Re: [amsat-bb] Right-sizing a sat [was: Antennas on the bird]

["Robert Oler" <cvn65vf94@xxxxxxx>]

>
>I don't think the P3D project was too big for a number of reasons:
>
>What if we'd built a "simple" spacecraft with a similar propulsion system.
>What would we have now if we only had put VHF and UHF on it?  Robert said 
>we
>should have had more AO-10/13 types.  Well, AO-10's computer is dead and
>AO-13 was vaporized.  While we learned from these, what's to make us think
>that bad things wouldn't happen to birds in the future.
>

What killed A0-10's computer and the orbital mechanics that tossed 13 into 
the autmosphere are well understood now (and I think that AO-10's rad 
problem was well understood to...I just dont think that they could get a 
better 1802) and have nothing really to do with the size of the satellite or 
the magnitude of the program....or really my comments.

Lets start off with my comments.  If one expects "bad things" to happen to 
satellites (and I really dont but thats another issue) then the insurance 
against those "bad things" is to have multiple oppurtunites to fly thus 
being able to imply lessons learned to the next vehicle.  I dont know what 
the lessons from AO-40 are but if the plan is to have another AO-40 sized 
satellite then it will be "at best" what 10 years till we implement them 
(assuming it takes as long to build and launch the next phase 3d as it did 
this one).  OK say it takes half the time...then there is five and by the 
time that goes there will be new mistakes made etc.

Had the Ariane gone up in smoke where would we be with one giant bird?  The 
more "criticality one" issues (ie ones which "lose the bird) there are the 
more the argument is for more satellites.

I agree that stretching technology is a good idea however as best I can see 
nothing with the current problems has to do with stretching technology in 
electronics it has more to do with "rocket science"...and if the talent pool 
for the rocket science is small among the amateur community (and it might 
be) then that again argues for smaller more mid sized spacecraft with less 
capabilities but flown more often.

It will be interesting to see what capabilities the bird actually ends up 
with and when.  Until fuel venting stops I dont think anyone is going to be 
willing to declare what is broke "the final broke list" (in other words I 
think bad things can still happen as long as things are venting).

We could end up with a slightly more capable Oscar 13 and in that event 
everything else that went into it was wasted.

My ultimate point is this.  IN the end the amateur community needs to figure 
out exactly what capability it wants in the satellites and that its willing 
to financially afford.  If we want one big new satellite every 10 years or 
so where litteraly everything is bet on that then I think thats a mistake 
but htat may be where the group wants to go.

You might look at the Mars Observer debate that followed its loss.  There is 
a lot of that in this.



Robert Oler WB5MZO Houston TX

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