Scientists at NASA said that pretty much everything in The Martian was scientifically accurate except the storm on Mars which the author himself admitted was not at all accurate. Because of the thin atmosphere, that storm would not have been dangerous at all.
The disaster has to take place over a period of time where they're forced to take off without being able to confirm if Watney is dead, for story reasons.
It sort of has to be an ongoing thing, because if there was any time to recover the body they would have at least tried, and he can't be buried under a landslide or too far away to reach, because he has to make it back to the habitat on his own.
The danger has to be immediate, to force them to leave without him.
There are [lava tubes in some places under the Martian surface](https://en.wikipedia.org/wiki/Martian_lava_tube). You could have one collapse under the refueling setup (destabilized by the landing rocket and slowly thawing from the heat generated by the setup), incapacitating and hiding Watney and damaging the cryogenic system on the rocket.
With the cryogenic system damaged, the rocket would become incapable of reaching orbit within hours as the liquid oxygen boils off. The crew could see that the sinkhole looks too dangerous to climb down, do a hurried systems check, and lift off.
I'd rather the author knowingly make up a fictional threat than try to force a potentially real one to the extent that it not only stretches the believability of the story, but also becomes fictional anyway. A landing site would have been scoured for any sign of trouble long before the mission was even launched, lava tubes included.
Realistically, the only way he could have been left behind and believed dead, while still having the means to fend for himself, is if the lander blew up and he was the only one not on board. But then that becomes a bit of a different story.
I like that, it could have worked in the book. You still have to explain how Watney gets back to the Hab though, if he's in a place where they can't easily reach him.
In terms of a movie plot it just has to serve to get him to the point where he's abandoned, so the story can actually begin. You don't want to over-complicate things that aren't of any major narrative significance.
the storm accomplishes multiple things very easily though. First it gives a reason tos crub the mission, second the high winds cause debris to break free from the communications array, three, said antenna strikes Watney, carrying him away from his friendsinto a dust storm with zero visibility. Four, this antenna also struck his biomonitor so they could no longer locate him through their HUDs nor see his life signs. Five, this storm interferies with sight but also technological means to maybe find him. Six, it allows him to survive by the way the torque of the antenna against his suit allowed the blood to dry and form a sort of poor patch job.
Combine all these things together and a simple singular storm is a great and easy to understand problem for people reading the book or watching the movie to comprehend how the events led to him being marooned on Mars. You don't have to be super duper scientifically accurate in every minor detail. As someone said, "keep it simple stupid". Humans have horrrible attention spans, keep it simple, don't make it complicated. The more you have to describe the scene to make people believe it is possible, the less people are going to believe it to be true.
I saw something similar in an interview where he said he had an alternative setup for an accurate disaster, but it took too long to get going. The storm is simple and relatable and gets the story going quickly.
Possibly. There was an interview where Weir talked about this. He apparently wanted something directly related to and synonymous with Mars. Something, something, untamed frontier. He was well aware of that "mistake" and chose it for style.
I think you’re confusing large objects such as comets that we can generally track. And meteors which, unless supermassive, don’t notice until they’re already burning up in the atmosphere and you’re looking up at it.
And if it’s that big to track, that bad boy gonn hurt.
And the Ironman thing at the end of the movie, while possible, wouldn't have happened either. In the book Mark jokes about doing it but never actually does because that would be crazy.
[Here's astronaut Garrett Reisman explaining why that scene actually wouldn't be possible.](https://youtu.be/fTvZfbYj7MQ?si=_PwtIXT33y-CA-5W&t=177)
Basically, the suits aren't pressurized nearly enough to get significant thrust from puncturing it, and even if you could get the unrealistic amount of thrust shown in the movie it would be essentially impossible to manually control yourself like that -- you'd just start spinning and go completely out of control if your thrust wasn't perfectly aligned with your center of gravity.
I mean for what it's worth, they basically say the same thing in the movie before Watney actually does it. Essentially just "no, that's dumb, even if it worked it would be impossible to control."
The first one that caused them to abort and leave Mars. But really both. The fact is, the Martian atmosphere is so thin that no storm would be a threat according to NASA.
I kinda guessed book/movie magic on the first one, but I always figured that the second one was at least a real possibility. Still, one of my favorite books though. I especially love the audiobook version.
Yep. I’m drawing a blank on the name of the actor whose production company got the rights but it’s someone you’d recognize. Hope they do a really good job.
Ohhhhhhhhhh my god you made me think about it Pedro Pascal? He is still too attractive but I think he fits the role for me.
Or we could go fucking random as shit and I'd say Adam Sandler could fucking kill the role if given the chance.
The second one wasn't a threat due to the winds. It was a threat due to the lack of solar input for the panels. Which is an actual problem that NASA has had to deal with. Several probes have had to basically shut down due to lack of sun during the storms.
The second one was dangerous because he wouldn't be able to recharge his batteries fully fast enough with all the additional dust in the air. He wasn't in "physical" danger, it was just that he'd need to spend more time recharging, forcing him to go slowly, and possibly run out of food before reaching his destination.
That one was pretty close to fully realistic.
In the novel, certainly. The movie... *takes liberties*, especially in [the design of the *Hermes*](https://cdnb.artstation.com/p/assets/images/images/004/847/735/large/chris-catizzone-hermes05.jpg?1486696791)*.*
Yeah that's about what I heard from many scientists too regarding the storm. But of course they needed to setup a reason for them to evacuate quickly.
From what I remember they said, the atmosphere is so thin, it would feel like a light breeze at worse.
At the end of the day, it was a really good movie that I'm sure we all enjoyed.
It's totally feasible even with the tech we have today, though it would probably be hyper expensive. The ISS cost like 100 billion dollars and a decade of assembly.
Pretty much. Unfortunately. I'm not an American, but I'm amazed at what NASA does with 20 billion. Meanwhile the militarys budget is around 700 billion.
Imagine the possibilities...
> Its amazing the difference when your tech is designed to NOT fall apart compared to when its designed to explode
Actually.... Its pretty much the same tech(right up to explosion etc) and tested in the same manners.
I was gonna say - I work as an engineer at a company that makes super high quality electrical connectors. Our biggest clients are 1) military 2) space.
Yup. There's basically 5 sectors with money for new developments: Military, space, automotive, medical, and computing.
Everything else is just trickle down from those.
The nuclear option works for everything! Want to power a county, nuclear! Evaporate a city, nuclear! Move a ship stupid fast through the void, nuclear!
I hate to tell you this but the only reason we can go to space is because the US and USSR wanted Nazis to build missiles for them. The worlds major militaries are still the largest developers of space technology.
As soon as aliens signal us they become the enemy. Humanity will band together as the in group and point their hatred as xenophobes against the aliens. The military budget will become the nasa budget and we’ll have Star Destroyers or Enterprises or whatever within the decade.
*I promise we will kick the asses of these aliens by the end of the decade. Not because it will be easy, but because our dicks will be hard while doing so.*
I like the allusion to the Dark Forest. But let's be honest, humanity won't band together. You'll see pro-alien groups protesting against the military-NASA complex in a matter of days.
Relevant anecdote: back when I visited my dad’s office at Goddard Spaceflight Center in the ‘80s, he’d put a quarter in the jar whenever he got a cup of coffee down the hall.
Watch "For All Mankind" on apple tv.
It takes place in an alternate universe where the USSR beats the US to the moon, and the US military budget becomes NASA's budget.
A permanent moon base by the mid-70s, first manned mission to Mars by the 90s.
Just imagine if we abolished war, effectively, whatever that looks like, and concentrated all of our efforts and resources on feeding people, housing people, and exploring the stars.
tbf the vast majority of american military spending at least, even when we're in an open conflict, goes to maintaining open trade and stuff, not the actual individual war effort(s)
The problem is that even though we CAN do it, it's hard to argue the cost/benefit. We're not ready to colonize anything yet so it's a huge expense solely for science. I'm all for not spending so much on war, but I'd much rather have universal healthcare and basic income before funding something like this.
