$51,000 Neil Armstrong-signed checklist stars at PBA Galleries

Space memorabilia continues to show an extraordinary degree of collectibility.

At PBA Galleries' Rare Americana Travel & Exploration auction March 10, the final version of the NASA flight plan for Apollo 11, the first manned space flight to land on the moon, sold for $51,000, five times the high estimate.

Neil Armstrong, the first man to set foot on the surface of the moon, inscribed the front cover of the flight plan to NBC News correspondent Dean Mell. The flight plan has several ink notations, most noting current time in relation to the hour into the mission.

Armstrong's signature has risen in price by 900% over the last 10 years, out-performing nearly all the major names on the industry's PFC40 Autograph Index.

According to Mell, flight plans were provided to the various news correspondents prior to the flight to be used for reference during broadcasts. Armstrong inscribed this volume for Mell, at a post flight news conference.

Signed flight plans are rarely seen and Armstrong has long since ceased to autograph material. His autograph is the most valuable of any living person, and represents an excellent investment.

Also in the sale was the final version of the NASA flight plan for Apollo 13, signed on the front cover by Commander Jim Lovell, which sold for $7,800.

Neil Armstrong signed flight plan

Intended to be the third manned space flight to land on the moon, the mission had to be aborted after an oxygen tank ruptured, severely damaging the spacecraft's electrical system and crippling the service module upon which the Command Module depended.

To conserve its batteries and the oxygen needed for the last hours of flight, the crew instead used the Lunar Module's resources as a "lifeboat" during the return trip to Earth. Despite great hardship caused by limited power, loss of cabin heat, shortage of potable water and the critical need to jury-rig the carbon dioxide removal system, the crew returned safely to Earth on April 17, 1970.