For inspiration like that, Frank Frazetta would be a lot better
If we're aiming for the late 21st/22nd century for the new start date of the ISA Outerra, and then returning 500-1000 years later, we won't look any different. Even our Cro-Magon ancestors looked remarkably like us. In order for any kind of genetic drift on that level would require tens of thousands of years, if not hundreds.
The Outerra as outlined in the story grabbed people from every walk of life. Many different ethnicities, religions, ages, etc, were selected to represent a wide range of diversity (and to ensure future colonists had plenty of widely varied genetic material to ... uh ... "work" from
My original thought was to include family units as well ... in a 6-10 year time period after the colony was setup, the children would have become adults to help with colonization. Without children going, it would take some 16-20 years before a new generation would be available.