[amsat-bb] Re: AO40 replacement !!!
John P. Toscano
tosca005 at tc.umn.edu
Wed Sep 5 08:06:56 PDT 2012
On 9/5/2012 8:57 AM, Kevin Muenzler wrote:
> On Tue, Sep 4, 2012 at 3:40 PM, Kevin Muenzler
> <kevin at eaglecreekobservatory.org> wrote:
> In my opinion (it's worth every penny you just paid for it) if they are
> going to create a new super sophisticated "Phase III Part Deux" it should
> perhaps be taken to the ISS in pieces, assembled there and blown into a
> long-period orbit. But then that's just my opinion. If I remember
> correctly AO-40 was damaged by a collision with the launch vehicle shortly
> after separation. Of course a new generation of easy-sats that can be
> worked using a J-pole setup would be nice too.
Keep in mind that astronaut time is a very precious commodity,
particularly astronaut EVA time. I seriously doubt you'd ever get buy-in
by the authorities to have the astronauts devote any of their precious
EVA time to assembling an amateur satellite in orbit. Furthermore, I'm
not sure of the benefit of on-orbit assembly, unless you believed that
you could break down the satellite into such small pieces that they
could go along for a "free ride" whenever astronauts or cargo were being
sent up. Even AO-40 would have fit into the cargo bay of the (now,
sadly, grounded) shuttles, although its nitrogen tetroxide oxidizer and
monomethylhydrazine fuel would never have allowed it to fly on a manned
Granted, it is easier to get a ride for a 1U cubesat than another AO-40,
and the best way to get a ride to orbit is to make the hardware as small
and light as possible. But other than shrinking the bird, I don't think
that it's so much a problem of re-engineering a whole new satellite
design. The design of AO-40 was incredibly good. The design failure was
in the step-by-step commissioning process that left a fuel port cap in
place prior to launch which then led to the explosion that crippled the
bird. People bemoan how "over-engineered" and how "excessively complex"
AO-40 was, but it was precisely that complexity and over-engineering
that allowed us to get any use out of the bird after the explosion.
Getting a ride to a satisfactory orbit is far and away the biggest obstacle.
Now I'll get onto my soapbox for a few moments. I do not understand why
we keep pouring our limited resources into single-channel FM satellites.
Even a cubesat is capable of carrying a linear transponder, and even if
it is put into a LEO, it has to be more useful than an FM transponder in
the same orbit. Since the big issue is getting a ride to orbit, why not
send up the most capable satellite that we can within the constraints of
the allowable package size and weight? I mean, in the worst case, if we
launched a linear transponder and "everyone" complained that it was too
hard to work it, it could still be operated as a single-channel FM
transponder if you allowed people to transmit in FM, much as it would
break my heart to allow it. You would not have lost anything by sending
up the linear transponder. Make every launch count for as much as
possible. Getting off my soapbox now.
My thanks go out to all the folks working behind the scenes to try their
darndest to get us new launch opportunities and to get new flight
hardware built and ready to go in case a launch opportunity is found.
The AMSAT BOD and staff and volunteers put a remarkable amount of effort
into this stuff, and seldom get the acknowledgement that they deserve,
since major breakthroughs like the launch of an AO-40 are prevented by
forces outside of their control. Which just means that they are working
all the harder, *NOT* that they are slackers.
And don't get me wrong, I think that cubesats are a good thing,
particularly if they are truly educational (teach us how to build
better, smaller satellites), and especially if they are able to someday
solve the problem of sufficiently safe and effective on-board propulsion
to achieve higher orbits. But please, try and put the best possible RF
hardware on them when they go up! (Sorry for the short jump back onto
the soapbox there!)
73 de W0JT
AMSAT-NA Life Member
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