The James Webb Space Telescope has a complicated deployment sequence. Beyond data from sensors aboard the spacecraft, does it have any cameras to take pictures of the process?
As of now, it does not and that's not likely to change. I asked this question of leaders of the JWST project at Goddard Space Flight Center. It isn't that it wouldn't be useful, the problem is funds and time. Considering the current cost of the project, any new addition would increase the cost and could impact the scheduled launch date of October 2018.
The camera would need to work in a vacuum. Is MLI (multi-layer insulation) sufficient to keep it's temperature in its operating range? How and where would you mount it? Would you need to supply artificial lighting? Where would you find the bandwidth to send the images back? Resolving these issues would require resources that are in extremely short supply now.
NASA published an extensive answer to this question on their blog today. Some key points as to why no cameras were added:
- You wouldn't actually be able to see anything useful: a wide-angle camera would not provide enough detail, and you would need so many narrow-angle to get enough details for them to be useful, that it would be too complex to be worth the effort.
- Wiring harnesses would have to be routed across already complex structures that unfold and move during deployment.
- The cameras would need to be able to work in either cryogenic temperatures (when on the cold side), or be encapsulated. They could become a noise source.
They actually did investigate adding cameras, but found it not worthwhile:
Notwithstanding these challenges, engineers mocked up and tested some camera schemes on full-scale mockups of Webb hardware. However, they found that deployment surveillance cameras would not add significant information of value for engineering teams commanding the spacecraft from the ground.
- would need several cameras at several locations
- would need artificial light
- should be constructed from scratch to resist the low temperature on the dark side
- In case of failures could create unwanted debris
- keep load to a minimum