When six astronauts share a 15 cubic meters spacecraft for weeks, how is it possible to avoid to be bothered by your fellows sweating and breathing? I've already written about staying clean in space, but NASA is going further this time. Its scientists are testing a lunar breathing system. The CAMRAS system (short for 'Carbon-dioxide and Moisture Removal Amine Swing-bed') has been tested by 23 volunteers who stayed inside a test chamber from April 14 to May 1, 2008. It looks like that the results are satisfying NASA which could use it for its Orion crew capsule and its Altair lunar lander. But read more...
You can see above how NASA "volunteers were bolted inside a test chamber and sweated for NASA scientists at Johnson Space Center in Houston to test a new system being developed for future space vehicles. The system, known as the carbon-dioxide and moisture removal amine swing-bed, or CAMRAS, is designed to make air breathable and the living space more comfortable by controlling carbon dioxide and humidity inside a crew capsule." (Credit: NASA) Here is a link to a larger version of this photo. And here is another link to a video of the CAMRAS test.
Above is a picture of a prototype of the CAMRAS system. (Credit: NASA) Here are some explanations from another document from NASA, "Exploration Life Support" (PDF format, 3 pages, 823 KB), from which the above image has been extracted. "The Johnson Space Center (JSC) manages the efforts to develop a technology that is included in the Crew Exploration Vehicle (CEV) baseline design to address the needs to remove both carbon dioxide (CO2) and humidity from the cabin atmosphere. The packaging of the solid amine in each CAMRAS takes advantage of the exothermic heat of reaction during the adsorption phase by adding energy to the endothermic reaction during the desorption phase. The energy is transferred by thermally connecting layers that alternate between adsorbing and desorbing cycles."
Now, let's look back at the latest NASA news release about CAMRAS. "This series of tests put volunteers inside a test chamber scaled to be the size of the Orion crew capsule, about 570 cubic feet. The volunteers, who were selected and grouped to replicate a typical crew, were asked to sleep, eat and exercise during test sessions that lasted from a few hours to overnight. 'The air smelled a little artificial, like on a plane, and it was a little crowded,' said Aaron Hetherington, one of the volunteers and a director for the test. 'But the air was fine; the temperature comfortable. My biggest observation is that it was unremarkable, which is good because that means the hardware was working.'"
NASA has published several technical reports about the CAMRAS system, but you have to pay to read them. For more information, you can go to the NASA Technical Reports Server and search for "System for Carbon Dioxide and Humidity Control" (without the quotes).
The latest report is named "Further Testing of an Amine-based Pressure-Swing System for Carbon Dioxide and Humidity Control" and is available -- today -- from this page. Here is the begoinning of the paper. "In a crewed spacecraft environment, atmospheric carbon dioxide (CO2) and moisture control are crucial. Hamilton Sundstrand has developed a stable and efficient amine-based CO2 and water vapor sorbent, SA9T, that is well suited for use in a spacecraft environment. The sorbent is efficiently packaged in pressure-swing regenerable beds that are thermally linked to improve removal efficiency and minimize vehicle thermal loads. Flows are all controlled with a single spool valve. This technology has been baselined for the new Orion spacecraft. However, more data was needed on the operational characteristics of the package in a simulated spacecraft environment. A unit was therefore tested with simulated metabolic loads in a closed chamber at Johnson Space Center during the last third of 2006."
But more tests have been necessary. "The third phase of tests was performed during the spring and summer of 2007. Tests were run with a range of operating conditions, varying: cycle time, vacuum pressure (or purge gas flow rate), air flow rate, and crew activity levels. Results of this testing are presented and potential flight operational strategies discussed."
When I was younger, I have dreamt to be an astronaut, probably like many of you. But when I read about the constraints imposed by space, I think it's better for me to live in Paris.
Sources: NASA news release, May 7, 2008; and various websites
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