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Re: Flight Computers



On Monday 29 April 2002 21:18, Tony Langdon wrote in "RE: [amsat-bb] 
Flight Computers":

> Better still, throw it close to a nuclear reactor, so you can hit it
> with some ionizing radiation as well.:-)  Only problem might be
> finding a facility willing to expose your dummy sat to stray
> radiation. :-)

Well, that's why IHU-2 (a StrongARM SA-1100) is on board AO-40: to 
throw it close to a nuclear reactor (the Sun) to space-qualify it. 
Notice that the LART project uses the same processor chip as the 
IHU-2--if anybody wants a Linux-based IHU most of the heavy lifting has 
already been done. Wanna write your control program in Perl? Java? 
Python? Fortran? Much of the software infrastructure is already in 
place.  

On Monday 29 April 2002 20:36, Tony Langdon wrote:

>> I think we should consider AO-40 to be the most successful amateur
>> spacecraft that ever blew up. :-)
> I like that one! :-)

Like most funny lines, there's a kernel of truth here. How many other 
spacecraft have experienced a catastrophic propulsion systems accident 
and still accomplished any significant part of their mission? Not too 
darn many. 

OK, so if we didn't have a propulsion system, we wouldn't have had a 
propulsion system accident...but we barely missed being 
up-close-and-personal to an Ariane propulsion system accident simply by 
not being ready for that ride.

The 400N motor was on-board for a very good reason: to try to convert 
an orbit we could get cheap (GTO) into an orbit we really wanted 
(Molniya with a moderate amount of inclination). That there are *any* 
transponder paths still operating (not to mention four uplink bands and 
a downlink), as well as two cameras, two GPS receivers and a boatload 
of digital capability we haven't even commissioned yet is nothing short 
of phenomenal.

I'm weary of hearing people complain about how dissappointed they were 
after they "built a station specifically" for a bird that wasn't even 
on orbit yet. What was *that* all about--so they could be a first day 
big gun? Would they have complained as loudly if P3D had caught the 
earlier bus and ended up totally toasted?
    
 73 de Maggie K3XS


-- 
-----/___.   _)   Margaret Stephanie Leber    / "The art of progress  /
----/(, /|  /| http://voicenet.com/~maggie   / consists of preserving/
---/   / | / |  _   _   _    `  _AOPA 925383/ order amid change and /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_  FN20hd / change amid order."   /
-/ (_/   '  K3XS  .-/ .-/    ARRL 39280   /___ --A.N.Whitehead ___/
/____ICQ 7161096_(_/_(_/__AMSAT 32844____/ <maggie@voicenet.com>

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