The Space Sorority: Fifty Years of Women in Orbit

The first man on the moon was a character in popular culture decades—even centuries, perhaps—before Neil Armstrong actually filled the role. The assumption was that humanity would reach the moon someday, and it was simply  a given that the first historic step would indeed be taken by a man. “This country should commit itself, before this decade is out,” President Kennedy declared in 1961, “to landing a man on the moon and returning him safely to the Earth.” There was no need for the gender-neutral “landing a person on the moon,” no clumsy “and returning him or her safely to the Earth.” Astronauts were supposed to be men and they jolly well would be.

But only until they weren’t. The boys-only rule ended fast, just two years later, when the Soviet Union sent Valentina Tereshkova into orbit for a flight that lasted just minutes shy of three full days. The 50th anniversary of that journey is June 16th, and in the half century since Tereshkova’s flight, 57 other women have strapped in and blasted off, representing nine different countries—most recently China. The U.S. did not join the space sorority until 1983, when Sally Ride flew, but America made up for that dallying, sending a total of 45 women into space since then. They have faced the same challenges as the men, experienced the same thrills as the men and, on occasion, paid the same price as the men. Four women—Christa McAulliffe, Judith Resnik, Laurel Clark, and Kalpana Chawla—died in the Challenger and Columbia disasters.

The U.S. space program is now in a state of drift, with no American vehicle currently capable of carrying human beings to space, and NASA thus dependent on the Russians to ferry our crews up to the International Space Station—at a cost of $70 million per seat. But China—as in so many other things—is a rising power in space and on June 11, sent its second female astronaut, Wang Yaping, into orbit on what is just the country’s fifth crewed mission. She was preceded last year by Liu Yang.

There was less global hoopla when Yang flew than when Rice did, and much less than when Tereshkova did. The fact that human beings travel in space continues to be—and should be—something that delights and even surprises us. The fact that women are among those explorers is, at last, becoming routine.

What It’s Like to Go to Mars

A trip to Mars would be the adventure of a lifetime. Just ask the 78,000-plus people who signed up to move there, as part of Mars One’s hypothetical colonization project.

But it would also be really, really unpleasant. And we’re not just talking about the general annoyance of spending a year-long voyage huddled in a tiny capsule with all kinds of strangers whose every irritating habit would play out thousands upon thousands of times.

Rocket scientists have long known that voyagers to Mars — or any space destination, really — would be bombarded to some degree with interplanetary radiation. Now, however, we know exactly how much: 1.8 millisieverts per day, which is roughly the equivalent to 100 full-body CT scans per round trip — enough to increase an astronaut’s lifetime risk of dying from cancer by at least 3%. “Even the best available shielding wouldn’t help much,” says Cary Zeitlin, of the Southwest Research Institute in Boulder, Colo., who authored a paper on the subject in the latest issue of Science.

How can Zeitlin be so sure? Because he’s got an expert source: the radiation detector that tagged along on Curiosity’s mission to Mars, whose job was to sniff out potential dangers to humans that might someday make the same journey.

The detector noted two kinds of dangerous particles slamming through the walls: solar energetic particles, or SEPs, flung away from the sun by solar flares and coronal mass ejections, and galactic cosmic rays, or bits of matter blasted across the Milky Way by exploding stars. It’s the latter, which was by far the most prominent, that “punch through any reasonable shielding,” says Zeitlin.

You could always go with unreasonable shielding, of course — lead or concrete walls a few feet thick, or a giant water-filled bubble (materials rich in hydrogen, like H2O, are excellent at keeping out space particles). But those would be impossibly heavy. And even something as seemingly impervious as a foot-thick hull of aluminum, says Zeitlin, “wouldn’t reduce the dose by much.”

But it isn’t just the journey that’s a problem — it’s the destination. On earth, our planet’s strong magnetic field keeps most dangerous particles at bay, and even the International Space Station orbits low enough to stay relatively safe. Mars doesn’t have much of a magnetic blanket, though, so astronauts would be bombarded with radiation on its surface, as well.

