N° 73–2000: Scientists, schoolteachers and students study physical and life sciences on parabolic flights with the European Space Agency

Parabolic flights are practically the only means on Earth of reproducing weightlessness with human operators on board. During a parabolic flight, the "Zero-g" Airbus pilot - flying at an altitude of approximately 6000 metres, usually in a specially reserved air-corridor above the Gulf of Gascogne - first performs a nose-up manoeuvre to put the aircraft into a steep climb (7600m). This generates an acceleration of 1.8 g (1.8 times the acceleration of gravity on the ground) for about 20 seconds. Then the pilot reduces engine thrust to almost zero, injecting the aircraft into a parabola. The plane continues to climb until it reaches the apex of the parabola (8500m), then starts descending. This condition lasts for about 20 seconds, during which time the passengers in the cabin float in the weightlessness resulting from the free fall of the aircraft. When the angle below the horizontal reaches 45°, the pilot accelerates again and pulls up the aircraft to return to steady horizontal flight. These manoeuvres are repeated 30 times per flight.

With Europe and its international partners now building the International Space Station, where research will be carried out for the next 15 years, parabolic flights are crucial to the preparation of experiments, equipment and astronauts, and allow scientists to have their experiments tested before they are actually flown on a space mission.

ESA's next parabolic flight campaign, the 30th, is scheduled for May 2001 and will have a mixed complement of experiments in life and physical sciences, again with student-proposed experiments.

More information on ESA parabolic flights can be found on ESA's special parabolic flight Internet pages at:

http://www.estec.esa.nl/spaceflight/parabolic

For further information, please contact:

Vladimir Pletser

ESA/ESTEC, Microgravity Payloads Division

Directorate of Manned Spaceflight and Microgravity

Tel: + 31.71.565.33.16

Fax: +31.71.565. 31.41

Anna Brück

ESA/ESTEC

Coordination Office

Directorate of Manned Spaceflight and Microgravity

Tel: +31.71.565.5445

Fax : +31.71.565.5441

For further information on ESA, visit our web site: http://www.esa.int

Experiments and scientists involved in the 29th ESA parabolic flight campaign

The four physical science experiments are related to fluid physics and investigate electrostatic effects in boiling liquids, particle motion in aerosols, annular liquid flows and plasma states.

 

1. "Study of the effect of an imposed electrostatic field on pool boiling heat transfer and fluids management" by Prof. W. Grassi and Dr P. Di Marco (University of Pisa, I). The experiment studies the enhancing effect of electrostatic fields on pool boiling of dielectric liquids. Results obtained during the 25th ESA parabolic flight campaign have shown that additional forces due to electric fields arise. These forces are usually at least partially masked by gravity on earth and a weightless state is needed to better understand their influence. Results will improve the design of heat exchangers, in particular for application in space vehicles.

    

2. "Three-dimensional tracking by digital holography of particle motion in non-equilibrium aerosols" by Prof. J.C. Legros and Dr A. Vedernikov (University of Brussels, B) and Prof. F. Prodi (Istituto ISAO-CNR, Bologna, I). The experiment prepares for the "Interactions in Cosmic and Atmospheric Particle Systems" (ICAPS) research project to be conducted on the International Space Station. The study of the motion of micron-sized particles in an aerosol gas gives information on the nature of chemical reactions taking place at the surface of the particles, allowing in the long run a better understanding of the chemistry of gas-particle systems, like our atmosphere for example.

    

3. "Annular flow film thickness and pressure drop measurements in microgravity". Part of an international collaboration between Canada and France (Prof. K. Rezkallah, University of Saskatchewan, CDN, and Dr C. Colin, Institute of Fluid Mechanics, Toulouse, F). The experiment investigates the characteristics of liquid films of annular flow in pipes. In annular channel flow, the liquid is forced to the channel's wall while gas flows in the centre. It is an important flow regime in many sectors, including nuclear, oil and gas industries, refueling space vehicles and heating and refrigeration systems. Two Canadian students will fly with the experiment.

    

4. "Preliminary tests for the International Microgravity Plasma Facility" by Prof. G. Morfill and U. Konopka (Max Planck Institute, Garching, D). The experiment investigates the shape and geometry of a newly designed experimental chamber in which a complex plasma, i.e. a mixture of ionized gas and microparticles, is formed, stimulated by radio-frequency electrodes. The effects produced and the impact of the chamber geometry and shape is investigated in order to prepare for the IMPF that will fly on the International Space Station.

