Whilst Apollo 11 is naturally remembered as the most groundbreaking space mission, Apollo 13 is remembered as the most gripping as the ever-present danger to Apollo astronauts became all too clear to the public for the first time.

This fact, and the joyful conclusion to the terrifying ordeal the crew went through, makes Apollo 13 collectibles some of the most desirable in the space markets (as well as offering a suitable plot line for a Tom Hanks film). This makes them excellent investments.

We've tried to bring out some of the story behind the 'Houston, we have a problem' quote through particular items, such as Jim Lovell and Fred Haise's frantic mission notes forged in the heat of the danger, and the facetious 'towing bill' passed to Rockwell, builders of the crippled spacecraft in the slightly manic glee which followed on the ground when it was clear the worst was over.

Here however, the Smithsonian tells some stories about the museum pieces behind the mission.