What is the theme in Rendezvous with Rama by Arthur C. Clarke?

Another theme in this book is time and space. In the world foreseen by the author of Rendezvous with Rama, time and space are the two major problems standing in the way of the human race's effort to understand Rama. While every single problem seems to have either a technological solution or at least a scientific explanation, the limitations of time and space are the real culprits for the exploration team. The first sign of the impact of time and space on the mission is Endeavour itself.