When the space shuttle Atlantis lands — planned for Saturday — it will cap off a mission to Hubble and mark the end of the servicing era.

The astronauts' fifth overhaul of the Hubble Space Telescope was the last planned mission to repair the telescope, or any satellite for that matter. And if NASA retires the space shuttle fleet in 2010 as planned, the agency will lose the ability to visit orbiting spacecraft and repair them in space.