  Space observatories are having major impacts on our knowledge of the
Universe, from the Solar neighborhood to the cosmological background, opening
many new windows out of reach to ground-based observatories. Celestial objects
emit all over the electromagnetic spectrum, and the Earth's atmosphere blocks a
large part of them. Moreover, space offers a very stable environment from where
the whole sky can be observed with no (or very little) perturbations, providing
new observing possibilities. This chapter presents a few striking examples of
astrophysics space observatories and of major results spanning from the Solar
neighborhood and our Galaxy to external galaxies, quasars and the cosmological
background.
