[amsat-bb] Re: how about an amsat moon mission?

Ric Letson, NB2E nb2e at amsat.org
Mon Oct 15 16:18:32 PDT 2007

"It also seems the cost of hardware (HD cameras, still cameras, video
transmission hardware...) and getting there would eat up a bunch of that
prize money."
Kenneth - N5VHO

I see some huge obstacles that would need to be overcome before an
undertaking like this could be even considered. Then again, amateurs are
well known for being able to overcome obstacles set before them.

The first obstacle I see is whether you can land the craft on the moon,
perform necessary diagnostics and then complete all the required tasks
during a single lunar day (14.5 days on earth). More specifically you should
be aiming for completing the tasks in the early part of the lunar day when
the sun is at a low angle. Temperatures vary from 138C during the peak of
the lunar day to -153C during the dead of lunar night. I don't even want to
think about a temperature swing 14 days long with a variation of ~290C. (I'd
stay away from aiming for that $5Million bonus based on surviving lunar
night and just say that if it happens then we surpassed our own

The second obstacle is the selection of individual components. What
electrical storage device (NiCd, NiMH, LiIon, Capacitors, etc) are you going
to use that will survive the temperature and hard vacuum of the moon? What
capacitors, resistors, IC's and other components are going to be durable
enough to perform? The vacuum present on the moon is many times greater than
that present at Low Earth Orbit, so great that there are few vacuum chambers
on earth that can even come close (10e-15 atm or 7.6 × 10e-12 torr). At this
level of vacuum plastics & rubbers degrade fairly fast due to outgassing,
this includes the materials that our components would be made from. I'm sure
AMSAT has engineers that handle component selection based upon environmental
conditions (or lack of environment, hi hi) but it's still something to take
into account.

The mooncast that is required for receiving the grand prize includes
transmission of High Definition video from the moon to be received here on
earth. Even if we aimed to provide the lowest of the HDTV resolutions (720p)
we're looking at a real-time data rate of 7-15MBps. I think this part of the
requirement is feasible only because there's no requirement for the video to
be transmitted in real-time, so we could theoretically store the video
locally and retransmit it at a lower data rate. (Anyone want to discuss data
rate vs. required RF bandwidth? Available frequency bands, or the square
inverse law and the power necessary to get the signal to earth?)

There is a separate requirement for near real-time video but it doesn't
specify that it has to be in color nor does it specify a frame rate. Wonder
if they'd consider a black & white stream at 2 or 4 frames per second to be

The 360 degree panorama of still photographs could be taken with the same
camera that's being used for the HD transmission. Just pull stills at
specified intervals as the camera and / or craft does a 360 on the surface.

In order to cut this post short and summarize my opinion, yes I think that
the goal is attainable and within the realm of possibility considering the
experience that the various AMSAT teams possess but it would monumental even
compared to the launch and operation of Eagle.

Ric Letson, NB2E
nb2e at amsat.org

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