Solar observation from space

Solar observations are carried out in space when necessary for technical reasons, such as detection of wavelengths that do not reach the ground, or to provide observing conditions that are difficult or impossible to achieve on the ground. Examples in the first category are observations at far ultraviolet or soft x-ray wavelengths and direct detection of solar wind particles; in the latter are precise measurements of variations in the solar luminosity and stereo observations of coronal mass ejections. This article samples the wide variety of techniques presently being used to study the Sun. We begin with an overview of the observational problem presented by the particular scientific questions involved in improving our understanding of the Sun, and of solar activity in particular. We then discuss the need for and advantages of observations from space, and give examples of scientific objectives which can only be met by such observations. We then describe in detail some representative examples of space missions and specific space-based experiments for solar studies. (C) 2003 American Institute of Physics.