Richard M . Linnehan Richard Michael Linnehan is an American veterinarian and a NASA astronaut . Personal . Linnehan was born September 19 , 1957 , in Lowell , Massachusetts , and was raised by his paternal grandparent s , Henry and Mae Linnehan . He grew up in the state of New Hampshire . He is single and enjoys various sports , outdoor activities and natural history . Career . After graduating from The Ohio State University College of Veterinary Medicine in June 1985 , Linnehan entered private veterinary practice and was later accepted to a two - year joint internship in zoo animal medicine and comparative pathology at the Baltimore Zoo and Johns Hopkins University . After completing his internship , Linnehan was commissioned as a Captain in the U . S . Army Veterinary Corps and reported for duty in early 1989 at the Naval Ocean Systems Center , San Diego , California , as chief clinical veterinarian for the U . S . Navy ’ s Marine Mammal Program . During his assignment at the Naval Ocean Systems Center , Linnehan initiated and supervised research in the areas of cetacean and pinniped anesthesia , orthopedics , drug pharmacokinetics and reproduction in direct support of U . S . Navy mobile marine mammal systems stationed in California , Florida , and Hawaii . NASA career . Selected by NASA in March 1992 , Linnehan reported to the Johnson Space Center in August 1992 where he completed one year of Astronaut Candidate training , qualifying him for Space Shuttle flight assignments as a mission specialist . Linnehan was initially assigned to flight software verification in the Shuttle Avionics Integration Laboratory ( SAIL ) . He was subsequently assigned to the Astronaut Office Mission Development Branch , working on payload development , and mission development flight support for future Space Shuttle missions . He first flew as a mission specialist in 1996 on STS - 78 , the Life Sciences and Microgravity Spacelab ( LMS ) mission . In 1998 , he served as the payload commander on the STS - 90 Neurolab mission . In 2002 , he was a member of the four - man EVA crew on STS - 109 . A veteran of four space flights , Linnehan has logged over 59 days in space , including six EVAs ( spacewalks ) totaling 42 hours and 11 minutes . Linnehan was recently assigned to mission STS - 123 . Spaceflight experience . STS - 78 LMS ( June 20 to July 7 , 1996 ) . The Life Sciences and Microgravity Spacelab mission was flown aboard Space Shuttle " Columbia " . The 17 - day flight included studies sponsored by ten nations and five space agencies , and was the first mission to combine both a full microgravity studies agenda and a comprehensive life sciences payload . STS - 78 orbited the Earth 271 times , and covered in 405 hours and 48 minutes . STS - 90 Neurolab ( April 17 to May 3 , 1998 ) was Linnehan ' s second Spacelab mission . During the 16 - day flight the seven person crew aboard Space Shuttle " Columbia " served as both experimental subjects and operators for 26 individual life science experiments focusing on the effects of microgravity on the brain and nervous system . STS - 90 orbited the Earth 256 times , and covered in 381 hours and 50 minutes . Both missions served as a model for future life sciences studies on board the International Space Station . STS - 109 HST Servicing Mission 3B ( March 1 to March 12 , 2002 ) was the fourth Hubble Space Telescope ( HST ) servicing mission and Linnehan ’ s third flight aboard " Columbia " . The crew of STS - 109 successfully upgraded the Hubble Space Telescope ’ s systems over the course of five consecutive EVAs , leaving it with a new power control unit , improved solar arrays , the new Advanced Camera for Surveys ( ACS ) , and an experimental refrigeration unit for cooling the dormant Near Infrared Camera and Multi - Object Spectrometer ( NICMOS ) . With his teammate John Grunsfeld , Linnehan performed three of the five spacewalks totaling 21 hours and 9 minutes . STS - 109 orbited the Earth 165 times and covered in just over 262 hours . STS - 123 ( March 11 to March 26 , 2008 ) was Linnehan ' s fourth spaceflight , and his first aboard the Space Shuttle " Endeavour " . The mission delivered the Japanese Logistics Module and the Canadian Special Purpose Dexterous Manipulator to the International Space Station . Linnehan performed three of the five scheduled space walks on STS - 123 with Garrett Reisman , Mike Foreman and Bob Behnken .