[eagle] Re: Eagle model

[Lee McLamb]

Just a reminder.  So far we've only seen Ken's preliminary analysis that 
covered a one year period.  While that interval is good for LEO missions and 
as a notional point to work from for GTO, that analysis needs to be expanded 
to account for the procession of perigee over a much longer period so we 
don't get an ugly surprise regarding eclipse lengths years into the mission.

73,
Lee-KU4OS


On Sunday 06 May 2007 19:06:08 Robert McGwier wrote:
> Yesterday at Space Day at the Air and Space Museum (D.C.) , Bob Davis
> revealed the Eagle structure 1/2 scale model.   I will put up pictures
> later to give everyone a look.  It is a very nice look.
>
> I have neglected to post my remarks on Dick Jansson's module designs.  I
> have had a regular module and a cut away of the heat sink module.  This
> is very fine work.  My final remarks on the work will await Bob Davis
> and Jim Sanford and I looking at this together.  But at this time, I see
> no reason at this time for us not to accept these modules and to thank
> Dick for his fine work.  Bob Davis has the modules now.
>
> Next,  we are doing more detailed work on the energy requirements of the
> spacecraft.  We have very short periods of eclipses and while the angled
> arrays do a great job of mitigating off pointing angle, NOTHING can
> mitigate no sun at all!  Given the amount of energy storage required to
> live through these eclipses, it is my OPINION that we are going to have
> to compromise on the periods of eclipse and TURN SOMETHING OFF.  The
> amount of solar panel and battery storage required to keep everything
> alive through these eclipses, upon more detailed study,  seems
> exhorbitant in terms of cost, weight, etc.  Lou, Bob Davis, and I have
> discussed this and Lou and Bob both have very nice study tools.  We need
> to write up a report on this for everyone to take into account.
>
> Juan Rivera and company have made great progress on the Stephensen 70cm
> RX recently.  They are really doing a fantastic job.  More will follow
> from them but it is good news.  We will be doing dynamics testing, noise
> testing, etc. soon!
>
> 73's
> Bob
> N4HY