When someone at a party asks you what you do for a living, working in space science is always a plus — you are virtually guaranteed to get a few raised eyebrows and some interested questions. While the day-to-day reality of my job does not quite match up to the rocket scientist clichés, it is certainly never boring.

I joined the Space Science and Technology Department of the Rutherford Appleton Laboratory (RAL) in Oxfordshire, UK, in 2002. While many people working in space science have always wanted to be involved in the subject, my career path was less planned. I enjoyed physics at school because I liked knowing how the world fits together, so it was not a difficult decision to study the subject at Manchester University.

After graduation, however, I was not keen on settling down to a regular job right away, and a career in research seemed a little too specialized. Instead, I decided to do a Master’s degree in applied optics at Imperial College London, which led to a job at a small firm designing commercial optical systems (such as specialist cameras for the electronics industry). After nine years there, I was looking for a change, and a job advert in Physics World for an optical physicist at RAL led me to work on space instruments.

Our department at RAL designs, develops and manufactures scientific instruments for both space-science missions and ground-based astronomy projects. A typical mission might have several scientific instruments on one satellite, each dedicated to making a particular measurement. Such projects are impossible to carry out in isolation, and we work with university groups, companies and national space agencies to make each project a reality. Our role in a project can range from defining the scientific requirements and designing the instrument right through to assembling and testing the flight hardware.

Of gravity and glue

When I first joined RAL, I worked on the Laser Interferometer Space Antenna (LISA) Pathfinder project. Its aim is to detect gravitational waves produced by massive objects like black holes, and I was part of the team that designed and constructed a prototype interferometer for the satellite, which is due to be launched at the end of 2009 (see Physics World September 2007 pp10–11, print version only).

One of the aims of LISA Pathfinder is to measure displacements of a pair of gold–platinum cubes that are free-falling in space. A passing gravitational wave will change the separation of the cubes but, because gravity is a relatively weak force, the effect is tiny and we need to be able to sense positions to an accuracy of picometres (10^–12 m) to detect a gravitational-wave signal.

The project became especially entertaining when we started building the interferometer. The lenses and mirrors were stuck onto a glass baseplate using a technique that ensured the bond line would not flex under changes in temperature — essential for reducing displacement noise due to thermal expansion that might otherwise swamp the gravitational-wave signal. Although the experiment will be operated in a room-temperature environment stable to millikelvin, tiny movements of the optics can still be enough to ruin the measurement.

Unfortunately, the glue we had to use took only about 30 seconds to cure. Within that short time, each part had to be precisely aligned, with little possibility of repair if something became stuck in the wrong place. This required meticulous preparation and planning, and ultimately a steady hand and nerve. However, after several weeks of tense work in the lab, by June 2004 we had built an instrument with a unique measurement capability. I have always enjoyed having a job with a tangible end product, and it is particularly satisfying when you know that you have built the first example of something.

Room for creativity

One of the advantages of working on scientific instruments is that you get involved in a variety of projects spread over many areas of physics. In my current job I can move between topics like solar physics and environmental observation of the Earth as well as gravitational-wave detection. This often means being the person in the room who knows least about a subject, particularly when the project scientists have been working on a proposal for many years. Asking questions all the time can feel intimidating, but if you enjoy thinking on your feet, then it can also be a stimulating way to learn.

Having the chance to be creative is another attractive aspect of working in space science. My job is fundamentally about problem solving, and when you are trying to do new science, you often need to find solutions without a textbook to guide you. You always want the next experiment to do more than the last one, and this pushes the boundaries of your ingenuity as well as the limitations of current technology and materials.

One downside of working in space science is that projects can take a long time to come to fruition. Occasionally a project is cancelled and you may find that your hard work has been in vain. When this happens, you need a robust, long-term outlook and the ability to shrug off disappointments and start looking for the next challenge. Fortunately, there is always a new project around the corner and each comes with a unique set of problems to get your teeth into.

On a day-to-day basis, my job involves a mixture of project management, instrument design, and assembling and testing hardware. I find it refreshing to have a variety of roles, and sitting round a table with a team of people to figure out how to solve a problem can be a welcome break from hours spent in front of a computer screen. Physicists who are used to logical problems with deterministic outcomes, however, may find managing budgets, schedules and teams of people a bit of a culture shock.

People (and sometimes budgets) are much less predictable than experiments, and to get the most out of the opportunity to build an instrument, you need to balance a mission’s science requirements against competing factors like finite budgets and timescales. This can be one of the most difficult aspects of the job, but it is also one of the most rewarding; when you get it right, you have the personal satisfaction of shaping the design of an instrument and an experiment.

For those interested in working in a similar field, my advice would be to keep your eyes open for opportunities and go in the direction that most interests you. There are opportunities to work in national laboratories like RAL, universities, commercial space companies and agencies such as the European Space Agency and NASA. A degree in physics and a willingness to have a go at things will get you a long way. I have found that there is no well-defined career path for a physicist; this can be a bit daunting at times, but it also means that you can find yourself doing things like building instruments for space missions and keeping people entertained at parties.