Question: Michael Foale and Dirk Frimout are both what type of physicist?

Context articles: Frank De Winne
STS-63
Dirk Reuyl
Dirk Frimout
Dirk Polder
Dirk Bouwmeester
Dirk Brockmann
Reuyl (crater)
Dirk Kreimer
Michael Foale

Frank, Viscount De Winne (born 25 April 1961, in Ledeberg, Belgium) is a Belgian Air Component officer and an ESA astronaut.
 He is Belgium's second person in space (after Dirk Frimout).
 He was the first ESA astronaut to command a space mission when he served as commander of ISS Expedition 21.
 ESA astronaut de Winne serves currently as Head of the European Astronaut Centre of the European Space Agency in Cologne/Germany (Köln).
STS-63 was the first mission of the US/Russian Shuttle-Mir Program, which carried out the first rendezvous of the American Space Shuttle with Russia's space station "Mir".
 Known as the 'Near-Mir' mission, the flight used Space Shuttle "Discovery", which lifted off from launch pad 39B on 3 February 1995 from Kennedy Space Center, Florida.
 A night launch and the 20th mission for "Discovery", it marked the first time a Space Shuttle mission had a female pilot, Eileen Collins, the first EVAs for both a UK born astronaut Michael Foale and a US astronaut of African heritage Bernard A. Harris, Jr. and it also carried out the successful deployment and retrieval of the Spartan-204 platform, along with the scheduled rendezvous and flyaround of "Mir", in preparation for STS-71, the first mission to dock with "Mir".
Dirk Reuyl (1906 – 1972) was a Dutch American physicist and astronomer.
 He was the cousin of astronomer Peter van de Kamp.
Dirk Dries David Damiaan, Viscount Frimout (born 21 March 1941 in Poperinge, Belgium) is an astrophysicist for the European Space Agency.
 He flew aboard NASA Space Shuttle mision STS-45 as a payload specialist , making him the first Belgian in space .
Dirk Polder (August 23, 1919 – March 18, 2001) was a Dutch physicist who, together with Hendrik Casimir, first predicted the existence of what today is known as the Casimir-Polder force, sometimes also referred to as the "Casimir effect" or "Casimir force".
 He also worked on the similar topic of radiative heat transfer at nanoscale.
Dirk (Dik) Bouwmeester (born 1967) is a Dutch experimental physicist specializing in quantum optics and quantum information.
 He currently holds faculty positions at the University of California at Santa Barbara and at Leiden University in the Netherlands.
Dirk Brockmann is a German physicist and Professor at the Institute for Biology at Humboldt University of Berlin and the Robert Koch Institute, Berlin.
 Brockmann is known for his work in complex systems, complex networks, computational epidemiology, human mobility and anomalous diffusion.
Reuyl is a crater in the Aeolis quadrangle of Mars, located at 9.8° south latitude and 193.2° west longitude.
 It measures 85.9 kilometers in diameter and was named after Dirk Reuyl, a Dutch-American physicist and astronomer (1906–1972) who made astronomical measurements of the diameter of Mars in the 1940s.
Dirk Kreimer (born 12 July 1960) is a German physicist who pioneered the Hopf-algebraic approach to quantum field theory with Alain Connes and other co-authors.
 He is a Humboldt professor at Humboldt University in Berlin.
Colin Michael Foale, CBE (born 6 January 1957) is a British-American astrophysicist and former NASA astronaut.
 He is a veteran of six Space Shuttle missions and extended missions on both Mir and the International Space Station.
 He was the first Briton to perform a space walk, and until 17 April 2008, he held the record for most time spent in space by a US citizen: 374 days, 11 hours, 19 minutes.
 He still holds the cumulative-time-in-space record for a UK citizen.