Satgen100    Mir and Project Juno    by GM4IHJ  24th Feb 91

On May 12th a Soyuz space taxi is scheduled to launch from Tyuratam in
Soviet Asia for rendezvous and docking with the Mir space station possibly
in the late afternoon 1500 to 1700 ut of 14th of May. On board the Soyuz
should be the British Cosmonaut Helen Sharman from the Project Juno
organisation. Much of the organisation of Project Juno comes from Brunel
University at Uxbridge in Middlesex.

Looking at Mir's orbit window 12 weeks ahead is always going to be very
approximate, but some things about orbits change very little , even if as
is likely Mir lifts itself with an engine burn between now and the Juno
flight. In particular the line up of the orbit with respect to the stars -
the Right Ascension of the ascending node equator crossing, will not
change much because is depends on the length of Mir semi major axis which
varies with orbital height above the earth's centre. So we are talking
about Mir making say a 30 or 40 km change in 6780 kms , one part in 170
approx to the power of 3.5 , which is quite a small amount. We can
therefore predict reasonably accurately the time at which Mir's 6 orbits
in range UK window will occur. What we cannot do is predict the exact
orbit times inside that window. Because a 40 km lift in orbit retards
Mir's arrival time by about 12.8 minutes per day. From which you can see
that a lift in orbit 20 days before Project Juno gets there can put actual
orbit times 20 x 12.8 = 256 minutes adrift. 

So trying to guess orbit times is hopeless, but predicting the rough time
of day when UK orbits will occur ( ie the orbit window ) is relatively
straight forward. By May 14th the orbit window for Northern England will
be roughly 1700 ut to 0100 ut next day. This tells us two things :-
UK stations may hear the Juno Soyuz docking with Mir between 1700 and 1900
ut on 14th May on 143.635 from Mir and 121.75 FM voice from Soyuz.
Secondly it tells us that only the horizon orbits at the begining of the
orbit window will occur before 2000 ut which is the Cosmonauts normal
bedtime. The best orbits over UK between 2000 and 2300 ut will only be
heard if the Cosmonauts stay up late. Please also remember to add an hour
to the times ut because UK will be on Summer time. More details of how to
use these orbit timing features are given in the Mir handbook which is
available now from same source as the Uo3 and Dove books.

This last 3 weeks a clear story has emerged about where Mir got its packet
from. Originally the Austrians announced in Sept 90 that packet gear would
go up to Mir in Jan/Feb 91 to be set to work by an OE cosmonaut. In fact
that gear is still on the ground. Unknown to the OEs and the rest of us,
what went up to Mir on 19 Jan 91 was commercially sponsored equipment from
American ICOM and PacCom. Hopefully the full education programmme planned
by the OEs will still go ahead . It is nice to have packet in Mir, but I
sympathise greatly with the gazzumped OEs and wonder if commercial action
conducted in this fashion is desirable or sensible. 73 de GM4IHJ @ GB7SAN