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By Alison Boyle on

Happy Birthday, XMM

It’s ten years this week since the XMM-Newton space observatory launched. The biggest scientific satellite ever built in Europe, it has studied black holes, tracked how chemical elements are scattered in supernova explosions, and revealed that Mars’s atmosphere is bigger than previously thought.

XMM stands for X-ray Multi Mirror (the Newton bit is in honour of a certain Sir Isaac). X-rays can pass right through ordinary mirrors, so each of XMM’s three telescopes contains 58 cylindrical gold-plated mirrors nested together. Incoming X-rays skim the inside of the mirrors, a bit like stones skimming off water, and come to a focus at the telescope’s detector. You can see what one of the mirrors looks like in our Cosmos & Culture exhibition.

XMM-Newton grazing mirror (Credit: Science Museum)
XMM-Newton grazing mirror (Credit: Science Museum)

Cosmos & Culture also has a whole X-ray telescope on display. The Joint European X-Ray Telescope (JET-X) is the largest telescope ever constructed in Britain. Unfortunately for the project team at the University of Leicester, the Soviet-led mission it was part of was cancelled after the USSR collapsed. But it’s fortunate for us, as it means we get to display a rare example of a real space telescope. Most of the space hardware you see in museums is prototypes or spares (like the XMM mirror), as the real thing is either waaaaaaaay up there, or has burned up on re-entry.

A view of JET-X from the Making the Modern World gallery. The project engineer reckons this is the highest the telescope has ever got above sea level. (Credit: Science Museum)
A view of JET-X from the Making the Modern World gallery. The project engineer reckons this is the highest the telescope has ever got above sea level. (Credit: Science Museum)

An example of a real space telescope that actually made it into orbit is the Spacelab 2 XRT (it stands for X-ray telescope, funnily enough). It flew on the Shuttle in 1985 and imaged the centre of our galaxy. XRT was in a pretty sorry state when we acquired it in 2005, as it had been dismanted and stored in a university building for years. The building was due for demolition so we had to collect XRT quickly before it ended up in a skip. We reunited the four members of the original University of Birmingham team at our Wroughton store. Working with our conservation team over several weeks they painstakingly pieced it back together, with only a few missing parts having to be re-made.

Spacelab 2 XRT in Exploring Space gallery (Credit: Science Museum)
Spacelab 2 XRT in Exploring Space gallery (Credit: Science Museum)

XRT now stands proudly in the centre of our Exploring Space gallery. It looks as it would sticking out of the Shuttle’s cargo bay, except that we haven’t put most of the white thermal blankets on so that you can see it better. The blankets also made it look a bit like a pair of giant space trousers…