The James Webb Space Telescope

The James Webb Space Telescope (JWST) has been making headlines around the world since the release of its first images in July. That first deep-field image was taken by combining images from two of the telescopes’ instruments, one of which is the Mid-Infrared Instrument (MIRI). Today’s guest played a key role in building it.

In this episode of the Create the Future podcast, we speak to Paul Eccleston—chief engineer at the Rutherford Appleton Laboratory—about the engineering behind MIRI. We hear what it was like to see first images nearly 20 years after starting work on MIRI, discover its biggest design challenge, and discuss all things instrument assembly, thermal design, integration, testing, and verification. We talk about the launch of JWST, hear what Paul is working on now, and find out why he likens engineering teamwork to an orchestra.

Episode highlights

• On seeing the first photos from the James Webb Space Telescope: “It was a real special moment because, although we knew that everything was working properly and all the telemetry seemed to indicate that things were as they were meant to be. The proof of the pudding is in the eating. And so when those first images came back, there was a combination of relief that everything had gone well and things were working perfectly, and a sense of pride that actually so many hours and years of hard work had actually been really worthwhile. They're such beautiful, stunning images, never mind the science and the new knowledge that's hidden inside them.”
• “I started work on MIRI back in 2003, when I first joined the Rutherford Appleton Laboratory. But people had been working on the concept since the late 1990s.”
• “We've got margins built into the system that enable us to have reasonable confidence that everything is going to work as planned. So we design for a particular temperature point about half of Kelvin below the limit for where the detectors start to get too noisy […] but we're designing to get the very best science on a mission like this. Where so much time and money is being invested into it, you want to be absolutely certain that that things are going to work properly. So you do build in that extra margin.”
• “For good teamwork, communication is the absolute key. Making sure that people are regularly talking to one another and not just talking to one another, but really understanding what each other are saying, both on a technical level but also on a personal level. Because those personal relationships that you build in a project and in project teams are the things that you fall back on when things get difficult. Every project and programme will have moments where things don't go to plan. And how you deal with those is really the thing that sets apart success and failure.”
• “We certainly do use permanent magnets, we use them within mechanisms for cryogenic cooling […] That contains both permanent magnets and electric coils to pump and generate the pressure in the gas. We also use magnets for position sensing of mechanisms where you'll have a magnetic field sensor, and a very small permanent magnet on a wheel and you're trying to gauge its distance. That can be very accurately calibrated using magnetic sensors.”
• “Engineering teaches you how to think, how to analyse, and gives you the skillsets, but then how you apply that is completely up to you […] It really is a career that anyone can find their place in and find their way and find something that's really fulfilling. They can be doing something that they think is really worthwhile and valuable to themselves or to society.”