Satgen 631  Problems,Cuts,Delays by GM4IHJ  (BID SGEN631)  2001-04-28

As the problem haunted Amsat AO40 continues to dominate most amateur
radio satellite user thinking, it is becoming clear that this is not
turning out to be a good year for either the amateurs or the
professional space men.

ESA the European Space Agency has belatedly discovered that all is
not well with the Huygens probe now well on its way to investigating
Saturns moon Titan. Time of arrival 2004. The trouble is the familiar
one of design incompatability between discrete units.

The intended descent orbit of the Huygens probe, dropping towards
Titan and using the much higher orbiting NASA Cassini mother ship to
relay it signals back to earth, will produce signal doppler shifts
which take the signal outside the Cassini receivers bandwidth. At
which point the Cassini receiver will get nothing and will pass
nothing to the Cassini high power transmitter and big antenna, for
relay back to Earth.

A frantic search has been going on for solutions . Noting that NASA
really need to consider them now. Changes in the Cassini orbit could
reduce the problem. But only at the expense of its main mission
objective involving an orbital tour of Saturns rings and very
interesting moons.

Yes , folks will say . We have heard all this before . Imperial
versus Metric confusion killing a Mars mission. Failure to note that
an inertial platform used at launch of rocket X , could not take the
higher acceleration of rocket Y = another total loss of mission . 

Optimists may feel that NASA has solved worse problems before.
Turning a Galileo antenna failure which looked as if it would spell
curtains for the mission , into, a very successful mission in spite
of the antenna problem. But do not hold your breath . This Huygens
problem looks to be very difficult.

Meanwhile the recently announced projected shortfall of 4 billion
dollars over the next 5 years of the ISS International Space station
project . Looks serious. NASA has recently announced the cancellation
of the crew rescue vessel, and the proposed living quarters module.
Which moves if uncorrected by input from France and Italy ( who are
said to be interested in providing a rescue vessel ), coul impact on
crew numbers. Noting that without the presence of a rescue vessel,
the station regular complement outside Shuttle/Soyuz  visits, will be
limited to 3, for safety reasons. Equally important even if the
rescue vessel does come from Europe, the restriction in living
quarters will also restrict long term stay crew numbers.

A sequence of events which could affect ISS amateur radio operating.
Reduced crew numbers will mean increased house keeping workload for
the depleted crew. Which will drastically curtail the time available
for amateur radio from space.