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MELINDA JAMES, PRESENTER: They're the size of the MCG, as thin as gladwrap and float up into the stratosphere. Giant balloons carrying scientific equipment that weighs two to three tonnes and is worth up to ten million dollars will soon be launched from Alice Springs. Associate Professor Ravi Sood is in charge of the massive balloon launch and I spoke with him earlier.
MELINDA JAMES: Associate Professor Sood, thanks for talking to Stateline.
ASSOC. PROF. RAVI SOOD, BALLOON LAUNCHING STATION DIRECTOR: A pleasure, Mel.
MELINDA JAMES: Just what is it that you're doing with these balloons?
ASSOC. PROF. RAVI SOOD: We got three balloon flights from Alice Springs and each balloon flight is going to carry its own instrument, its own payload. All three payloads are specifically designed to look for x-rays and gamma rays coming from violent objects in the universe. Objects like exploding stars, colliding galaxies, black holes and neutron stars.
MELINDA JAMES: How will you apply what you discover from the data you collect - are there implications here for our understanding of other galaxies and the nature of space, that type of thing?
ASSOC. PROF. RAVI SOOD: That is correct, the research that comes out of this is purely to do with advancement of knowledge. It is not the type of result that is going to help us travel better in space, it is simply advancement of knowledge in the field of astronomy and astrophysics.
MELINDA JAMES: Let's talk about these balloons - what kind of properties do these balloons have to have to fly that high and withstand the conditions in the stratosphere?
ASSOC. PROF. RAVI SOOD: Ok, the reason why we need to fly high, that high, is first of all one is looking for gamma rays and x-rays. This type of radiation gets absorbed in the atmosphere and you can't do this research from the surface of the earth - unlike your optical telescopes and your radio telescopes. So you need to take your instruments to the top of the atmosphere. A typical instrument will weigh 2 tonnes and to carry that to a height of 40kms you need a very large balloon. The larger the balloon, the heavier it is going to be so you actually then try and make it as thin as possible. That's where the problems start to arise, a very large thin balloon is very difficult to launch and we have all sorts of problems in trying to launch these balloons from here.
MELINDA JAMES: These telescopes - getting them to Alice Springs from the United States has been quite a feat in itself, hasn't it?
ASSOC. PROF. RAVI SOOD: Oh yes, there have been some unique problems and one of the most unusual problems was with the detector that comes from the University of California, Berkeley, which had to be kept cold at minus 196 degrees throughout the time that it left the United States to the time it arrived in Alice Springs and it will have to stay at that temperature throughout its working life.
MELINDA JAMES: What kind of control do you have over the balloons once they're launched, they're unmanned of course?
ASSOC. PROF. RAVI SOOD: That's correct. The only control you have on the balloon is to be able to send it up a little bit higher by dropping ballast and a typical balloon will carry about 500kg of ballast in the form of sand or iron pellets, or there is a plate at the top of the balloon which you can open to bring the balloon down in altitude. That's the only control you have, otherwise the balloon is at the mercy of the winds and at this time of the year what is going to happen is that the winds are going to carry the balloon towards Western Australia so we have a down range tracking station in Newman to pick up the signal once we lose it from Alice Springs.
MELINDA JAMES: How do you get them down again? They're containing some pretty valuable equipment, I'm assuming you don't want them to just crash land in the middle of nowhere?
ASSOC. PROF. RAVI SOOD: A typical balloon experiment costs 5-10 million dollars and takes many years to build, so certainly one needs to recover the instrument. As far as the balloon is concerned, you can use it only once. So, at the end of a flight you put a rip in the balloon and you bring it down separately from the instrument which comes down on a parachute. We watch the instrument come down on the parachute and as soon as it impacts the ground you release the parachute from the instrument and the only reason for that is that if the wind gets into the parachute then it can drop the instrument for many many kilometres across the ground.
MELINDA JAMES: That brings me to the question of why Alice Springs is the perfect place to launch these balloons. There are vast open spaces that I suppose make it ideal, but are there any other reasons why Alice Springs is one of the international centres for stratospheric balloon research?
ASSOC. PROF. RAVI SOOD: You have described the first reason perfectly, and the second reason is equally important and in fact even more important. You can do a lot of good science from these latitudes. At the latitude of Alice Springs, you can see the centre of our galaxy almost vertically or ahead, you can't do that from the Northern Hemisphere which is why scientists from the Northern Hemisphere actually come to our part of the world. There are a lot of other interesting objects in the Southern Hemisphere, close by galaxies, fast rotating neutron stars and so on. So there are a lot of interesting objects which you can observe from Alice Springs and from similar latitudes around the world.
MELINDA JAMES: Given their size, they'll be hard to miss, I'd imagine. But will people in Alice Springs be able to watch the balloons being launched?
ASSOC. PROF. RAVI SOOD: People can see this from their backyards, I mean when the balloon takes off the flight train is about 200 metres high and the sun is on it on the plastic material so that is visible from a long long way away. Now, come sunset when the sun has set at the surface of the earth but is still there at the altitude of the balloon which is 40kms. The balloon actually stands out like a brilliant star, you imagine that the balloon envelope is more than a million cubic metres - about the size of a large football field. You can see it very clearly, it's a spectacular sight.
MELINDA JAMES: Professor Sood, good luck with the launch and thanks for talking to us.
ASSOC. PROF. RAVI SOOD: Thank you Mel.
*** Vision - Courtesy NASA CSBF ***