WASHINGTON — NASA announced July 9 two new directives regarding planetary protection for missions to the moon and Mars that implement recommendations of an independent review board last year.
The two directives, announced by NASA Administrator Jim Bridenstine during a “Moon Dialogs” webinar, are part of an effort by NASA to modernize guidelines that are decades old and which the agency believes could hinder its long-term human exploration plans.
The directives reflect “how NASA has evolved on its thinking as it relates to forward and backward harmful biological contamination on the surface of the moon and, of course, on Mars,” Bridenstine said.
The first of what are formally known as NASA Interim Directives revises planetary protection classification of the moon. Mission to the moon had been in Category 2, which required missions to document any biological materials on board but set no cleanliness standards on them. That classification was driven by concerns spacecraft could contaminate water ice at the lunar poles.
Under the new directive, most of the moon will be placed in Category 1, which imposes no requirements on missions. The exceptions will be the polar regions — north of 86 degrees north latitude and south of 79 degrees south latitude — which will remain in Category 2. Regions around Apollo landing “and other historic sites” will also be in Category 2, primarily to protect biological materials left behind by the crewed Apollo landings.
“NASA is changing its thinking on how we’re going to go forward to the moon,” Bridenstine said. “Certain parts of the moon, from a scientific perspective, need to be protected more than other parts of the moon from forward biological contamination.”
The second directive addresses future human missions to Mars, a planet with much greater planetary protection requirements. Those requirements include setting strict limits on the level of terrestrial contamination that many have argued are incompatible with human missions.
“We can’t go to Mars with humans if the principle that we’re living by is that we can’t have any microbial substances with us, because that’s just not possible,” Bridenstine said.
The Mars directive doesn’t change the planetary protection requirements for missions to that planet, but instead calls for studies for how to do so. Those studies range from research that can be done on the International Space Station to potentially sending a precursor robotic mission to a location near the proposed landing site for the crewed mission to measure what organic materials are present.
“NASA will develop risk-informed decision making implementation strategies for human missions to Mars, which account for and balance the needs of human space exploration, science, commercial activities, and safety,” the directive states.
That effort, Bridenstine said, would be a long-term process that will require more changes to policies in the future. “As we learn more, we’re going to have to continue making adjustments,” he said.
The two directives implement some of the recommendations of the Planetary Protection Independent Review Board, which released a report last October calling for modernization of planetary protection protocols. Among its recommendations was reclassifying much of the moon from Category 2 to Category 1, as well as for NASA to develop planetary protection guidelines for future Mars missions.
“Planetary protection has not really had a look under the hood in a bottoms-up assessment in something like 40 years,” Alan Stern, the planetary scientist who chaired that independent review, said in a panel discussion after Bridenstine’s remarks. “So much has changed in that time in so many areas.”
The NASA directives apply to the agency’s own missions as well as those in which the agency participates in some way, such as joint missions with other agencies or commercial missions where NASA is a customer. It does not apply, though, to missions by other space agencies or strictly commercial missions.
“There are NASA’s interim directives, but what NASA does has a tremendous influence on the private sector,” argued Mike Gold, acting associate administrator for international and interagency relations at NASA, during the panel discussion. “We have to establish the right precedent. The [directives] we put forward today will demonstrate a path for the private sector.”
The directives also do not affect international planetary protection guidelines maintained by the Committee on Space Research (COSPAR). However, when the independent review board’s report was released last fall, people such as Len Fisk, president of COSPAR, said they expected the recommended changes to ultimately be accepted by COSPAR.
One space law expert said that approach should be sufficient. “It is an evolving process,” said Tanja Masson-Zwaan, deputy director of the International Institute of Air and Space Law at Leiden University. Countries have been voluntarily implementing those guidelines for decades, she noted, as a means of adhering to the Outer Space Treaty’s requirement to avoid “harmful contamination” of celestial bodies.
She rejected in the panel discussion the idea of a new international organization to oversee planetary protection. “In pragmatic terms, this is not something that will happen, but I also do not think it is necessary.”
