The first crewed mission to Mars should be all female. Here’s why.

Men have crewed every mission to the Moon so far, but when we finally send humans to Mars it would be wise to send only women — at least at first.

Mind you, this wouldn’t primarily be for fairness — a correction for the rampant sexism that denied American women the title of “astronaut” until Sally Ride‘s historic flight in 1983 — but rather a practical decision based on calculations as cold as deep space. Available evidence bluntly suggests that women would be more efficient and capable crewmembers on long-duration missions away from Earth.

Dr. W. Randolph Lovelace II and Brigadier General Don D. Flickinger, the former chair and vice chair of NASA’s Special Committee on Life Sciences, originally made the pragmatic case for female astronauts in the late 1950s. The duo noted that women are lighter and thus require less oxygen; they have fewer heart attacks; their reproductive systems are less at risk from radiation. Of course, Lovelace and Flickinger were overruled amid the era’s prevailing sexism.

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Long-term space missions

NASA scientist Geoffrey Landis reiterated the argument in 2000, applying it more strictly to deep-space flight, where the only resources available are the ones you take with you.

“Women are on average smaller than males: women use less oxygen, consume fewer consumables, produce less carbon dioxide. They have lower mass and take up less volume. The argument for an all-female crew is simple: such a crew would require considerably less support… and allow a smaller spacecraft. This would produce considerable savings in cost,” he wrote.

A recently published study put some concrete numbers behind Landis’ contentions. Scientists with the Space Medicine Team at the European Space Agency calculated that the average female astronaut requires 26% fewer calories, 29% less oxygen, and 18% less water than the average male.

This translates to some sizeable resource savings. A 1,080-day space mission crewed by four women would need 1,695 fewer kilograms of food than an all-male task. That’s about 10% of a SpaceX Falcon Heavy rocket’s payload to Mars — valuable space which could be filled with additional scientific projects and equipment to ensure a safe and successful mission.

Beyond physical practicality, there are psychological reasons women might be better suited to extended missions away from Earth.

“Statistics show that all-woman groups are far more likely to choose non-confrontational approaches to solve interpersonal problems, and most definitely are more likely to deal with a situation without resorting to violence, which could be a big problem on a Mars journey, where the crew must live in close quarters for 2-3 years,” Landis wrote. “Numerous sociological studies have shown that women, in general, are more cooperative, and less given to hierarchical social structures.”

Just over 60 years ago, the Women in Space Program put 19 female aviators through astronaut training, with more demanding testing than NASA gave to the original Mercury 7 astronauts. The 13 women who passed arguably topped the men both physically and psychologically. The first crewed mission to Mars, which will likely not occur until 2029 at the very earliest, will require every advantage possible, so it only makes sense that an all-female team should be the first to step onto the red planet.

The first time that women made up 50% of the NASA astronaut candidate class. But looking forward, should NASA try to go even higher? Should the first human Mars mission be all women? Look, it’s no secret that we here at “Space-Time “The Questionlove the idea of cloud cities on Venus.

But unless our #OccupyVenus Twitter campaign works miracles, humans will probably end up going to Mars first. The question is, which humans? See, several articles in journals or the press have asked whether it might make sense for a Mars crew to consist mostly or even entirely of women.

It’s an interesting proposal that warrants discussion, but we need to get some facts straight first. Today, I’m going to review some of the data underlying the various arguments. Are you guys ready? All right. Let’s start with the physiological arguments for all-female missions beyond Earth’s moon.

A lot of us want to become astronauts, but let me tell you, becoming one is not easy. Lots of factors disqualify you from NASA before you even begin including, current, height restrictions. Health ConcernsYou’s got to be 4’11 to 6’3.That’s it.

In all likelihood, scrutiny will be even greater for the first manned trip to Mars, because we can’t have these pioneers falling apart 200 million miles from Earth. So physiologically, what’s the biggest health concern for astronauts right now? Well, according to a 2014 NASA study that we link in the description, it’s not bone loss.

Instead, it’s an issue where women appear to have a big advantage– vision impairment. Several male astronauts have experienced confirmed vision problems, often accompanied by anatomical changes to the eye, both during and after space flight.

