https://phys.org/news/2023-05-jwst-miri-instrument-problems.html

More instrument problems with MIRI on the James Webb.

Previously, friction in the wheels was a problem. Now it’s been found that MIRI is collecting less light than it should at long wavelengths, and less than it did during commissioning.

Another problem pointed out in a completely different paper, is that the viewing of even Spritzer was limited by background radiation. And since Webb is operating at a hotter temperature than Spritzer, the image quality is further degraded. The solution there is that this is true for small viewing times, bit with longer viewing times the background removal is better and the higher resolution of MIRI Webb begins to make itself felt.

mollwollfumble said:

https://phys.org/news/2023-05-jwst-miri-instrument-problems.html

More instrument problems with MIRI on the James Webb.

Previously, friction in the wheels was a problem. Now it’s been found that MIRI is collecting less light than it should at long wavelengths, and less than it did during commissioning.

Another problem pointed out in a completely different paper, is that the viewing of even Spritzer was limited by background radiation. And since Webb is operating at a hotter temperature than Spritzer, the image quality is further degraded. The solution there is that this is true for small viewing times, bit with longer viewing times the background removal is better and the higher resolution of MIRI Webb begins to make itself felt.

probably got some CO₂ in the works.

ChrispenEvan said:

mollwollfumble said:

https://phys.org/news/2023-05-jwst-miri-instrument-problems.html

More instrument problems with MIRI on the James Webb.

Previously, friction in the wheels was a problem. Now it’s been found that MIRI is collecting less light than it should at long wavelengths, and less than it did during commissioning.

Another problem pointed out in a completely different paper, is that the viewing of even Spritzer was limited by background radiation. And since Webb is operating at a hotter temperature than Spritzer, the image quality is further degraded. The solution there is that this is true for small viewing times, bit with longer viewing times the background removal is better and the higher resolution of MIRI Webb begins to make itself felt.

probably got some CO₂ in the works.

Webb only uses passive cooling. But does a startlingly good job of keeping cool that way. As opposed to Spitzer which carried refrigerant until the refrigerant ran out.

Shit

If it does a better job that anything else currently in use its still a win.

Could they put some vanes on it and use the solar wind to cool it?

dv said:

Shit

Yeah.

Well, it is still working.
They just have difficulty pointing it in the correct direction and it is picking up less light than it ought to.