Does anyone know this short story I read many years ago? It's about a group of people who decided to get to a distant planet on a spaceship that isn't very advanced. Some time after they started their trip, new technology got developed that allows space travel at a much faster speed. A second group of people who set out for the same destination end up arriving a lot earlier than the first group of people.
I think this would be a good story to introduce my kids to space travel but couldn't remember the name of the book.