As in any profession, these are of two kinds: Internal and External.
We are all internally driven by the pressure to discover something new and to be the best in what we do. We constantly seem to be involved in internal dialogs like:
Why am I doing this particular project? Why am I using this technique rather than some other one? Is there something I have forgotten that could explain the result I am getting? Has someone else already done this and what did they conclude? Do I really trust someone else's results on this subject? Why isn't this computer program still not working after three weeks of debugging? Will I be able to finish my research before my grant run's out?
External pressures consist, primarily, of:
Worrying about whether your job is stable. Anxiety over whether you will get the grant money you asked for. Concern over what the Referee will say about the paper you just submitted.Overall, there is tremendous pressure to perform, and to perform brilliantly all the time. Your reputation as a scientists is determined by how accurate your findings are when other's try to check your work, or build upon it in their continuation of your research. We all dread hearing that we made a bonehead mistake in math or in analyzing some data.
There is the stress, often welcomed, of having to reinvent your research program every year or so as new data come in and you have to modify the direction of your research program to keep it relevant to the questions of the day. You will never be famous if you work in a dead-end area with nothing fundamental to say about the 'big questions' in astronomy. If your area is becoming a 'sleeper' you have to be prepared to retool yourself and embark on some other research line that interests you and that is closer to the front-line. If you don't, no college will want you in a tenured position, and no government lab will hire you. This means you have NO JOB PROSPECTS. Without a job, and the opportunity to do research and get someone to pay the page charges for its publication ( typically $100 per page in most journals) you are not 'doing astronomy'.
Right now, for about 1/2 of all astronomers who are employed on soft-money from NASA or the NSF, there are major career stresses going on. I know many astronomers in their 30's and 40's who are just one grant away from unemployment. There is no way that you can plan a 2 - 10 year research program under these conditions. If you cannot find a snappy, sexy project and finish it in a few months, you may be out of luck. Many of us actually work for other astronomers on research teams under various contracts. If you like what the 'Principle Investigator' is doing, this isn't a problem. But, if you would much prefer doing your own research on another topic, forget it. You are not being paid to do YOUR research unless it matches with what the PI wants to get done on THEIR grant which is paying your salary! N