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.

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.

The actual test of the optics involved a piece of support equipment called the ASPA, a nested acronym that means “AOS Source Plate Assembly.” The ASPA is a piece of hardware that sits atop Webb’s Aft Optics Subsystem (AOS), which is recognizable as a black “nose cone” that protrudes from the center of Webb’s primary mirror. The AOS contains the telescope’s tertiary and fine-steering mirrors. The ASPA is ground test hardware, and it will be removed from the telescope before it is launched into space.

Read more at NASA/Goddard Space Flight Center

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. (Credits: Ball Aerospace)