Satgen 30 25th Oct 89  AO13 OK ? - Packsat Delay - Rudak ? - Mir problems

Oscar 13   Preliminary reports suggest the HouseKeeping computer has been
reprogrammed BUT check first before you use the satellite that it has been
released for use. AO13 appears to have suffered a memory wipe out.Some
suggest this was due to solar flares. As far as I know this has never 
happened before .What has happened in Solar storms is that geosats and
Phase III birds and Molniyas which go far out from Earth, can be caught
by solar flares where they have very little protection from the Earths
magnetic field. In this situation a solar flare can produce very heavy 
build up of static charges on the sats outer surfaces. These charges can
flash across causing local "lightning", and the magnetic fields the
flashes generate is quite enough to wipe any memory in the vicinity.
Several geosats suffered mysterious memory failures and power relay trips
before it became common practise to sheath the sat outer surfaces in
conductive shielding.Lets hope AO13 suffers no after effects what ever the
cause.

Packsat launch has now gone back to 19 Jan 90 because Arianespace
continues to have a problem with 3rd (last) stage ignition, which has 
occured on and off since the first Ariane launch.The problem is cryogenic
fuel. The first 2 stages use ordinary fuel, but the 3rd stage uses super
cooled hydrogen and oxygen, and at low temperature this fuel is difficult 
to ignite.Ariane uses pyro igniters , a mixture of spark plugs and
fireworks,and it is now clear that recent flights have had problems.It is
noteworthy that both the Russians and the Americans have had exactly the 
same problems which they have not yet completely sorted out.

Rudak 1 the digital link on AO13 may at last be responding to treatment.
Don't hold your breath, but it might soon be working.

Mir still has power supply problems , a hangover from last April by the
sound of it. In addition the new module due to go up to Mir has failed its
control circuit preflight tests ,so it will be delayed perhaps to December
Maybe this will allow the onboard Cosmonauts a bit more time for Amateur 
Radio . 73 de John GM4IHJ@GB7SNE