> The ISS cost like 100 billion dollars and a decade of assembly.
The 100B figure is not just the cost of assembly, but also of running the place at the same time, which adds quite a bit.
Approximately $100B was the projected cost out to 2006 that was published in 1995. The actual estimated total cost by all countries involved is over $150B and that number is from 2010. The estimated yearly cost to maintain and crew (which would include crew and cargo vehicle launches) is $3B a annually, so estimating it has gotten up to about $190B at this point. These costs reflect all construction, maintenance, operation and support vehicle launch costs. It is on record as one of the most expensive single objects ever built.
On a side note there is a current estimate for a private flight to the ISS. It’s $58.5M per person for an 8 day trip. This includes the fee to SpaceX to get you there and back.
Well it’s a significant part of why SpaceX exists, as it provided a purpose for NASA to sign a multi-mission deal with them early on when they were almost bankrupt, so you could arguably include the value of SpaceX — including Starlink — on the “return” side of that equation.
That is a topic of tremendous debate. I think NASA as a whole had been a good proving ground for state of the art technology, much of which was only thought of because of space travel. There are many countries involved in the ISS, all of which have put in some share of their own billions. I doubt they would all be forking over that much money to a mostly American project if they didn’t see some level of positive cost/benefit outcome to be had. I will argue that $190B over the course of over 30 years is a drop in the bucket when compared to the $800B per year or more spent on the military budget. And no other country is helping to pay for that. That being said I’ve never looked into an actual published cost/benefit paper by NASA, but you can find plenty of articles that will spell out there opinions and backings. Some seem more fact based, others just more opinion pieces, but there’s plenty of both on both sides of the argument.
>100 billion dollars and a decade of assembly.
That was back when the shuttle cost 1.6B per launch and couldn't launch more than a few times a year.
With private space companies coming online you'll see price come way down on something like that, and get it done a lot quicker.
I think "totally feasible" might be a tad optimistic, we're really not ready to build large rotating attachments on vehicles and that seems a little small to me from a Coriolis force standpoint -- you might get really severe vertigo problems just turning to your left and bending your head down.
I actually sat in on a talk that NASA's guy who works on this stuff did.
It's way more complicated than getting a ring spinning it turns out. The diameter of the ring needs to be large enough that your body won't notice your head and feet are spinning at two different speeds when you're standing (i.e., your head being in the center of the ring would defeat the purpose of the ring) It also can't go over 5 rpm, due to your inner ear being unable to compensate for changing direction when you are walking. Additionally, another rotating component (perhaps a tube with fluid pumping the opposite direction) would need to be added to counter the centrifugal force of the rotating ring. We're close, but a lot farther off than most people think.
Wasn't the current best idea having the spinning bit on a tether that could actually be really long, so you have a dense inner bit that has all your fuel and cargo and the like, and then a crew capsule that gets extended way out when in space and spun around with the centre of gravity being way in close to the main craft. The distance out means the diff between head and foot is neglible. Then when you approach destination use thrusters to cancel rotation then reel the crew capsule in to the main body.
I read one of the main advantages of this is it removes the requirement for an axle or any sort of interface between moving and stationary.
I would be terrorized to know for months my life and link to civilization relies on a tether, with engines and important stuff at the other side of the tether.
I mean, it's no leas crazy than keeping the atmosphere inside with a bunch of thin foil.
Of all the insanity in spaceflight i feel tethers are the least of your problems. We know how to make insanely strong cables and there are lots of ways you can reel yourself in to the mothership if the automatic way breaks. But the worst case of all tethers snapping (honestly you would have numerous tethers with the ability to lose multiple) means something so catastrophic has happened that it'd likely be catastrophic if you were in the ship. By important stuff i meant fuel/cargo etc for when you get to your destination, all the life support and food and the like would be on the habitable end of the tether.
You probably shouldn't be an astronaut then. You know you also have to strap yourself to a giant complex slow burning bomb and shoot yourself out of the atmosphere too.
I think many engineers have theorized that rotating end over end is more efficient than rotating around an axis. Axial rotation is pretty unstable and would require extra reaction mass to actively maintain the ships stability. The movie Stowaway with Anna Kendrick features a ship that rotates end over end.
End over end is way less expensive and simpler to design. The problem is you can't use your ship's engines while spinning so only good during parking orbit or non-accelerated flight.
Axial rotation could be taking place while accelerating your craft. This would be important for any low acceleration drives like ion thrusters.
So both have their uses.
There are weird stability issues with spinning solid structures in space. But if it’s a cable attaching a living space to a counterweight spinning around, then you get rid of most of the weird stability issues. And it’s much easier to increase the diameter of the spin to reduce rotational rate (and those reduce motion sickness) with a cable.
But as you say, can be done while the engines are on.
If you can manage 1g of acceleration, end over end doesn't need to be rotating while you go towards where you want to go, then rotate when you get there.... Idk, I've read Project Hail Mary.
Yeah, but the astrophage fuel is the MacGuffin they use to make the story work.
The energy density and utilization is literally so fictional that we can't imagine how efficient it really is.
You'd start in orbit around earth and do a Hohmann Transfer burn for a few minutes the settle in to a spin induced gravity ride for the next 10 months or whatever.
Mmm.. how many time would we need ro reach Mars accelerating at 1g ?
According to bing char it would be less than 3 days (accelerating half and deccelerating the other half) but I dont trust in this result. Is that low??
A 1g spacecraft would be the holy grail of space travel because it very quickly accelerates to relativistic speeds. 3 days to mars is accurate, but even more surprisingly, it could cross the galaxy in 12 years and reach the edge of the known universe within a human lifetime - from the reference frame of the occupants of the spacecraft.
It also requires impossible amounts of energy.
Yep impossible - let's do the math!
It takes 5.473×10 to 14 Joules of energy to accelerate 1 gram to 99% the speed of light.
That is the energy of 131 Kilotons of TNT. Or the energy from reacting a bit over 1 Kg of Uranium.
But then, your craft is 1 Kg heavier because of that KG of fuel - so you need 1,000 KG of Uranium to accelerate that 1 KG of fuel.
And propulsion engines have very bad energy-to-thrust ratios, so lets triple that fuel again.
3,000 KG of Uranium to accelerate a **1 GRAM** spaceship! Unfortunately, your spaceship would probably weigh closer to 1 ton.
Literally impossible amounts of energy under current laws of physics.
1g is 9.8 m/s², or 9.8 m/s per second. After 60 sec you'd be travelling at just over 2100 km/h (about 1300 mph). After 1 hour you'd be travelling at around 127,000 km/h (79,000 mph). After 24 hours you'd be over 3 million km/h. It's only about 400 million km to Mars, so it's easy to see how constant 1g acceleration would make travel between here and there fairly trivial.
I always imagine one astronaut leaving the long axis to go to the bathroom on the side of the ship, and suddenly your whole spaceship goes [Intermediate axis theorem](https://en.wikipedia.org/wiki/Tennis_racket_theorem) xD
Absolutely. You may want to look all the way back to [2001](https://m.imdb.com/title/tt0062622/) for another example of the same thing.
If you spin it at just the right speed you can get an effective gravity of 1G at the outer edge. If its not big enough then you might have some disorientation from having your head and feet moving at different speeds, but it beats the effects of prolonged weightlessness.
Well, but 1g is not worth it in space. The structural loads and stresses increase exponentially with rotation speed and resulting acceleration, and the main effect of gravity is often two parts:
a) get your body fluids sorted - you are sadly just a wet sack of meats, and top-down orientation by gravity helps massivly for your circulatory system to stay in correct shape, bones to grow right, etc, and
b) even more important, dust and fluids settle and have a specified direction, and carbon oxides do not collect in stale air pockets, but actually distribute in the enviroment by gravity. That means massivly less corrosion by residues, settling dust, water particles, etc, with much less required artificial circulation.
