mardi 17 mai 2011

Interview de Bjarni Tryggvason, astronaute canadien qui a volé à bord de la navette lors de STS-85

Bjarni Tryggvason est pilote avec plus de 4500 heures de vol à son actif (Instructeur dans l'Armée de l'Air Canadienne, pilote de voltige et brevet de pilote de ligne) et scientifique avec une spécialisation en mathématiques appliqués et mécanique des fluides.
En décembre 1983, il est sélectionné comme astronaute dans le premier groupe d'astronautes canadiens.
Il est doublure de Steven MacLean pour la mission STS-52 en 1992.
Il est le responsable du programme LMIM, et s'occupe donc de la mise au point du grand support d'isolation contre les vibrations en microgravité (LMIM), qui volera à de nombreuses reprises à bord du KC-135 et du DC-9 de la NASA.
L'application de ce programme, qui est baptisée MIM (support d'isolation contre les vibrations en microgravité) volera entre avril 1996 et janvier 1998, et servira pour de nombreuses expériences en sciences des matériaux et des fluides.
Il élabore le MIM-2, et volera avec lui, lors de la mission STS-85 du 7 au 19 août 1997.
Il quitte l'Agence Spatiale Canadienne en 2008.
Interview réalisée en mai 2011.
How many years were you connected to the space program prior to your flight ?
I was with the Canadian Space Agency for 14 years before my first flight.
How did you feel prior to the flight ?
In the months, weeks, days prior to the flight I felt increasingly ready for the mission.
We trained hard for 10 months and I felt completely ready by the launch date.
I also felt very fortunate and grateful that I had the opportunity to fly in space.
What kinds of sensations did you experienced during lift off ?
During lift off, the first sensation is that of a great push against your back and tremendous vibrations.
This lasts for the first two minutes.
Once the solid boosters are dropped off the rest of the launch is very smooth but with increasing g-load.
When the shuttle main engines shut down at 8.5 minutes, your seat springs forward as the acceleration load is relieved and you get a sensation of tumbling forward.
This goes away quickly.
What does weightlessness feel like, and what did you think about during the flight ?
Once unstrapped from the seat and free to float the immediate reaction is to use the legs to move - but this does not work at all and one quickly gets on with using the hands to push off from walls, ceiling, etc., to move around within the spacecraft.
It is really easy to move around in the free fall environment, and it feels so gentle.
Not at all like Star Wars where the actors run along floors - that just does not work in space !
What were some of the problems you encountered and how did you fixed them ?
We had no technical issues with the space shuttle on our flight.
I did have an issue with the hard drive on the MIM (Micrgravity Vibration Isolation Mount) but had a spare.
We did discover that the cause was a software issue and were able to use alternate programs to avoid this recurring.
This was an unexpected type of failure, but the team on the ground supporting the flight did an excellant job of determining what the issue was and sending up a detailed procedure for correcting it.
It was a real team effort that resolved it and I was able to press on with the remaining experiments.
We lost only a half day of work.
What did you eat, and did it taste real ?
I had the normal NASA space fare : fresh food only for the first two or three days, canned food, freeze dried foods to which you add water, quite a bit of trail mix with nuts and dried fruit, and Kona coffee.
Drinks are all in powdered form to which we add either hot or cold water.
The water on the shuttle had iodine in it so that was not so pleasent after 12 days.
What was re-entry like ?
Rentry in the space shuttle is very smooth.
At Mach 25 winds do not bother one very much.
The rentry is a critical phase of the flight.
You slow the shuttle down over Australia, intersect the atmosphere over Hawai, and transition from orbital mechanics based flight to aerodynamic based flight as you slow from 7.8km/s to Mach 5.
Then continue slowing to achieve a final approach speed of 300kts to a smooth touchdown.
It was all quite impressive and our commander did a great job of the landing.
During the transion from orbital to arodynamic flight the g-load increases to about 1.8g and this is held for quite a long time.
I inflated my g-suit to counter the tendency of fluid pooling in the legs and gray-out.
Were you glad to be back on Earth, or did you feel you could have spent the rest of your life up there ?
I was glad to be back home.
My kids were there waiting for me and this was a special treat.
Having a good shower - there are none on the space shuttle - and fresh food was also a great treat.
At the same time I knew I would miss being in space with its fabulous view of the Earth and the ease of movement in the free-fall environment.
My flight in space was the highlight of my career, but I am now busy doing many other very interesting things.

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