David Saint-Jacques (born January 6, 1970 in Saint-Lambert, Quebec) is a Canadian astronaut with the Canadian Space Agency (CSA).
 He was also an engineer, an astrophysicist, and a physician prior to joining the CSA.
 He was selected to join the CSA in the 2009 CSA selection along with Jeremy Hansen.
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).
It was co-founded by filmmaker Grigorij Richters, B612 Foundation COO Danica Remy, Apollo 9 astronaut Rusty Schweickart and Brian May, Queen guitarist and astrophysicist.
 Over 200 astronauts, scientists, technologists and artists, including Richard Dawkins, Bill Nye, Peter Gabriel, Jim Lovell, Apollo 11 Astronaut Michael Collins, Alexei Leonov, Bill Anders, Kip Thorne, Lord Martin Rees, Chris Hadfield, Rusty Schweickart and Brian Cox co-signed the Asteroid Day Declaration.
 Asteroid Day was officially launched on December 3, 2014.
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 .
StarTalk is a podcast on space, science, and popular culture hosted by astrophysicist Neil deGrasse Tyson, with various comic and celebrity co-hosts and frequent guests from the worlds of science and entertainment.
 Past co-hosts have included Colin Jost, Lynne Koplitz, Leighann Lord, Eugene Mirman, Chuck Nice, John Oliver, and Kristen Schaal.
 Guests have included astronaut Buzz Aldrin, actor Morgan Freeman, George Takei, comedian Joan Rivers, Arianna Huffington, Richard Dawkins and writer Mary Roach.
 StarTalk has a segment called Cosmic Queries, in which listeners send in questions about the universe to be answered on the show.
Umberto Guidoni (born in Rome 18 August 1954) is an Italian astrophysicist, science writer and a former ESA astronaut, being the first European to visit the International Space Station.
 He is a veteran of two NASA space shuttle missions.
 He was also a Member of the European Parliament (MEP) from 2004 to 2009, elected within the Party of Italian Communists.
Frank Curtis "Curt" Michel, Ph.D. (June 5, 1934 – February 26, 2015) was an American astrophysicist; a professor of astrophysics at Rice University in Houston, Texas; a former United States Air Force pilot; and a NASA astronaut.
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.
Klaus-Dietrich Flade (born August 23, 1952) is a German pilot and former German Aerospace Center astronaut who visited the Mir space station in 1992 aboard the Soyuz TM-14 mission, returning to Earth a week later aboard Soyuz TM-13.
Hubble Live, fully titled Hubble Live: The Final Mission, was a one-hour live American television special presentation that premiered on May 11, 2009 on the Science Channel.
 The program covered the launch of Space Shuttle "Atlantis" on NASA's Servicing Mission 4 (HST-SM4), the eleven-day fifth and final mission to repair the Hubble Space Telescope.
 The program was hosted by Josh Zepps, who is the host of science news series "Brink", and featured interviews with NASA astrophysicist and space telescope expert Kim Weaver and former NASA astronaut Paul William Richards.

Question: Who is older, astronaut Klaus-Dietrich Flade or astrophysicist Dirk Frimout?
Answer: Dirk Dries David Damiaan, Viscount Frimout