Space begins at an altitude of 100 km above the earth's surface. Space there is not empty. Besides electromagnetic radiation from the sun, there are many other components. The main components are: Earth's magnetic field, the upper residual atmosphere, plasma, UV and X-ray radiation, particle radiation (electrons, protons and heavier ions) from the Sun and from other galactic sources, dust and meteoroids, asteroids and comets, and also space debris. These components of the space environment have an impact on all objects in space and sometimes on Earth. Examples include the aurora, electrostatic discharges on satellites, radiation risk to astronauts and electronic components of satellites, interference with communications and navigation, impacts of meteoroids and space debris on satellites, meteors and near-Earth asteroids. This work area deals with measurements and modelling of the space environment and its effects.