NOA-2 is an alternative application to the NO device, compared to the NOA-1 experiment performed on earlier increments for indication of disturbance of the lining tissue in the airways.

This disturbance can be substantiated by measureing the production and exhalation of Nitric Oxide (NO) from the lungs. As a basis for the NOA-2 experiment, ground-based experiments have substantiated that potential decompression sickness can be estimated using this method.

For this reason, the measurements will be take place around times for EVA activities, as they entail so-called pre-breathing and different air pressure regimes. The regimes mentioned have the potential of developing decompression symptoms.

The Principal Investigator was Professor Dag Linnarsson, Karolinska Institutet, Stockholm, Sweden.