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As principal investigator for the NASA moon mission GRAIL, Maria Zuber was the first woman to lead a competitive planetary mission.

Bill Ingalls/NASA

Women make up just 15% of NASA’s planetary mission science teams. Here’s how the agency is trying to change that

Sometimes, change starts with a single sentence.

In December 2016, NASA began accepting bids for its next New Frontiers competition, a chance to mount a $1 billion mission to solar system destinations such as the moon, Venus, or Saturn's moon Titan. It is a careermaking opportunity, and scientists devoured the rules in the announcement. In the second paragraph, they read something new: a sentence stating that "NASA recognizes and supports the benefits of having diverse and inclusive" communities and "fully expects that such values will be reflected in the composition of all proposal teams."

Many scientists hope the language will help NASA get out of a rut. Over the past 15 years, women have made up just 15% of planetary mission science teams, even though at least a quarter of planetary scientists are women. The disparity is even worse for ethnic minorities: Blacks and Hispanics make up 13% and 16% of the country, respectively, but each group makes up just 1% of the nation's planetary scientists. (Firm numbers for specific missions are not available.)

The New Frontiers deadline arrived last week, and although the proposals are not public, observers say that women lead at least four of the dozen or so NASA received. "I suspect teams that come in will be significantly more diverse than previous rounds," says Louise Prockter, director of the Lunar and Planetary Institute in Houston, Texas.

NASA's move was spurred by scientists like Julie Rathbun, an expert on jovian moons at the Planetary Science Institute in Claremont, California, who has tried to quantify NASA's diversity problem. She and her peers dug up press releases and records to count the women on 26 missions. The lack of women on the 78-person science team for the Viking probes, sent to Mars in 1975, may not have been so surprising. But Rathbun expected women to be better represented on a newer generation of missions, and she was shocked to see no improvement in the past 15 years. "It hasn't happened yet," she says.

A long way to go

Over the past 15 years, women made up on average just 15% of the initial science teams for NASA planetary missions. Participating scientist programs, which add new members to the missions over time, have improved the teams' diversity.


Rathbun presented her analysis at meetings over the past 2 years, and the message eventually reached Curt Niebur, NASA's program scientist for New Frontiers in Washington, D.C. He says that pushing for more diversity is in NASA's interest. "The research now shows the best teams are those that take advantage of the diverse skills, knowledge, and viewpoints that are available," he says.

Planetary science is not unique in its diversity problem. Many scientific disciplines, even those fed by academic pipelines that are majority female, such as biology, still have a disproportionate number of men in leadership roles. Janet Vertesi, a sociologist at Princeton University who studies planetary missions, says researchers have found that female and minority scientists can suffer even in the absence of conscious bias from majority scientists. Through the Matilda effect, for example, readers tend to assign more credit to male co-authors than female ones. And when minorities of any sort make up less than a third of a team, they face pressure to show that they were not selected because of their identity, which can cause conflicts. Some defenders of the status quo have claimed that it simply reflects merit. But Vertesi says that, without explicit criteria for "merit," people look for candidates from their existing social networks and exclude outsiders.

As a federal agency, NASA won't impose sex- or race-based quotas in judging the New Frontiers proposals. And including demographic information on the mission proposals is still technically optional. But the change in the application language is a start, says Maria Zuber, vice president for research at the Massachusetts Institute of Technology in Cambridge, and the first woman to be a principal investigator for a NASA planetary mission. "If NASA gives it sufficient airplay, I think it will at least make people think." When it comes time to evaluate the mission proposals, Niebur says, he will require review panelists to perform exercises to raise awareness of unconscious biases they may have.

NASA can take other tangible steps to boost diversity. For example, the agency has provided money to add outside scientists to many in-progress missions, a move meant to add new expertise to their research teams. Such participating scientist programs, as they're known, tend to improve diversity as well, according to a report from NASA's scientific advisory groups that was led by Prockter and released this week. She says she thinks that such programs should be mandatory for every mission.

Other glimmers of progress are evident. Two years ago, women led four of the five proposals that were finalists in the competition for Discovery—a NASA line of missions with a $450 million limit. One of the two winners was led by Lindy Elkins-Tanton, a planetary scientist at Arizona State University in Tempe who, with her mission to a metallic asteroid, has now become the second woman to lead a competitive planetary science mission. Elkins-Tanton supports the new language, which could push the field one step closer toward a culture where all good ideas are heard. "We're trying to make it a meritocracy," she says.