Throughout the history of the U.S. human spaceflight program, a peculiarly American rhetoric of manifest destiny, frontier conquest and exploitation has dominated official and public discourse. Take, for example, the credo of the Space Frontier Foundation, an American nonprofit advocacy group “dedicated to opening the Space Frontier to human settlement as rapidly as possible ... creating a freer and more prosperous life for each generation by using the unlimited energy and material resources of space.” Such rhetoric reveals an ideology of human spaceflight—a set of beliefs about the nation's right to expand its boundaries, colonize other lands and exploit their resources.

This ideology rests on a number of assumptions about the role of the U.S. in the global community and American national character. According to this ideology, the U.S. is and must remain “number one” in the world community, playing the role of political, economic, scientific, technological and moral leader, spreading democratic capitalism. The metaphor of the frontier, with its associated images of pioneering, homesteading, claim staking and taming, looms large in this belief system.

The rhetoric of human spaceflight advances a conception of outer space as a place of wide-open spaces and limitless resources—a space frontier. From John F. Kennedy to Barack Obama, U.S. presidents have embraced this rhetoric of frontier conquest and exploitation. So have nasa administrators, members of Congress and decades of expert panels.

I have heard a White House official tout a concept for large-scale industrialization of the moon as “a phenomenally inspiring long-term vision” for the U.S. space program. The invitation-only Pioneering Space National Summit, held in February in Washington, D.C., yielded a declaration that “the long-term goal of the human spaceflight and exploration program of the United States is to expand permanent human presence beyond low-Earth orbit and to do so in a way that will enable human settlement and a thriving space economy.” One of the groups that participated in this summit, the Tea Party in Space, advocates “applying the core principles of fiscal responsibility, limited government, and free markets to the rapid and permanent expansion of American civilization into the space frontier.”

Rhetoric matters. More than 30 years of my own observations, along with results from public opinion surveys over at least as many years, indicate that the community of American human exploration advocates is predominantly white and male. The rhetoric of frontier conquest and exploitation may appeal to this demographic, but I doubt it has much allure more broadly. Women constitute half of the world's population. A majority of people on Earth are not American, or European, or “white.” In my many years of critiquing the American rhetoric of manifest destiny, non-Americans have repeatedly told me that they are baffled, if not offended, by this rhetoric.

Other spacefaring nations take a more pragmatic approach to plans for space. In his foreword to the European Space Directory 2015, European Space Agency director general Jean-Jacques Dordain wrote that the aim of his agency is to “maintain its role as one of the world-leading space institutions, addressing its key relationships with its partners and its efficiency.” The Japan Aerospace Exploration Agency's slogan is “explore to realize,” expressing “our philosophy of becoming an agency of realizing a safe and affluent society.”

At a time when the U.S. needs to be building sustainable partnerships with other nations to continue exploring space, “USA, Number One!” is not a good way to start productive conversations. In a 2012 paper Jacques Blamont, a founding director of the French space agency CNES, argued that people are losing interest in the human exploration of space “because spacefaring nations, and especially the USA, have clung on to outmoded cold war ways of thinking about it. The US attitude of ‘command’ over its international partners will no longer work.” It is time for human spaceflight space advocates to reexamine their rhetoric—to think about what these words mean to the vast variety of people who are not American, not white, not male, and not interested in moving to Mars.