[sarex] ARISS Frequencies
Frank H. Bauer
ka3hdo at comcast.net
Sun Aug 13 09:25:27 PDT 2006
I have seen the back and forth chatter on frequencies. Let me say that the
ENTIRE ARISS international team have discussed this subject and debated it
for over 10 years now. And the Mir and Shuttle teams have worked on this
for about 13 years before the ARISS team. Collectively, we have spent many
hours in international meetings discussing this issue. And the ARISS team
has developed and implemented an INTERNATIONAL human spaceflight plan for 2
meters. This plan represents the best compromise that can be developed,
given the substantial differences that exist in band planning from one area
to the next.
Several things to think about:
1) We have many astronauts/cosmonauts using the equipment.
2) Those on-board that use the ARISS equipment do not like to hear the
uplink chatter of Packet, APRS or SSTV.
3) 1 & 2 above result in the need to separate the uplinks of these
non-voice modes from voice.
4) One of the big joys (and learning experiences) of ARISS is to hear the
downlink of the on-board crew member. One cannot do this well when some
local ham is transmitting on the same freq. This is especially true in big
cities where there are a lot of hams. I personally experienced the
frustration of hams transmitting on the downlink many times while Mir used
simplex. And the reason that DXers use split mode is to prevent this
issue, so that all can hear the DX station.
5) ARISS is the ultimate DX, so split operation emulates the DX operations
done on the ground.
6) Remember---unless the repeater is in use, you cannot hear who is
transmitting from the ground and when they will stop. So it is generally
hard to know when to start. For simplex operations, this results in
frequency collisions with people on the ground uplinking at the same time
that the on-board crew is downlinking.
7) I am really surprised at all the chatter about wanting to get crew
members to talk more on the radio. We just had Bill McArthur on
board. And Pavel is working hard to get SSTV on the air. Kenneth Ransom
and Sergey Samburov have done an outstanding job in getting the on-board
crews motivated to use the ham radio systems. I think this community has
been around long enough to realize that it is the crew member's prerogative
to pick up the mic. Simplex or split.
8) Constant complaints or slams at the space agencies and our crew members
will ultimately limit or eliminate our future operations on ISS and other,
future vehicles. Remember, there are many that subscribe to these systems
that are members of the various space agencies. And we have also have
several crew members that subscribe to these systems.
9) Because of the significant frequency contention on 2 meters, we have
developed a dedicated, international human spaceflight frequency segment on
10) If we continue to foster a great relationship with the international
space agencies, Human spaceflight opportunities beyond low Earth orbit
could potentially be in our future. Many of us in the ARISS program are
working this very aggressively. These opportunities will dictate the use
of much higher bands with smaller antennas and less doppler. We need to
prepare for these opportunities by using some of our higher bands on
ISS. Something to think about for the future.
Personally, I really appreciate the feedback from the amateur
community. This is how we learn and grow. But we need to do this in a
very constructive way. And while we reminisce about Shuttle or Mir, we
need to realize that THESE are the good old days. Let's use them to the
best of our abilities.
WRT the simplex issue and additional 2 meter frequencies, it is my opinion
that we have all beat it to death. We have squeezed just about all we can
get from 2 meters. And for those in the US---please remember that our 2
meter band is 2 times larger than that in many other countries.
Thanks for all the interest in ARISS. And don't forget that our next
international meeting will be in the US this year in conjunction with the
AMSAT-NA meeting in San Francisco. This is your opportunity to interact
and participate more fully in the ARISS program. I hope to see you there!
73, Frank Bauer
ARISS International Chairman
AMSAT V.P. for Human Spaceflight Programs
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