When students visit our laboratory they usually want to know, before anything else, "What do you do?." We'll try to answer that by addressing the more general question, "What do space scientists do?" There really are many different kinds of space scientists. [We can say that about scientists in any field.] But one thing all space scientists have in common is that they are all nature's detectives with the goal of obtaining a better understanding of facts and processes about Space. One really simple classification of kinds of space scientists comes to mind which is: (1) theoretical, (2) experimental, (3) observational, (4) modeler, and (5) scientist-manager, where the fourth one is more-or-less a hybrid, made up of the first two or three, but we'll discuss it separately, because it often has some unique features. Below we explain each of the five categories in the order shown, in the context of the space science, but first we try to answer the question "What do we mean by Space?" In most general terms, it is that region of the solar system above the part of the atmosphere where we see clouds. So Space usually includes the Earth's ionosphere, the planets, cosmic rays, and the wind from the Sun, etc. And some people want it to include regions well outside of the solar system. Some do not; they say we call scientists who study regions outside of the solar system astrophysicists. It is generally not a very important issue, except to some scientists!

The five basic kinds of space scientists are:

1) Theoretical: One who usually devotes most of her/his time to the fundamentals or principles of space science and uses mathematics as a tool of implementation, so that the principles can be made to yield predictions or estimates. When there is success it sometimes leads to new principles or modification of the old ones.

2) Experimental: One who works in a laboratory and usually has some control of the conditions of input into the experiment, using instruments, etc. She/he might be someone who creates an instrument to be flown on a spacecraft to measure some property of space or who, for example, develops a subsystem on a spacecraft to condense data to send them back more efficiently, etc.

3) Observational: One who gathers data from nature with or without sophisticated instruments, but in this modern age the instruments are usually complex. A spacecraft is a "platform" for such instruments, and modern spacecraft are always complex. An astronomer is an example of an observational scientist.

4) Modeler: One who uses fundamentals or principles of the science and resulting mathematical equations with the help of computers (often considerable help) to do computations, in order to make predictions. Some experimental or observational facts from categories 2 or 3 go into the calculations (i.e., initial or boundary conditions to start the computations) and the predictions are compared to what really happens in nature, to estimate the model's real value. The term modeler can also refer to a scientist who concentrates on the analyzes of data or their interpretation, where there is use of, but less emphasis on, a model itself.

5) Scientist-manager: A scientist who directs other less experienced scientists and can do so because of her/his past experience in doing science. Such people often help develop science policy for her/his group or consult for other groups, or testify before political leaders about science programs or future initiatives.

Most space scientists are some combination of these five categories. For example, some scientist-managers are part time managers and part time theoretical or experimental researchers, but some (usually who were research scientists or teachers of science in the past) are full time managers of other scientists. And the more theoretical and observational facts that modelers know the much better chance of success they have.