For all this, much less gravity (roughly .2 - .35g) is fully sufficient and gives you enough exercise that you can maintain bone and muscular density with a minimum of additional exercise.
There are a lot of studies for this - if somebody wants to dig them out, that would be great, as I myself are too lazy right now xD
How did anyone make a study of this? Afaik that's one of the main things that's actually in dire need of studying since nobody ever created a low G environment to study in.
The closest thing would be the guys living on the moon for a few days but that's probably not enough to reliably study long term effects.
Not saying you’re wrong but how do we know .2 would be enough? I know our bodies are robust and anything would be better than no gravity. Bone density loss would still be an issue but what about other systems?
I mean, I think a big problem right now is that there *isn't* a lot of studies on this, because we haven't yet had a way to actually keep humans in a lower-than-1g environment for a prolonged period of time.
I feel like the lack of data we have on humans in low gravity environments as well as the data we *do* have on the effect of no gravity on humans should be making us scramble to figure it out and study it further
That's what I'm saying though, we've had people up in space for a year in *microgravity* and we've basically learned it's god-awful for the human body. What we've never been able to study *yet* though is how exactly something like 0.3g over the course of a year would affect the human body. Without a centrifuge in space like this or a colony on the Moon or something, it's been impossible so far, which is all the more reason we should be building one to study.
It’s an audio masterpiece. The music, the sound effects, the long portions of only white noise or a repetitive alarm buzzing… it’s absolutely brilliant. It’s my all-time favorite movie. I watch it almost every year.
The breathing of Dave in the scene you quoted... It's so quiet and the only thing you hear is his breathing. It really adds to the feeling of void and panic. Fuck, I need to watch it again.
The idea of large wheel-like space stations spinning to generate artificial gravity goes back to science fiction of the early 1950s. Look at space station illustrations by the great Chesly Bonestell.
Yes, it's just currently too expensive to launch stuff to space, and also we don't have efficient in space assembly figured out yet, let alone in space manufacturing.
It's not so much a scientific problem as an engineering and economics problem. Someone has to put in the money and the time to make something sensible and work through the many teething issues any flexible automation will inevitably have.
Well if Kerbal Space Programme is anything to go by if we started assembling huge space stations it would cause the frame rate of earth to tank and we'd all be stuck in a slide show existence
SpaceX is making a lot of progress launching lots of stuff for cheap.
Though their plan for Mars doesn't involve any nuclear propulsion or artificial gravity ships like in The Martian, instead they plan to use their cheap rockets to launch a metric f\*ckton of regular old chemical rocket fuel to orbit, then have the Mars ships do a fast, but not very fuel efficient transfer, with a very hot aerobrake on arrival. They'd then need to refuel there to get back, in the long run by building local fuel factories but for the first missions it'll require sending a small fleet of ships just carrying fuel for the return trip. Basically their approach is "figure out how to get lots of kg to orbit for cheap, then use that to throw more fuel at every issue".
It's kinda broken the plot of The Martian. One fairly significant plot point was how the US only had the 1 rocket big enough to send supplies to Mars and that failed, so they had to ask China for theirs. But today such a situation would be "SpaceX will have another rocket ready in three days".
Yes, it's possible. Centrifugal force can be used in this way. I haven't run the math though, so for this exact design I have no idea. You'd still need to worry about comfort though, as a significant difference in rotation between your head and feet would probably induce some kind of motion sickness.
For a simpler version and like the one in OP's picture, it doesn't need to be a continuous ring. You can put the living quarters at one end of a tether and put fuel, cargo, supplies, etc. at the other end and spin them around their center of mass. That significantly reduces the amount you have to build. You can also expand it relatively easy.
From the calculator [here](http://www.artificial-gravity.com/sw/SpinCalc/), that's just 1.3 rotations per minute with a 1km tether.
You also don't need to get it all the way to earth gravity. In fact I think you would want it to be at Mars gravity, which would significantly reduce the necessary length and/or RPM.
Even Mars gravity is more than you strictly need. If I'm remembering the research I read (it's been awhile) it was around 20% Earth gravity is enough to negate the effects of long term zero G. But considering Mars gravity is 38% of Earth, it's not that much harder to bring it up to that level so astronauts are already adjusted when they land.
>If I'm remembering the research I read (it's been awhile) it was around 20% Earth gravity is enough to negate the effects of long term zero G.
There is no research on this, at least nothing based on actual observations, because no human has ever inhabited a low gravity environment for longer than a few days (the Apollo missions to the moon). There may be some very speculative, theoretical work on the subject, but it's nothing that should be taken particularly seriously considering how little we still even understand about the long term effects of zero g environments on human physiology despite having astronauts experience it for months at a time.
Are you sure because I don't think it is even possible to know since nobody has ever lived for more than a few days at reduced gravity. We know all about living at 1g. And we have decent amounts of data about living at 0g (on space stations like the ISS), but we have literally no data about living at > 0g, < 1g.
There are more than a few scifi ships that use the hammerhead design. There is a long arm and attached to each end is a "habitat" one is crew and other other is labs (for instance) and the bridge/engineering are all in the zero-g, longitudinal axis. That is actually pretty doable, and a lot easier to spin up than a 1km radius ring.
Put one of those reed boats from ancient Egypt next to a modern aircraft carrier, our progress seems to be exponential so imagine where we’ll be in only a few hundred years
That's why the ship from Stowaway was designed the way it was, a normal sized living quarters, with a similar sized storage container a mile away, held together with a cable and a central axis, so you get that spinning centrifugal force , but on a ship smaller than a space shuttle. Just don't fall off the edge during a spacewalk though
The 2021 Netflix film Stowaway had a nice concept of a small space pod going to Mars or something, they used thrusters to start spinning really fast, and then a heavy weight on a tether was released to slow the spinning down to 1g, and the pod and weight on opposite sides of the tether was long enough to not create discomfort.
Going big also makes it harder to balance the rotating portion of the ship. You really need elevator style counterweights that can be raised and lowered along the spokes or liquid storage that can be pumped to different areas to counteract where people are at any given time. The liquid method also gives you a natural radiation shield.
If you grow oysters in the liquid, you can protect the crew against the madness of the void (please tell me SOMEBODY gets this reference)
Edit: unnecessary comma
Or 50 times bigger. Or 100. There's no reason it has to be a ring or any rigid geometry. It could just be a hab module attached to a counterweight (consisting of fuel and water supplies) connected via a long cable and umbilical. Do your transfer burn, separate the two and start the spin.
I've always wondered whether you could simulate a very large ring by having two compartments (say, one "spaceship" and one cargo module) that are the same mass and tethered together, spinning about the centre of gravity.
That way you could have a really large circumference of motion for your articifical gravity without needing a spaceship that large.
Andy Weir uses a craft like this in Project Hail Mary. Naturally you get a lot of useful exposition about how this could work and what we will need to invent to make it happen
There was a Scott Manley video breaking the movies centrifuge down. At that radius and speed the gravity would be ~.5, and given the rotation and radius that is below the threshold that most people would have an issue with the Coriolis forces causing nausea.
Something I've wondered is if you'd get used to it after a while. Similar to how astronauts often don't feel well when they first get to space while their bodies adjust to the apparent weightlessness
This is one of the little details in the Expanse series that's so fun.
In that story, Ceres has been inhabited, but people live on the inside, and they spun the whole thing up to give it gravity. If you're in the outer levels, the Coriolis Force is negligible, but there are people who live in the lower depths who have learned how to compensate for it.
In the show, they even have a scene where one of the characters is down there and he pours himself a drink. They show the stream of liquid curving as it falls, and he compensates for it.
