40 years after the last Apollo spacecraft launched, readings from the Apollo 14 and 15 dust detectors have been restored by scientists with the National Space Science Data Center (NSSDC) at NASA's Goddard Space Flight Center. 

The newly available data will make long-term analysis of the Apollo dust readings possible. Digital data from these two experiments had not been archived before, and it's believed that roughly the last year-and-a-half of the data have never been studied. The recovery of these data sets is part of the Lunar Data Project, an ongoing NSSDC effort, drawing on researchers at multiple institutions, to make the scientific data from Apollo available in modern formats.

 The Lunar Dust Detectors that were placed on the lunar surface during Apollo 14 and 15 measured dust accumulation, temperature and damage caused by high-energy cosmic particles and the sun's ultraviolet radiation. The same kind of instrument had flown earlier on Apollo 11 and 12.  Apollo 17 carried a different type of dust detector.

An Apollo 14 astronaut deploys the Apollo Lunar Surface Experiments Package's power source (foreground) and "Central Station" (background), where the Lunar Dust Detector was mounted. Credit: NASA/JSC

Restoring the data was a painstaking job of going through one data set and separating the raw detector counts from temperatures and "housekeeping" information that was collected to keep an eye on how healthy the Apollo instruments were.

A second, less complete data set indicated how to convert the raw counts into usable measurements. But first, the second data set had to be converted from microfilm, which had been archived at NSSDC in the 1970s, and the two data sets had to reconciled because their time points didn't match up exactly.

Most of this meticulous work was carried out by Marie McBride, an undergraduate from the Florida Institute of Technology in Melbourne who was working with NSSDC data specialist David Williams through a NASA internship. Newer missions, such as NASA's Lunar Reconnaissance Orbiter (LRO), have continued to study lunar dust. "It's one of those questions that scientists keep coming back to," said McBride.  

 The Apollo Lunar Surface Experiments Package, the descent stage of the lunar module, and the paths left by astronauts Alan Shepard and Edgar Mitchell are visible in this image of the Apollo 14 site taken by NASA's Lunar Reconnaissance Orbiter. Credit: NASA/GSFC/ASU

The main objective of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), scheduled to launch in 2013, is to characterize the moon's atmosphere and dust environment.

This offers another example of how profoundly influential the Apollo data continues to be, observed Noah Petro, a member of the LRO project science team at NASA Goddard. "A mission ends when it ends, but the science continues forever."

 Presented at the American Geophysical Union meeting in San Francisco.