Re: [amsat-bb] satellite propulsion thrust equations

[Robert McGwier <rwmcgwier@xxxxxxxxxxx>]

While not at its peak intensity, the radiation environment would be 
intense and I think your bird would spend more time in this area than a 
Phase 3 HEO.  We would have to do some detailed calculations but my 
intuition tells me the total dosage would be higher in your bird.   
Secondly,  the complexity in these satellites is not strictly the height 
of the orbit BUT the need to carry a propulsion at all.  Once you have 
crossed that threshold,  you might as well  optimize it for 
communications.  You have also discovered what a huge boost (pun 
intended) we are given in delta-V by getting off at GTO rather than at 
LEO altitudes. To get to your altitude the satellite would have to carry 
more fuel than a Phase 3 bird.  You would have to do two or more burns 
to raise the satellite to your orbital height.   Pick two points on your 
low orbit "180 degrees apart".  Align your rocket motor to the orbit at 
ONE of them.  You burn the motor to raise the altitude of the OTHER 
one.  Then you have to realign the satellite to orbit at the (now raised 
high) other point and do the same burn.  This is called a Hohman 
transfer and this exact scenario may be seen pictorially here:


http://liftoff.msfc.nasa.gov/academy/rocket_sci/satellites/hohmann.html

I view your MEOSAT mission as likely to be of greater complexity than 
Phase 3.  That said,  those of us who pretend to be rocket scientists,  
can always miss a good idea.

Bob
N4HY

-- 
Laziness is the number one inspiration for ingenuity.  Guilty as charged!
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org