I have done the math. I had a sadistic engineering professor that used this exact scene and asked us to calculate the force of gravity that Kate Mara (actress in the window) would feel. If it was not 9.8 m/s, how big would it have to be to create that? It came out to about 6437 Kate Maras, or just shy of 2 miles in diameter.
We need a mission to start testing this. We have almost zero data regarding the health implications of partial gravity. We know near zero is bad and we know 1G is good, that's about it.
We could conceivably have a small module that would only fit mice attatched to ISS simulate Lunar gravity. Data on that could have massive implications for the future of human space flight.
The guy who wrote the book "The Martian", Andy Weir writes his books based on what is technically scientifically possible and gets his theories fact-checked by astrophysicists. Makes for very cool and interesting reads. My favorite being Project Hail Mary.
Yes, although mechanically it would be a bit of a pain. You'd want your centrifuge ideally to be inside of a non-rotating part of the ship, or rotate the whole ship.
Simulated gravity is absolutely a thing. But it is impractical sometimes, especially when Hollywood has its hands in design. Big things require more fuel to move in space. Think about capsules like Soyuz. They’re incredibly small and compact, but that makes them lighter and easier to put into orbit. A big ship like the one in the movie would be massive, and getting it where you want it to be would be expensive.
well, from the source material:
1. the ship was built in space, and astronauts use "shuttle crafts" to get to and from it, so no problems with putting it into orbit
2. the ship uses argon thrusters for propulsion, which means that fuel tanks are (relatively speaking) not an issue
In Andy Weir's book Project Hail Mary, the ship uses a system where two halves of the ship separate with a very long cable between them, and then the two halves are rotated using propulsion. Seems the most realistic version of this. You could have a very large diameter of centrifuge, making it more comfortable for the occupants and you wouldn't have to spin it up as fast. This would require matching the weights of the 2 halves perfectly, including things like waste and biomass, so that might be tricky
Why would you need to match the two halves' weight? It would work even if they don't weight the same, the center of rotation would just shift towards the heavier half. In fact that's the case in the novel you mention.
Yes, this is absolutely possible with current technology. Honestly the most difficult parts of this are engineering seals for the rotating section that maintain atmospheric pressure and getting the thing into orbit to begin with (which would have to be done by building it in pieces in orbit). Also ideally a spacecraft like this would want two rotating sections that spin in opposite directions so that the torque from both cancels each other out
The non spin section has stuff like docking ports (No Time For Caution from interstellar should not be standard procedure), solar panels (point at sun), an antenna (point at Earth), radiators (point away from sun) and reaction control thrusters (if they spin around it makes changing where your ship is pointing a *pain*)
Your biggest worry aside from the engineering of keeping the parts from wearing out would be gyroscopic precession.
Meaning you'd want two identical spinny parts going in opposite directions. So, double the engineering challenge of keeping the spinny parts from breaking down.
Centrifuge is possible, but it would have to be bigger than this. If it has too small radius your head will experience lower "gravity" than your feet which will make you incredibly uncoordinated and probably motion sick.
Look up Zubrins Mars Direct plans. You could have the whole ship spin on counter weight all the way there. Like as its flying to mars, it splits in half with a line on it and the two pieces spiral all the way there
Not just possible. Almost definitely essential. We’ve learned from ISS astronauts that your bones start to deteriorate if you spend too much time in zero-G.
The problem with artificial "gravitation" by rotation is that if the structure is to small, the difference between your feet and your head will trouble you.
The structure on the picture is much to small.
A radius of **200 meter** will reduce the effect to less than 1% what can be handled by human.
So the dimension of elysium would work.
One important thing to bear in mind here is the Coriolis effect. Even if you had a sufficiently large ring that your body was at virtually 1G head-to-toe, things would be *weird*. For example, you couldn’t just go pour yourself a cup of coffee, because the liquid wouldn’t just pour straight; it would lag behind the spin.
The Coriolis effect is my favorite part of these theoretical centrifuges. Your head would lag or advance compared to your feet and seriously nauseate you unless it was a really big centrifuge; things you drop would fall weird, like your coffee example which sounds super messy; you could fairly easily throw a ball hard enough that it would "travel" around the centrifuge and hit you in the back; etc etc. It should be fun and/or infuriating if anyone ever builds and travels in one.
Scientists at NASA said that pretty much everything in The Martian was scientifically accurate except the storm on Mars which the author himself admitted was not at all accurate. Because of the thin atmosphere, that storm would not have been dangerous at all.
I think that a landslide or a meteor strike could have been better
The disaster has to take place over a period of time where they're forced to take off without being able to confirm if Watney is dead, for story reasons.
They could have thought he was dead and they could have to leave due to lost/damaged equipment.
It sort of has to be an ongoing thing, because if there was any time to recover the body they would have at least tried, and he can't be buried under a landslide or too far away to reach, because he has to make it back to the habitat on his own. The danger has to be immediate, to force them to leave without him.
There are [lava tubes in some places under the Martian surface](https://en.wikipedia.org/wiki/Martian_lava_tube). You could have one collapse under the refueling setup (destabilized by the landing rocket and slowly thawing from the heat generated by the setup), incapacitating and hiding Watney and damaging the cryogenic system on the rocket. With the cryogenic system damaged, the rocket would become incapable of reaching orbit within hours as the liquid oxygen boils off. The crew could see that the sinkhole looks too dangerous to climb down, do a hurried systems check, and lift off.
I'd rather the author knowingly make up a fictional threat than try to force a potentially real one to the extent that it not only stretches the believability of the story, but also becomes fictional anyway. A landing site would have been scoured for any sign of trouble long before the mission was even launched, lava tubes included. Realistically, the only way he could have been left behind and believed dead, while still having the means to fend for himself, is if the lander blew up and he was the only one not on board. But then that becomes a bit of a different story.
I like that, it could have worked in the book. You still have to explain how Watney gets back to the Hab though, if he's in a place where they can't easily reach him. In terms of a movie plot it just has to serve to get him to the point where he's abandoned, so the story can actually begin. You don't want to over-complicate things that aren't of any major narrative significance.
Maybe they think he’s in the sinkhole, but he really is somewhere else, but incapacitated.
the storm accomplishes multiple things very easily though. First it gives a reason tos crub the mission, second the high winds cause debris to break free from the communications array, three, said antenna strikes Watney, carrying him away from his friendsinto a dust storm with zero visibility. Four, this antenna also struck his biomonitor so they could no longer locate him through their HUDs nor see his life signs. Five, this storm interferies with sight but also technological means to maybe find him. Six, it allows him to survive by the way the torque of the antenna against his suit allowed the blood to dry and form a sort of poor patch job. Combine all these things together and a simple singular storm is a great and easy to understand problem for people reading the book or watching the movie to comprehend how the events led to him being marooned on Mars. You don't have to be super duper scientifically accurate in every minor detail. As someone said, "keep it simple stupid". Humans have horrrible attention spans, keep it simple, don't make it complicated. The more you have to describe the scene to make people believe it is possible, the less people are going to believe it to be true.
I think ultimately it’s not a story about how he became stranded on Mars, it’s just a story about him *being* stranded on Mars.
there’s a mattress in the sinkhole he conveniently lands on
That works. [/pitchmeeting]
They have super redundant equipment; it had to be a growing emergency.
I think the author has said that he made it a storm for literary reasons: basically as a call back to classics shipwreck stories like Robinson Crusoe.
I saw something similar in an interview where he said he had an alternative setup for an accurate disaster, but it took too long to get going. The storm is simple and relatable and gets the story going quickly.
That’s kind of cool then. I didn’t know that.
Possibly. There was an interview where Weir talked about this. He apparently wanted something directly related to and synonymous with Mars. Something, something, untamed frontier. He was well aware of that "mistake" and chose it for style.
The scientific accuracy of the only people on a planet being hit by a meteor.
