and no station
keeping it was abandoned.

articles on the net say tumbling is common with large solar panels
that provide drag that induces tumbling if theres no station keeping.
its possible to dock with a tumbling vehicle provided both have the
same tumble rate. obviously larger vehicles will be harder, espically
if while attempting to match for docking a solar panel or other part
hits the approaching vehicle....

one day a emergency supplies to orbit may be needed for any reason and
fred will look stuid again, but he is used to that.......

the better the backups and redundiencies the safer the operations

On Dec 26, 7:53*pm, Fred J. McCall wrote:
bob haller wrote:

heck even skylab tumbled. in skylabs case once controllers got it back
under nominal control, they stoped the tumble to get it in as log a
drag position as possible to try and direct it to a water impact, and
only ordered it to tumble just before decay....

Things don't just start tumbling on their own, Bobbert. *Jesus, I wish
you'd bloody learn something about physics if you're going to continue
to expound here. *I'd think even a high school level course would
prevent you from saying some of the stupider things you've emitted
over the years.

Skyl;ab tumbled, at first because there weas no control and no station
keeping it was abandoned.

You've got your timing mangled. *Skylab tumbled BECAUSE IT REENTERED.
That happened years after the last flight. *So an 'emergency launch
capability' than can launch within a year or so would have been more
than adequate. *However, at the time, we didn't have one because the
Shuttle scheduled slipped.



articles on the net say tumbling is common with large solar panels
that provide drag that induces tumbling if theres no station keeping.
its possible to dock with a tumbling vehicle provided both have the
same tumble rate. obviously larger vehicles will be harder, espically
if while attempting to match for docking a solar panel or other part
hits the approaching vehicle....

It would appear that your uncited "articles on the net" have got it
wrong. *Drag is pretty insignificant unless you measure it over YEARS
or you're already so low you're going to reenter.



one day a emergency supplies to orbit may be needed for any reason and
fred will look stuid again, but he is used to that.......

And some day monkeys may fly out my butt, too.



the better the backups and redundiencies the safer the operations

No. *UNNECESSARY expenditures, like you keep calling for, don't make
missions safer at all. *They merely waste money so that missions don't
happen.

Grow a pair, Bobbert....

--
"Insisting on perfect safety is for people who don't have the balls to
* * live in the real world."
* * * * * * * * * * * -- Mary Shafer, NASA Dryden

skylab tumbled slowly after being abandoned, actually a slow tumble
with roll. just one receiver, tied directly to the solar panels was
left on in case nasa ever wanted to contact the station after
abandonment.... after its last mission they didnt plan reuse
ever...heck nasa even had a space certified additional station with
boosters left over and didnt bother launching it. the boosters were
left outside to rot, the station cut open for display at the
smithsonian.

all the money was sucked up for shuttle,,,,,,,

earths atmosphere expanded casing additional drag

when nasa realized the station was going to re enter, they radioed it
to see what shape it was in....

the unstable power caused the primary channel to fail, the station
didnt like unstable power, so they sent skylab one command every time
they could communicate, charge batteriess.

eventually charge level got good enough to regain control and station
keeping....

nasa only ordered skylab to tumble during its last orbit or two, so it
would dig into the atmosphere and re enter over water.....

this all from memory, it was a amazing effort at the time

In article 6021ff7c-d755-4911-a34d-f7cbcd8036c7
@n9g2000vbv.googlegroups.com, says...

skylab tumbled slowly after being abandoned, actually a slow tumble
with roll. just one receiver, tied directly to the solar panels was
left on in case nasa ever wanted to contact the station after
abandonment.... after its last mission they didnt plan reuse
ever...heck nasa even had a space certified additional station with
boosters left over and didnt bother launching it. the boosters were
left outside to rot, the station cut open for display at the
smithsonian.

What you say is not correct.

http://history.nasa.gov/SP-4011/part3c.htm

Following the final manned phase of the Skylab mission,
ground controllers performed some engineering tests of
certain Skylab systems-tests that ground personnel were
reluctant to do while men were aboard. Results from these
tests will help to determine causes of failures during
the mission and to obtain data on long term degradation
of space systems.

So, Skylab continued to be commanded and controlled from the ground for
some time after the last crew left. The crew being gone did not impact
its ability to be commanded from the ground.

