[meteorite-list] Why did they not use the leftover propellant to heighten the orbit and push the rogue satellite into space?

[MexicoDoug]

oops:

"Slow it down 600 mph (to 16,400 mph) and burn up vs. speed it up 600
mph (to 17,600 mph) and get to an orbit 300 miles higher in altitude "

should read:

"Speed it up 600 mph (to 17,600 mph) and burn up vs. slow it down 600
mph (to 16,400 mph) and get to an orbit 300 miles higher in altitude "

****







-----Original Message-----
From: MexicoDoug <mexicodoug at aim.com>
To: jim_brady611 <jim_brady611 at o2.co.uk>; meteorite-list 
<meteorite-list at meteoritecentral.com>
Sent: Mon, Sep 12, 2011 12:32 pm
Subject: Re: [meteorite-list] Why did they not use the leftover 
propellant to heighten the orbit and push the rogue satellite into 
space?


Its going a bit under 17,000 mph.

Slow it down 600 mph (to 16,400 mph) and burn up vs. speed it up 600
mph (to 17,600 mph) and get to an orbit 300 miles higher in altitude
where gravity is still 75% what it is on earth's surface, and
completely lost control of what happens after that since there is no
fuel.

Move it down 300 miles and you've burnt up already in the atmosphere,
problem solved.

It was a 340 miles altitude.  The gravity is about 85% the value it is
on earth there, or about 8.31 m/s2 (at sea level g=9.8 m/s2).  They
wouldn't have blasted it out very far considering it weighs 12,500
pounds. Just because you have cleared the atmosphere with a heavy duty
launch vehicle doesn't mean you can just kick a little out of orbit
with the limited onboard fuel tank.

It is a misconception that there is no gravity in lower earth orbits.
This is because of the weightlessness.  The weightlessness is caused by
the orbit being a continuous free fall where roughly no energy is
required to maintain the orbit... just like being on a ride at an
amusement park you feel reduced gravity:
http://www.youtube.com/watch?v=4_YycEG4IkA&feature=related.

If the satellite tried to stand still, it would burn its fuel out
maintaining its altitude almost immediately.

Of course, they could have done as you said and used it to raise the
orbit until the fuel ran out.  Then there would be no risk from fuel
since it would be all gone.  But it would still be there as space junk,
intelligence information, and depending on how much propellant maybe
decaying sooner rather than later anyway.

Kindest wishes
Doug



-----Original Message-----
From: jim_brady611 <jim_brady611 at o2.co.uk>
To: meteorite-list <meteorite-list at meteoritecentral.com>
Sent: Mon, Sep 12, 2011 10:31 am
Subject: [meteorite-list] Why did they not use the leftover propellant
to heighten the orbit and push the rogue satellite into space?


from Rons original posting

"...When NASA
decommissioned the 12,500-pound satellite in 2005, controllers used
leftover propellant to lower its orbit from 340 miles to expedite its
re-entry. "

Surely if they are already in orbit it would only take a tiny amount
of fuel to push it completely out of orbit?


can someone enlighten me please? The only thing I can guess is that it
would endanger other satellites or possibly the ISS if they had
propelled it away instead of towards the Earth.

2424


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