The Martian - November 2015 - Starring Matt Damon

[Eternal_Freedom]

Yeah it doesn't exactly detract from from the film. But, addressing the "not enough fuel for the MAV" part, why would you design a mission of 31 days duration where your only option if something goes wrong on Day 3 is to hightail it back to Earth.

Now, if you allow enough fuel for multiple launches and landings (and given the size of Hermes, it would hardly have been a make-or-break payload) then if something does go wrong, you can retreat into orbit and return a day later when the storm clears, thus avoiding wasting a huge amount of resources and planning due to a sandstorm.

Well, while you can do a single-stage-to-orbit ascent on Mars ... that's still a lot of mass Hermes would have to schlep around. Also, you'd have to make the MAV much heavier, since now you're designing it to sustain multiple ascent/descent cycles without the luxury of mostly tearing it down after each mission ... maybe if you had some sort of in-situ resource extraction operation taking place on Phobos ... some ideas for a manned Mars mission assume using Phobos as a sort of base of operations.

See the rational part of my brain understands that, but it's also thinking "surely someone thought about this in the planning stages." They're already committed to building Hermes, which must have taken a lot of effort, and since said vehicle only has to to round trips from Earth to Mars, I see no reason why the requisite fuel could be carried, a heavier MAV taken. So Hermes herself needs more fuel, she already has a continual-thrust engine of some kind with a lot of delta-V. Surely it can't be that hard.

The sad part is, the film itself shows just how much NASA loves redundancies, from WAtney explaining that everything in the Hab is fireproof to Vincent objecting to JPL planning to remove secondary and tertiary comm system from the MAV. Why does a MAV need three sets of comm gear if there is no-one aboard Hermes to be talking to, and Mission Control is too far away for an answer tog et back to them in time? They'll spend all that mass on systems the MAV cannot possibly need, but won't spend extra mass on a reusable space-to-surface craft and it's fuel? That makes no sense.

Also, I'm still not clear how they landed in the first place. Sure, Watney mentions getting fuel from the Mars Descent Vehicle, but that appeared to be nothing but what the MAV rested on before it launched. And we know it can't be used for landing, since the Ares IV MAV was already there. So...yeah, my brain is tying itself in knots right now.

Basically, this film is a brilliant depiction of how to survive/recover from a situation that shouldn't have arisen, even if we allow the handwave about the super-dust-storm.

[GrandMasterTerwynn]

Yeah it doesn't exactly detract from from the film. But, addressing the "not enough fuel for the MAV" part, why would you design a mission of 31 days duration where your only option if something goes wrong on Day 3 is to hightail it back to Earth.

Now, if you allow enough fuel for multiple launches and landings (and given the size of Hermes, it would hardly have been a make-or-break payload) then if something does go wrong, you can retreat into orbit and return a day later when the storm clears, thus avoiding wasting a huge amount of resources and planning due to a sandstorm.

Well, while you can do a single-stage-to-orbit ascent on Mars ... that's still a lot of mass Hermes would have to schlep around. Also, you'd have to make the MAV much heavier, since now you're designing it to sustain multiple ascent/descent cycles without the luxury of mostly tearing it down after each mission ... maybe if you had some sort of in-situ resource extraction operation taking place on Phobos ... some ideas for a manned Mars mission assume using Phobos as a sort of base of operations.

See the rational part of my brain understands that, but it's also thinking "surely someone thought about this in the planning stages." They're already committed to building Hermes, which must have taken a lot of effort, and since said vehicle only has to to round trips from Earth to Mars, I see no reason why the requisite fuel could be carried, a heavier MAV taken. So Hermes herself needs more fuel, she already has a continual-thrust engine of some kind with a lot of delta-V. Surely it can't be that hard.

They probably blew most of their budget building Hermes. Which probably gave Congress fits, complete with continual threats to shitcan the whole manned mission to Mars thing (so they can afford more missiles to aim at the Soviet Socialist Republic of Putinstan, or something,) so the only way NASA could actually carry out the manned Mars program would be to award low-cost contracts to Boeing or Space X to build inexpensive, disposable, descent and ascent vehicles.