Upon completion of the engineering tests, Skylab was
positioned into a stable attitude and systems were
shut down.

What caused Skylab to tumble was drag from the earth's atmosphere over a
period of time when it was not being actively controlled from the
ground. It did *not* start tumbling because it was unmanned. It was a
choice not to continue to actively control it, not something that
happened simply because it was unmanned.

Your assertion that ISS will somehow tumble out of control the minute
the crew leaves it is completely unsupported. In fact, the assertion is
counter to both physics and history.

all the money was sucked up for shuttle,,,,,,,

earths atmosphere expanded casing additional drag

As Skylab's orbit fell and atmospheric drag increased over the years, it
started to tumble. If it had remained under ground control, it's
extremely doubtful it would have tumbled *at all*.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Dec 27, 8:38*am, Jeff Findley wrote:
In article 6021ff7c-d755-4911-a34d-f7cbcd8036c7
@n9g2000vbv.googlegroups.com, says...



skylab tumbled slowly after being abandoned, actually a slow tumble
with roll. just one receiver, tied directly to the solar panels was
left on in case nasa ever wanted to contact the station after
abandonment.... after its last mission they didnt plan reuse
ever...heck nasa even had a space certified additional station with
boosters left over and didnt bother launching it. the boosters were
left outside to rot, the station cut open for display at the
smithsonian.

What you say is not correct.

http://history.nasa.gov/SP-4011/part3c.htm

* *Following the final manned phase of the Skylab mission,
* *ground controllers performed some engineering tests of
* *certain Skylab systems-tests that ground personnel were
* *reluctant to do while men were aboard. Results from these
* *tests will help to determine causes of failures during
* *the mission and to obtain data on long term degradation
* *of space systems.

So, Skylab continued to be commanded and controlled from the ground for
some time after the last crew left. *The crew being gone did not impact
its ability to be commanded from the ground.

* *Upon completion of the engineering tests, Skylab was
* *positioned into a stable attitude and systems were
* *shut down.

What caused Skylab to tumble was drag from the earth's atmosphere over a
period of time when it was not being actively controlled from the
ground. *It did *not* start tumbling because it was unmanned. *It was a
choice not to continue to actively control it, not something that
happened simply because it was unmanned.

Your assertion that ISS will somehow tumble out of control the minute
the crew leaves it is completely unsupported. *In fact, the assertion is
counter to both physics and history.

all the money was sucked up for shuttle,,,,,,,

earths atmosphere expanded casing additional drag

As Skylab's orbit fell and atmospheric drag increased over the years, it
started to tumble. *If it had remained under ground control, it's
extremely doubtful it would have tumbled *at all*.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

it wasnt under control for very long and nasa never intended reuseat
the time it was abandoned....... only later with money tight was that
idea floated. many systems like cooling werent designed for in orbit
service. skylab design was a throw away station..

at ,most nasa was going to visit the station and raise its orbit, the
last crew left a christmas tree of stuff for a later visiting crew.....

In article 6406bb1f-3dc2-43bd-a3b8-008adb13c544
@hf3g2000vbb.googlegroups.com, says...

On Dec 27, 8:38*am, Jeff Findley wrote:
In article 6021ff7c-d755-4911-a34d-f7cbcd8036c7
@n9g2000vbv.googlegroups.com, says...



skylab tumbled slowly after being abandoned, actually a slow tumble
with roll. just one receiver, tied directly to the solar panels was
left on in case nasa ever wanted to contact the station after
abandonment.... after its last mission they didnt plan reuse
ever...heck nasa even had a space certified additional station with
boosters left over and didnt bother launching it. the boosters were
left outside to rot, the station cut open for display at the
smithsonian.

What you say is not correct.

http://history.nasa.gov/SP-4011/part3c.htm

* *Following the final manned phase of the Skylab mission,
* *ground controllers performed some engineering tests of
* *certain Skylab systems-tests that ground personnel were
* *reluctant to do while men were aboard. Results from these
* *tests will help to determine causes of failures during
* *the mission and to obtain data on long term degradation
* *of space systems.

So, Skylab continued to be commanded and controlled from the ground for
some time after the last crew left. *The crew being gone did not impact
its ability to be commanded from the ground.

