World / US astronauts share their pics from NASA's 1st all-female spacewalk

On Friday, NASA celebrated a monumental first in its 61 years of history: a spacewalk performed by two women astronauts — without any men suited up alongside them. While it was a much-lauded step for the agency, the milestone also left many wondering why it took so long.

The answer is different depending on who you ask. During the event, one NASA official insinuated that a woman’s physique makes it difficult to perform spacewalks, which is why more men have traditionally done spacewalks. “There are some physical reasons that make it harder sometimes for women to do spacewalks,” Ken Bowersox, the acting associate administrator for human exploration at NASA and a former astronaut, said during a press conference on Friday. “It’s a little bit like playing in the NBA. You know, I’m too short to play in the NBA, and sometimes physical characteristics make a difference in certain activities. And spacewalks are one of those areas where just how your body is built in shape, it makes a difference in how well you can work a suit.”

Others disagree, arguing that height and size don’t matter when you’re in space. In a microgravity environment, the right skills involve meticulous movements and the ability to twist oneself in the proper direction, regardless of physique. The one time a person’s size really does come into play is if they do not have the right suit to accommodate their body.

Spacesuit design has long been biased toward men’s physiques, both due to technological constraints and the fact that NASA preferred male astronauts throughout most of its lifetime. “These repairs and tasks can be performed by anyone in the astronaut corps, that’s for sure,” Dava Newman, the former NASA deputy administrator who is working on a new spacesuit design at MIT.

The spacesuits that astronauts work in today are masterful feats of engineering. In essence, these ensembles are spaceships made in the shape of a human body, providing a tiny bubble of Earth’s atmosphere around a person while in space. “A spacesuit has to basically have all the functionality of a spacecraft with as little excess volume as possible, so the crew member can operate within the suit,” Daniel Burbank, a former astronaut and senior technical fellow at Collins Aerospace, which helped to design the suits on the International Space Station, tells The Verge.

Operating one of these suits is tough. A suit needs to be flexible, so that the person wearing the outfit can move their limbs and do the tasks at hand. But at the same time, a suit must be relatively strong to contain the pressurized gas inside it and protect the wearer from the vacuum of space. Most suits are pressurized to around 4 psi with extra oxygen inside. It’s less than one-third the pressure of sea level here on Earth, about 14.7 psi, which would be impossible to move inside a suit.

But even being able to move against gas pressured to 4 psi does require a certain amount of strength. “We humans cannot operate on a lower pressure,” Pablo de León, professor of space studies at the University of North Dakota, where he specializes in spacesuit technology, tells The Verge. “It’s not like you can say, ‘well I’ll build a spacesuit where you don’t need any physical effort at all and you’ll be able to operate it.’ You just can’t.” However, the strength required to move within a spacesuit is something that every astronaut trains for, regardless of gender. “The training is very rigorous so anyone who’s selected in the astronaut corps has what it takes to perform spacewalks,” says Newman. “The physique is not the issue; they have the capabilities in terms of athletic performance.”

NASA’s Bowersox also suggested on Friday that taller people are somehow more capable of doing spacewalks than others, which is why so few women have done them. “Well, there are some things that, you know, if you look at just statistics, women are probably a little bit smaller than men,” said Bowersox. “It’s a very subtle thing, and you’ll have a larger selection of men with certain amount of strength.” Bowersox also noted that taller people have had easier times during spacewalks, such as repairing the Hubble Space Telescope in orbit around Earth, because they have an easier time reaching around things and getting into crevices. “If you look at some of the Hubble repair missions and things like that, there’s always a tall person or a tall man or two on the crew,” he said.

But Newman also disagrees with this assessment, noting there are a wide variety of tasks that need to be accomplished when performing spacewalks, some that are better for smaller people and some that are better for taller ones. “There are a lot of tight places in a Hubble repair, so actually a smaller person has some advantages in terms of getting into some tight spaces and some tight repairs,” says Newman. “Of course, if you need a large arm-length across and that might be, you know, you might want the crew member that has the largest span. So there’s a lot of tasks to do, but definitely universally no one is... disadvantage.” Newman cites the success of former NASA astronaut Kathryn Thornton, for instance, who was the smallest astronaut to repair the Hubble Space Telescope.