In the 1950s the AVRO company was working on plans to luanch rockets out of the Arrow aircraft it had develop for the Canadian Air Force. The Arrow was an extremely high-speed, high-altitute interseptor. It had the misfortune of being unvield on the same day the world found out about Sputnik, which sort of foretold the aircraft's fate. It was eventually scraped due to high costs, and replaced with bomarac land-based missiles.
http://www.avroarrow.org/history.html
Keep the Arrow program going, and you will give Canada a chance to develop smaller plane-luanched rockets an an alternative to the massive US and Soviet style land-luanched bohemiths. Of course many of the scientists and engeniers that made the "Apollo" and other US missions a success were former AVRO employees. If the ARVO compnay is still going they won't be available to be poached by NASA and the US space program will be retarded vis-a-vis OTL.
Back to the point, OTL Canada was the third nation to put a satellite into orbit after the US and USSR. Keep the AVRO company going and Canada could build up a community of aerospace experts capable of advancing a space program.