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Paris, 28 March 2003
Information Note
Nx 07-2003

Space Shuttle Columbia - Information Note No. 4
Failure investigation technical update

The Columbia Accident Investigation Board (CAIB) continues their work
into the investigation of the accident and a number of hearings are
now being held in public.   The chairman of the NASA Columbia Task
Force (the body that supports the CAIB) gave a detailed briefing a
few days ago to ESA and the other International Partners on the
status to date.

Over 40,000 lbs of debris have been recovered, representing 20% of
the total Shuttle mass. However, nothing has yet been recovered west
of Texas despite the fact that there is filmed evidence that debris
had fallen over California. The search for debris in this area still
continues. 

The Orbiter Experiments Recorder is the latest piece of important
equipment to be found.  This is a magnetic tape recorder that records
data from various sensors during ascent and re-entry, which had not
been tele-metered down to the ground. The recorder is currently at
the Kennedy Space Centre and undergoing analyses.

Positive evidence has also been found that a piece of debris, about
30 cm x 15 cm, had separated from the Shuttle on Flight Day 2 and had
re-entered the atmosphere 3 days later. This was discovered from
radar plot searches carried out after the accident.
 
Extensive analysis of the aerodynamic behaviour of the Orbiter during
its descent has taken place. Synthesis of the data indicates that
there was already some form of damage at the point of 'entry
interface' and there is evidence of gas (plasma) entering the left
wing several minutes before loss of signal.

There is evidence also of much greater damage having occurred 2-3
minutes before loss of signal.  During this time, Columbia was
rolling on its longitudinal axis in an anti-clock-wise motion and
yawing to the left. 

Wind tunnel and thermal analyses have been conducted to show that
shock interactions over a damaged left wing could produce similar
temperatures as have been indicated by Columbia's sensors, and that
plasma flow through the natural vents of the wings and, eventually,
the main landing gear wheel well, would lead to similar temperature
excursions in that location as had been measured.

Attention still focuses on the shedding of insulation foam from the
External Tank during lift-off, and impacting the left wing as being a
significant contributory event to the accident.

The left wing main landing gear door has not yet been found, but all
six tyres and two of the landing gears.

The External Tank team is looking at improved foam adhesion and the
feasibility of an on orbit inspection and repair capability for
external Orbiter surfaces for future Shuttle missions.

Also under investigation are improvements in the photographic
coverage of critical mission events and alternative trajectory
options for minimising re-entry heating.

ISS status and short term plans

All international partners involved in the ISS agree that the station
should remain permanently manned.

Discussions are currently underway with regard to the Shuttle's
return to flight and a specialised 'Return to Flight' team has been
established by NASA.

It has been agreed in principle that given the temporary grounding of
the Shuttle fleet, the permanent crew should be reduced to two. This
would come into effect from April 2003 when the next Soyuz flight
would be used for a crew rotation.

Agreements have been reached between ESA and Rosaviakosmos with
respect to the scheduled Soyuz flights of ESA astronauts Pedro Duque
and Andre Kuipers.  Duque will now fly in October/November this year
and Kuipers will fly in April/May 2004.

The present three ISS crew members continue to focus on routine
maintenance of the station systems and a survey of the station using
the Canadarm2 robotic arm.

ESA's Microgravity Science Glovebox is again in operation. This
allows the crew to carry out experimentation in a number of fields of
research, including materials and fluid science, combustion, crystal
growth and biotechnology.

A detailed logistics plan covering the rest of 2003 and 2004 has been
developed, including the role of ESA's Automated Transfer Vehicle
(ATV).  The ATV is expected to be launched in September 2004 for the
re-supply and re-boosting of the ISS.

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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