All of them were in orbit for six months or less, which is a lot less time than the eight months of zero-G in each direction that you’d have on a Mars mission. Now, countermeasures are being studied, but it’s tough because the exact cause of the phenomenon isn’t entirely understood yet. What we do know is that so far no women have experienced lasting vision issues.

And since vision is a pretty critical faculty on a Mars mission, and given the uncertainty about underlying causes, this might be a major checkmark in the pro-all womenOther Physiological Concernscolumn. So are there physiological areas where women do worse than men? Sure. Let’s look at the same NASA study. Women are more prone to space motion sickness when they first hit zero-G, but that goes away.

Women get more urinary tract infections, but they can be treated with antibiotics. And women faint more easily from standing up to fast once they get back to Earth, which may not be as big a deal in Martian gravity– still unclear. Now, none of these rise to the same mission-critical level as impaired vision. However, women do have another physiological minus that does have to be considered– radiation.

Women have about twice the risk of radiation-induced cancer that men do. It’s why NASA allows women only half as much lifetime space flight as it allows men. Radiation would be a big issue for a Mars mission, no question. However, given current shielding technology, even men might exceed the allowed radiation safety levels.

So while it’s a negative for women, radiation risk might be one of those things that you have to solve for everyone to send anyone. Anyway, absent testing for or countermeasures for vision problems, women may have a physiological advantage just because of that. Psychological SuitabilityOK.

What about psychological suitability? Well, the same NASA study reports no sex-based difference in psychology or behavior during spaceflight. They attribute this to the robust screening and training that NASA astronauts undergo. However, other sources and space programs tend to give women the edge in this category.

For example, the British newspaper “The Guardian” reported Chinese space officials as saying that their female astronaut candidates exhibit better communication skills and adapt better to isolation than their male counterparts. Similar results were found during the testing of the Mercury13. That’s a group of women who were put through the same tests as the male Mercury astronauts back in 1960.

Incidentally, the story of those women and the subsequent political battle to try to have women admitted to the US astronaut corpses is fascinating. It’s covered in an episode of the PBS “Makers” series, which I highly recommend. There’s a link to the video in the description. Anyway, it looks like women might have a slight psychological edge on longer-duration missions.

But let’s suppose that nothing we’ve said so far was true.No physiological or psychological edges for women. There’s still another argument for preferring women to men on longer space missions–namely that it costs less to send them to other planets. How come? It’s about food.FoodWhile you can recycle air and water, you need to take all the food mass with you on a trip to Mars.

And that’s true even if you manage to grow plants. Now, it turns out that women need less food to do the same activity as men, which means less mass to transport, less propellant, and thus lower cost. Now, this argument has been made many times over the years, including by some NASA employees. But it got a lot more attention in late 2014 when writer Kate Greene wrote an article to this effect in “Slate.”

Greene was one of six volunteers–three men and three women– in the first four months of study at High Seas, a NASA-funded, enclosed, isolated habitat on Mauna Loa in Hawaii that simulated aspects of conditions on a Mars mission. Greene noticed that the women in her cohort consumed about half as many calories as the men, despite comparable activity and exercise.

This was consistent with what had been seen earlier by current and former NASA analysts that she cites in her article. But what Greene doesn’t give us is an actual numerical estimateMathof the savings, so I did some rough math. Let’s consider the long version of a NASA Mars mission.

It would be a 910-day round trip with over a year on the Martian surface. For whatever reason, the calorie requirements in space and on Earth are the same. So taking into account the water you need to rehydrate the food, each person would eat about a kilogram of food per day.

That’s about 1,000 kilos, or one metric ton, per person for the round trip. So how much food mass could you save if you used all women? Well, the crew would probably be four people, but let’s say six just to highball it. That’s six metric tons of food. I’m assuming our comparison baseline is three men and three women, replacing all the men with women.

Since my one kilo, a day is an average of both genders and since we’re only replacing the three men with women–that’s half the crew– you can knock out about a third of your total food mass. So our savings would be two metric tons.

So how does that mass savings translate into dollar savings? To ballpark that you need to work out how much fuel it wouldCosttake to get that food from Earth orbit to Mars orbit and back, and then estimate the cost of getting the food plus all that fuel off of Earth’s surface to begin with.