   In life sciences, two physiology experiments study the cardiac system and two biology experiments investigate plant gravitaxis and cell and particle motion by ultra-sounds.

    

5. "An assessment of the feasibility and effectiveness of a method of performing cardiopulmonary resuscitation during microgravity" by S. Evetts (School of Biomedical Sciences, King's College, London, UK) and Prof. T. Russomano (Univ. do Rio Grande do Sul, Porto Alegre, Brazil). The experiment examines a newly proposed method of cardiopulmonary resuscitation (CPR) in microgravity. On earth, CPR is practised by applying external cardiac massage (ECM) by chest compression in the direction of the gravity vector on a patient who is lying down and by additional mouth-to-mouth resuscitation. In microgravity, conventional ECM is not possible on a free-floating patient. A new approach has been proposed, the hetero-arrest resuscitation vice, in which the physician encircles the patient's thorax with his legs to maintain a close enough proximity to perform CPR. This new method is tested on a mannequin designed to simulate a human patient.

    

6. "Acute heart response to weightlessness conditions during parabolic flights" by Prof. A. Aubert, Dr F. Beckers and Dr D. Ramaekers (University of Leuven, B). This experiment investigates heart rate variation occurring during parabolic flights at transitions from 1g to 1.8g and to 0g, in order to monitor the response of the autonomic nervous system (the part of the nervous system concerned with the regulation of bodily functions). This new discipline, "Neurocardiology", combines the fields of neurosciences and cardiovascular physiology and is concerned with the variation of the basic heart rate and its modulation due to alterations in autonomic activity.

    

7. "Investigation of physiological parameters of gravitaxis in Euglena gracilis" by Prof. D.-P. Häder (University of Erlangen-Nuremberg, D) investigates the phenomenon of gravitaxis, the motion away from the center of gravity. On earth, without other stimuli, Euglena gracilis, a fresh water flagellate, orients itself upward in the water column. Some theories claim that gravitaxis is exclusively based on passive buoyancy effects. The experiment investigates possible physiological mechanisms in the gravitactic orientation, involving physico-chemical reactions inside the cells which contribute to the phenomenon of gravitaxis.

    

8. "Ultrasonic particle and cell manipulation in microgravity" by P.I. Dr. L.G. Briarty (University of Nottingham, UK). The experiment manipulates and separates particles in suspension, such as biological cell cultures, by ultrasonic fields. This new method has considerable advantages in microgravity on classical separation methods based on filtration and centrifugation. Identifying the effect of gravity or its absence on the behaviour of particles, such as suspension cell cultures, allows optimization of the filter use for applications on earth. The experiment is a cooperative effort between the Universities of Nottingham and Cardiff and the Technical University of Vienna, and is supported by the EC TMR programme UltraSonoSep.

   Two experiments were proposed by students and selected after two international competitions, one in a medical field and the other in space technology.

    

9. "Pulse transit time for the non-invasive determination of arterial wall properties" by P.F. Migeotte, T. Dominique and R.C. Sá (University of Brussels, B). This experiment studies the properties of arterial walls using a newly proposed non-invasive method. The time that the pressure wave created by a heart beat takes to arrive at the periphery (e.g. fingers) is called the pulse transit time. This parameter can be determined by the measure of the time delay between the peak of a heart beat monitored by an electro-cardiogram and the arrival of the corresponding pressure wave at the finger or toe measured by means of a Portapres device or a pulse oximeter.

    

10. "Globular Cooking Facility " by S. Podhajsky and G. Grillmayer (University of Stuttgart, D). The Globular Cooking Facility is an ingenious facility for preparing and cooking food in microgravity, with an obvious application for the International Space Station. The GCF is basically a spherical structure with an opening on the 'top' to allow the insertion of fresh food and removal of prepared food. It is complemented by several subsystems making it possible to sterilize, stew, cook, bake or fry the food.

     

11. The last experiment has promotional and educational purposes. Several secondary-school teachers, detached to the Euro Space Center in Transinne, Belgium, conduct simple classroom experiments in physics and chemistry emphasizing the role of gravity or its absence during parabolic flights. These simple experiments will be recorded and shown later to the general public and school pupils attending space classes at the Center to promote early awareness of the characteristics and possibilities of the space and microgravity environment. Springs, yo-yos, gyroscopes, magnetic balls, pendulums, simple food (sweets, bananas, grapes) will be used in microgravity to explain different behaviour in weightlessness and the difficulties that astronauts may encounter in their everyday life in orbit.