Small step in quality could become giant leap if lost tapes are recovered.
NASA has released digitally restored broadcast footage of the Apollo 11 moonwalk but the one-inch telemetry tapes recorded at tracking stations in Australia and the U.S. remain lost.
The restored video, which commemorates the 40th anniversary of the moon landing mission, combines broadcast-format video from a variety of sources, including the Parkes radio observatory in Western New South Wales.
The remastered footage also includes shots from the CBS News Archive recorded via direct microwave and landline feeds from NASA's Johnson Space Center in Houston and kinescopes found in film vaults at Johnson that had not been viewed for 36 years.
Because the video camera on the lunar module used a non-standard scan format that commercial TV couldn't broadcast, NASA had to use a scan converter to adapt the images to a standard broadcast signal.
This was done at tracking stations including Honeysuckle Creek near Canberra and the video switching centre in Sydney.
The converted signals were then transmitted to mission control using a mix of microwave, satellite and analogue links, and re-broadcast to the world. But the final broadcast image quality was degraded, NASA said.
The tracking stations also recorded video separately onto a series of one-inch telemetry tapes as a backup in case live transmission failed, or for review at a later date.
Each tape contained 14 tracks of data, including bio-medical, voice, and other information.
One channel was reserved for video, NASA said, but the location of these high-quality back-up tapes remains a mystery, despite three years of searching by a team of engineers in the US and Australia.
The CSIRO cited NASA sources today saying the tapes "may be lost forever, as it is likely that these tapes were erased and reused."
But at least one of the CSIRO scientists involved in the search, John Sarkissian, has raised the possibility that backup tapes recorded at Parkes might still exist.
He said the tapes, if found, would be far superior in quality to the original broadcast images.
Sarkissian said a letter written in the early 1990s by former Parkes director John Bolton and "subsequent talks" with the engineer responsible for making the recordings confirmed the tapes existed.
"I and my search team colleagues have spent the last few years looking for those tapes and, although we haven't found them yet, we are still hopeful particularly as there is no record or other evidence that they were destroyed or lost," Sarkissian said.
"They could still be stored somewhere and, with a bit of luck, the publicity about the release of details of NASA's report on the official search for the tapes might jog someone's memory."
A final report on the investigation is anticipated "in the near future".