* *Upon completion of the engineering tests, Skylab was
* *positioned into a stable attitude and systems were
* *shut down.

What caused Skylab to tumble was drag from the earth's atmosphere over a
period of time when it was not being actively controlled from the
ground. *It did *not* start tumbling because it was unmanned. *It was a
choice not to continue to actively control it, not something that
happened simply because it was unmanned.

Your assertion that ISS will somehow tumble out of control the minute
the crew leaves it is completely unsupported. *In fact, the assertion is
counter to both physics and history.

all the money was sucked up for shuttle,,,,,,,

earths atmosphere expanded casing additional drag

As Skylab's orbit fell and atmospheric drag increased over the years, it
started to tumble. *If it had remained under ground control, it's
extremely doubtful it would have tumbled *at all*.

it wasnt under control for very long and nasa never intended reuseat
the time it was abandoned....... only later with money tight was that
idea floated. many systems like cooling werent designed for in orbit
service. skylab design was a throw away station..

at ,most nasa was going to visit the station and raise its orbit, the
last crew left a christmas tree of stuff for a later visiting crew.....

None of this has anything to do with Skylab tumbling in orbit after the
final manned mission. The fact remains that control was still possible
from the ground at the end of the unmanned test phase of the program.
The historic fact that control of Skylab was regained despite the
tumbling supports this assertion. The fact is that being unmanned had
nothing to do with why Skylab tumbled.

Your attempt to use the history of Skylab to support your assertion that
an unmanned ISS will tumble out of control has failed miserably.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Dec 27, 11:27*am, Fred J. McCall wrote:
bob haller wrote:
On Dec 27, 8:38*am, Jeff Findley wrote:
In article 6021ff7c-d755-4911-a34d-f7cbcd8036c7
@n9g2000vbv.googlegroups.com, says...

skylab tumbled slowly after being abandoned, actually a slow tumble
with roll. just one receiver, tied directly to the solar panels was
left on in case nasa ever wanted to contact the station after
abandonment.... after its last mission they didnt plan reuse
ever...heck nasa even had a space certified additional station with
boosters left over and didnt bother launching it. the boosters were
left outside to rot, the station cut open for display at the
smithsonian.

What you say is not correct.

http://history.nasa.gov/SP-4011/part3c.htm

* *Following the final manned phase of the Skylab mission,
* *ground controllers performed some engineering tests of
* *certain Skylab systems-tests that ground personnel were
* *reluctant to do while men were aboard. Results from these
* *tests will help to determine causes of failures during
* *the mission and to obtain data on long term degradation
* *of space systems.

So, Skylab continued to be commanded and controlled from the ground for
some time after the last crew left. *The crew being gone did not impact
its ability to be commanded from the ground.

* *Upon completion of the engineering tests, Skylab was
* *positioned into a stable attitude and systems were
* *shut down.

What caused Skylab to tumble was drag from the earth's atmosphere over a
period of time when it was not being actively controlled from the
ground. *It did *not* start tumbling because it was unmanned. *It was a
choice not to continue to actively control it, not something that
happened simply because it was unmanned.

Your assertion that ISS will somehow tumble out of control the minute
the crew leaves it is completely unsupported. *In fact, the assertion is
counter to both physics and history.

all the money was sucked up for shuttle,,,,,,,

earths atmosphere expanded casing additional drag

As Skylab's orbit fell and atmospheric drag increased over the years, it
started to tumble. *If it had remained under ground control, it's
extremely doubtful it would have tumbled *at all*.

it wasnt under control for very long ...

Yeah, it was only under command whenever they wanted it to be.



...and nasa never intended reuseat
the time it was abandoned.......

Irrelevant to all your prior claims.



only later with money tight was that
idea floated. many systems like cooling werent designed for in orbit
service. skylab design was a throw away station..

at ,most nasa was going to visit the station and raise its orbit, the
last crew left a christmas tree of stuff for a later visiting crew.....

Still all irrelevant to your prior claims about 'tumbling' and 'out of
control'. *It took it YEARS to come down after it was abandoned, so an
'urgent emergency launch' system that could launch in a year or so
would have been more than adequate to the task.

So why do we need your proposed 'urgent launch' system, again?

