GREECE: Falling from a great height for science

University professors are no longer white-haired, bespectacled, elderly gentlemen; they are young, fit, well versed in the use of computers and state of the art laboratory equipment, have left the campus and carry out experiments in the most unlikely places under extraordinary conditions - including inside an airplane cascading towards the earth from a height of 10 kilometres with its engines switched off.

Associate Professor Theodore Karapantsios headed a research team from the chemistry department of the Aristotle University of Thessaloniki. The team participated in the European Space Agency's programme for a series of experiments titled Heat transference by molecular diffusion in liquids in reduced gravity conditions.

The programme took place last month during a series of parabolic flights over the Atlantic Ocean, as part of a drive for the recruitment of a new generation of European astronauts. Initial tests and experiments in the previous space agency's parabolic flights last November had been carried out with simpler liquids, such as water and glycerine; this time more complex systems such as frozen liquids and dispersed objects of various sizes and concentration were used.

It was essential the experiments were carried out in a reduced gravity environment so the heat transfer was not influenced by the phenomenon of natural buoyancy. Reduced gravity was created during parabolic flights with the use of an appropriately equipped Airbus A-300.

Such flights are the most appropriate way of creating conditions of reduced gravity for short periods. This is the first step before the experiments are carried out in the International Space Station, which is in a permanent orbit around the earth and where protracted conditions of reduced gravity exist.

Each parabolic dive occurs when the aircraft climbs to 10 kilometres above the ground, the engines are switched off and the aircraft dives for two kilometres, achieving reduced gravity conditions for up to 30 seconds. The aircraft switches on its engines again and climbs to 10 kilometres for the next dive.

Up to 100 such dives are made during which the experimental equipment inside the aircraft is switched on and those inside perform various measurements under reduced gravity conditions.

The team from the Aristotle University is the most experienced Greek group for experiments in reduced gravity conditions and the members were participating in parabolic flights before Greece became a full member of the European Space Agency. Previous experiments concerned the thermal degassing of liquids from 1995-2004.

Apart from Karapantsios, the team consists of two PhD students as well as a chemical engineer who also serves as a ground engineer.

makki.marseilles@uw-news.com