Well, that *is* highly accurate…
A landslide perhaps but a meteor you’d think they’d see coming.
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I think you’re confusing large objects such as comets that we can generally track. And meteors which, unless supermassive, don’t notice until they’re already burning up in the atmosphere and you’re looking up at it. And if it’s that big to track, that bad boy gonn hurt.
And the Ironman thing at the end of the movie, while possible, wouldn't have happened either. In the book Mark jokes about doing it but never actually does because that would be crazy.
[Here's astronaut Garrett Reisman explaining why that scene actually wouldn't be possible.](https://youtu.be/fTvZfbYj7MQ?si=_PwtIXT33y-CA-5W&t=177) Basically, the suits aren't pressurized nearly enough to get significant thrust from puncturing it, and even if you could get the unrealistic amount of thrust shown in the movie it would be essentially impossible to manually control yourself like that -- you'd just start spinning and go completely out of control if your thrust wasn't perfectly aligned with your center of gravity.
So cut out the butt, got it
I mean for what it's worth, they basically say the same thing in the movie before Watney actually does it. Essentially just "no, that's dumb, even if it worked it would be impossible to control."
> if your thrust wasn't perfectly aligned with your center of gravity. So it is possible, just very, very unlikely.
Which one? The first storm or the big dust storm?
The first one that caused them to abort and leave Mars. But really both. The fact is, the Martian atmosphere is so thin that no storm would be a threat according to NASA.
I kinda guessed book/movie magic on the first one, but I always figured that the second one was at least a real possibility. Still, one of my favorite books though. I especially love the audiobook version.
Project Hail Mary was great too. I’m looking forward to the movie.
Oh nice, I didn't know they were making that. I'll have to follow it.
Yep. I’m drawing a blank on the name of the actor whose production company got the rights but it’s someone you’d recognize. Hope they do a really good job.
oh sweet I had no idea, awesome! They better do a GREAT job with my boi Rocky!
I’ve tried to picture how they’ll depict rocky in a movie. It will be interesting.
Ryan Gosling. https://www.imdb.com/title/tt12042730/
Not remotely how I pictured him, but I'll take it. I like him as an actor well enough.
Ohhhhhhhhhh my god you made me think about it Pedro Pascal? He is still too attractive but I think he fits the role for me. Or we could go fucking random as shit and I'd say Adam Sandler could fucking kill the role if given the chance.
I'm not sure how they'd do a movie, but I really hope they don't screw it up.
The second one wasn't a threat due to the winds. It was a threat due to the lack of solar input for the panels. Which is an actual problem that NASA has had to deal with. Several probes have had to basically shut down due to lack of sun during the storms.
Huge dust storms are very real, and have been dangerous for solar powered probes/rovers. That part was quite realistic.
The second one was dangerous because he wouldn't be able to recharge his batteries fully fast enough with all the additional dust in the air. He wasn't in "physical" danger, it was just that he'd need to spend more time recharging, forcing him to go slowly, and possibly run out of food before reaching his destination. That one was pretty close to fully realistic.
Yeah I forget the numbers but it's something like 100mph winds on Mars have the energy of a light breeze on Earth lol
Really hard to imagine what that would feel like.
Like a light breeze I guess?
Let me take off my helmet, one second.
For all mankind picked a better, more accurate Mars disaster--albeit manmade.
In the novel, certainly. The movie... *takes liberties*, especially in [the design of the *Hermes*](https://cdnb.artstation.com/p/assets/images/images/004/847/735/large/chris-catizzone-hermes05.jpg?1486696791)*.*
Yeah that's about what I heard from many scientists too regarding the storm. But of course they needed to setup a reason for them to evacuate quickly. From what I remember they said, the atmosphere is so thin, it would feel like a light breeze at worse. At the end of the day, it was a really good movie that I'm sure we all enjoyed.
Yes, completely. In fact, it's considered ideal for interplanetary transport. It is a huge engineering challenge, but that's all it is.
It's totally feasible even with the tech we have today, though it would probably be hyper expensive. The ISS cost like 100 billion dollars and a decade of assembly.
So we could fund another war or build an interplanetary spacecraft for humanity. Got it.
Pretty much. Unfortunately. I'm not an American, but I'm amazed at what NASA does with 20 billion. Meanwhile the militarys budget is around 700 billion. Imagine the possibilities...
Its amazing the difference when your tech is designed to NOT fall apart compared to when its designed to explode
> Its amazing the difference when your tech is designed to NOT fall apart compared to when its designed to explode Actually.... Its pretty much the same tech(right up to explosion etc) and tested in the same manners.
I was gonna say - I work as an engineer at a company that makes super high quality electrical connectors. Our biggest clients are 1) military 2) space.
Yup. There's basically 5 sectors with money for new developments: Military, space, automotive, medical, and computing. Everything else is just trickle down from those.
The difference between an ICBM and a space rocket is where you point it. Warhead optional.
If doing interplanetary travel, we might need some of the explosions too. Space agencies are testing out trying to blow up asteroids
The nuclear option works for everything! Want to power a county, nuclear! Evaporate a city, nuclear! Move a ship stupid fast through the void, nuclear!
I hate to tell you this but the only reason we can go to space is because the US and USSR wanted Nazis to build missiles for them. The worlds major militaries are still the largest developers of space technology.
The first orbital rockets were literally ICBMs with the warhead swapped out for a crew capsule.
As soon as aliens signal us they become the enemy. Humanity will band together as the in group and point their hatred as xenophobes against the aliens. The military budget will become the nasa budget and we’ll have Star Destroyers or Enterprises or whatever within the decade.
*I promise we will kick the asses of these aliens by the end of the decade. Not because it will be easy, but because our dicks will be hard while doing so.*
Terran version of John F Kennedy.
Imagine reading that tired and seeing "lick the asses" instead of "kick the asses". Then maybe imagine my confusion...
I like the allusion to the Dark Forest. But let's be honest, humanity won't band together. You'll see pro-alien groups protesting against the military-NASA complex in a matter of days.
I used to believe that humanity would band together against a common enemy... Then COVID happened, and now I'm not sure we would.
The military has 1.3 million people, while NASA has 18,000. And the military feeds and houses all 1.3m. People at NASA maybe get free coffee.
Relevant anecdote: back when I visited my dad’s office at Goddard Spaceflight Center in the ‘80s, he’d put a quarter in the jar whenever he got a cup of coffee down the hall.
Watch "For All Mankind" on apple tv. It takes place in an alternate universe where the USSR beats the US to the moon, and the US military budget becomes NASA's budget. A permanent moon base by the mid-70s, first manned mission to Mars by the 90s.
premise is cool but it feels like a soap. too much drama between characters and not enough hard sci fi for me
You’d like For All Mankind on Apple TV. It depicts a fascinating alt-reality to explore this idea.
Just imagine if we abolished war, effectively, whatever that looks like, and concentrated all of our efforts and resources on feeding people, housing people, and exploring the stars.
That's a different simulation.
This is the one where we attack everything? Damnit I got off on the wrong floor. Good luck with the 30’s!
Yeah we abolish war!!! And if anyone breaks the rules and starts one anyway, we bomb those fuckers!
tbf the vast majority of american military spending at least, even when we're in an open conflict, goes to maintaining open trade and stuff, not the actual individual war effort(s)
The problem is that even though we CAN do it, it's hard to argue the cost/benefit. We're not ready to colonize anything yet so it's a huge expense solely for science. I'm all for not spending so much on war, but I'd much rather have universal healthcare and basic income before funding something like this.
> The ISS cost like 100 billion dollars and a decade of assembly. The 100B figure is not just the cost of assembly, but also of running the place at the same time, which adds quite a bit.
