In conjunction with the European Commission's 'European Week for Scientific and Technological Culture' in November, ESA organised the second parabolic flight campaign for students. Students selected through a competition, were again given the unique opportunity of experiencing weightlessness as they performed their own scientific experiment during a parabolic flight. The experiments covered a wide variety of disciplines. Some illustrated well the effect of microgravity while others may offer new and far-reaching scientific results.
The primary goal, however, is to educate and motivate the students rather than to obtain new research. It is hoped that the campaign will stimulate the next generation to think about space and the potential of microgravity. It is in that way that an innovative future user community for the International Space Station Alpha can be built. The great enthusiasm shown by many students and the wide coverage provided by the media also demonstrate the interest in space and the promotional value of the campaign.
Although it is always important that the next generations are well aware of the opportunities that space offers, it is now of the utmost importance. Europe is entering into the era of the International Space Station, a long-term programme extending well into the next millenium, and ESA will also begin implementing its outreaching vision defined by the Long-Term Space Policy Committee, which expresses the need for innovation and new technologies. Today's young people will be the ones who eventually take over and become responsible for implementing much of today's plans. Action is therefore required now to ensure that they are made interested in space-specific technologies early enough and are aware of the unique potential for research that the Space Station will offer. Only by giving young people the opportunities now, will innovative R&D in Europe be guaranteed for the future.
One aspect of that, to give students the opportunity to develop an understanding of weightlessness and how it can be used aboard the Space Station, is already being addressed: ESA has now organised two parabolic flight campaigns dedicated to students and their experiments. The first one was held in 1994 and the second one in 1995. Attempts are now being made to make it an annual activity.
The Aerospace Students Association of the Delft University of Technology (NL) first proposed the idea to hold a parabolic flight campaign for students. ESA accepted to organise such a campaign. The participants are selected through a competition based on their proposal for an experiment that can be carried out in 25 seconds of zero gravity, including the experiment's originality, its demonstration value for microgravity research and its educational value. They are then invited to carry out their experiment aboard a special parabolic flight. This year's competition was launched in March with a deadline for submissions in June. An international jury, under the author's chairmanship, selected 23 experiments covering a wide variety of disciplines (Table 1). The 55 students chosen represented 11 countries (Table 2).
Scientific field Experiment and experimenter Reference ---------------------------------------------------------------------------------------------------- General physics Convection of vibrated granular material under G-12 the influence of microgravity Volkhard Buchholtz & Jan Freund (Technical University of Berlin) Three-dimensional visibility of a magnetic field G-19 Lutz Kunath (Technical University of Berlin) Orbital simulation model I-3 Zaky El Hamel & Paolo Sabatini (University of Milan) Modes of vibration and control of bobbing on a tethered system I-4 Danielle Innorta & Luca Soli (University of Milan) Wave-movements in a free-hanging rope without gravitational force NL-4 Evert-Jan de Theije, Femke de Theije & Koen Koustaal (Universities of Nijmegen and Eindhoven, The Netherlands) Visual gravity by measurements experiments, & Space table N-1/3 Bjorn Ottar Elseth, Laurent Van Ham (Delft University, The Netherlands) Synchronous picosecond sonoluminescence US-1 Thomas J. Matula (University of Washington, Seattle, USA) Fluid Physics Capillary effects in two-phase flow in porous media for enhanced B-2 oil recovery and contaminant in soil transport modelling Nicolas Boseret & Eric Istasse (University of Brussels) Capillary waves without the disturbing effects of gravity G-7 Tamim Sidiki & Christian Berg (Bergische University of Wuppertal, Germany) Experimental confirmation of thermo-vibrational convection I-6 in a fluid cell Cicalla & Massimo Piccirillo (University of Naples) Study of a liquid mirror under microgravity CH-1 Alexandre Cuva (University of Geneva) Thin liquid film experiment UK-6 Thomas Gribovszki & Raghuram Tumkur (Utah State University and Mullard Space Science Laboratory, Surrey, UK) Combustion Diffusion flames in hyper- and microgravity P-1 Ahmed Abatorab & Piotr Podobinski (Warsaw University) Material processing Solidification of hypermonotectic Al-Pb-Bi alloys in aerogel crucibles G-18 Gudrun