Dirk Dries David Damiaan, Viscount Frimout (born 21 March 1941 in Poperinge, Belgium) is an astrophysicist for the European Space Agency.

During the nine-day flight, the crew aboard Atlantis operated the twelve experiments that constituted the ATLAS-1 (Atmospheric Laboratory for Applications and Science) cargo.

In addition, this was the first time an artificial beam of electrons was used to stimulate a man-made auroral discharge.

[4] At mission conclusion, Frimout had traveled 3.2 million miles in 143 Earth orbits and logged over 214 hours in space.

He is a senior engineer in the Payload Utilization Department of the Columbus Directorate, responsible for the ESA support to the European experiments on ATLAS-1, and the Microgravity Measurement Assembly to be flown on D2.