Now, I worked out that you need about 50 tons of propellant to move those two tons of food there and to bring back the half-ton or so you’d need for the return trip. Why so much? Because as you add fuel to move your payload, you then need to add fuel to move that fuel and so on and so on– this is why space flight costs so much money.

Now, my number is conservative. I assume that we wouldn’t need any fuel for the descent to Mars, that you’d leave all the food for the return trip in orbit around Mars, and that you’d leave all your waste down on the Martian surface. So what’s the dollar savings? At today’s launch prices, it’d be between $0.5 billion and $5Savingsbillion.

Our 50 metric tons of food plus food fuel would thus represent around 5% to 7% of the mission mass and 5% to 7% of the launch cost, which might be 0.5% to 1%of the estimated total mission budget. That’s not crazy, but it’s not entirely negligible either.

Now, granted, launch costs are dropping so these projections could change. But even if SpaceX manages to get those launch costs to 1/10 bottom line of what I’ve quoted, we’re still talking about savings of hundreds of millions of US dollars if we sent only women.

So I guess my bottom line question to all of you is this. Suppose it turns out that by the time we’re ready for the Mars mission we can manage radiation but cannot manage the vision issues. And suppose that further testing shows that four to six women locked in a tiny can in a black void for two to three years would work as a team with a lower risk of flipping out as well as or better than a mixed-sex crew would.

If all that turns out to be true, and taking into account the cost issues we discussed, should an all-female crew be given preference for the first Mars mission?Because remember, the first Mars mission needs to succeed. So it seems, to me at least, prudent to eliminate every risk that you know about and can manage.

But let’s see what you guys have to say. Have at it in the comments, and feel free to point out anything that I missed or got wrong. I’ll report on the evolving discussion in the next episode of “Space-Time.”CommentsLast week we asked what the most realistic artificial gravity in sci-fi is. You guys had a lot of really great comments. If I don’t get to yours individually, don’t feel bad.

We have limited time. A lot of you brought up sci-fi series that I did not mention in the episode. Let me run through these things in order. “Ender’s Game.”I agree that the novel seems pretty realistic, but the movie is less so. But since I don’t have any numbers, I have no way to confirm this. “Interstellar”–guess what, I haven’t seen the movie yet because I have no life.

But I looked at the specs, and the ship rotates at five to six RPMs.You would notice a Coriolis force.”Rendezvous With Rama,” which is another novel by, Arthur C. Clarke. I agree it has slow RPMs and low Coriolis effects, but it only has 0.7 earth Gs, which might be intentional. I don’t know. The “Gundam” anime series– yet something else I’ve never seen.

However, Scina Bocere pointed out that its design is based on something called an O’Neill Cylinder that you can look up on Wikipedia. And Watchit1337 supplied numbers for the “Gundam” ships, which if right, I agree would produce minimal Coriolis effects. Thumbs up.

Finally, some people brought up using an accelerating ship to get artificial gravity. So go 9.8 meters per second squared acceleration in one direction. This is done apparently in “Mass Effect,” the “Expanse” series and another Niven work called “The Mote in God’s Eye.”

The problem is, where do you get the fuel to keep that acceleration going? There are lots of reasons that are not realistic, which is why I didn’t bring it up. The remaining comments are about things that happened in the episode itself.

Greg Peden points out that around three minutes, 47 seconds, where we had the ball sort of being thrown away in the carousel, it shouldn’t go as straight as we had it in the video. It should tilt slightly to the right because of the already tangential momentum that it had. You’re right.

I’m glad you guys picked that up. Davide Conte asked why we didn’t bring up gravity gradient effects, namely that in a small ring– this is not as a big problem as large rings– there would be a gravity differential between what you’d feel at your feet and your head. I didn’t bring this up because we don’t entirely know the effects of that.

There might be fluid redistribution in the body, and you might get more bone leeching in your neck because there’s less gravity there compressing your spine. But in the short term, the Coriolis effects are a lot more significant.

