SP. Ace: a hands-on space project for ambitious secondary school students Abstract Erik de Schrijver, M.Sc, Sint-Pieterscollege Jette, L. Theodorstraat 167, 1090 Brussels, Belgium, eds@sint-pieterscollege.be Since 2004, students at the Brussels' Sint-Pieterscollege have been given the opportunity to engage in a unique hands-on space project that combines powerful formal and informal training/learning opportunities in scientific and technological fields. Secondary school students revel in designing, building and testing dataloggers flying to about 30km on stratopsheric balloons. As the balloons fly from the US, Sweden or Portugal, the project is international in nature and, being a hands-on project at heart, it calls upon students to learn about a plethora of subjects covering curriculum-listed topics from the fields of physics, chemistry, earth science and astronomy as well as non-curriculum related topics in these fields and practical things like soldering. 1. How it all began In the United States, amateurs have been flying high-altitude balloon missions for decades. One of these groups carries small experiments for schools, free of charge, and with only a limited number of restrictions on the payload. These are obvious and straightforward: no live animals, no reacting chemicals, no experiments producing any kind of radiation liable to interfere with the groups own equipment. Furthermore, every science experiment should come in below 100grams and be packed in a ping pong ball. Such simple experiments, dubbed pongsats, are considered ideal to get students involved in high-altitude or near-space research. The balloons carrying these pongsats are mostly balloon sondes, rising to approximately 30km before bursting and making a parachute landing. They provide an easy but vital enabler for hands-on space education in high school [1]. Figure 1. DIY pongsat-making 2. Getting started It is a common misconception that doing anything space-related takes billions of euros and a zillion volts. A simple pongsats is just a package of plant seeds or lower animal eggs, the experiment being to investigate whether life cycle properties are affected by exposure to near-space conditions (at 30km altitude, air pressure is <3% of sea level values and UV intensity is much higher). Students chose Artemia salina (brine shrimp) as an animal species that is easy to grow and well documented. Extensive counting experiments have shown hatching rate increases from 10-20% in unexposed egg batches, to 60-70% after Figure 2. Improved packaging for biological samples. a 3 hour exposure to near-space conditions [2].
3. First electronics Figure 3. A 24 pin DIP microcontroller uses a 8 pin DIP temperature sensor to make up a simple datalogger. Without PCB, all connections are made trough hard wiring, frequently causing in-flight failures. For those wishing to investigate the physical properties of space, electronics is the way. A variety of sensors is available commercially which, connected to a microcontroller, make a datalogger that will monitor a specific parameter during the ascent and float phases of a balloon flight. Developing such dataloggers provide learning opportunities in a variety of fields, ranging from analog and digital sensors, analog to digital conversion, signal amplification, data storage issues, software development and sensor resilience (power, temperature, air pressure, ). Circuit quality proved an important issue as all first-generation dataloggers failed in flight. Failing modes included batteries freezing over, software problems due to power interruptions, wires breaking loose, 4. Things to learn Besides the obvious practical issues involved in the development of a datalogger, a number of scientific topics pop up, whether curriculum-related or not. For example, the problems involved in measuring the temperature of air under low pressures prompt questions on the nature of temperature, and therefore calls for an introduction to molecular kinematics. Combining the Hydrostatic Equation with the Universal Gas Law, one can calculate the mean molar mass of the air. Measuring both pressure and temperature at various altitudes, one can determine up to what altitude the atmosphere is subjected to vertical mixing. Clearly, the physics curriculum and atmospheric science show cross-fertilization, each gaining from the other through two basic measurements. Other scientific learning opportunities include cosmic radiation and its possible impact on DNA, atmospheric layering, 5. Improving electronics Since most failures of our first generation dataloggers were caused by wires breaking loose, it was decided that we would develop the knowhow and means to produce printed circuit boards. This decision caused the failure rate of our dataloggers to drop from 100% to about 30%. The first data from the upper atmosphere were returned with these second generation circuits, imperfect as they still were. Another major cause of failures turned out to be the extremely low temperatures encountered during balloon ascent: -60 C was not uncommon and both batteries and components suffered as a result. So another battery type was selected, power management improved and a number of components replaced to better cope with the cold.