The sad part is, the film itself shows just how much NASA loves redundancies, from WAtney explaining that everything in the Hab is fireproof to Vincent objecting to JPL planning to remove secondary and tertiary comm system from the MAV. Why does a MAV need three sets of comm gear if there is no-one aboard Hermes to be talking to, and Mission Control is too far away for an answer tog et back to them in time? They'll spend all that mass on systems the MAV cannot possibly need, but won't spend extra mass on a reusable space-to-surface craft and it's fuel? That makes no sense.

They're probably high-gain communications equipment suitable for direct transmission to Earth, for those occasions when a drunken astronaut knocks down the habitat's antenna, or Hermes (or whatever other orbiters are in place at the time) is below the horizon. The thing that makes no sense is that the habitat has a huge, astronaut impaling, high-gain antenna. The sensible thing to do would be to run an Ethernet cable from the habitat to the ascent vehicle and use its communications equipment ... after all, if a given ascent vehicle misses its landing and spatters all over the Martian landscape, they'd have to scrub the mission it was intended for anyway.

Also, I'm still not clear how they landed in the first place. Sure, Watney mentions getting fuel from the Mars Descent Vehicle, but that appeared to be nothing but what the MAV rested on before it launched. And we know it can't be used for landing, since the Ares IV MAV was already there. So...yeah, my brain is tying itself in knots right now.

Yeah, the lack of a visible descent vehicle is a huge omission (although one might be able to handwave it away by suggesting that the habitat was the crewed descent vehicle ... the habitat is a kind of giant inflatable structure, so they might've simply inflated that part of it after landing.) The thing the ascent vehicle was resting on, is actually the descent vehicle for the MAV.

[Adam Reynolds]

So, it's not quite the best space disaster flick I've ever seen. I think Apollo 13 is a better example; it gave me fewer "fridge logic" moments. I think it would've helped a lot if I hadn't re-read the book a couple weeks before seeing the movie. Still, for what it is, it's a good movie.

Agreed on the point about the book. I was just looking the book after watching it and realized just how much they left out. Though the comparison to Apollo 13 is slightly unfair. That actually happened.

I wonder if the zero G effects in The Martian were CGI? Those in Apollo 13 were amazingly shot with the Vomit Comet giving actual weightlessness in 60 second intervals. Talk about high stress takes.

See the rational part of my brain understands that, but it's also thinking "surely someone thought about this in the planning stages." They're already committed to building Hermes, which must have taken a lot of effort, and since said vehicle only has to to round trips from Earth to Mars, I see no reason why the requisite fuel could be carried, a heavier MAV taken. So Hermes herself needs more fuel, she already has a continual-thrust engine of some kind with a lot of delta-V. Surely it can't be that hard.

How likely would an early abort like this even be? If it isn't likely, why would anyone worry about it? It is worth protecting your astronauts and aborting early. It is not worth sending them back if something went wrong. And you are underestimating the amount of fuel that would need to be carried. It would need to take 13 times as much fuel as was actually taken for each launch.

Have you read the book? It did a much better job than the movie explaining the details of things. The process of an abort was somewhat more drawn out. It wasn't immediate as in the film. It also has an excellent opening line: "I'm pretty much fucked."

[Terralthra]

Reusable rocket engines are incredibly non-trivial to design and build, not to even mention a reusable orbital/reentry vehicle. I mean, holy shit. The Space Shuttles took up to 100 days to recondition and recheck before they could be reused, and that's with a hell of a lot more equipment and staff to evaluate. I doubt the six astronauts could even do a cursory checkover of the MAV after a re-landing before they'd have to relaunch to hit their Earth transit window.

[Nephtys]

The zero-G scenes were almost certainly not vomit comet. They looked to me a lot more like like wirework plus CGI.