Korekt & Stefan Hofacker (Cologne University, Germany) Fabrication of a metal matrix composite in microgravity UK-4 Jason Maroothynaden (Imperial College London) Crystals and glass Structural relaxation in microgravity F-3 Christophe Le Deit & Benedicte Friot (University of Rennes, France) Behaviour of a heap of marbles in microgravity F-1 Oliver Savin, Guillaume Faure (ENSAE Toulouse, France) Optics Focussed by air: large air lenses AU-1 Manuel Reiter & Robert Holzer (Linz University, Austria) Biology Microgravity as a release of nastic reactions explored on the example G-22 of rapid leaf movements by Mimosa pudica Wolfgang Neumann (Munster University and Bonn University, Germany) Investigation into the behaviour of invertebrates in microgravity UK-2 F.J. Bell (Guildford Grammar School, UK) Technology Welding in microgravity G-9 Thomas Kluge & Oliver Kropla (Technische Hochschule Aachen, Germany) Test of the Rapunzel deployer and the Star Track project NL-6 Michiel Kruijff, Eric-Jan van der Heide, Dieter Sabath & Manfred Krischke (Delft University, The Netherlands, and Munich University, Germany) Artificial cat NL-7 Roland Vissers, Quirien Wijnands, Bastiaan Willemse, Jeroen Deweerd & Robin Biesbroek (VSV, Delft University)
Austria 1 Belgium 1 France 2 Germany 6 Italy 3 Netherlands 3 Norway 1 Poland 1 Switzerland 1 United Kingdom 3 USA 1
The campaign was held in the week of 20-24 November as part of the European Commission's 'European Week for Scientific and Technological Culture'. The time remaining for the selected students to prepare their experiments was extremely short, much shorter than is normally given for the preparation for a professional experiment. In spite of the tight deadline, all experiments were ready on time.
The student campaigns are set up like regular ESA parabolic flight campaigns although they must take place in Europe, in keeping with the philosophy of the European Week for Scientific and Technological Culture. The 1994 campaign was performed from the CEV base in Brétigny, south of Paris, with CNES's 0-g Caravelle aircraft. This year's campaign was held at the Valkenburg Naval Air Station in The Netherlands. NASA's KC-135 aircraft was used; it was ferried from Houston because the Caravelle is no longer available. It was the first time that the NASA plane had made parabolic flights abroad. The company Novespace which had made the arrangements for the Caravelle was responsible for the arrangements for the KC-135 with NASA.
The company Orbitics had been contracted to oversee the accommodation of the experiments on the aircraft and their safety. They visited each experiment development site to inspect the experiment and to advise where necessary. The student teams managed, with strong enthusiasm and professionalism, to get their experiments ready in time while satisfying the safety regulations. Each of the students, who ranged from 17 to 31 years of age, also had to undergo medical examinations and physiological testing before they could be accepted for flight.
The campaign took place during the week of 20-24 November 1995. The students, some with additional 'ground support' in the form of family and friends, gathered in a hangar at the air base to ready their experiments for flight. Before the actual flight programme started, a safety review was held and extensive flight briefings were given to address the emergency procedures. Participants were given optional medication against motion sickness.
On each of the five days of the campaign, the NASA KC-135 conducted a two-hour flight, which provided at least 30 parabolas. Up to 15 students flew on each flight along with the campaign manager, a medical doctor, two photographers and up to four journalists. The NASA crew was very experienced and efficient.
The various experiments were accommodated on the different flights in such a way that each experiment could fly twice if necessary. If an experiment encountered problems during its first flight, it could be improved and flown again on a second flight. In that way, all experiments had a fair chance and each of the 55 students could experience at least one flight.
The more than 100 participants in the second parabolic flight campaign for students, in front of NASA's KC-135 which is specially-equipped for parabolic flights
The payload had to be reconfigured after each flight. The students did not spare their efforts and energy to work until late to be ready for the flight the next day. A very strong team spirit evolved, not least due to the fact that the day's video footage was shown and discussed each evening.
The students proved to be an excellent work force. During the flights, about a quarter of them became sick (which is typical for first-time flyers), but that did not hinder them from performing their experiments enthusiastically. All students were greatly impressed by the effect and the experience of weightlessness. Such an experience cannot be fully anticipated. They became aware of a new environment and started to think differently about what microgravity is and how it can be used.
