The European Space Agency reports that small oxygen sensors developed for spacecraft re-entry vehicles are finding applications in a variety of other fields, including healthcare, pollution control and fuel cell operations. According to ESA, the birth of these special sensors began at the University of Stuttgart’s Institute of Space Systems, where researchers were trying to reduce the mass and energy draw of existing units designed for the extreme conditions of space flight. “[W]e had to develop a new type of miniaturized sensor to measure re-entry conditions for spacecraft. The sensors had to be very small and capable of measuring oxygen at high altitudes and during re-entry,” explained Rainer Baumann, a member of the Stuttgart team from the Technical University of Dresden. ESA’s Technology Transfer Programme brought the sensor to the attention of various industries, and ideas for more down-to-earth uses began to blossom. “It is very easy to find terrestrial applications for this miniaturized gas sensor. The sensor reacts very fast and this is useful in many cases where you need to measure ambient conditions on Earth,” says Rainer Baumann. “One application where the sensor is particularly useful is measurement of the human breath. With this sensor we can measure oxygen, carbon dioxide and the flow of human breath, and obtain the results immediately; something which is impossible with the conventional systems.” Baumann says the small, lightweight sensor can be integrated into a mask used on medical patients and is being fine-tuned for use in the training of top athletes. According to Baumann, another possible application is in the reduction of air pollution, because the sensor can easily be adapted for monitoring home exhaust gases and commercial heating systems. When placed in exhaust gas, it can control a heater in real time by using a special algorithm, ensuring the burner operates at an optimum level. Baumann notes this would also reduce fuel consumption by about 10-to-15 percent. The sensor might also be a great tool for fuel cell developers because it is able to spot hydrogen leaks, Baumann suggests, predicting it could be integrated into portable, hand-held testing units.