The space agency admitted in 2006 that no one could find the original video recordings of the lunar landing.
On Thursday, NASA acknowledged that it must have erased some of the original footage so that it could re-use the videotape.
NASA and a Hollywood film restoration company have taken television video copies of what Apollo 11 beamed to Earth 40 years ago and have made the pictures look sharper.
The 230-thousand US dollar refurbishing effort is only three weeks into a month-long project, and only 40 percent of the work has been done.
Forty years ago next Monday, the three-man U.S. astronaut crew of Neil Armstrong, Buzz Aldrin and Michael Collins made history aboard Apollo 11, the first space vessel to carry man to the surface of the moon and back.
Mission commander Neil Armstrong was the first to step on the moon's surface. He spoke the famous words,"That's one small step for man, one giant step for mankind."
