[amsat-bb] What on earth (or in space...) is going on?

Daniel Schultz n8fgv at usa.net
Tue Dec 29 00:47:19 UTC 2015

> I have been sucked into a discussion that makes me feel like I have spent
> the last six months in a coma...

Dear Pete MM0TWX,

Attending the annual AMSAT Space Symposium is certainly the best way to get
caught up on the newest developments but I recognize that not everybody can
come, although we do try to move the symposium to different parts of the
country each year to give everyone a chance to attend at least once. If you
want to bring the symposium to your city, form a local organizing committee
and make a proposal to AMSAT!

The AMSAT forums and exhibits at Dayton are also a good place to get caught
up, but I recognize that not everybody can come to Dayton. Lacking that, the
AMSAT Journal is your best source of up to date information and it is included
in the price of your membership. If you are not a member, then I guess you
have only yourself to blame. Most of the really active AMSAT volunteers are
too busy to read AMSAT-BB on a regular basis, the signal to noise ratio can
get a bit rough sometimes. 

Please recognize, as Jerry and Tom pointed out, that we live in a brave new
world where a 6U Cubesat might be the largest thing that we can launch, and it
has to have a scientific, technological or educational purpose that NASA or
some other sponsor will buy into. Sometimes I feel like we are trying to fit
50 pounds of satellite into a 5 pound sack, and this requires some tricky
space engineering to make it work. Getting the antennas to fit on such a tiny
satellite is one challenge, generating enough solar power is another
challenge. With AO-10 and AO-13, we could cover the body of the satellite with
solar cells and tolerate the inefficiency that comes when the cells don't
always point directly to the sun. With a Cubesat that might be only 10 x 20 x
30 centimeters, we really have to have three axis attitude control to keep
those cells pointing at the sun most of the time. This is challenging
technology for AMSAT. (And for those who love the older RS birds, remember
that they were attached to larger satellites that provided an ample amount of
power for their transmitters. You would have to ask the Russians if they have
any plans to do more such satellites in the future.)

I think we will include some type of analog transponder in most future
satellites, the SDR radios can most likely be programmed to relay analog
signals, but these signals will come from small antennas with limited
transmitter power, they will be weaker than what you received in the past, and
we are doing this for those hams who enjoy a challenge. Please do not complain
that we are only interested in serving the "elite" hams, yes, the analog
transponders are for those hams. The digital ground system group is working
hard to make a 5 GHz up, 10 GHz down digital transponder kit that average hams
can buy and assemble, and we intend to design future satellites that can all
use those bands and modes so that your equipment investment will not be wasted
when one satellite dies. The geosynchronous transponder might be about as
challenging as a Skype call, but think about what that might do for those hams
who work in public service and emergency communications. This is the sort of
thing that attracts attention from the FCC and Congress when they are
considering the future value of amateur radio to the nation. 

Please also recognize, as Bob pointed out, that some things CAN'T be released
to the membership, and you will just have to trust that he knows what he is
doing. There are also some things that are just too darn speculative and we
may be reluctant to talk about them in public until our ideas firm up. The
symposium is the best place to get the latest gossip on the really far out

Finally, if you see something that needs to be done, please step forward and
do it. The absolute best way to keep up with our progress is to work alongside
those AMSAT volunteers who are making things happen, because in the end, AMSAT
is nothing more than the passion and energy of its volunteers. 

73, Merry Christmas and Happy New Year

Dan Schultz N8FGV

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