Death Sentence for the Hubble?

"rk" wrote in message
...
http://www.nytimes.com/2005/02/13/opinion/13sun2.html?

Death Sentence for the Hubble?

snip

I think a controlled de-orbit makes a lot more sense than what Skylab got.

"Neil Gerace" wrote:

"rk" wrote in message
...
http://www.nytimes.com/2005/02/13/opinion/13sun2.html?

Death Sentence for the Hubble?

snip

I think a controlled de-orbit makes a lot more sense than what Skylab got.


Reality check: Skylab got a controlled de-orbit.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

In article , Derek Lyons
wrote:

"Neil Gerace" wrote:

"rk" wrote in message
...
http://www.nytimes.com/2005/02/13/opinion/13sun2.html?

Death Sentence for the Hubble?

snip

I think a controlled de-orbit makes a lot more sense than what Skylab got.


Reality check: Skylab got a controlled de-orbit.

Reality check check: Skylab's deorbit was not completely uncontrolled,
but they didn't intend to hit Australia. The same level of control
authority (changing its orientation and solar panel position) is
available for Hubble.

--
David M. Palmer (formerly @clark.net, @ematic.com)

"David M. Palmer" wrote in message
...

Reality check check: Skylab's deorbit was not completely uncontrolled,
but they didn't intend to hit Australia. The same level of control
authority (changing its orientation and solar panel position) is
available for Hubble.

And this time the appropriate people know that in advance, instead of
finding it out after four years of no attention with one year to do
something.

Neil Gerace wrote:
"David M. Palmer" wrote in message
...

Reality check check: Skylab's deorbit was not completely uncontrolled,
but they didn't intend to hit Australia. The same level of control
authority (changing its orientation and solar panel position) is
available for Hubble.

And this time the appropriate people know that in advance, instead of
finding it out after four years of no attention with one year to do
something.

That sort of control authority would be available only if decay
happens while those systems still work, which is not guaranteed.
I do note that HST has an independent last-ditch attitude-control
system (designed to stabilize it enough for capture, but not
operations), but if the batteries all go first, that may not be
available. Can't put my hands immediately on where the reserve
system gets its power...

Bill Keel

In article ,
Derek Lyons wrote:
I think a controlled de-orbit makes a lot more sense than what Skylab got.

Reality check: Skylab got a controlled de-orbit.

Controlled only in a rather loose sense -- controlled a little bit, by an
untried technique which had rather more effect than expected (delaying
reentry to be clear of the US east coast unexpectedly delayed it far
enough to hit western Australia).

The modern definition of "controlled de-orbit" is that it goes down where
and when you want it to, on a trajectory and to a target that minimize the
effect of remaining uncertainties.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"Derek Lyons" wrote in message
...

Reality check: Skylab got a controlled de-orbit.

Hardly. It didn't go down where the controllers wanted it to.

"Neil Gerace" wrote:

"Derek Lyons" wrote in message
...

Reality check: Skylab got a controlled de-orbit.

Hardly. It didn't go down where the controllers wanted it to.


Doesn't change the fact that it was controlled and not random.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Derek Lyons wrote:

Doesn't change the fact that it was controlled and not random.

One really needs to quantify randomness. If the process is completely
random, the correlation between desired and actual re-entry location for
all reasonable scenarios is 0. If control is perfect, the correlation
is 1.

In this case, it seems likely that correlation tended to the
lower half of the scale. That is, it was "influenced" more than it was
controlled.

--
Dave Michelson

"Derek Lyons" wrote in message
...

Doesn't change the fact that it was controlled and not random.

It was neither.