[Eternal_Freedom]

So, it's not quite the best space disaster flick I've ever seen. I think Apollo 13 is a better example; it gave me fewer "fridge logic" moments. I think it would've helped a lot if I hadn't re-read the book a couple weeks before seeing the movie. Still, for what it is, it's a good movie.

Agreed on the point about the book. I was just looking the book after watching it and realized just how much they left out. Though the comparison to Apollo 13 is slightly unfair. That actually happened.

I wonder if the zero G effects in The Martian were CGI? Those in Apollo 13 were amazingly shot with the Vomit Comet giving actual weightlessness in 60 second intervals. Talk about high stress takes.

See the rational part of my brain understands that, but it's also thinking "surely someone thought about this in the planning stages." They're already committed to building Hermes, which must have taken a lot of effort, and since said vehicle only has to to round trips from Earth to Mars, I see no reason why the requisite fuel could be carried, a heavier MAV taken. So Hermes herself needs more fuel, she already has a continual-thrust engine of some kind with a lot of delta-V. Surely it can't be that hard.

How likely would an early abort like this even be? If it isn't likely, why would anyone worry about it? It is worth protecting your astronauts and aborting early. It is not worth sending them back if something went wrong. And you are underestimating the amount of fuel that would need to be carried. It would need to take 13 times as much fuel as was actually taken for each launch.

Have you read the book? It did a much better job than the movie explaining the details of things. The process of an abort was somewhat more drawn out. It wasn't immediate as in the film. It also has an excellent opening line: "I'm pretty much fucked."

No I have not read the book. And I should not have to in order to enjoy the film. Honestly, if everyone I discuss this with is just going to say "have you read the book? It explains it there" then that's the film's fault for not showing the actual important setup and not mine for not reading the book.

[Adam Reynolds]

The zero-G scenes were almost certainly not vomit comet. They looked to me a lot more like like wirework plus CGI.

I'm sure they were. Especially given the gravity effects of the spinning ship. I was making that as a comment to the amazing work put into Apollo 13.

No I have not read the book. And I should not have to in order to enjoy the film. Honestly, if everyone I discuss this with is just going to say "have you read the book? It explains it there" then that's the film's fault for not showing the actual important setup and not mine for not reading the book.

I wasn't recommending the book because it fills plot holes as much as because it was an excellent read. It was easily my favorite book that I have read in the last couple years. The film was definitely dumbed down at several points, especially the ending rescue.

[NeoGoomba]

Saw it and loved it. My only question is why it wasn't called "Duct Tape and Sheet Plastic: The Movie" instead, because they were the real heroes.

[Eternal_Freedom]

Saw it and loved it. My only question is why it wasn't called "Duct Tape and Sheet Plastic: The Movie" instead, because they were the real heroes.

That's true. I heard some people complaining about the crew having duct tape on hand at the pub tonight and I said "why wouldn't they? It's bloody useful stuff."

[Adam Reynolds]

That's true. I heard some people complaining about the crew having duct tape on hand at the pub tonight and I said "why wouldn't they? It's bloody useful stuff."

That was another major change from the book. In the scene where his helmet is breached, in the movie he uses duct tape several times. In the book, he removes the arm from his suit, folds his arm into the body of the suit and glues the hole shut using a suit repair adhesive. He then takes the rest of the arm and glues it over the hole in the helmet.

The problem with simply using duct tape is that the pressure is in the wrong direction. It is going outwards rather than inwards and so should push the tape out rather than sucking it in to close the hole.

[Zaune]

That's true. I heard some people complaining about the crew having duct tape on hand at the pub tonight and I said "why wouldn't they? It's bloody useful stuff."

Actually, one thing I was mildly disappointed to see left out of the film version was Watney waxing lyrical about what a wonderful thing duct tape is, which he does at least twice in the book. Presumably whoever owns the trademark wanted too much money to let him call it by name on screen.