--
"Some people get lost in thought because it's such unfamiliar
*territory."
* * * * * * * * * * * * * * * * * * * --G. Behn

a non controlled ISS will tumble because of varying drag largely from
solar panels...... but also from its general shape

station needs regular re boosts because of atmosphere drag at it
realtively low orbit.... choosen so both russia and US can reach it.
the orbit selected was a compromise that really constrained shuttle,
most modules were lofted empty because of weight, later missions took
the racks

In article 79c8cd29-02da-4198-94e2-
, says...

On Dec 27, 11:27*am, Fred J. McCall wrote:

Still all irrelevant to your prior claims about 'tumbling' and 'out of
control'. *It took it YEARS to come down after it was abandoned, so an
'urgent emergency launch' system that could launch in a year or so
would have been more than adequate to the task.

So why do we need your proposed 'urgent launch' system, again?

a non controlled ISS will tumble because of varying drag largely from
solar panels...... but also from its general shape

You've certainly not "done the math" to prove this assertion. Do you
have a cite from someone who has "done the math"? Also, just how long
would it take to build up a Salyut 7 sort of "tumble"?

And do note that in the case of Salyut 7, a Soyuz was still able to
successfully dock to the powerless, tumbling, station almost a full *3
months* after ground control lost contact with it. Also note that it
didn't "fall out of the sky" during that time, even though it was
without power and could not re-boost itself! Cite:

http://en.wikipedia.org/wiki/Salyut_7

Again, history does *not* support your "quick launch" argument in the
least.

station needs regular re boosts because of atmosphere drag at it
realtively low orbit.... choosen so both russia and US can reach it.
the orbit selected was a compromise that really constrained shuttle,
most modules were lofted empty because of weight, later missions took
the racks

Even if all re-boost capability were lost, ISS would take quite a long
time to reenter. Cite:

http://spacemath.gsfc.nasa.gov/weekly/WeekAK.pdf

Worst case scenario (high solar activity year like the year 2000) would
still take ISS *over a year* for its orbit to decay.

In the real world, "quick launch" is simply *not* needed for this,
highly unlikely, scenario.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Dec 27, 3:46*pm, Jeff Findley wrote:
In article 79c8cd29-02da-4198-94e2-
, says...



On Dec 27, 11:27*am, Fred J. McCall wrote:

Still all irrelevant to your prior claims about 'tumbling' and 'out of
control'. *It took it YEARS to come down after it was abandoned, so an
'urgent emergency launch' system that could launch in a year or so
would have been more than adequate to the task.

So why do we need your proposed 'urgent launch' system, again?

a non controlled ISS will tumble because of varying drag largely from
solar panels...... but also from its general shape

You've certainly not "done the math" to prove this assertion. *Do you
have a cite from someone who has "done the math"? *Also, just how long
would it take to build up a Salyut 7 sort of "tumble"?

And do note that in the case of Salyut 7, a Soyuz was still able to
successfully dock to the powerless, tumbling, station almost a full *3
months* after ground control lost contact with it. *Also note that it
didn't "fall out of the sky" during that time, even though it was
without power and could not re-boost itself! *Cite:

* *http://en.wikipedia.org/wiki/Salyut_7

Again, history does *not* support your "quick launch" argument in the
least.

station needs regular re boosts because of atmosphere drag at it
realtively low orbit.... choosen so both russia and US can reach it.
the orbit selected was a compromise that really constrained shuttle,
most modules were lofted empty because of weight, later missions took
the racks

Even if all re-boost capability were lost, ISS would take quite a long
time to reenter. *Cite:

* *http://spacemath.gsfc.nasa.gov/weekly/WeekAK.pdf

Worst case scenario (high solar activity year like the year 2000) would
still take ISS *over a year* for its orbit to decay.

In the real world, "quick launch" is simply *not* needed for this,
highly unlikely, scenario.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

once the tumble is bad enough it will be impossible to dock with ISS,
the large structure could hit the vehicle aattempting to dock, plus if
the tumble gets bad enough parts will rip off the station, think
modules.

now i hope nothing bad ever occurs, but if and when it does we can
discuss this again..

personally given russias recent record i think a soyuz failure should
be expected..... now wether fast launch will help who knows but it
sure cant hurt.......