Intelligent Machines

Surface Restoration

Engineers restore high-resolution photos of the moon.

Aug 18, 2009

The images of the moon’s surface taken by five NASA Lunar Orbiter satellites in 1966 and 1967 are still among the most detailed ever made. The original analog data, beamed down to Earth to plan landing sites for the Apollo missions, was recorded on magnetic tapes that collected dust for decades and were nearly discarded.

Intelligent Machines

Surface Restoration

Engineers restore high-resolution photos of the moon.

by Katherine Bourzac

Aug 18, 2009

Now a team of engineers at an abandoned McDonald’s at Moffett Field in Sunnyvale, CA, is processing the data using restored and custom-built equipment, enabling a public that saw only snapshots of these historic images to view them at their full resolution for the first time.

The images used to plan the Apollo landing sites were photographs of photographs: as the Lunar Orbiter data came in, NASA scientists displayed it on monitors and shot pictures of the images on the screen. But NASA did make backup recordings of the raw image transmissions. Each of the hundreds of tapes contains the data for a single high-resolution photo.

To recover them, the team first had to restore an old FR-900 tape drive, beginning by washing it in the former restaurant’s sink. It is connected to a custom-built demodulator to extract the image, an analog-to-digital converter, and a monitor for viewing the images.

These are reels used to verify the coördinates of moon images on tapes whose labeling system has been forgotten.

The back of the FR-900 has been signed by the people who brought the project to life, including Nancy Evans, a former NASA scientist who kept the tapes in her garage for 20 years.

To restore the machine, they collected tools and extra parts scavenged from other tape readers.

In order to read the tapes, the team also had to find one of the few remaining people who knew how to repair the tape drive’s read heads, visible above. The heads apply a magnetic field to the tape, inducing a change in electrical current. The data is then run through the demodulator to pull out the image signal, which in turn is run through an analog-to-digital converter.

The recovered digital data is then processed on a computer. The orbiters sent out each image in multiple transmissions, each of which makes up a different strip of the whole. Using custom software and Photoshop, the researchers integrate the data strips into nearly seamless images at the full potential resolution. The best of these images show the lunar surface at a resolution of less than a meter. The group, led by ¬Dennis Wingo, a space entrepreneur, has restored 12 images so far. The above image, which was taken in February 1967 by Lunar Orbiter 3, shows the landing site that was chosen for the failed Apollo 13 mission and subsequently explored by the Apollo 14 astronauts in 1971.

Alan Shepard and Edgar Mitchell took photos of rock outcroppings at the rim of the dark crater at the bottom right of the previous frame; the newly restored image is so sharp that it can be blown up to reveal these very rocks.

This is a restored image of the interior of the Copernicus crater that Lunar Orbiter 2 took by chance, in November 1966, as it was advancing the roll of film before shooting potential landing sites. Scientists at NASA and elsewhere have become more interested in the site since then: it’s thought there might be water there. Now that they’re restored, these remarkably detailed images of the lunar surface will be used to plan future NASA missions to the moon.

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