# What Lurks Beneath NASA's Chamber A

Hidden below Chamber A at NASA's Johnson Space Center in Houston is an area engineers used to test critical contamination control technology that has helped keep NASA's James Webb Space Telescope clean during cryogenic testing. This voluminous area is called the plenum, and it supports the weight of the chamber above as well as houses some of the cabling and plumbing for it. Before Webb's cryogenic testing in the chamber commenced, engineers ventured to the plenum's depths to test NASA-developed technology designed to remove molecular contaminants from the air. Catching contaminants Nithin Abraham, a coatings engineer at NASA's Goddard Space Flight Center in Greenbelt, Maryland, is part of a contamination control team tasked with ensuring Webb remains as clean as possible during its testing in Chamber A. Abraham developed and tested a highly permeable and porous material called molecular adsorber coating (MAC), which can be sprayed onto surfaces to passively capture contaminants that could be harmful to Webb's optics and science instruments. Not to be confused with absorption, adsorption is the process in which microscopic materials (for example, atoms and molecules) adhere to a surface — in this case, to the surface of a panel coated with the MAC. The MAC panel secures contaminants released through outgassing, a process that occurs when gas that was dissolved, absorbed, or otherwise trapped within a substance is released into the surrounding environment. An example of this…

- Kind: Film
- Year: 2019
- By: NASA Goddard Space Flight Center
- Genres: Science, Space
- Archive: [NASA Image and Video Library](https://images.nasa.gov/details/MAC_Panels_Plenum_Contamination-h264)
- Licence or status: [NASA media guidelines](https://www.nasa.gov/nasa-brand-center/images-and-media/) (as the archive states it)
- Credit: NASA Goddard Space Flight Center
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/nasa/MAC_Panels_Plenum_Contamination-h264?play=1)