Orbital Economy

>
> Is this so because failure is such an expensive
> option that the
> testing phase and even the design phase has to
> "prevent failure at
> all costs?"
>
> If launch failure and operational failure were not
> "bankrupting
> events" without insurance, do you think the
> satellites could be
> designed and built cheaper, even on an assembly
> line, so that a
> number are launched (because it's cheap) and once in
> orbit they are
> tested for surviving the launch process, then those
> that made it are
> deployed either into operation or parking orbits to
> be called on
> when the lower standards catch up with the
> satellites after a few
> years and it fails.
>
Part of it is testing against failure, which is why
the AIT phase is generally 8 months. Part of it is
that this is a cutting edge technology and just hasn't
been done yet. A good example of this is many recent
comm sats are looking at moving to Ka-band (form more
traditional C and Ku band) due to the ability that you
can fit more information at this wavelength. You can
also use this wavelength in terms of spot beam
coverage so as to concentrate signals to particular
geographies (very import for direct broadcasting
services).

However, to accomplish this, very precise waveguides
have to be installed and these can break easily. It
is also very hard (if not impossible) to do
repeatability testing on these. Now in order to work
with this band, completely new equipment had to be
manufactured and new skills had to be learned. I will
not even pretend to know all the complexities of this
other than to say we had to have quite a few phds
working on getting this to work in my company alone.

Thankfully, NASA laid down the ground work for us to
follow with the ACTS satellite in the early 90s. This
demonstration satellite allowed customers in the
commercial sector to have the confidence to order such
a satellite. I bring this up for two reasons: 1) to
show that nasa has a great role it fulfills by proving
specific technologies can work, 2) putting up new
hardware is tough thing, customers shy away from
unproven technologies. Look at what happened with the
Boeing 702 solar array design. They tried to be
innovative but instead produced a spectacular failuer
that destroyed their good name in the satellite
manufacturing world and ultimately costs them
contracts.

>
> Let's just look at communications satellites because
> each satellite,
> I'm sure, is complicated in its own way. Aren't
> communications
> satellites only as complicated as telephone or
> internet switching
> devices or are they is there something more to it?
> Other than the
> receiving and transmitting components.
>
part of the payload of a commsat is that, and that is
the easy part. The hard part is as I mentioned
before, the communication to the ground. You need
some fairly powerful antannaes operating over a very
broad range of frequencies. The higher the frequency,
the higher the power demand. So you have all the very
complicated rf stuff which goes way over my head
compounded with the all the bus related functions
which provide a stable platform for the payload to
rest on. A typical commsat has a minimum of about
9000 parts, not exactly a trivial thing.

Ryan Z