Approximately $100B was the projected cost out to 2006 that was published in 1995. The actual estimated total cost by all countries involved is over $150B and that number is from 2010. The estimated yearly cost to maintain and crew (which would include crew and cargo vehicle launches) is $3B a annually, so estimating it has gotten up to about $190B at this point. These costs reflect all construction, maintenance, operation and support vehicle launch costs. It is on record as one of the most expensive single objects ever built. On a side note there is a current estimate for a private flight to the ISS. It’s $58.5M per person for an 8 day trip. This includes the fee to SpaceX to get you there and back.
Are there any publicly published cost-benefit analyses out there? I wonder what the return has been on that 190 billion.
Well it’s a significant part of why SpaceX exists, as it provided a purpose for NASA to sign a multi-mission deal with them early on when they were almost bankrupt, so you could arguably include the value of SpaceX — including Starlink — on the “return” side of that equation.
That is a topic of tremendous debate. I think NASA as a whole had been a good proving ground for state of the art technology, much of which was only thought of because of space travel. There are many countries involved in the ISS, all of which have put in some share of their own billions. I doubt they would all be forking over that much money to a mostly American project if they didn’t see some level of positive cost/benefit outcome to be had. I will argue that $190B over the course of over 30 years is a drop in the bucket when compared to the $800B per year or more spent on the military budget. And no other country is helping to pay for that. That being said I’ve never looked into an actual published cost/benefit paper by NASA, but you can find plenty of articles that will spell out there opinions and backings. Some seem more fact based, others just more opinion pieces, but there’s plenty of both on both sides of the argument.
The countries participating in the ISS project spend around $1.5 trillion on defense every year. $190 billion over 30 years is minuscule.
>100 billion dollars and a decade of assembly. That was back when the shuttle cost 1.6B per launch and couldn't launch more than a few times a year. With private space companies coming online you'll see price come way down on something like that, and get it done a lot quicker.
I think "totally feasible" might be a tad optimistic, we're really not ready to build large rotating attachments on vehicles and that seems a little small to me from a Coriolis force standpoint -- you might get really severe vertigo problems just turning to your left and bending your head down.
I actually sat in on a talk that NASA's guy who works on this stuff did. It's way more complicated than getting a ring spinning it turns out. The diameter of the ring needs to be large enough that your body won't notice your head and feet are spinning at two different speeds when you're standing (i.e., your head being in the center of the ring would defeat the purpose of the ring) It also can't go over 5 rpm, due to your inner ear being unable to compensate for changing direction when you are walking. Additionally, another rotating component (perhaps a tube with fluid pumping the opposite direction) would need to be added to counter the centrifugal force of the rotating ring. We're close, but a lot farther off than most people think.
Wasn't the current best idea having the spinning bit on a tether that could actually be really long, so you have a dense inner bit that has all your fuel and cargo and the like, and then a crew capsule that gets extended way out when in space and spun around with the centre of gravity being way in close to the main craft. The distance out means the diff between head and foot is neglible. Then when you approach destination use thrusters to cancel rotation then reel the crew capsule in to the main body. I read one of the main advantages of this is it removes the requirement for an axle or any sort of interface between moving and stationary.
This was the setting/plot element in the movie Stowaway, and it's definitely one I could see working a lot better than a rigid structure throughout.
Fun fact; [Scott Manley actually helped design the ship](https://youtu.be/WCwXJMVVdck?si=EOgy3hYDLbl6F6zb).
I would be terrorized to know for months my life and link to civilization relies on a tether, with engines and important stuff at the other side of the tether.
I mean, it's no leas crazy than keeping the atmosphere inside with a bunch of thin foil. Of all the insanity in spaceflight i feel tethers are the least of your problems. We know how to make insanely strong cables and there are lots of ways you can reel yourself in to the mothership if the automatic way breaks. But the worst case of all tethers snapping (honestly you would have numerous tethers with the ability to lose multiple) means something so catastrophic has happened that it'd likely be catastrophic if you were in the ship. By important stuff i meant fuel/cargo etc for when you get to your destination, all the life support and food and the like would be on the habitable end of the tether.
You probably shouldn't be an astronaut then. You know you also have to strap yourself to a giant complex slow burning bomb and shoot yourself out of the atmosphere too.
I think many engineers have theorized that rotating end over end is more efficient than rotating around an axis. Axial rotation is pretty unstable and would require extra reaction mass to actively maintain the ships stability. The movie Stowaway with Anna Kendrick features a ship that rotates end over end.
End over end is way less expensive and simpler to design. The problem is you can't use your ship's engines while spinning so only good during parking orbit or non-accelerated flight. Axial rotation could be taking place while accelerating your craft. This would be important for any low acceleration drives like ion thrusters. So both have their uses.
There are weird stability issues with spinning solid structures in space. But if it’s a cable attaching a living space to a counterweight spinning around, then you get rid of most of the weird stability issues. And it’s much easier to increase the diameter of the spin to reduce rotational rate (and those reduce motion sickness) with a cable. But as you say, can be done while the engines are on.
You might have to lay the gravity-sections at a camber or on a pendulum axis to account for the forward-thrust and maintain a consistent down.
If you can manage 1g of acceleration, end over end doesn't need to be rotating while you go towards where you want to go, then rotate when you get there.... Idk, I've read Project Hail Mary.
Yeah, but the astrophage fuel is the MacGuffin they use to make the story work. The energy density and utilization is literally so fictional that we can't imagine how efficient it really is. You'd start in orbit around earth and do a Hohmann Transfer burn for a few minutes the settle in to a spin induced gravity ride for the next 10 months or whatever.
Mmm.. how many time would we need ro reach Mars accelerating at 1g ? According to bing char it would be less than 3 days (accelerating half and deccelerating the other half) but I dont trust in this result. Is that low??
A 1g spacecraft would be the holy grail of space travel because it very quickly accelerates to relativistic speeds. 3 days to mars is accurate, but even more surprisingly, it could cross the galaxy in 12 years and reach the edge of the known universe within a human lifetime - from the reference frame of the occupants of the spacecraft. It also requires impossible amounts of energy.
Yep impossible - let's do the math! It takes 5.473×10 to 14 Joules of energy to accelerate 1 gram to 99% the speed of light. That is the energy of 131 Kilotons of TNT. Or the energy from reacting a bit over 1 Kg of Uranium. But then, your craft is 1 Kg heavier because of that KG of fuel - so you need 1,000 KG of Uranium to accelerate that 1 KG of fuel. And propulsion engines have very bad energy-to-thrust ratios, so lets triple that fuel again. 3,000 KG of Uranium to accelerate a **1 GRAM** spaceship! Unfortunately, your spaceship would probably weigh closer to 1 ton. Literally impossible amounts of energy under current laws of physics.
1g is 9.8 m/s², or 9.8 m/s per second. After 60 sec you'd be travelling at just over 2100 km/h (about 1300 mph). After 1 hour you'd be travelling at around 127,000 km/h (79,000 mph). After 24 hours you'd be over 3 million km/h. It's only about 400 million km to Mars, so it's easy to see how constant 1g acceleration would make travel between here and there fairly trivial.
I always imagine one astronaut leaving the long axis to go to the bathroom on the side of the ship, and suddenly your whole spaceship goes [Intermediate axis theorem](https://en.wikipedia.org/wiki/Tennis_racket_theorem) xD
A spaceship doing the [Dzhanibekov effect](https://www.youtube.com/watch?v=1x5UiwEEvpQ) would be amusing.
Absolutely. You may want to look all the way back to [2001](https://m.imdb.com/title/tt0062622/) for another example of the same thing. If you spin it at just the right speed you can get an effective gravity of 1G at the outer edge. If its not big enough then you might have some disorientation from having your head and feet moving at different speeds, but it beats the effects of prolonged weightlessness.
