[amsat-bb] Suitable transceivers for Earth-Moon communication? And a question about allocations

[Tomas Härdin]

Hi

(attempt #3 at sending this mail. maybe this list doesn't allow
attachments?)

Tomas SA2TMS here. I am involved in a group that's trying to put
together a scientific probe that will hitch a ride to the moon,
courtesy of PTscientists (one of the Lunar XPrize teams) [1,2]. One of
my major concerns is how get a reliable backup link going for running
operations during the lunar night. The lander acts as downlink relay
during the lunar day, but is not available during the night (and likely
not after the night either). Hence the need for a secondary link.

Throughput requirements are quite modest, as little as 10-100 bits/s
may be acceptable. There is an average of around 800 mW of electrical
power available. The geometry is somewhere between a 4U and 5U CubeSat.

I have two questions for this list, assuming it's the right place to
ask them:

1) What are some transceivers that may be suitable for this problem? I
have found some candidates, but I'm interested in hearing more
suggestions. The path loss is obviously quite significant (197 dB on
70cm). Choice of band(s) comes down to possible antenna geometries. 2m
is a bit on the low side for a dipole to fit (it'd have to fold). 70cm
is OK. At 23cm and above patch antennas start to become feasible (a
huge plus).

2) Where do I go to apply for frequency allocations in the amateur
satellite bands? Some sources say IARU, some say AMSAT. Others indicate
I should talk to my national agencies (PTS, SSA).

That's all for now. If you have any questions, ask :)

/Tomas

[1] http://scube.se
[2] http://ptscientists.com/