Preparations for parabolic flight
Johannes: There are three 'working blocks'. Firstly, there is a phase when people are only sitting. Then there is a section during which they are required to concentrate fairly hard on mental / problem-solving tasks using a computer. During this time, the test subjects wear special spectacles to block any events that may be occurring around them from their peripheral vision. The third task faced by the test subjects is to ride a bicycle during the weightlessness phases. First-time flyers feel least well when they are simply sitting around doing nothing. While they are solving tasks, mental concentration prevents or at least mitigates the onset of nausea. The physical strain of riding a bicycle also constitutes a requirement that 'structures' the body – and this also frequently helps to alleviate the response to the stressful situation of parabolic flight.
Question: Can individuals personally influence how they react to stress?
Johannes: No. One week before the flight, we record data from the test candidates when not exposed to weightlessness. However. this does not lead to any firm conclusions about how any individual is going to respond to the conditions experienced during parabolic flight. Sometimes, the person who responds most acutely is the one you would least expect — 'laboratory tigers' are still a long way from becoming 'space tigers'. A parabolic flight is a fairly robust stimulus. Participants suffering from symptoms of nausea are likely to find their reactions far from mitigated after 15 parabolic flights, instead the symptoms remain at the same level of severity. The hardest thing would be the transition back from weightlessness to normal gravity.
A female test candidate before the flight
Question: Does that mean that astronauts may also exhibit reactions of this kind when they return from the Space Station?
Johannes: Even fully-trained astronauts react to this change. What interests us is to find out exactly what is taking place inside the body. This could, for example, prove to be important if we were ever required to bring back a sick person to Earth. To date, we have recorded data from 30 test candidates on parabolic flights. Our aim is to learn more about the different regulatory mechanisms that give rise to motion sickness.
Question: Is your HealthLab measuring device also in service on the ISS?
Johannes: During this German-Russian collaborative programme, the astronauts wear our measuring system during their training sessions for the manually-controlled docking procedure. Once a month, they train on the manual docking sequence for a Soyuz spacecraft – and we record data during this stressful situation. This investigation started back in 1996 on the Russian Mir space station. The long-term aim is to devise a diagnostic procedure that can be used to forecast the ability to act reliably in stressful situations.
This interview was conducted by Manuela Braun.
Deutsches Zentrum für Luft- und Raumfahrt (DLR) - German Aerospace Center
Tel: +49 2203 601-3882
Fax: +49 2203 601-3249
Dr. Bernd Johannes
German Aerospace Center
Institute of Aerospace Medicine
Tel: +49 40 513096 36