Rosalind, a New Mars Rover, Is in Rare Company

When you read through the list of missions humankind has launched into space over the past 60 years, a pattern emerges.

There’s Hubble, the telescope that sighted countless glittering galaxies. Cassini and Galileo, which orbited Saturn and Jupiter, respectively, for years. Kepler, the discoverer of thousands of exoplanets; Herschel, the chronicler of the Milky Way’s star-forming regions; Huygens, the lander that plopped down on a Saturnian moon.

Magellan, Einstein, Newton, Planck, Euclid, Chandrasekhar, Fermi, Van Allen—these missions have provided scientists with heaps of information about the universe. And they are all named for men.

So it was a nice surprise when the European Space Agency recently announced that its next rover mission to Mars, launching in 2020, would bear the name of a woman: Rosalind Franklin, the English chemist whose work led to the discovery of the double-helical structure of DNA in the 1950s.

Read: The women who contributed to science but were buried in footnotes

The news was warmly received. It seemed fitting to name a rover designed to search for evidence of life on one planet after a scientist who studied the molecular basis of life on another. And the choice seemed just—recognition for a brilliant scientist whose contributions were overlooked and uncredited for years.

Many space missions aren’t named for anyone, actually. Some receive abstract labels intended to capture the grandeur of exploration: Endeavor, New Horizons, Curiosity. Some get inventive descriptions that are easily squished into charming acronyms: Consider JUICE (JUpiter ICy Moons Explorer) and MAVEN (Mars Atmosphere and Volatile EvolutioN. There's even a ground-based mission called—and this is quite the reach—SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars). Still others bear the names of figures in mythology: Juno, the Roman queen of the gods; Ulysses, the hero of Greek mythology; Chang’e, the Chinese goddess of the moon.

But the missions named for human beings are disproportionately named for men. This isn’t surprising. The namesakes were meant to honor the scientists and researchers who presented new theories and published groundbreaking papers—and for most of human history, these were men. There were certainly women in these fields, but their contributions were likely to be downplayed or forgotten. When the people in charge of naming spacecraft reach into the past for inspiration, the names of men, buoyed for centuries, float to the top.

Most of the missions named for women are close to Earth, in both purpose and physical proximity. Satellogic, an Argentinian company, has launched Earth-observing satellites named after Ada Lovelace, the English mathematician who wrote about computer programming a century before the machines appeared, and Maryam Mirzakhani, an Iranian mathematician who was the only woman ever to win the Fields Medal, the “Nobel Prize of math.” Spire Global, an American company that makes satellites to track weather and ship traffic, names satellites after its employees, some of whom are women. India’s first meteorological satellite, now defunct, was named for Kalpana Chawla, the Indian American astronaut who was killed in the space shuttle Columbia disaster in 2003.

Push deeper into space, beyond the influence of Earth’s gravity, and there’s only one. Sojourner, an old NASA rover, explored the Martian surface for three months in 1997, taking photographs and probing the soil before it stopped communicating with Earth. It was named for Sojourner Truth, the escaped slave who became one of the most prominent civil-rights activists in the United States.

NASA is currently working on a new mission to Jupiter called Lucy, but it’s not named after a human woman. The namesake is an incomplete skeleton of a female Australopithecus afarensis, an extinct hominin.

Franklin and Sojourner both received their names from public campaigns. For Franklin, the European Space Agency solicited and reviewed 36,000 nominations for “creative and bold” names. For Sojourner, scientists and engineers at NASA’s Jet Propulsion Laboratory reviewed 3,500 essays from students who had been asked to select a “heroine” in history and describe her accomplishments.

The finalists were Truth, the chemist Marie Curie, and Judith Resnik, a NASA astronaut who died in the Challenger explosion in 1986. Submissions were scored not only on the quality of the essay, but also on “the appropriateness of the name for a Mars rover.” The Jet Propulsion Laboratory said it chose Sojourner in part because the name means “traveler.” It sounded better than the others.

Such caveats don’t seem to apply to missions named for men. The decisions don’t tend to be crowdsourced either. Take, for example, one of NASA’s most ambitious missions of the 21st century so far, the James Webb Space Telescope. The telescope will become the most powerful in history when it launches in 2021, carrying the name of a former NASA administrator who served during the Mercury and Gemini programs that put men into orbit in the 1960s.

Sean O’Keefe, another former NASA administrator, picked the name in 2002, when the telescope project was in its early stages. O’Keefe says the effort was shaping up to become a massive undertaking that would require a successful leader of the space agency. His predecessor sprang to mind. “He was, in my estimation, the most extraordinary guy to ever serve in that job,” O’Keefe says, adding that he didn’t consider opening up the decision to the public. “There was no established standard at the time [for naming missions], and I don’t know if there is much of one now either.”

Male figures dominated the cosmos long before any spacecraft left Earth, in the names of planets, moons, and constellations of stars. They came from classical myths, which rarely ended well for the women involved. These stories were rippled with misogyny, and so is the night sky, wrote Leila A. McNeill in an Aeon essay in 2016. The constellation Andromeda is in the shape of a woman chained to a rock as punishment from Poseidon. The Pleiades, a cluster of stars in the Taurus constellation, are named for seven sisters who were pursued by Orion the hunter, and the way Orion is mapped onto his constellation, he’s still in pursuit.

The appeal of traditional naming practices persists. NASA is currently developing the Orion capsule, which may someday carry humans to the moon again and beyond. A spacecraft launched in 2011 to orbit Jupiter is called Juno, after the Roman god’s wife.

Read: Jupiter will never stop surprising scientists

Perhaps the naming of spacecraft seems like a passing detail in the scheme of things, especially in a cosmic sense. After all, these things eventually run out of fuel. Some of them even crash into planets and disintegrate into nothing. But some will remain in space for hundreds, perhaps thousands, of years. They are built to last, and in turn to outlast. They will become part of humankind’s record as a spacefaring civilization. The late Carl Sagan wrote in 1976 about the historical importance of naming things in the solar system:

Some may think that the naming of the solar system is a pointless, or at least a thankless, task. But some of us are convinced it is important. The place names assigned are likely to apply for a very long time. And our remote descendants will be using our nomenclature for their homes on the broiling surface of Mercury, by the banks of the Martian valleys, on the slopes of Titanion volcanoes, or on the frozen landscape of distant Pluto, where the sun appears as a point of bright light in a sky of unremitting blackness. Their view of us, of what we cherish and hold dear, may be determined largely by how today we name the moons and planets.

His argument concerned the surfaces of other planets, which the Voyager spacecraft were about to reveal in phenomenal detail. But it applies well to the missions themselves too. Already, Apollo and Challenger are part of space history; it’s impossible to tell the story of Charles Darwin without mentioning The Beagle. Without spacecraft to reach faraway places, the hypothetical homes Sagan imagined would not be possible. If and when humanity moves off Earth, the vehicles that take us there will forever be part of our story in space.