a m lightner

Looking for a book that I read as a kid in the early 80s or late 70s. Would probably be classified as YA SciFi. The background was that the Olympics had moved into space, and each planet would send a team. The colonists in a sparsely-settled new region of the galaxy did not have the resources...

The book would've been published in the late 60s through the mid 70s. The protagonist is a young African girl living in an African civilization (kingdom?) after the West has perished in an atomic war. I think the novel ends with contact being made with someone from the West.