[amsat-bb] HEO opertunity
zleffke at vt.edu
Mon Oct 24 15:20:46 UTC 2016
Given my recent interest and the previous thread on 'deep space
tracking,' a linear transponder on a HEO bird could offer an
interesting 'test bird' to conducting ranging operations and orbit
determination with. It is more 'deep space like' than the current LEO
birds, but is still in earth orbit and can be modeled with TLEs (so that
we can check against NORAD updates to see how 'good' we are doing).
If the design is similar to what will be used on the CQC bird (or at
least an approximation that could work in a 1U), then we (as in the
amateur satellite community) could test out the required earth station
hardware / backend processing for something like this, as well as get
vital training for future missions such as the CQC bird and potential
other HEO missions.
Couple of points to back up the idea:
1. I'm guessing a 1U in HEO is probably tough power budget wise, so
link budgets will probably be tight. PN sequence ranging (in my limited
understanding of the subject) requires way less SNR than normal
communications and data transfer since your just looking for
correlations against the known PN sequence, so it is maybe viable given
a tighter link budget.
2. A 5GHz up/10 GHz down payload is probably not viable in a 1u (link
budgets, size constraints, etc). So, something like a 23cm up, 70cm
down bent pipe transponder would be interesting. The problem here will
likely be community 'backlash' in that L-band uplink stations are less
common in the Amateur Community. I would offer the argument of 'use it
or lose it' to help protect the 23cm uplink band, and also the fact that
AMSAT is planning an L-Band uplink for two of the 5 foxes (including 1E
which will be a linear transponder). So maybe having another 23cm
uplink bird will interest people in adding a band to their station (if
two birds isn't enough, maybe three is?). If L-Band up is too hard to
swallow, then a 2m up/70cm down bent pipe in HEO would still be
interesting, compatible with most Amateur ground stations, and could
still be used to test ranging operations.
3. Heavy Forward Error Correction on a separate low rate TLM downlink
would probably be a good idea (like AO-73, again due to probably tight
4. training, Training, TRAINING! I know AMSAT has conducted ranging on
their own in the past, but its been a while. There are probably new
members in the community that would like to get into this sort of thing
and learn this type of skill (I include myself in that list), and the
folks that have done it before could help train up a younger/newer
generation of AMSAT folks, which would help protect the 'technical
leadership in the field of small sats' future of AMSAT.
I have no good answer for the radiation part of your question. Also, I'd
love to help out the students, but have my hands full here with our own
students at VT.
Just throwing out an idea for a payload.......
Congrats on getting a ride!
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305
On 10/24/2016 2:38 AM, Nick Pugh wrote:
> Hello AMSAT-ers
> The University of Louisiana has a slot on a ULA mission to GTO launch to
> GTO for a 1u. WE are asking the community what payload should we fly, how to
> mitigate the radiation and who wants to help the students?
> egory=News> &Category=News
> 73's and see you on the baot
> nick k5qxj
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