Skybadger Background For Sale Leyenda website Home

Mike Harrison.

This website is the website of Mike Harrison, used for astronomy oriented 'stuff'.

This page attempts to explain why I am interested in astronomy and provides a potted history of astronomy experience and publications.

I started out in astronomy around '82 or so when I was 10 -ish.
My first scope was a department store 50mm refractor on a alt-az stand (up & down ) which was really shaky and had no tracking. That thing did not get much use.

After pestering and wheedling and working hard I scored a set of optics for an 8" reflector for a christmas present spanning a couple of Christmas's and more. This led to a 10" field drain being purchased for scrap from a local supplier and the fitters in the local factory being sidetracked for fags and favours into turning and welding a simple German Equatorial stand for the tube. Half of a pair of broken binoculars were used for a finder scope for this magnificent instrument. The view was spectacular.
Meanwhile I talked my school into letting me take the 'O' level in Astronomy from the London board as a self-taught course based on the Zeilik and Smith book and also, with some other students there, to re-open the school observatory which housed the 6" Cooke Refractor on a very large antique German Equatorial mounting. So between home and school I had a tracking mount and solar filters and old SLR camera for the photography and solar observations required for the 'O' level practical.

Follow this up with scientific 'A' levels and a university education in BSc Astronomy and you have an astronomer, ready for action.
Except that to get a job as a professional astronomer you need a PhD ( not strictly true ) which leads to a Research Associate (RA) or teaching post for which you are paid to teach and produce science. These last 2 to 4 years and then you need to get another one. After several of these you might get a job with tenure, that is a more long-term contract with more job security but you have to be well-known, well-respected and well-published.

So I went and did the PhD in Mid-Infrared Spectroscopy using Fabry-Perot spectrometers evolved from those developed on the ISO mission at University College London. This involved:

  • building and calibrating a computer-controlled mid-infrared grating monochromator as a test source, with a HgCdTe nitrogen cooled detector as the sensor
  • Building and calibrating a pair of fabry-perot interferometers. These operated as a crossed pair was the main part of the instrument
  • Assembling the optical train from the monochromator to the fabry-perot spectrometer to the stressed Si/Ga detector, the last two were in seperate Helium-cooled dewars.

I'm afraid that I must admin I ran out of money and interest right at the last minute. Personal pressures required sensible wages and a job to provide them and the funding for the Helium coolant costs was no longer available. So having got right to the end of the 3-years PhD period with an 'almost' working system. I stopped.
I also don't regret it.
I moved on to a job as CCD detector engineer at Rutherford Appleton Laboratory, working in the Space Science Department on CCD-based instruments for observatories and space missions. In this remit I was involved in :

  • Assembly & Calibration of the JET-X star-tracking cameras. These cameras were part of the UK-Russian X-Ray Astronomy collaboration platform - Spectrum-X. The cameras provided the platform with pointing information based on bright star detection and orientation information derived from the astrometry. The 6-month process of assembly consisted of mechanical alignment, assembly and CCD validation followed by thermal and vibration testing and then final mating testing at the Leicester University Assembly facility.
  • Design of an Infrared Camera for the Rosetta Spacecraft mission to Comet Wirtanen, as a UK part of the instrument team providing the visual CCD imaging system. This design required a cold filter and mechanical detector cooler based around the NicMos detectors of the day.
  • Model validation for the design and implementation of a wide-field startracker camera. This required modelling the spatial distribution of all stars in the SAO catalog ( down to mag 7.5 ) to analyse the sensitivity and field of view required by a camera attempting to maintain platform orientation by astrometry alone. This produced maps of the sky giving field densities of stars per field of view at a given magnitude range.
  • Model design and validation for a large telescope in High earth orbit ( 300km - geosynchronous ) observing the earth - expected resolution, spectral sensitivity/li>
  • Adaptive optics camera mechanical design for Durham University : This produced an Adaptive Optics water cooled camera to monitor synthetic stars at 1000 Hz from a 128 by 128 pixel EEC CCD 20 detector.
  • Linear CCD camera: mechanical and electrical design and implementation for a SGS Thompson evaluation board housing using their 3000 pixel colour linear device
  • Design and papers evaluating a X-Ray spectrophotometer for the ESA M3 mission candidate Moon Orbital Ranger & Observer or MORO for short. This instrument used an EEV CCD hardened for X-ray usage ( large depletion zone ) to enable individual spectrometry of X-ray flourescence photons from the surface of the moon while in orbit.
  • Beagle Mars lander gas and mass chromatography design testing. This project attempted to condense a laboratory gas chromatograph the size of a UK fridge, and a mass spectrometer, the size of an American fridge (!) into a single box the shize of a shoebox, to take to Mars. The two key parts I was working on were
    1, How to implement the valves
    2, How to implement the electron gun for the mass spectrometer.
  • And various other smaller projects - like , design a camera for monitoring the spacecraft in the thermal testing labs when the cryostat is shut - from the inside...

The end result is that I consider myself moderately knowledgeable about CCD detectors, instrumentation electronics and chunks of detector physics.

Following the end of the three years at RAL, I moved to a video company based at Brunel University Technology Park , producing multi-platform video acquisition cards. After three years there of device driver programming for NT and Unix and small embedded device programming, I moved to a document management system company in Chiswick for two years and then on to Tumbleweed UK, a UK branch of the Tumbleweed US secure communications firm.
So now I come full circle to being a 'professional' amateur astronomer doing what the professional should be doing with much larger telescopes, with my small and humble equipment but enjoying the wage and benefits I think I deserve and allow me to afford it.

All I have left to do is prove it.


A High Resolution Mid-Infrared Fabry-Perot Spectrometer

April 1994

Edinburgh National Astronomy Meeting (ENAM94) .

Poster at National Astronomy Week presentation

Infra-Red Camera section in ESA ROSETTA red book

April 1995

ESA publ. # SCI(95)3, 1995

Contributing author

X-Ray Spectrometer

Jan 1996

ESA publ. #SCI(96)1, 1996

Section Author and editor of document.

MORO X-Ray spectrometer

Feb 1996

Proc. Conf. DLR MORO, Berlin

Principal author

CHRIS -Compact High Resolution Imaging System

Feb. 1997

Proc. R. Aero Soc.

Boscombe Down Conf, Principal author