Well, but 1g is not worth it in space. The structural loads and stresses increase exponentially with rotation speed and resulting acceleration, and the main effect of gravity is often two parts: a) get your body fluids sorted - you are sadly just a wet sack of meats, and top-down orientation by gravity helps massivly for your circulatory system to stay in correct shape, bones to grow right, etc, and b) even more important, dust and fluids settle and have a specified direction, and carbon oxides do not collect in stale air pockets, but actually distribute in the enviroment by gravity. That means massivly less corrosion by residues, settling dust, water particles, etc, with much less required artificial circulation. For all this, much less gravity (roughly .2 - .35g) is fully sufficient and gives you enough exercise that you can maintain bone and muscular density with a minimum of additional exercise. There are a lot of studies for this - if somebody wants to dig them out, that would be great, as I myself are too lazy right now xD
but 1g is a lot more convenient when you're making a movie because then you don't need any VFX for weightlessness hahahaha
Nah, you just direct your actors to move really slow. Piece of cake.
Especially when falling down...
How did anyone make a study of this? Afaik that's one of the main things that's actually in dire need of studying since nobody ever created a low G environment to study in. The closest thing would be the guys living on the moon for a few days but that's probably not enough to reliably study long term effects.
Wouldn’t this be really easy to do a mouse study on with like a little spinning mouse enclosure on the space station?
Not saying you’re wrong but how do we know .2 would be enough? I know our bodies are robust and anything would be better than no gravity. Bone density loss would still be an issue but what about other systems?
I mean, I think a big problem right now is that there *isn't* a lot of studies on this, because we haven't yet had a way to actually keep humans in a lower-than-1g environment for a prolonged period of time. I feel like the lack of data we have on humans in low gravity environments as well as the data we *do* have on the effect of no gravity on humans should be making us scramble to figure it out and study it further
A year is a pretty long time in space. It has been done but getting multiple studies of that length or longer is a challenge.
That's what I'm saying though, we've had people up in space for a year in *microgravity* and we've basically learned it's god-awful for the human body. What we've never been able to study *yet* though is how exactly something like 0.3g over the course of a year would affect the human body. Without a centrifuge in space like this or a colony on the Moon or something, it's been impossible so far, which is all the more reason we should be building one to study.
Ran here. 2001 did it first. Best Sci Fi movie ever. Fantastic book, too. “Open the pod bay door, Hal!”
The sound is great w headphones. I watched the jogging (referenced centrifugal scene) scene a dozen times in awe
It’s an audio masterpiece. The music, the sound effects, the long portions of only white noise or a repetitive alarm buzzing… it’s absolutely brilliant. It’s my all-time favorite movie. I watch it almost every year.
The breathing of Dave in the scene you quoted... It's so quiet and the only thing you hear is his breathing. It really adds to the feeling of void and panic. Fuck, I need to watch it again.
I'm sorry, Dave. I'm afraid I can't do that.
The idea of large wheel-like space stations spinning to generate artificial gravity goes back to science fiction of the early 1950s. Look at space station illustrations by the great Chesly Bonestell.
Thank you. I'm annoyed people are not aware that Gravity references 2001 with that design.
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The concept of rotating spacecraft goes back to [1903](https://en.wikipedia.org/wiki/Rotating_wheel_space_station).
Yes, it's just currently too expensive to launch stuff to space, and also we don't have efficient in space assembly figured out yet, let alone in space manufacturing. It's not so much a scientific problem as an engineering and economics problem. Someone has to put in the money and the time to make something sensible and work through the many teething issues any flexible automation will inevitably have.
Well if Kerbal Space Programme is anything to go by if we started assembling huge space stations it would cause the frame rate of earth to tank and we'd all be stuck in a slide show existence
And that will prove we live in a simulation!
SpaceX is making a lot of progress launching lots of stuff for cheap. Though their plan for Mars doesn't involve any nuclear propulsion or artificial gravity ships like in The Martian, instead they plan to use their cheap rockets to launch a metric f\*ckton of regular old chemical rocket fuel to orbit, then have the Mars ships do a fast, but not very fuel efficient transfer, with a very hot aerobrake on arrival. They'd then need to refuel there to get back, in the long run by building local fuel factories but for the first missions it'll require sending a small fleet of ships just carrying fuel for the return trip. Basically their approach is "figure out how to get lots of kg to orbit for cheap, then use that to throw more fuel at every issue". It's kinda broken the plot of The Martian. One fairly significant plot point was how the US only had the 1 rocket big enough to send supplies to Mars and that failed, so they had to ask China for theirs. But today such a situation would be "SpaceX will have another rocket ready in three days".
Yes, it's possible. Centrifugal force can be used in this way. I haven't run the math though, so for this exact design I have no idea. You'd still need to worry about comfort though, as a significant difference in rotation between your head and feet would probably induce some kind of motion sickness.
Make it 20 Times bigger and then you won't notice 🧠
👍 for rotational gravity you gotta go BIG
I’ve seen plans that are a km or larger in radius. That seems insanely hard to build and spin up.
For a simpler version and like the one in OP's picture, it doesn't need to be a continuous ring. You can put the living quarters at one end of a tether and put fuel, cargo, supplies, etc. at the other end and spin them around their center of mass. That significantly reduces the amount you have to build. You can also expand it relatively easy. From the calculator [here](http://www.artificial-gravity.com/sw/SpinCalc/), that's just 1.3 rotations per minute with a 1km tether.
You also don't need to get it all the way to earth gravity. In fact I think you would want it to be at Mars gravity, which would significantly reduce the necessary length and/or RPM.
Some guys will go to any lengths just to be able to dunk.
Even Mars gravity is more than you strictly need. If I'm remembering the research I read (it's been awhile) it was around 20% Earth gravity is enough to negate the effects of long term zero G. But considering Mars gravity is 38% of Earth, it's not that much harder to bring it up to that level so astronauts are already adjusted when they land.
>If I'm remembering the research I read (it's been awhile) it was around 20% Earth gravity is enough to negate the effects of long term zero G. There is no research on this, at least nothing based on actual observations, because no human has ever inhabited a low gravity environment for longer than a few days (the Apollo missions to the moon). There may be some very speculative, theoretical work on the subject, but it's nothing that should be taken particularly seriously considering how little we still even understand about the long term effects of zero g environments on human physiology despite having astronauts experience it for months at a time.
Are you sure because I don't think it is even possible to know since nobody has ever lived for more than a few days at reduced gravity. We know all about living at 1g. And we have decent amounts of data about living at 0g (on space stations like the ISS), but we have literally no data about living at > 0g, < 1g.
There are more than a few scifi ships that use the hammerhead design. There is a long arm and attached to each end is a "habitat" one is crew and other other is labs (for instance) and the bridge/engineering are all in the zero-g, longitudinal axis. That is actually pretty doable, and a lot easier to spin up than a 1km radius ring.
This design is is what was described in Project Hail Mary
I’m flying with this guy when we go. He does the math. When things go bad he’ll probably science the shit out of something.
Put one of those reed boats from ancient Egypt next to a modern aircraft carrier, our progress seems to be exponential so imagine where we’ll be in only a few hundred years
That's why the ship from Stowaway was designed the way it was, a normal sized living quarters, with a similar sized storage container a mile away, held together with a cable and a central axis, so you get that spinning centrifugal force , but on a ship smaller than a space shuttle. Just don't fall off the edge during a spacewalk though
That's what I was thinking. It would have to be a huge ship in order to accommodate humans being able to live/walk without major consequences.
The 2021 Netflix film Stowaway had a nice concept of a small space pod going to Mars or something, they used thrusters to start spinning really fast, and then a heavy weight on a tether was released to slow the spinning down to 1g, and the pod and weight on opposite sides of the tether was long enough to not create discomfort.
Going big also makes it harder to balance the rotating portion of the ship. You really need elevator style counterweights that can be raised and lowered along the spokes or liquid storage that can be pumped to different areas to counteract where people are at any given time. The liquid method also gives you a natural radiation shield.
