Today I’m in….. January 19, 2009Posted by Sarah in science.
Tags: astronomy, belgium, instruments, jwst, me, nasa
Today, and for the rest of this week, I’m in the city of Leuven, Belgium. Together with some colleagues from the Catholic University of Leuven and various other institutes in Europe I’m spending a few days working on some aspects of calibration and testing for MIRI, the mid-infrared instrument for the James Webb Space Telescope. The JWST, although offcially its “successor”, will differ from Hubble in that it will be optimised for observations in the infrared, rather than the optical or ultraviolet. Although great science can be done at the shorter wavelengths, achieving top notch image quality is more demanding at shorter wavelengths – with the costs for JWST far exceeding initial estimates as it is, who knows what the budget would have had to be for an optical JWST?
Before I started working on this project I don’t think I appreciated the importance of instrument testing and calibration. An entire suite of optical equipment and instruments were developed in parallel to the instrument, just to test the instrument before launch. Once MIRI is in space on board the telescope, none of this stuff is used anymore. Quite amazing really.
For MIRI, the consortium developed an engineering model for the instrument – essentially a full copy of MIRI with just a few units missing or not quite up to flight standards – to check for any major design flaws and to calibrate this outfit of ground support equipment (GSE). We had a thorough run of testing last autumn at the Rutherford Appleton Lab, near Oxford, and are now processing the terabytes of data that were churned out to get to know every nook and cranny of the GSE and of MIRI itself. With the MIRI flight hardware following hot on the heels of the engineering model, the pressure is on to get the most we possibly can out of the test data to prepare ourselves for flight testing.
Calculating the statistics of detector background noise is hardly the sexiest of science – but what’s cool is that I’m getting to know the instrument inside out. In fact, of any photon that enters the instrument, we’ll have a pretty good idea what pixel it will end up in. Scientists take note: instruments are only as good as their calibration lets them be!
Next week I’m in another lovely city, Munich – more updates will follow from there!
Image credit: UK Astronomy Technology Centre