MIRNEWS.423    31 MAY 1998

MIR-routine:

After the docking of Pr-M39 at MIR the cosmonauts started the
unloading of that freighter. while Andy Thomas already started the packing of
approx. 30 bags with things which will go to Earth with the Discovery. Andy
also tried to accomplish some of his experiments. Passes for our position took
place during the night hours. The crew also used the Altair-2 geostationary
satellite for phone- and TV-communications in which interviews and private
conversations, for instance Andy with his relatives and Musabayev with the
Kazakh ambassador in Moscow. On 19.05.1998 Altair-2 was used for a so called
tele-bridge between MIR and the communications centre Burum (in the Dutch
province Fryslan) with pupils from a grammarschool in the city of Groningen.
Communications started long after the scheduled time, but the cosmonauts and
the children very much enjoyed the happening.

The crew continued medical, and other experiments. Andy had to undergo an
extensive test of his cardio-vascular system in relation to his oncoming return
into earth-gravity conditions. Musabayev took care for the proper connections
of sensors and the right commands in coordination with a lady-specialist on
earth.

Now and then minor technical problems with the lifesupport systems,
watermanagement and power supply (a malfunctioning accumulator in Module-D)
emerged during radio-conversations. The crew solved all problems and nothing
seemed to hamper the STS-91 mission so far.

Regularly there were problems with the exchange of radiograms by Packet Radio
and often the crew had to fall back on the old RTTY (radio-teletype system),
even via Altair-2. Obviously not all Russian tracking stations can handle
Packet Radio. Often the crew relies on the tracking facility Petropavlovsk
Kamchatka for Packet Radio links.

Now and then the crew speaks about the BDD (Betriebstechnik Deutschland
Direkt). This system enables European scientists to execute experiments
directly via Altair-2 without interference of the Russians. This is possible
via the DLR trackingstation Oberpfaffenhofen near Munich (Germany). Possibly
the experiments with this system have been suspended or concluded. Sigmund
Jaehn, the former DDR cosmonaut and now a DLR employee so far acted as
coordinator of that system.

During one of the sessions via Altair-2 Musabayev asked TsUP to forward a
request to Houston. The guitar, which was delivered to MIR by Progress-M39 was
a present for him from his fellow-countrymen. He would like to take the guitar
back to earth, but that is impossible with the Soyuz-TM27. So he hopes to get
late permission to send the guitar to earth with the Discovery. Whether he got
this permission or not is not known yet. The room for cargo in Discovery this
time is also very limited (single instead of a double Spacehab module).

Failure of attitude control computer: After a very long time this problem again
disturbed the Russians. On Saturday, 30.05.98, this computer failed, causing
the well-known chain reaction, i.e. deterioration of the proper angles of
sunlight on the solarpanels, the reduction of power-supply, and so on.

The crew had to use the attitude control possibilities of the Soyuz-TM27 to
correct the station's attitude as efficient as possible to regain a part of the
needed power-supply.

This happened during my absence and when I came home late Saturday night I
heard that something was wrong during a nightly pass. Regretfully I missed the
previous passes for using my time-switch had been impossible: the meteo-office
had predicted heavy thunderstorms. After all my precautions had been
superfluous for the bad weather did not reach my position.

On 31.05.1998 the crew replaced the attitude control computer and started
tests.

At deadline for this report I had no further information.

Expected launchtime Discovery for Mission STS-91:

Still scheduled for 2.06.1998 at about 2210UTC.
At deadline for this report there was still 'go' for this
launch. If so it is worthwhile for listeners in Western-Europe to listen
between 2225 and 2235UTC on the airtraffic control frequency 259.700 mc (AM-
wide). At this moment the shuttle does not have the possibility to use the TDRS
and traffic with Houston is possible via a tracking station in Spain.

Here some old news for the statistics:

Progress-M38:

This old freighter separated from MIR on 15.05.1998 at 1841UTC.
(So 3 minutes earlier than reported in MIRNEWS.422). The original plan to
maintain Pr-M38 in orbit until the safe docking of Pr-M39 had been abandoned.
Progress-M38 entered the dense layers of the atmosphere on 16.05.98 at 2220UTC
and decayed over a designated area in the Pacific East of New Zealand.

C.M. van den Berg, NL-9165/A-UK3202.