Students working during a parabolic flight
There was much media interest in the campaign. More than 30 journalists from TV, radio and the printed press, from 10 European countries, visited the base to cover the campaign. Some 19 journalists also participated in the flights.
In spite of the fact that scientific results were not the prime objective of the campaign, the level of research undertaken could well withstand the criticism of professionals. As was the case in the first campaign, the students showed their limitless creativity and great enthusiasm. Many proposals received were unique and the experiments selected covered a wide range of disciplines. The experiments are described below.
To study the convection process in microgravity, two students from Berlin made sand grains of different sizes and colour shake, which causes the grains to move in an upward motion called convection. They demonstrated that this process is different in weightlessness. The samples, which are fixated in an emulsion, will be cut in slices back in the laboratory to observe the convection process, indicated by the coloured layers that formed.
Another student from the same university looked at how small magnets float around a large magnet in weightlessness and the shape of the magnetic field lines. It required some negative g impulses, which the pilot specially provided, to make all the small magnets come loose from the floor and show very clearly the field. Several good photos were taken.
Despite the many experts who doubted that the quality of the zero-g would be sufficient, students from the University of Milan successfully simulated the solar system (Fig. 1). They were able to make a small ball make a full elliptical orbit around a sphere, attracted by the high electric voltage of the sphere (3 kV).
Figure 1. Two Italian students perform an orbit simulation using a small mass attracted by the high electrical potential of a central sphere
Italians are known for their interest in tethered satellites and two students, again from the University of Milan, are no exception. They were able to simulate a tethered satellite system in the aircraft. They subjected a small (10 cm) satellite with an elastic tether to a magnetic force that simulated the gravity gradient.
One of the multinational teams, consisting of a Norwegian and a Dutch student, designed a 'pizza table' that uses air suction to hold the pizza on the table in microgravity and, just as importantly, to collect the crumbs. Such a table has drawn quite a lot of interest from Space Station engineers.
A team from the US undertook a definite first. They observed for the first time the variations of the light emitted by a small cavity created by ultrasound in water. The accoustically-excited cavity was expected to be brighter in weightlessness. The 2-g phase, however, showed the brightest bubble, an effect that the team will now need to explain.
A team of Belgian students observed how water drives out another fluid (isotane) by capillary forces in a stack of small glass spheres. This is a model for the cleaning of oil-contaminated soil. Contrary to their calculation, the surface of the water did not move in zero-g. A second try with water only, fortunately, confirmed the theory that they had learned from their professor. They returned home with good data and a puzzle to solve.
A student from Wuppertal, Germany, was very pleased with his results. He was able to take photos of gravity-free waves on the surface of silicon oil in zero-g.
Students from the University of Naples heated a fluid cell on one side to create so-called Marangoni convection. Small particles or tracers allowed the currents that formed four cells, two clockwise and two counter-clockwise, to be seen just as the students had learnt in the classroom.
The production of a mirror by rotating liquid mercury did not reach the desired shape although interesting photos were taken. The enthusiasm of the students, from Switzerland, was not hampered. On the contrary, they are now eager to analyse the pictures and learn why the shape turned out to be different.
A team of students from Surrey, UK, and Utah State University, USA, were able to pull very thin films of soapy water from a dish. They were studying the possibility of making thinner films in weightlessness. Thin films will eventually be needed for solar sail propulsion.
A team from Warsaw studied flames and showed how the slow burning in weightlessness can allow part of a flame to break off and float away, eventually burning itself out. This is very relevant research for the fire protection of future space laboratories.
Students from London worked with a special composite that melts in boiling water, to determine its reaction in weightlessness. The experiment had to be discontinued on its first flight because the water container leaked so badly. Back in the hangar, the students worked hard to resolve the problem and, the next day, on the second flight, they successfully melted and solidified samples (using a jet of cold water). Few others in the world are able to claim the possession of a so-called metal matrix composite sample that is 'space- made'.
Students from Cologne were able to make new alloys from aluminium, lead and bismuth, using rapid cool-down and solidification within the 25 seconds of zero-g. They now have many samples to analyse in their laboratories.
