Nasa takes steps to restore Apollo 11 footage

As Nasa celebrates the 40th anniversary of man's first trip to the moon, the space agency is working to restore the TV footage of the Apollo 11 mission.

Nasa acknowledged on Thursday that the original TV footage of the moon landing on 20 July, 1969, was accidentally erased from a videotape reel. However, it said it has enlisted a Hollywood post-production company to restore the images by digitally stitching together existing copies of the Apollo 11 footage, retrieved from various sources around the world.

"The restoration is ongoing and may produce even better video," said Richard Nafzger in a statement from Nasa. Nafzger is an engineer at Nasa's Goddard Space Flight Center who oversaw television processing at the ground tracking sites during Apollo 11. "The restoration project is scheduled to be completed in September and will provide the public, future historians and the National Archives with the highest-quality video of this historic event," Nafgzer said.

The first phase of the restoration, undertaken by Lowry Digital, was released on Thursday by Nasa. The 15 scenes in the footage represent the key moments in the three-and-a-half hours astronauts Neil Armstrong and Buzz Aldrin spent on the moon's surface, according to the space agency.

Lowry's rescue work has won good reviews. The Associated Press reported that "some of the details seem new because of their sharpness. Originally, astronaut Neil Armstrong's face visor was too fuzzy to be seen clearly. The upgraded video of Earth's first moonwalker shows the visor and a reflection in it."

The images of Armstrong's moonwalk were not that clear to begin with. TV sets in that era did not offer the sharpest images, at least compared with the picture quality offered today. Also, the pictures were transmitted from the moon at 10 frames per second, with 320 lines of resolution for the live telecast.

As the original one-inch videotape recordings had been "degaussed, re-certified and reused", according to Nasa, the space agency had to do some sleuthing to dig up copies. The best were narrowed down to four sources, including one from a handheld camera that was pointed at a monitor within Mission Control, according to a statement from Lowry Digital.

One of the biggest hurdles for Lowry's technicians to overcome was that all four source materials were in different formats, frame rates and resolutions. The digital restorers therefore have to blend different levels of brightness, contrast and clarity.

Lowry's technology uses temporal image processing that collects information from clips and uses them to determine the correct contrast, resolution and noise level in each frame, the company said.

The process uses imaging algorithms that have been "fine-tuned over the course of more than 400 major feature-film restorations" including "Casablanca", Lowry said.

At Nasa's request, some flaws will be kept in the restored version. Dust particles on the lens of the camera that taped Armstrong coming down the lunar module's ladder were visible in the original telecast. Nasa officials think they, too, should be preserved, as the idea is not to enhance the record of the landing, but to re-create it, Lowry said.