Bit offtopic but I'm interested because I've never seen the answer.
Does JWST's imaging censors are 20 years old tech, or the team could used a modern sensor that fits the 20+ years old design specification?
Does JWST's imaging censors are 20 years old tech, or the team could used a modern sensor that fits the 20+ years old design specification?
It's not like the JWST folks said "we're going to fly a canon 5D!" and then were 20 years out of date when the JWST flew. Pretty much all of the sensors are built from scratch, using very advanced/specialized techniques. Given that the tech is all custom, including some stuff that probably had to be invented or otherwise figured out to begin with, it's hard to say the "tech is old," given it's just now flying.
In other ways, some of it looks old: one of JWST's main sensors images at 1024x1024. There might be other constraints at play here—how much data you get per pixel is directly related to your telescope's angular resolution and sensitivity of sensor.
Here's a page that discusses the JWST's sensors:
https://webb.nasa.gov/content/about/innovations/infrared.htm...
The journal article linked at the bottom of that page is also quite interesting as it talks about the science of the sensor technology and also the background of astronomer's requirements too. You can find it easily on google with a `filetype:pdf` filter.
There's a big construction project near me where the architect was chosen 20 yers ago and now the costs explode, i was thinking whether this is a cause (outdated plans because one didn't follow through immediately).
In essense, using more off the shelf parts for the Mars rovers is part of the science experiment.
Pathfinder cost <$300M. “Better cheaper faster” became Discovery class missions, “capped” at $500M. Curiosity and Perseverance cost about $2.5B each. Not in the same category.
Supply Chain Risk Management, https://sma.nasa.gov/sma-disciplines/supply-chain-risk-manag...
“NASA’s Reliability and Maintainability (R&M) program ensures that the systems within NASA’s spaceflight programs and projects perform as required throughout their life cycles to satisfy mission objectives.” https://sma.nasa.gov/sma-disciplines/reliability-and-maintai...
The sensors on JWST have are outdated and do have some issues. For instance, some of the microshutter on NIRSpec are stuck (they knew before launching). The MIRI has some image artifacts due manufacturing techniques.
The sensors were bespoke, even nowadays, we can't get sensors like the on on JSWT off the shelf. There isn't much use case for most of them outside space telescope. But we could do better with today technology.
https://www.nasa.gov/mission_pages/webb/instruments/index.ht...