Canada's 1st man in space will blast into the federal Liberal leadership race this week.

Former astronaut Marc Garneau will tell a Montreal audience Wednesday that he's challenging for the party's top job.

He'll join a field including MPJustin Trudeau & Martha Hall Findlay.  Vancouver MP Joyce Murray who is expected to launch her leadership bid on Monday.

63-year-old Garneau flew 3 space shuttle missions before running the Canadian Space Agency. After being defeated in his 1st run for office in 2006, Garneau was elected in the  Montreal riding of Westmount-Ville-Marie in 2008 & again in 2011.

With files from the Canadian Press