International Space Station astronauts use airlock to test lungs

LONDON: Astronauts onboard the International Space Station (ISS) are using the orbital lab's airlock to monitor lung inflammation as well as charting their lung health.

Air was pumped out of the ISS's airlock for the first time last week. Inside the cylindrical Quest airlock, ESA astronaut Samantha Cristoforetti and NASA's Terry Virts monitored their breathing.

With each lungful of air, our bodies absorb oxygen and exhale waste-product molecules such as carbon dioxide and the important 'signalling' molecule nitric oxide.

The Airway Monitoring experiment looks at the amount of nitric oxide the astronauts expelled by the astronauts in the airlock.

Nitric oxide is a gas found in cigarette smoke and car exhaust, for example, and it is produced in our bodies to regulate blood vessels and act as an antibacterial agent.

Doctors measure the amount of nitric oxide exhaled by patients to help diagnose inflamed lungs and asthma.

On Earth, dust drifts to the floor where vacuum cleaners or a damp cloth remove it easily. In weightlessness, dust circulates freely and often irritates and inflames eyes and lungs.

In addition, dust on the Moon and probably Mars sticks to astronauts through static electricity and has sharp edges - all making it more likely that dust will enter astronauts' lungs and do harm.

The Airway Monitoring experiment will test the use of nitric oxide as a tool to monitor lung inflammation as well as charting lung health in astronauts.

Four sessions will see the pair exhale into the equipment. Samantha and Terry made their first contributions before flight at NASA and ran their first space session in space in January.

Last week, they entered the Station's Quest airlock for their last run and reduced the pressure by 30 per cent - equivalent to being on a mountain at 3000 m altitude.