English: What appears to be a unique selfie opportunity was actually a critical photo for the cryogenic testing of NASA’s James Webb Space Telescope in Chamber A at NASA’s Johnson Space Center in Houston. The photo was used to verify the line of sight (or path light will travel) for the testing configuration.

During Webb’s extensive cryogenic testing, engineers checked the alignment of all the telescope optics and demonstrated the individual primary mirror segments can be properly aligned to each other and to the rest of the system. This all occurred in test conditions that simulated the space environment where Webb will operate, and where it will collect data of never-before-observed portions of the universe. Verifying the optics as a system is a very important step that will ensure the telescope will work correctly in space.

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Image: Ball Aerospace optical engineer Larkin Carey is reflected in the James Webb Space Telescope’s secondary mirror, as he photographs the line of sight for hardware used during an important test of the telescope’s optics. Credit: Ball Aerospace