Crystals and glass
Students from France used a furnace to melt glass and then dropped pieces into a cooler during the zero-g phase, such that new samples of glass are formed, to determine how the crystallisation of glass differs in microgravity. They had some bad luck. First, they were not aware that only the American airplane had a 110-volt power supply and that the hangar, where preparations were made, did not. Then, during the experiment's second flight, a glass sample got stuck in the cooler and the team could not make anymore samples. Whether the few samples of glass they were able to obtain will satisfy their objective will have to be seen.
Some other French students carried out a rather theoretical study of the order of many small ball-bearings held between two transparent plates as a model of a crystalline structure. After difficulties adapting to the somewhat wild environment in the airplane, the students finally managed to obtain some results on the amount of disorder that the balls show when in reduced gravity.
An Austrian team attempted to test their novel idea of using the mirror effect created by hot air, like one sees on a hot road ('fata morgana'), to produce an air lens inside a hot tube (Fig. 2). Despite some problems with the optical bench, a laser produced a clearly visible beam and, for the smaller diameter tubes at least, the lens effect was indeed witnessed.
Figure 2. Students from Austria attempt to produce a large air lens inside a hot tube and observe it with a laser
A German student attempted to study the possible rapid motion of mimosa leaves in microgravity. Mimosa plants are particularly sensitive, their leaves open and close rapidly when disturbed. The plants proved however not to be 'relaxed' enough, the student found, as their leaves stayed folded from the outset.
British students flew a small aquarium containing tropical fish. The students were surprised to see the fish swimming in nose-down loops when in weightlessness. What once was a professional and costly experiment in Skylab, was now repeated by students in a simple and cheap manner.
A team from Aachen, Germany, tested the well-designed setup that they had developed for welding steel pipes together in weightlessness (Fig. 3). Many welds were made. The students have a wealth of material to investigate.
Figure 3. A student from Aachen, Germany, places two steel tubes together, ready to be welded in weightlessness
Another international team, from Munich and Delft, investigated quite a new approach for orbit transfer, the use of long tethers. They looked at the initial deployment of a re-entry capsule attached by a tether. A journalist with a tether attached to her belt was 'deployed' as a replacement for the capsule. After being giving a slight push, she floated through the airplane, and the students were able to measure the tension of the tether and observe the characteristics of its deployment. The students from the Delft University of Technology who
organised the competition also flew an experiment. Using a mechanical 'space cat' that they had created, they successfully demonstrated the cat's ability to turn itself while in free fall (Fig. 4), a capability that cats use to always land on their feet.
Figure 4. Students from Delft practise rotating artificial 'cat' in weightlessness, by remotely controlling its and body
All students are now analysing their data. Many of the experiments will undoubtedly show interesting results. The participants will meet in the near-future to discuss their latest findings.
This year's ESA student parabolic flight campaign was again a great success. The 55 European students who participated experienced for themselves the weightlessness in which they performed their experiments. They demonstrated the potential of tomorrow's microgravity science community. These young European researchers proposed innovative ideas and implemented them in an unusually short time. The cooperative spirit that they displayed was very encouraging, not only for themselves but, just as importantly, for the supporting technicians, operators, managers and pilots.
For many of the students, the campaign was a significant
experience in their life and should have a positive impact on
their future careers. The experience has increased their interest
in science and technology, made them aware of a large variety of
other scientific disciplines, and has given each one valuable
contacts with European partners.
It is highly recommended to repeat such an event in the following years. With new students entering university each year, it is in fact justified to create an annual student parabolic flight campaign programme as an activity to enhance Europe's scientific culture.
The campaign was sponsored by ESA and the European Commission. Its success was a result of the hard work of many professionals, i.e. engineers, technicians, pilots, and companies. The efforts of the students, particularly of the initiators and organisers of the competition represented by the chairman of the Delft Aerospace Students Association, Querien Wijnands, were also invaluable.
The generous contributions of the Netherlands Minister of Defence, namely the use of the Valkenburg Naval Air Station and the required airspace, and the air traffic control services provided, were an essential part of the success. The NASA crew also showed an excellent spirit of cooperation, which bodes well for future cooperation in Space Station activities.