MacLean attended
Merivale High School in
Nepean, Ontario. He received a
Bachelor of Science degree in
physics in 1977 and a
doctorate in physics in 1983 from
York University in
Toronto. In 1977, he received the President's Award at York University (Murray G. Ross Award). He is a recipient of a
Natural Sciences and Engineering Research Council post graduate scholarship in 1980, two Ontario graduate scholarships, one in 1981 and the other in 1982, and a Natural Sciences and Engineering Research Council postdoctoral fellowship in 1983. He is an honorary fellow of Norman Bethune College at York University and president of the board of directors for the
Mont Megantic Observatory project. From 1974 to 1976, MacLean worked in sports administration and public relations at York University. From 1976 to 1977, he was a member of the Canadian National Gymnastics Team. He taught part-time at York University from 1980 to 1983. In 1983, he became a visiting scholar at
Stanford University under
Nobel Prize laureate
Arthur Leonard Schawlow. He is a laser-physicist, and his research has included work on
electro-optics, laser-induced fluorescence of particles and crystals and multi-photon laser spectroscopy. . From October 22 to November 1, 1992, MacLean flew onboard Space Shuttle
Columbia as a payload specialist for Mission
STS-52. During this mission, he performed a set of seven experiments known as CANEX-2, which included an evaluation of the Space Vision System. MacLean served as a mission specialist on
STS-115, which launched on September 9, 2006, and returned on September 21, 2006. He became the first Canadian to operate the robotic arm
Canadarm2. On September 13, he performed his first spacewalk, a 7-hour
EVA to activate the solar panels on the P3/4 truss – the second Canadian to do so, after
Chris Hadfield. ==Honours==