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From: Dan Dubrick
To: All
Date: 2003-06-10 00:52:00
Subject: 6\05 New Soyuz TMA cleared for next mission with ESA astronaut

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Paris, 5 June 2003
Information Note 
Nx 13-2003

New Soyuz TMA spacecraft cleared for next mission with ESA astronaut


The new Soyuz TMA spacecraft, which will carry ESA astronaut Pedro
Duque to the ISS and back in October 2003, has been fully approved
for operations. This was announced by Nikolai Zelenshikov, First
Deputy President of RSC Energia, at an official briefing in Moscow on
26 May to present the findings of the enquiry commission's
investigation of last month's ballistic re-entry by Soyuz TMA-1.

The maiden flight of the new series by the Soyuz TMA-1 spacecraft was
launched from the Baikonur Cosmodrome in Kazakhstan on 30 October
2002. The crew consisted of ESA astronaut Frank De Winne from Belgium
and Russian cosmonauts Sergei Zaletin and Yuri Lonchakov. After
completion of his mission tasks on the ISS, Frank De Winne returned
to Earth in a Soyuz TM-34, one of the previous series of Soyuz
spacecraft. 

Soyuz TMA-1 remained at the ISS to act as the station's 'lifeboat'
for six months, thereafter executing the first re-entry by a TMA on its return to
Earth on 4 May 2003 with the ISS Expedition 6 crew, Russian cosmonaut
Nikolai Budarin and American astronauts Kenneth Bowersox and Donald
Pettit, after completing their 162-day mission aboard the station.
 
Despite the unplanned re-entry in what is known as 'ballistic' mode, all
the new systems used within the Soyuz TMA-1 spacecraft performed according
to plan, including, in particular, the new soft-landing system, which
incorporates new engines and a new frame. This reduces the landing shock
from 12g in the old Soyuz TM series to 5g in the Soyuz TMA family. The
Soyuz TMA-1 parachutes also functioned correctly.

The problem, which caused Soyuz TMA-1 to perform the re-entry in ballistic
mode and land 150 km north of Baikonur 400 km short of the intended
landing site, was due to a failure in the BUSP-M guidance system, which is
necessary in order to carry out a controlled re-entry. This guidance
system reads gyroscopes and accelerometers and sends appropriate commands
to attitude control thrusters.

The yaw control channel, a sub-unit of the BUSP-M produced 'undefined'
readings, indicating a malfunction. This caused higher control functions
to take the BUSP-M system out of the control loop and convert to the
ballistic re-entry mode.

In this mode of re-entry the trajectory is steeper than in a controlled
re-entry and the capsule rotates around its axis of trajectory to increase
stability. The steeper trajectory reduces flight time and increases
deceleration. This had the effect of applying an 8g gravity load to the
crew of Soyuz TMA-1 as compared to a maximum of 6g in a controlled
re-entry mode.

The BUSP-M guidance system, where the problem occurred, first flew on
Soyuz T-5 in 1979 and has since executed 49 faultless controlled
re-entries. Tests as part of the official commission's enquiry, which was
set up following the return of Soyuz TMA-1, could not find any problems
with the guidance unit. The problem could only be reproduced through
mathematical simulation. The chance of this problem occurring has been
determined to be about one in 7000.

This is only the third time in the history of the Soyuz programme
that such a mode of re-entry has occurred, though the ballistic mode
is one of four nominal re-entry modes that the Soyuz T, TM and TMA
capsules could employ under different conditions. The others are the
automatic and manual control modes, and a back-up ballistic mode.

The enquiry commission concluded that there is no need to modify
Soyuz TMA-2. This is the 'lifeboat', which is currently stationed at
the ISS and is due to bring ESA's Spanish astronaut Pedro Duque back
to Earth after completion of his mission later this year. Duque will
be flying to the ISS in Soyuz TMA-3 in October. Certain modifications
will be made to this capsule as recommended by the official enquiry
commission. 

The first of these recommendations was to improve communications
capability by including a mobile satellite telephone in the return
capsule. This will be implemented immediately on Soyuz TMA-2 and the
telephone is to be transported to the ISS by an unmanned Progress
vehicle. The incorporation of a satellite communications capability
such as Cospas-Sarsat is also recommended in the longer term.

Secondly, modifications will be made to reduce the chances of
incorrect commands by crew members to an absolute minimum. The
Expedition 6 crew switched on the KURS rendezvous/docking system by
mistake during the re-entry procedure, though it is confirmed that
this did not result in the switch to ballistic mode.

Nikolai Zelenshikov also addressed some questions concerning the
length of time it took to locate the Soyuz TMA-1 capsule and crew
after re-entry, which was longer than expected but within the
regulation recovery period of three hours.

The Russian mission control centre in Moscow and the search plane,
which was flying over the expected landing area in Kazakhstan, were
not aware that a ballistic re-entry had taken place even though there
was radio contact with the Expedition 6 crew before the landing; the
crew had not mentioned the mode of re-entry in their discussions with
the ground teams. This led the search plane and helicopters to search
the expected landing area first rather than the ballistic re-entry
landing area. 

When they found nothing the recovery crew concluded that a ballistic
mode re-entry had taken place and proceeded to the corresponding
landing area 400 km away. After landing, it seems that mistakes were
made in certain procedures, with the result that the onboard antennas
were not deployed and the radio signalling was not switched to an
external transmitter once the crew had erected an antenna outside the
capsule. This added to the delay in locating the crew. When the
recovery team arrived, the Soyuz crew had left the capsule by their
own means. 

To avoid any recurrence of these procedural problems, there are
further recommendations on  revision of onboard documentation of
procedures and additional training for future Soyuz TMA crews.

"Though recommendations have been made for improvements for future
flights, they have no bearing on the systems of the new Soyuz TMA
series of spacecraft," said ESA Director of Human Spaceflight, Jorg
Feustel-Buechl, commenting on the Russian enquiry commission's
findings. "I am happy that the way is now clear for the next Soyuz
mission in October, the crew for which includes ESA astronaut Pedro
Duque. This will be a mission to relieve the ISS crew and to perform
scientific, technological and educational experiments. The exact time
and date of this launch will depend upon ISS orbital parameters and
operating status." 

For further information, please contact:
ESA Media Relations Service
Tel: +33(0)1.53.69.7155
Fax: +33(0)1.53.69.7690

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@Message posted automagically by IMTHINGS POST 1.30
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 * Origin: SpaceBase(tm) Pt 1 -14.4- Van BC Canada 604-473-9358 (1:153/719.1)
SEEN-BY: 633/267 270
@PATH: 153/719 715 7715 140/1 106/2000 633/267


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