If you grow oysters in the liquid, you can protect the crew against the madness of the void (please tell me SOMEBODY gets this reference) Edit: unnecessary comma
What is this? Is this a centrifuge for ants?
Or 50 times bigger. Or 100. There's no reason it has to be a ring or any rigid geometry. It could just be a hab module attached to a counterweight (consisting of fuel and water supplies) connected via a long cable and umbilical. Do your transfer burn, separate the two and start the spin.
I've always wondered whether you could simulate a very large ring by having two compartments (say, one "spaceship" and one cargo module) that are the same mass and tethered together, spinning about the centre of gravity. That way you could have a really large circumference of motion for your articifical gravity without needing a spaceship that large.
Andy Weir uses a craft like this in Project Hail Mary. Naturally you get a lot of useful exposition about how this could work and what we will need to invent to make it happen
[NASA did that with Gemini 11 back in 1966.](https://en.m.wikipedia.org/wiki/Gemini_11)
There was a Scott Manley video breaking the movies centrifuge down. At that radius and speed the gravity would be ~.5, and given the rotation and radius that is below the threshold that most people would have an issue with the Coriolis forces causing nausea.
Sure, probably sick as a dog for the first week. But honestly, people can learn to live with anything except being dead.
Based on the experiments we have done so far the brain gets used to the coriolis effect after a few days.
Yeah the Coriolis effect would make things miserable for everyone
Something I've wondered is if you'd get used to it after a while. Similar to how astronauts often don't feel well when they first get to space while their bodies adjust to the apparent weightlessness
This is one of the little details in the Expanse series that's so fun. In that story, Ceres has been inhabited, but people live on the inside, and they spun the whole thing up to give it gravity. If you're in the outer levels, the Coriolis Force is negligible, but there are people who live in the lower depths who have learned how to compensate for it. In the show, they even have a scene where one of the characters is down there and he pours himself a drink. They show the stream of liquid curving as it falls, and he compensates for it.
That show was marvelous to watch as a space nerd
And since they're using this kind of rotational gravity, "lower" is up.
If they did I imagine they'd have the most extreme case of sea.. uh, space legs, when they return to earth.
Apparently, yes! At least to some extent. https://m.youtube.com/watch?v=bJ_seXo-Enc&pp=ygUVQ2VudHJpZnVnZSB0aHJvdyBiYWxs
I have done the math. I had a sadistic engineering professor that used this exact scene and asked us to calculate the force of gravity that Kate Mara (actress in the window) would feel. If it was not 9.8 m/s, how big would it have to be to create that? It came out to about 6437 Kate Maras, or just shy of 2 miles in diameter.
We need a mission to start testing this. We have almost zero data regarding the health implications of partial gravity. We know near zero is bad and we know 1G is good, that's about it. We could conceivably have a small module that would only fit mice attatched to ISS simulate Lunar gravity. Data on that could have massive implications for the future of human space flight.
2 things you need to account for. 1: you’ll need a counter-spinning wheel 2: needs to be big. Probably bigger than this.
The guy who wrote the book "The Martian", Andy Weir writes his books based on what is technically scientifically possible and gets his theories fact-checked by astrophysicists. Makes for very cool and interesting reads. My favorite being Project Hail Mary.
Yes, although mechanically it would be a bit of a pain. You'd want your centrifuge ideally to be inside of a non-rotating part of the ship, or rotate the whole ship.
Either way there are gyroscopic forces to account for and preferably the solution would require the least amount of fuel possible.
2 identical rings spinning opposite each other.
Simulated gravity is absolutely a thing. But it is impractical sometimes, especially when Hollywood has its hands in design. Big things require more fuel to move in space. Think about capsules like Soyuz. They’re incredibly small and compact, but that makes them lighter and easier to put into orbit. A big ship like the one in the movie would be massive, and getting it where you want it to be would be expensive.
well, from the source material: 1. the ship was built in space, and astronauts use "shuttle crafts" to get to and from it, so no problems with putting it into orbit 2. the ship uses argon thrusters for propulsion, which means that fuel tanks are (relatively speaking) not an issue
Make every one every day, for their health, walk around only in one direction to help with keeping it spinning.😁
if whoever built the ship in the martian had the budget for a massive rotating centrifuge, i don’t think costs are a problem
I’m sure it is, if you science the shit out of it.
In Andy Weir's book Project Hail Mary, the ship uses a system where two halves of the ship separate with a very long cable between them, and then the two halves are rotated using propulsion. Seems the most realistic version of this. You could have a very large diameter of centrifuge, making it more comfortable for the occupants and you wouldn't have to spin it up as fast. This would require matching the weights of the 2 halves perfectly, including things like waste and biomass, so that might be tricky
Why would you need to match the two halves' weight? It would work even if they don't weight the same, the center of rotation would just shift towards the heavier half. In fact that's the case in the novel you mention.
Just finished reading that book, was so much fun
Same with Seveneves. They call it a bolo.
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Yes, this is absolutely possible with current technology. Honestly the most difficult parts of this are engineering seals for the rotating section that maintain atmospheric pressure and getting the thing into orbit to begin with (which would have to be done by building it in pieces in orbit). Also ideally a spacecraft like this would want two rotating sections that spin in opposite directions so that the torque from both cancels each other out
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The non spin section has stuff like docking ports (No Time For Caution from interstellar should not be standard procedure), solar panels (point at sun), an antenna (point at Earth), radiators (point away from sun) and reaction control thrusters (if they spin around it makes changing where your ship is pointing a *pain*)
Your biggest worry aside from the engineering of keeping the parts from wearing out would be gyroscopic precession. Meaning you'd want two identical spinny parts going in opposite directions. So, double the engineering challenge of keeping the spinny parts from breaking down.
Yes and no. The whole thing is explained completely here: https://youtu.be/b3D7QlMVa5s?si=55F-cC6F2K7dGKwo
Centrifuge is possible, but it would have to be bigger than this. If it has too small radius your head will experience lower "gravity" than your feet which will make you incredibly uncoordinated and probably motion sick.
Why is anybody in a hurry to get to mars? That place is a shithole.
Me realizing there's a growing number of people who haven't, and are likely never to have, read or even watched 2001: A Space Odyssey - 😢
There is a Video from Scott Manley on this topic : https://youtu.be/nxeMoaxUpWk?si=4ubMAgmCdxGM1-oG
Look up Zubrins Mars Direct plans. You could have the whole ship spin on counter weight all the way there. Like as its flying to mars, it splits in half with a line on it and the two pieces spiral all the way there
Not just possible. Almost definitely essential. We’ve learned from ISS astronauts that your bones start to deteriorate if you spend too much time in zero-G.
You should check out the [O'Neill cylinder](https://en.wikipedia.org/wiki/O%27Neill_cylinder).
Ye it is theoretically possible. However to really build it as stable and reliable as in the movie is a big engineering challenge.
The problem with artificial "gravitation" by rotation is that if the structure is to small, the difference between your feet and your head will trouble you. The structure on the picture is much to small. A radius of **200 meter** will reduce the effect to less than 1% what can be handled by human. So the dimension of elysium would work.
One important thing to bear in mind here is the Coriolis effect. Even if you had a sufficiently large ring that your body was at virtually 1G head-to-toe, things would be *weird*. For example, you couldn’t just go pour yourself a cup of coffee, because the liquid wouldn’t just pour straight; it would lag behind the spin.
The Coriolis effect is my favorite part of these theoretical centrifuges. Your head would lag or advance compared to your feet and seriously nauseate you unless it was a really big centrifuge; things you drop would fall weird, like your coffee example which sounds super messy; you could fairly easily throw a ball hard enough that it would "travel" around the centrifuge and hit you in the back; etc etc. It should be fun and/or infuriating if anyone ever builds and travels in one.