hi maggie- sorry for being short with you. Thank you for the more detailed posting. For low power sleep mode or standby of control electronics, super capacitors become more practical and longer lasting than batteries. I believe someone in the group has or is experimenting with supercaps.

One possible group to approach for inclusion of an auxilliary payload is NOAA since they are prolific satellite builders and have a preexisting relationship with the amateur community. Take care, pat

------- Original Message -------

From : Margaret Leber[mailto:maggie@voicenet.com]

Sent : 7/8/2007 10:05:41 AM To : amsat-bb@amsat.org Cc : Subject : RE: [amsat-bb] Re: Future radical satellite designs

On 7/8/07, Patrick McGrane N2OEQ@aceweb.com wrote:

Hello maggie- I hate it when people snip or take things out of context. Go back to the original entire email to absorb the reason. thanks, patrick

I did read the whole thing.

The challenges to amateur secondary payloads on commercial or military spacecraft have been discussed here at length in the past. *My* comment was that a standalone bird *designed* without battery-powered transmitters might be an interesting approach.

As it stands now we have several birds on-orbit designed with larger battery systems (that have subsequently failed) that come up in various random control system states when they come out of eclipse. These birds only transmit when in sunlight anyway; what if we designed one that way on purpose? Now *that's* a "radical satellite design".

The payload weight that would have gone to bigger batteries to power transmitters during eclipse could be used for other equipment. A smaller (more reliable? certainly simpler and cheaper) auxiliary battery system could keep the control systems alive during eclipse. A lot of work is being done with ultra-low-power processor chips for mobile applications these days.

Imagine if AO-40 had used this approach (admittedly not at all in-line with the elaborate something-for-everyone AO-40 design philosophy); it might still be usable. As it is, when the complex power system failed, we lost the whole bird. And the only hope of recovering it is the outside chance that it might fail *again*.

-- 73 de Maggie K3XS Editor, Phil-Mont Mobile Radio Club Blurb - http://www.phil-mont.org Elecraft K2 #1641 -- AOPA 925383 -- ARRL 39280 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb