Why are there no cameras on world's most powerful James Webb Space Telescope? (2024)

New Delhi,UPDATED: Jan 7, 2022 10:42 IST

When Nasa landed its perseverance rover on Mars, the world stuck to their screens to see the incredible footage of a crane dropping it on the alien surface. The cameras, placed onboard, captured not just a historic moment but showed to the world the technological advancement of a species that had learnt to fly just over 100 years ago.

When the James Webb Telescope launched late last year, people were hopeful of witnessing similar footage showing it unfolding in the vacuum of space, opening up its iconic golden mirrors and stretching its wings. But, none of that has happened.

The only fleeting view that we could see before it went on its 15,00,000-kilometre-long journey away from Earth was its deployment and unfurling of its solar panels moments after launch.

So why don't we have cameras on board the James Webb Telescope?

“Adding cameras to watch an unprecedentedly complicated deployment of such a precious spacecraft as Webb sounds like a no-brainer, but in Webb’s case, there’s much more to it than meets the eye. It’s not as straightforward as adding a doorbell cam or even a rocket cam,” Paul Geithner, Webb's deputy project manager, said in a blog post.

Engineers said that the reason no cameras are placed on the telescope to capture the deployment of the equipment on the most powerful observatory is because the mirror side of Webb is pitch dark in space and the other, sun-facing side of Webb is so shiny that cameras there would have glare & contrast issues.

"We would have to run cables and power out to cameras on Webb, and the power balance on the cold side of Webb is especially delicate. More cables add more of a threat of heat and vibration transfer through the wires, which could impact image quality," the Webb team explained.

They added that temperature-wise, a camera that would work at the cryogenic conditions on the cold side of the sun shield would have to be specially designed. Plastics fall apart, shrink, and crack, and glues don’t hold together. Meanwhile, it would have been logistically complicated to place a camera onboard since Webb is big and changes configuration during deployments. Narrow-field cameras would add complexity, wide-field ones don’t give detailed information.

HOW DO THEY KNOW DEPLOYMENTS ARE SUCCESSFUL?

Engineers said that in order to confirm that the deployment has been successful, they rely on the mechanical, thermal, and electrical sensors, which provide telemetry to our ground teams. Meanwhile, the ground mission control has a special visualisation tool to check the status of the telescope.

Engineers had tested some camera schemes on full-scale mockups of Webb hardware. However, they found that deployment of surveillance cameras would not add significant information of value for engineering teams.

WHERE IS WEBB NOW?

The James Webb Telescope has travelled 10,00,000 kilometres away from Earth since its launch on December 25, 2021, as it gets closer and closer to its intended orbit at the second Lagrange point. The world's most powerful telescope still has over five months of commissioning period after it reaches its orbit on January 30, before it beams back first images.