The moon is sprinkled with historical hardware hurled from Earth that signifies the pioneering steps taken over decades in robotic and human exploration of Earth's celestial next-door neighbor.
But numbers of spacefaring nations, including commercial enterprises, are readying their respective assaults on the moon. That fact has sparked growing concern about safeguarding lunar heritage sites, keeping them free of future "Kilroy was here" graffiti-like abuses.
This issue was aired at the NASA Lunar Science Conference staged here July 20-23 by the new NASA Lunar Science Institute situated at the space agency's Ames Research Center.
"The Apollo sites are, in fact, historic. They are treasures that need to be preserved," said noted author and authority on space exploration Andrew Chaikin. His books include the acclaimed "A Man on the Moon" (Viking, 1994), the impetus for the Tom Hanks HBO television miniseries, 'From the Earth to the Moon.'
"We need to think very, very carefully about how we are going to revisit those sites and not destroy the record of the first human explorations of another world," Chaikin said. "But having said that ... not every footprint on every Apollo site need be preserved."
Chaikin pointed out that there's likely to be very interesting science to be gained from visiting Apollo landing spots, given safe approaches to those locales.
"We need to figure out which of the footprints you don't want to wipe out. That powdery surface is unlike any historical site on the Earth ... and the footprints could be wiped out at a moment's notice with our first revisits," he said.
Bonus prize money
Preserving exploration heritage in the era of private ventures to the moon was flagged by Philip Stooke, associate professor in the Department of Geography at the University of Western Ontario, London, Ontario, Canada.
Stooke said that commercial lunar efforts — such as the Google Lunar X Prize — have the potential to interact with artifacts from the first era of lunar exploration.
The Google Lunar X Prize is a $30 million competition for the first privately funded team to send a robot to the moon, travel some 1,640 feet (500 meters) and transmit video, images and data back to the Earth. Bonus prize money can be won by taking on other mission tasks, including the imaging of human-made artifacts, such as Apollo hardware.
That being the case, Stooke has posed: What rules or guidelines exist, or might be involved in the future, to mediate this interaction? He suggested that guidelines are needed to treat old sites with respect without placing undue restrictions on future activities.
What about other early artifacts such as the former Soviet Union's Luna 9 — the first spacecraft to achieve a lunar soft landing and to transmit photographic data to Earth — or that nation's automated Lunakhod rovers? Similarly, what about old NASA Surveyor robot landers that were plopped down on the moon?
Opinions range from complete protection to complete lack of regulation, Stooke observed.
Untouchable real estate
But the Apollo 11's Eagle landing zone in the Sea of Tranquility back in July 1969, Stooke commented, should be regarded as an untouchable piece of real estate.
"It shouldn't be trampled over and scavenged by private sector rovers," Stooke told SPACE.com. "Don't mess it up with little rovers doing wheelies over the footprints ... or backing up a rover and hitting the flag by mistake."
However, other Apollo landing sites might be treated differently, Stooke suggested.
Six Apollo lunar landers touched down on the moon between 1969 through 1972. These two-person vessels enabled moonwalkers — often tagged the "dusty dozen" — to carry out work on the lunar terrain from Apollo 11's modest 2.5 hours to Apollo 17's campaign of forays that added up to over 22 hours.
It turns out that the Apollo 17 lunar lander — Challenger — was documented pre-launch with samples taken from various items that would be emplaced on the lunar surface during the moonwalking mission. The intent was, perhaps sometime in the future, these materials might be returned to Earth for comparative appraisal with non-flight to the moon items.
Crash and trash
Those unique samples kept here on Earth are still in a storage box at the NASA Johnson Space Center in Houston, Texas, explained Wendell Mendell, chief of the Office for Lunar and Planetary Exploration in the Constellation Systems Program Office.
"It raises the question as to whether the Apollo 17 site then has historical importance ... or whether it has practical importance, assuming we get back there," Mendell told SPACE.com. Taking a look at how some of those deployed assets on the Apollo 17 mission withstood exposure to the lunar and space environment, he added, would help designers figure out hardware designs intended for much longer stints on the harsh moon.
Mendell emphasized that the concern that someone is going to go crash into and trash an Apollo site is overblown. "Nobody has that kind of disregard of the importance of the first explorations on the moon," he said.
Margaret Race is a principal investigator for the SETI Institute in Mountain View, Calif. An ecologist, she is a leading expert on the importance of planetary protection.
Race noted that the issue of protection of special regions, wilderness areas, set asides and pristine sites on the moon is gaining scientific attention, most recently at the Committee on Space Research Scientific Assembly held July 13-20 in Montreal, Canada.
"There's plenty of debate out there as to how it should be implemented," Race reported.
Playing nice: ethics and legality
One of the teams now vying for the Google X Prize is led by Bob Richards, Chief Executive Officer of Odyssey Moon Ltd. He said that there are two dimensions to the question of lunar heritage site preservation: ethics and legality.
"I grew up a country boy where showing respect for private property was simply the right thing to do. Additionally, by international space treaty, anything on the moon belongs to the people who put it there. Odyssey Moon is about the responsible development of the moon and in the absence of any laws covering our activities ... we will do what's ethically right," Richards told SPACE.com.
Odyssey Moon will respect the property of others, Richards continued, and will not risk disturbing it without permission to do so. "We will also expect the same respect and protection for any commercial private property we place on the moon."
Sites like Apollo 11 are monuments to our history as a species that should be preserved and honored, Richards said. "However, there are also important reasons why going back to a lunar heritage site has value for scientific, educational or cultural reasons. For instance, knowing the amount of radiation degradation or dust effects on hardware is important for future exploration and settlement," he said.
Not every single footprint or scrap of metal on the lunar surface is hallowed ground, Richards explained, but much of it is. "It's a question of showing common sense and always asking permission to visit or disturb something that's not yours. Odyssey Moon hopes to help establish the legal and regulatory precedents for everyone playing nice and developing the moon for the benefit of all humanity," he concluded.