Figure 4. Second generation electronics: the first printed circuit boards. 30000 25000 20000 15000 10000 5000 0 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 8000 7000 6000 5000 4000 3000 2000 1000 0-50 -40-30 -20-10 0 10 20 30 6. Past and current projects Figure 5. The first graphs were produced from second generation dataloggers: altitude and temperature as a function of time. Besides the enormous motivation students will find in designing, building and flying hardware, there are more opportunities to get students to learn about the scientific enterprise and the way information is exchanged. Conferences and symposia that pay attention to student work are increasingly numerous and as some are willing to have secondary school students present their work, a wonderful opportunity arises: have students write actual scientific papers and go talk about their work in front of an unfamiliar, if positive, audience. Fig 6. Secondary school students have presented their results on dataloggers and space biology at a number of European Symposia over the years.
Sometimes, targets of opportunity are coming up, and a flexible approach to science education makes the program even more rewarding for all parties concerned: the students, their parents, the school team and the teacher involved: clearly win-win situations! Examples are the Zero-G competition organized in Belgium in 2006, the Straplex-campaign in Portugal in 2008 [3] and the European Cansat competition in Norway in 2010. Fig. 7: Secondary school students studying fluid physics during the SPFC 2006 parabolic flight campaign. Fig.8: Secondary school students flying a homebread Geiger-Müller Counter on the Straplex campaign in Evora, Portugal in 2008. Fig 9. For the 2010 European Cansat Competiton, students will develop a postion and attitude determination system. (Credit Cansat Nederland) 7. Conclusions A motivated student will learn more, faster and more thoroughly than his uninterested sibling. Any approach that enhances motivation is therefore to be welcomed wholeheartedly. It has long been recognized that hands-on projects are among the most powerful motivators available to educators, and space is known to appeal strongly to young and old alike. The SP.Ace-project offers secondary school students the opportunity to design, develop, build, test and fly a variety of experiments on high-altitude balloon missions and/or sounding rockets. However imperfect, these experiments, whether electronic or not, capture the imagination and enhance students performance while offering both formal and informal training opportunities. Some important aspects should not be neglected though. Flying opportunities are absolutely vital, so access to frequent high altitude balloon flights is an essential enabler, turning the project into a program as building and flying experiments are no longer single shot events, but become embedded
into normal school life. For the whole of the school, space is no longer inaccessible, it is the place where the science guys go, and even students not normally interested look upon space endeavours with an attitude less marked by misconceptions (too hard, too expensive). Parents are among those to benefit too as their children are given opportunities that are normally in the realm of graduates or postgraduates only. Teachers benefit from being challenged to develop knowledge and skills in a variety of fields, and from being energized by a program that unleashes talent in their students. Hands-on 'rules', in secondary schools as well as universities! 8. References [1]. E. de Schrijver, Taking Secondary School Students Hearts and Minds Up, Up and Away, Proceedings of the 17 th ESA Symposium on European Rocket and Balloon Programmes and Related Research, Sandefjord, Norway, 30 May 2 June 2005 (ESA SP-590, August 2005) [2]. E. de Schrijver, SP. Ace 2005-2007: Seizing and Creating Opportunities for Space Education in High School, Proceedings of the 18 th ESA Symposium on European Rocket and Balloon Programmes and Related Research, Visby, Sweden, 3-7 June 2005 (ESA SP-647, November 2007) [3] SP. Ace 2007-2009: Building and Mastering Tools and Technologies for Space Education in high School, Proceedings of the 19th Symposium on European Rocket and Balloon Programmes and Related Research, Bad Reichenhall, Germany, 7-11 June 2009 (under print).