I drove down a quiet street in Ottawa and parked beside an unassuming commercial building. From the curb, there was nothing to suggest a space test operation was underway inside. I walked into the office and was guided past the desks and workstations of Mission Control Space Services before the landscape suddenly changed. The Moon Yard opened up ahead, and we stepped onto the terrain designed to mimic the geological features of the lunar surface.

McMillan declared bankruptcy on July 31, marking “the end of an era for one of Ottawa’s most respected agencies,” the head of its parent company, The S3 Agency, confirmed Thursday.

The summer is drawing to a close and while some employees may have taken...