When I tell people I’m a member of the European team for JWST instrument MIRI, they typically assume that this project was wrapped up when we sent the instrument across the Atlantic to our colleagues at NASA. That’s not the case. We’ve had all sorts of activities going on in recent months, and just had a big team meeting in Cologne to discuss what’s happening next.
MIRI now is at the Goddard Space Flight Center in Maryland, under the care of NASA. An instrument isn’t just nuts and bolts: it’s data, and software, and calibration. During the test campaigns at the Rutherford Appleton Lab in Didcot we generated several terabytes of test data, from which we learnt a lot about how the instrument behaves and what the science date might look like when the spacecraft starts sending it back in a few years’ time (hint: really good!). But there’s much to learn from this huge amount of data, and more analysis has been going on.
Infrared detectors are notoriously temperamental and much of our work has gone into getting acquainted with those in MIRI. First frames look funky, last frames are weird, some pixels respond different to being illuminated than others….. It’s a relationship we have to work hard at. Everyone who’s worked with infrared arrays will know what I’m talking about! Over at the Jet Propulsion Lab in California, MIRI teamers are carrying out more tests on detectors just like those inside the instrument to understand them even better over their full range of operation – long exposures, short exposures, very bright or very faint sources.
From next year, MIRI will start to get integrated with the spacecraft structure – step by step, as more hardware and the other instruments become available. As much of the MIRI expertise is here in Europe, we’ll be helping out with these tests at Goddard. I hope that my other project commitments will allow me to go out there with the other test team members for a few weeks to help out. After spending so many hours at the testing console in Didcot and analysing the data afterwards, I’d love to see the instrument take its next steps on the way into space.
In parallel to all this we’re also working on producing data files that will help calibrate the instrument, which is of course crucial for converting “light on pixels” into actual science. So I’m continuing my work on the optical calibration of the low-resolution spectrograph for a while longer.
So while MIRI is now with our US colleagues, the European Consortium is still very much in the picture and we’re all gearing up to collaborating more closely with NASA and the Space Telescope Science Institute to prepare MIRI further for launch.