The dose would only be half as much: “In space, radiation comes from all directions,” Zeitlin explains. “When you’re on a planet, it only comes from above.” (The radiation detector is now on the surface with Curiosity, putting actual numbers to that general rule of thumb.)

Still, it all adds up — and there’s no protective solution in sight. Which means that if we were sending astronauts to Mars today, the only thing NASA could do is inform them of risks and hope for the best, which is ethically dubious.

“Fortunately,” says Zeitlin, evidently discounting the Mars One fanatics, “nobody’s going to Mars anytime soon.”

Albert Einstein Discovers New Planet. Really.

Albert Einstein didn’t care much about planets, and you can hardly blame him. After all, when you’re busy transforming physics with such revolutionary discoveries as the four-dimensional curvature of spacetime and the equivalence of matter and energy, you don’t have time to worry about trivia.

Yet one of Einstein’s weirder ideas has led to the identification of a new planet, about twice as massive as Jupiter, orbiting a star some 2,000 light-years from Earth — a discovery Einstein never even envisioned but one that may never have happened without him. Indeed, David Latham, a Harvard astronomer who collaborated on the discovery, originally doubted it was even possible to do what he (under Einstein’s guiding hand)  recently succeeded in doing. “I thought it was silly,” he says. “I thought the effect was so small we’d never detect it.”

The effect in question is “relativistic beaming,” and it dictates that when a bright object is coming right at you, the warping of spacetime caused by that motion will force its light into a narrower, more focused beam that looks brighter than it really is. While Einstein never suggested using that phenomenon to look for planets, Latham’s Harvard colleague Avi Loeb and Ohio State’s Scott Gaudi did, in a theoretical paper published in 2003.

Their reasoning: as a planet orbits its star, its gravity pulls on the star, first one way, then the other. If the planet is lined up more or less edge-on from the perspective of Earth, that pulling will yank the star toward Earth, then away. When it’s coming toward Earth, relativistic beaming will make the star look brighter, and when it’s moving away, it should get dimmer.

In fact, the very first exoplanets were found in a similar sort of way, back in the 1990’s, except that those first planet-hunters were looking for a shift in color, not brightness. That’s because motion toward the observer makes starlight look a little bluer than it really is, while motion away stretches the light wave and makes it look redder (this so-called redshifting applies to entire galaxies, not just stars; it’s how astronomers discovered, back in the 1920’s, that the universe is expanding).

Finding planets by shifts in color is hard enough: first-generation planet hunters like Berkeley’s Geoff Marcy faced a lot of skepticism from  colleagues for even bothering. But this new technique is even tougher, requiring measurements of changes in brightness  as small as a few parts per million. Back in 2003, when Loeb and Gaudi proposed the idea, it was indeed silly to try.

But once the Kepler spacecraft went into orbit in 2009, it wasn’t quite so ridiculous, so Latham, along with Israeli astronomers Simchon Faigler and Tsevi Mazeh, plus several others set out to see if it could be done. They weren’t looking just for the beaming effect: the star-planet system, they figured, should brighten and dim for two other reasons. First, a close-in orbiting planet should raise tides on the star, making it bulge into a very slightly oval shape that follows the planet as it orbits, just as tides in Earth’s oceans follow the Moon in its orbit. When the bulge is pointed right at Earth, the star looks just a little smaller than normal, and thus a bit dimmer. When the bulge points off to the side, the star looks bigger and brighter.

Finally, the star heats up the planet, which glows with its own light — but that light isn’t visible when the planet is in front of the star, just as the Moon is dark when it’s between the Earth and the Sun. When the planet swings around to the other side of the star, it’s like seeing the full Moon. There’s just a bit more light, and Kepler can measure the extra.

Each of these effects — extra light from the planet, extra light from the bulging star and extra light from relativistic beaming — is incredibly subtle. “It’s very dim,” says Latham, “so we had to observe through hundreds of orbits to be sure we were seeing it.”

Clearly, they were, and they may be seeing it in other places as well. “We have several other candidates,” says Mazeh, “and we’re learning how to do this better all the time.”

That’s important enough in the planet-hunting game, but it’s also a reminder of Einstein’s brilliance: even the ideas he never had himself turn out to be some of his most ingenious ones.