The lost NASA tapes: Restoring lunar images after 40 years in the vault

Computerworld - Liquid nitrogen, vegetable steamers, Macintosh workstations and old, refrigerator-size tape drives. These are just some of the tools a new breed of Space Age archeologists is using to sift through the digital debris from the early days of NASA, mining the information in ways unimaginable when it was first gathered four decades ago.

At stake is data that could show Earth's risk of an asteroid strike, shed light on global warming and -- perhaps -- even satisfy those who think the moon landings were a hoax.

The most visible of the archeologists is arguably Dennis Wingo, head of Skycorp Inc., a small aerospace engineering firm in Huntsville, Ala. He's the driving force behind the Lunar Orbiter Image Recovery Project, operating out of a decommissioned McDonald's (since dubbed McMoon's) at NASA's Ames Research Center in Mountain View, Calif. The project's goal is to recover and enhance as many of the original lunar landing images as possible.

Between 1966 and 1967, five unmanned probes were sent into lunar orbit to map possible landing sites within the moon's equatorial regions at one-meter resolution and to map the rest of the surface at a resolution of 40 meters or better, Wingo explains. Those probes, known as Lunar Orbiters, sent back about 1,800 images that modern technology should be able to greatly improve.

The project's great scientific value to NASA is in enabling a comparison between the lunar surface as mapped by the Lunar Reconnaissance Orbiter, launched on June 18, with the lunar surface as it appeared 43 years ago, according to Wingo. The goal is to "get a fix on how many meteor impacts have occurred in the meantime," by cataloging the new craters.

"If we know the changes, we can establish the risk of working on the moon and even determine the small-body asteroid population of the inner solar system," Wingo says. Another valuable contribution: the ability to plot the possible risk to Earth of the impact of an asteroid.

Detail of the Earthrise picture taken by the first Lunar Orbiter in 1966, as rendered at the time.
Click to view larger image

The original black-and-white images were shot on 70mm film that was automatically developed and scanned within the robot spacecraft. The signal from the scanner was sent to Earth and was then displayed as partial frames on a monitor. Each monitor image was then captured with a film camera. These pictures were fit together, and then another picture was taken of the finished mosaic. Each step imposed a certain amount of image degradation.

The resulting Lunar Orbiter images are the basis of a digital lunar atlas. But Wingo figured that if he could process the tapes of the original signals, he could improve the dynamic range of the images by a factor of four, revealing far more surface features.

Although this theory has proved correct, the path has been challenging. Wingo first had to acquire the tapes, then reconstruct drives to read them and finally perform the actual processing.

Next steps

It turns out that the original 2-in. tapes were available. Around 1986, NASA archivist Nancy Evans, who is now retired, was contacted by a federal records center asking what to do with them. Feeling that the data should not be discarded, she persuaded the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., to put them into climate-controlled storage.