We’re excited about the imminent launch of the James Webb Space Telescope.

James Webb Space Telescope

As we work in a sector that bridges technology and science with a focus on cleanrooms and contamination control expertise, you probably won’t be surprised to hear that we are excited about the imminent launch of NASA’s new James Webb Space Telescope (JWST). The launch has been postponed a number of times but is set to go ahead on Wednesday 22nd December (at the time of writing – 16th December).

There are some truly staggering facts about the new telescope that give you some idea why its manufacturing space must be meticulously clean. Nothing less than pristine will do – no one wants flecks of dust or other tiny contaminants being launched into zero gravity where they can float around freely and cause potential disruption.

A sunshield the size of a tennis court will protect the telescope’s infrared instruments from the sun’s heat, allowing them to cool passively. That shield is too big to fit in the launch vehicle, so it needs to unfold once in orbit. The gold-coloured mirror is manufactured in 18 sections from beryllium (which holds its shape at very low temperatures) and coated with a layer of gold just a few hundred atoms thick. The four infrared instruments are so sensitive that they can detect their own infrared glow, so the entire telescope must cool down to a stable operating temperature of 40 Kelvin (-233 degrees Celsius). That will take several months. Only then will the instrumentation be brought online. And some of the detectors in those instruments need to be cooled further to just 7 Kelvin (-266°C).

The JWST is essentially the replacement for Hubble, which has now seen over 30 years of service in Earth’s orbit. Hubble’s mirror is 2.4 metres in diameter. The JWST mirror is 6.5 metres. And it’s 100 times more powerful than Hubble. That has huge implications into the distance (back in time) that astronomers expect to be able to see. As the BBC headlined it: “A $10bn machine in search of the end of darkness.

For us, a more tangible measure is that the Webb telescope will be able to detect the light of a candle on one of Jupiter’s moons. At its closest point, that would be a mere 365 million miles from Earth!

We can only imagine what a small flake or speck of contamination would do to an instrument with such out-of-this-world sensitivity. That’s why a pristine cleanroom environment has been imperative throughout the telescope’s 20-year manufacturing process – quite a challenge for an assembly the size of a single-decker bus.

You may enjoy this interview with Amber Straughn, an astrophysicist on NASA’s JWST science team.

Picture © NASA