Last Wednesday took place one of the most important milestones in recent years in the history of aerospace science. A tube called Philae , getting land on Comet , 67P , something that had not happened ever before . One of the architects of this success is the engineer of mechanical space Spanish Alejandro Blazquez . Blazquez, who spent eight years working in the CNES of France (CNES), has been one of those responsible for calculating the trajectory was to take Philae from the Rosetta probe to the comet. A few hours after having experienced one of the most exciting days of your life, we serve.
What was your involvement in the Rosetta mission?
The CNES has worked on the mission since the nineties by calculating trajectories, I have five. Rosetta is a mission of the European Space Agency (ESA), while Philae is a collaboration between the French and the German space agency. We were responsible for charting the way to Philae from Rosetta to comet 67P. We had to calculate the forces involved, what was the gravity of the comet, the degassing … We have also participated in the process of choosing the place of landing, providing technical input for scientists chose where to land and where not.
How does that do when you have the object of study to over 500 million miles away?
Until early July were completely blind. Until then we had studied all kinds of small bodies, trying to see where he could land, so that when he arrived July and we began to have the first models submitted by Rosetta we were able to choose a place to land safely.
understand. First they went blind and then they came for actual photos of 67P. And then he thought …
Well, we were prepared for everything but that. No one was expected to have the two-headed way. It is also true that we had no history, no one had come to a comet. What I had done was to study asteroids, rocks that have no inert gas, and are much closer. It has always been the objects that pass close to Earth, always less when Americans hurled a comet with the goal of crashing. But of course, one thing to crash and another is circling a comet in a controlled manner, which is what has gotten the ESA team.
You know the comet and from then begin to calculate the trajectory …
That’s right. And in that process many factors, but mostly we take into account the laws of Kepler-the attraction of masses divided by the distance to the square- applied equally around the Earth about a comet. The Newton’s apple go [laughs]. Basically you have to take into account the gravity and the gas issuing from the comet.
I understand …
All bodies in the solar system with gravity. Gravity is just a feature of the masses and all bodies have mass. And gas is characteristic of comets. They are composed of water, and this water is in a solid state is sublimated as snow when exposed to the sun too long and starts dating a gas. The ice becomes water vapor.
Y is the wake behind the comet in its path.
Indeed. That’s the base. After other factors. The better you know the forces involved, the easier it is to calculate the trajectory. At this point I must say that the ESA calculated a second accuracy. They predicted that Philae was going to land at 15:34:55 and did so at 15:34:54. Until that point comes the knowledge that has managed to get the kite.
I guess what alighting on him would not be easy …
Scientists say that the objective of the mission was not land, but to analyze the comet . That means no use land in a part where there is no activity, because we will not teach anything. There was the challenge, choosing the easiest or the most interesting site.
What a task …
Keep in mind that we did not know almost nothing the object you want to land. One of the things he said the leader of the scientists was that when Philae mission took place last Mars mission spent two years in deciding where they landed, and that had data, photographs, and knew what the weather was, stations and the chances of sandstorms. For 67P, four months ago we knew nothing, neither size nor shape or density, or rotation, nor the rate of degassing.
But in the end set a place, I understand would not be easily accessible …
There were more complicated sites that land, but not chosen the easiest. The images showed us that the chosen site had some activity. Although it is not my specialty, I am a specialist in trajectories, which scientists say is the chosen landing site, in the small head of the comet was not inert, but active site.
Although in the end did not fall Philae where intended.
The point where the probe touched the first comet itself was the site chosen. But what happens is that a glitch, Philae bounced. We believe that the probe has been placed in a nearby large crater that is located in the small lobe of the kite spot.
Wow …
That’s the decision that we had. After ten years in space, anchoring systems that were planned did not work as expected. And this has been what has made us bounce. That means we are not on site we wanted, we are in a different place, although the scientists graded interesting. But the truth is that not all instruments will be able to work.
And that’s a problem.
The extra mission accomplished wanted not be able to do. The idea was to stay anchored to the kite in a quiet, 67P expected to come closer to the Sun and its evolution in order to observe in situ. And that part can not be done. Philae work will be over in a few days when ‘die’, and we will only Rosetta data. Probably the Rosetta mission will last twenty months.
What can not be done just for the bonus mission anchors problem?
The fact bounce led us to a website not have enough energy. Solar panels will not be able to keep alive Philae. In the place where we landed impossible that the probe receives enough to keep working to the point where we wanted energy.
Beyond this mishap with harpoons, did they expect the mission was so successful?
There have been times that we thought would be impossible to do and times when we told ourselves, why not? I was very confident anyway. One in two of us who were on the project we thought we would get to land.
I guess hours after living one of the most important days of your life, is now something quieter.
Yesterday was very tense. We’ve spent years talking about November 11, 2014. And when you see that the time is right and that the probe is about to land, everything seems to indicate that all is well, it is fantastic … It was pretty exciting.
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