For storm asks, wouldn’t a rotating station has trouble turning because its angular momentum vector would have trouble being shifted? He’s hearkening back to our barrel roll episode there, and the answer is yes. That’s why O’Neill Cylinder, which I’ve already referenced in the comments, would have two counter-rotating sections so that there would be gravity here and gravity here but no net angular momentum, and thus no net gyroscope effects.

Excellent questionThomas Archuleta points out another scene from “Babylon 5″that I remember in which Michael Garibaldi drives a motorcycle at a pretty fast clip but doesn’t seem to have any weird Coriolis effects. The reason is that if he’s driving along the axis of the space station, there would be no Coriolis effects.

The Coriolis effects would only be there if you move along the rim, not along the axis.CGIAgent asks, in a rotating ship like “Babylon 5,” Assuming that you had atmospheric pressure at the rim and that atmospheric pressure dropped with altitude, would there be some point near the center of the rim where the atmosphere got so thin that you’d suffocate and there’d be a suffocation zone? I think that would depend on the specs and how the air was being blasted in there.

You might be able to have something on the axis to sort of inject more air out and artificially increase the air pressure there. But I don’t know. I’d be interested if you worked it out. Finally, John Nielson, who likes the show, says he doesn’t know what to do with himself.

The idea of having the first crewed mission to Mars be all female is an interesting proposal, and it’s worth exploring the potential benefits and considerations surrounding such a mission. It’s important to note that any decision regarding crew composition should prioritize qualifications, expertise, and overall fitness for the mission. However, let’s examine some points that have been raised in favor of an all-female crew:

Equality and representation

Promoting gender equality and providing opportunities for underrepresented groups, such as women in space exploration, is a valid consideration. It can inspire and empower women around the world, demonstrating that they too can participate in and lead ambitious scientific endeavors.

Breaking stereotypes

Historically, space exploration has been predominantly male-dominated. By sending an all-female crew to Mars, it could challenge stereotypes and misconceptions about women’s capabilities in high-risk and high-stakes environments, encouraging gender inclusivity in scientific and technological fields.

Team dynamics

Some argue that an all-female crew might have better teamwork and collaboration due to potentially reduced hierarchical tendencies or communication styles. This perception suggests that such a crew could establish a unique dynamic that enhances mission efficiency and cohesion.

Scientific research

Studying the physiological and psychological effects of space travel on an all-female crew could provide valuable data. Women’s bodies may respond differently to the challenges of long-duration space missions, such as microgravity or radiation exposure. This knowledge could lead to tailored solutions and improve the overall understanding of human space exploration.

Public engagement and interest

An all-female crewed mission to Mars might capture public attention and generate increased interest in space exploration. This can help stimulate public support, funding, and participation in space-related endeavors, inspiring the next generation of scientists and engineers.

Role models and inspiration

Sending an all-female crew to Mars could create a new generation of role models for girls and women, inspiring them to pursue careers in STEM fields and space exploration. Representation plays a crucial role in encouraging diverse participation and breaking down barriers.

Overcoming societal challenges

By showcasing women successfully undertaking a mission to Mars, it could challenge and overcome societal stereotypes and biases that have hindered women’s progress in traditionally male-dominated fields. It can help foster a more inclusive and equitable society, encouraging broader acceptance of women in leadership roles and non-traditional careers.

Long-duration mission considerations

A mission to Mars would require long periods of isolation, confinement, and limited resources. Some argue that an all-female crew might be better suited to cope with these challenges, as they might have a higher tolerance for extended periods of social isolation or psychological stress, based on anecdotal evidence and studies in analogous environments.

Cultural and diplomatic impact

A diverse crew composition, such as an all-female crew, can foster international collaboration and promote cultural understanding. It could be seen as a symbol of global unity and cooperation in the pursuit of scientific discovery, showcasing the power of diversity and breaking down barriers across nations.

Reducing biases and discrimination

By deliberately selecting an all-female crew, it can help mitigate biases or discrimination that might exist in the selection process, ensuring equal opportunities and challenging unconscious biases that may unintentionally influence decision-making.

It’s important to remember that the decision regarding crew composition for a mission to Mars should be based on a careful assessment of various factors, including expertise, skills, compatibility, and mission requirements. The primary goal should always be to assemble the most capable and qualified crew members, regardless of gender, to ensure the success and safety of the mission.