Re: [Phys-l] ISS orbit

["Robert Cohen" <Robert.Cohen@po-box.esu.edu>]

Perhaps you can look up the U.S. Standard Atmosphere to get an estimate.
For example, if you go to <http://www.digitaldutch.com/atmoscalc/> and
plug in 31000 m as the height, you'll get a pressure of 1008 Pa.  That
is 1% of the pressure at the surface, which means that ~99% of the air
is below that altitude (assuming hydrostatic balance).

Robert A. Cohen, Department of Physics, East Stroudsburg University 
570.422.3428   rcohen@esu.edu    http://www.esu.edu/~bbq 


-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Anthony
Lapinski
Sent: Tuesday, November 15, 2011 1:01 PM
To: phys-l@carnot.physics.buffalo.edu
Subject: Re: [Phys-l] ISS orbit

Thanks for this link -- very informative and detailed. 

I guess what I'd like to know is a formula/relationship between air
altitude and density. For example, at what altitude is 99% of the air
below it? Can this somehow be measured, or only the effects from
satellite drag? And what minimum altitude must a satellite be to have no
orbital decay (like a geostationary orbit)?

betwys1@sbcglobal.net writes:
> On 11/15/2011 5:10 AM, Anthony Lapinski wrote:
> > I'm teaching about circular motion and gravitation and mentioned in
> class
> > about the space shuttle and International Space Station. After 
> > searching online, I found that the ISS orbits at an altitude of about

> > 350 km. I
> was
> > surprised to learn that it loses about 100 m each day due to 
> > atmospheric friction, and it has to be boosted to higher orbit 
> > several times each year. I always thought that the atmosphere 
> > extended up to about 70
> miles,
> > so how does the ISS orbit decay? And is this true for all orbiting 
> > satellites? Does it have to do with the Sun heating/expanding the 
> > upper layers of the atmosphere? I remember a satellite entered our 
> > atmosphere
> a
> > few weeks ago, and the famous Skylab satellite burning up decades
ago.
> > _______________________________________________
> > Forum for Physics Educators
> > Phys-l@carnot.physics.buffalo.edu
> > https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
> This note appears to speak to the issue. For some reason it assailed me

> with unprecedented soporificity, so I may be mistaken to offer that it 
> stresses the role of temperature and Solar activity on a satellite 
> sailing at 350 km altitude.
>
> http://cosmos.phy.tufts.edu/~zirbel/laboratories/Satellite.pdf
>
> Brian W
> _______________________________________________
> Forum for Physics Educators
> Phys-l@carnot.physics.buffalo.edu
> https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l


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