[amsat-bb] Re: Path to HEO

[g0mrf at aol.com]

Hi all.

Deployable gain antennas are possible, but unfortunately attitude 
control is a real issue. If the orbit has a high perigee then the 
magnetic field for magnetorquing is minimal. With limited fuel and 
little or no magnetic field, keeping the antennas pointing correctly is 
difficult. Also, all of this getting to HEO is challenging given our 
lack of experience with low mass / ion propulsion.
A compromise could be 4 Watts (ish) from MEO.  That can be done with 
omnidirectional antennas, so when the batteries die and the fuel is 
exhausted we still have a useful satellite even if we cannot control 
attitude.

Would be great to team up with a group who want to test a propulsion 
system and apply for a launch opportunity.

Thanks

David

Here's an oldie but goodie.....   http://www.g0mrf.com/MEOSAT.htm




-----Original Message-----
From: Joe <nss at mwt.net>
To: amsat-bb <amsat-bb at amsat.org>
Sent: Tue, 30 Apr 2013 17:18
Subject: [amsat-bb] Re: Path to HEO


On the Outside? :-)

just like 90% of the earlier birds they are rolled or folded up until
after deployment. IIRC: one of the first actually did use a rolled up
tame measure for the elements.

Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 4/30/2013 9:51 AM, Andrew Glasbrenner wrote:
> Where do the gain antennas go on a 10x10x30cm HEO?
>
> 73, Drew KO4MA
>
> Sent from my iPhone
>
> On Apr 30, 2013, at 9:01 AM, N0JY <n0jy at lavabit.com> wrote:
>
>> I wonder about the amount of time spent in the Van Allen belts on 
the way up
there.  We're concerned about radiation at a 650 km orbit, it might 
take some
heavy duty ($$) radiation tolerant components to survive a few years 
trip
through the radiation belts as well as the final high orbit?
>>
>> Jerry
>> N0JY
>>
>>
>>
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