NASA explains why James Webb Space Telescope does not have any cameras onboard

The James Webb Space Telescope is just weeks away from reaching its destination at the second Lagrange point (L2) after it was launched into space on December 25, 2021. The team of engineers managing the telescope recently achieved a major milestone by executing the most complex parts of the mission, deploying Webb’s sun shields and its secondary mirror. These two parts are one of the many crucial elements of the telescope which would help scientists unravel the secrets of the early universe. However, one instrument that Webb does not have in its arsenal is a camera, and NASA explains why.

Why does Webb not carry a camera?

NASA has enlisted four main factors due to which engineers decided not to equip the telescope with cameras. 
According to the agency, a camera located onto the telescope would not have been of much help because both sides of the telescope have bad conditions for taking photographs. The gold-plated mirrors, despite being photogenic on Earth, would not have been suitable for photography as the mirror side of the telescope is currently pitch dark in space. Besides, the other side of Webb is too shiny which would have caused glare and contrast issues.

The second factor is the issue of power as a camera would have required cables and energy to function. NASA explained that the power balance on Webb’s colder side is delicate and the addition of cable adds threat heat and vibration transfer through the wires, resulting in deteriorated image quality. The third factor why Webb does not have a camera is low temperature. According to NASA, a camera that would be capable of working in cryogenic temperatures needs to be specially designed as plastic in space shrink, crack and eventually fall apart. The final factor is complexity as engineers face too many already owing to Webb’s configuration changes during deployments. Another issue is that narrow-field cameras add to the complexity whereas the wide-field ones don’t give detailed information. 

Webb engineers are currently celebrating their success after they deployed a 2.4-foot-wide secondary mirror into position. Supported by three 25-foot-long lightweight struts, the secondary mirror of JWST is designed to withstand the space environment and dons specialised heating systems. Tap here to read more about the deployment.

Image: Twitter/@NASA