Exhaled Nitric Oxide-2 (NOA-2) - 03.04.14
ISS Science for Everyone
Science Objectives for Everyone Decompression sickness (gas bubbles in the bloodstream) is a concern and common occurrence in scuba divers. It is unknown if astronauts experience the same type of phenomenon from extravehicular activities (EVA). NOA-2 is designed to compare the amount of nitric oxide that is exhaled before and after an EVA to determine if the astronauts experience decompression sickness.
Science Results for Everyone
Aerocrine, Solna, , Sweden
Karolinska Institute, Stockholm, , Sweden
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
October 2005 - October 2008
Previous ISS Missions
This experiment has also been known as ESANO-2.
- Decompression sickness or gas emboli (bubbles in the bloodstream) can occur without symptoms following resurfacing for scuba divers. It is unknown if astronauts experience the same following extravehicular activities (EVA).
- The objective of this investigation is to test the amount of nitric oxide (NO) exhaled before and after an EVA. (An elevated NO level indicates that they are experiencing decompression sickness.)
- Determining if the astronauts experience gas emboli will lead to countermeasure to ensure the health of the crew following EVAs.
In scuba divers the presence of gas emboli (bubbles) in the bloodstream as a result of decompression is well-known and can be common after normal dives with no subjective signs of decompression sickness. The occurrence of decompression sickness in astronauts following decompression in connection with extravehicular activity (EVA) is not known. It has though been demonstrated that using the corresponding decompression techniques on the ground gives rise to symptoms of decompression sickness in approximately 6% of the cases. This suggests a much higher frequency of gas emboli without clear symptoms of decompression sickness. A non-invasive and simple technique for assessing current decompression techniques before and after EVA would be beneficial.
In this experiment astronauts will perform a simple inhalation-exhalation procedure (as in the NOA-1 protocol) as late as possible before starting standard EVA preparations and again as soon as possible after completing the EVA. An increased level of expired Nitric Oxide compared to pre-procedure levels will indicate the presence of gas emboli, suggesting a need for adaptation of existing EVA procedures. (Description provided by ESA: Astrolab Mission)
Karlsson LL, Kerckx Y, Gustafsson LE, Hemmingsson TE, Linnarsson D. Microgravity Decreases and Hypergravity Increases Exhaled Nitric Oxide. Journal of Applied Physiology. 2009: 1431-1437.
Ground Based Results Publications
The information on this page is provided courtesy of the ESA Erasmus Experiment Archive.
The Platon device is used to detect Nitric Oxide in the NOA-2 experiment. Image courtesy of ESA.
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NASA Image: ISS012E24271- The Planton Unit and Medical kits in the Zvezda Service Module (SM). The Platon unit, Nitric Oxide Analyzer (NOA), used in the European Space Agency Nitric Oxide 1 (ESANO 1) experiment is in the mid-left of the image. This image was taken during Expeditions 12/13 Joint Operations.
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