mercredi 25 mai 2011

Interview de Gerhard Thiele, astronaute allemand de l'ESA qui a volé à bord de la navette spatiale

Gerhard Thiele est un physicien allemand.

Il est sélectionné en 1987 par l'Agence Spatiale Allemande DLR et il sera doublure pour la mission STS-55.

Il est sélectionné dans le groupe des astronautes ESA en 1996. Et se prépare à sa future mission spatiale STS-99.

Il effectue une mission spatiale du 11 au 22 février 2000 à bord de la navette spatiale Endeavour pour la mission STS-99.

De 2002 à 2003, il le responsable des astronautes (chief-astronaut) de l'ESA.

En 2003-2004, il est la doublure d'André Kuipers pour la mission Soyouz TMA-4.

Interview réalisée en mai 2011

Q :  How many years were you connected to the space program prior to your flight ?
A: I joined the German Space Agency (DLR) in 1987 as science astronaut and flew into space in 2000. So overall I was for more than twelve years in the space programme before my first flight.

Q : How did you feel prior to the flight ?
A : From a professional point of view we were very well trained and prepared to discharge the mission. We were convinced that with some luck we could be highly successful and get the results, which the scientist worked for and hoped for.

On the personal side I sensed a certain anxiety, which was in my opinion the result of two major things: first, a dream was about to come true. And second, I have never flown into space before, you never know what is going to happen ! 

The good thing: As soon as you are strapped into your seat in the orbiter the concentration focuses on the work at hand. The anxiety seems to fade away and in the end disappears, which allows one to focus on what needs to be done at the moment.

Q : What kinds of sensations did you experienced during take-off ?
A : Lift-off feels extremely powerful!!

This is all the more astonishing as we have no sensors in our body, which measure acceleration or force.

And though the g-level at take-off is rather mild, one weighs only twice as much as normally, I felt an enormous pressure. I assume this has to do with the fact that we know that we are sitting in a rocket and that this knowledge affects our perception and feeling.

Q : What does weightlessness feel like, and what did you think about during the flight ?
A : Weightlessness feels like the jaunty lightness of being.

It is just the opposite as in Milan Kundera’s novel: The unbearable lightness of being.

Q : What were some of the problems you encountered and how did you fixed them ?
A : We encountered relatively little problems during our mission.

The first one was that one of the reaction control jets (RCS) failed. As these jets are also important for maintaining the proper attitude, this could have been potentially dangerous for the mission objective, which was to map the Earth’s landmass with high precision.

This of course requires that the various data are taken in the same (ideal) or at least similar attitude.

Luckily, the failure occurred while we were over the pacific ocean. Over water we didn’t take any data (only for reference close to the coast) and so we didn’t loose any data while dealing with the rcs failure.
Moreover, we were able to reconfigure the system just before Africa again, we had been really fortunate!

A second failure was that the container, into which the 60m long mast was retracted after the measurements, did not close.
It turned out that the cables which had been exposed to the chilly temperatures of space for about ten days became too stiff and prevented the lid from closing the container.
So we turned on the heater system, which was designed exactly for this case and moved the shuttle into a “baking attitude”.
This means, we allowed the sun to help heating the container as much as possible as well.
And it worked. After some hours (I forgot the exact number) the cables were warm enough, lost their stiffness and the mast could be fully retracted.

Q : What did you eat, and did it taste real ?
A : The food is actually quite good and tastes pretty well.

Generally the food is dehydrated, so you have to add a specified amount of water to the food container. Then the food is heated in the oven for some ten or twenty minutes and you are good to go, i.e. to eat.

My favorite food was shrimp in a horseradish sauce, which shows that the taste seems to shift towards more spicy food.

On Earth I love sweets. In space I avoided them for almost a full week.

Q : What was re-entry like ?
A : During re-entry I was seated in the middeck of the orbiter and therefore was not involved into any re-entry procedures flying the shuttle back home.

I was surprised to hear the noise as we entered the atmosphere and it became significantly warmer inside the cockpit.
Luckily, our suits had a cooling system integrated, which made the temperatures bearable.

Crossing the sound barrier was also very noticeable, below the speed of sound the shuttle just glides gently through the final miles towards the runway. Although this is a rather steep glide.

Most noticeable is of course “the return of gravity”. The initial weightlessness turns initially into a barely noticeable gravitational force, which increases steadily as the shuttle enters thicker and thicker layers of the atmosphere. Back on ground the “normal” weight feels actually quite heavy and not normal at all !

Q : Were you glad to be back on Earth, or did you feel you could have spent the rest of your life up there ?
A : Yes and No. I was glad to see my family again. And I would have loved to stay in space.

      Yes I could have envisioned living in space for a very prolonged period of time!

Q : Which memory(ies) have you of the spaceflight of Yuri Gagarin and about the Apollo 11 lunar landing ?
A : I have no memories of Yuri Gagarin’s flight, I assume for two reasons.
When Yuri Gagarin flew into space I was just seven years and at this age I certainly did not understand what it means to go to space.
To the best of my recollection I did not have any romantic approach to spaceflight, at least not at the age of seven.
The second reason is that the Soviet Union made a big secret out of this flight and the world learned that the flight has happened only after the fact.
This however means that people couldn’t participate in it “emotionally”, when it happened. Of course I realized that Gagarin became a big hero after his flight.

The situation was very different with Apollo.
The American space program was open and we were able to follow it in any detail we wanted to follow it.
And therefore memories of this historic moment are much more present and dominant for this historic achievement.

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