The Netherlands was responsible for two satellites:

• Astronomical Satellite Netherlands (ANS), 1974-1976. Mapping UV and soft X-rays. The orbit was intended to be polar-circular at 500 km, but became elliptical.
• Infra-Red Astronomical Satellite (IRAS), 1983. Mapping infrared 12-100 µm, at 900 km height.

After this period satellites became a multinational undertaking, mainly in ESA context. However, small research experiments are incidentally piggy backing on bigger launches.