[Simon_Jester]

No I have not read the book. And I should not have to in order to enjoy the film. Honestly, if everyone I discuss this with is just going to say "have you read the book? It explains it there" then that's the film's fault for not showing the actual important setup and not mine for not reading the book.

Thing is, the book is 130000 words long. And there's not a lot of irrelevant exposition that can be cut- cutting things like Watney's wisecracks would undermine the artistic quality of the movie.

So unless you want, oh, a six hour movie, you're going to have to accept that at some sufficient level of detail, details of the exposition and backstory are being left out or at best alluded to in an ambiguous way.

[trekky0623]

I haven't seen the movie yet, but I've read the book, and because its gimmick is the accurate science, I have to ask, did they fix the glaring error with the stoichiometry and turning liquid oxygen into liquid water? In the book, one of the most glaring errors that took me completely out of the story was Watney saying that 125 L of liquid oxygen would make 250 L of liquid water, which isn't true because their densities are different.



Even assuming that the oxygen will react completely to make water, Watney only gets about 1.28 L of water for every 1 L of liquid oxygen. I don't know, for a book that claims to be scientifically accurate, that one part just completely ripped me from the story, and I want to know if the error was ever fixed for the movie.

[Elheru Aran]

I haven't seen the movie yet, but I've read the book, and because its gimmick is the accurate science, I have to ask, did they fix the glaring error with the stoichiometry and turning liquid oxygen into liquid water? In the book, one of the most glaring errors that took me completely out of the story was Watney saying that 125 L of liquid oxygen would make 250 L of liquid water, which isn't true because their densities are different.

[cutting that horribly artifacted image]

Even assuming that the oxygen will react completely to make water, Watney only gets about 1.28 L of water for every 1 L of liquid oxygen. I don't know, for a book that claims to be scientifically accurate, that one part just completely ripped me from the story, and I want to know if the error was ever fixed for the movie.

They don't go into *that* much science in the movie, probably as a concession to largely non-nerdy movie watchers. His trick for getting water is mostly 'burn hydrazine, get blown up, burn less hydrazine, see the dew form'.

[trekky0623]

They don't go into *that* much science in the movie, probably as a concession to largely non-nerdy movie watchers. His trick for getting water is mostly 'burn hydrazine, get blown up, burn less hydrazine, see the dew form'.

That's a shame given that the science-y parts were what people were most excited about. Seems like if you're going to make a movie about this book, you shouldn't just make it another Hollywood sci-fi movie.

[cutting that horribly artifacted image]

Aw shucks, it looked fine to me, but I think that's because my forum theme has a white background. It's supposed to look like this if anyone cares.

[GrandMasterTerwynn]

They don't go into *that* much science in the movie, probably as a concession to largely non-nerdy movie watchers. His trick for getting water is mostly 'burn hydrazine, get blown up, burn less hydrazine, see the dew form'.

That's a shame given that the science-y parts were what people were most excited about. Seems like if you're going to make a movie about this book, you shouldn't just make it another Hollywood sci-fi movie.

To be fair, it's probably the best Hollywood sci-fi film to have come out this decade, and probably among the best to have come out in the last twenty years. Although, if you were looking for a 100% nerd-gasm film, you probably should've started adjusting your expectations downward when they announced that it'd be a big-budget Ridley Scott film starring Matt Damon ...

[Anacronian]

I saw it and liked it a whole lot, Only thing that disappointed me was the complete lack ofSpoiler

Pirate ninjas

[Iroscato]

I saw it and liked it a whole lot, Only thing that disappointed me was the complete lack ofSpoiler

Pirate ninjas

This is indeed a persistent oversight that Hollywood has yet to address.

[GuppyShark]

That's because those two factions are diametrically opposed, and Spoiler

Watney was officially a pirate, like, for reals

Get OUT.

[Adam Reynolds]

I saw it and liked it a whole lot, Only thing that disappointed me was the complete lack ofSpoiler

Pirate ninjas

This is indeed a persistent oversight that Hollywood has yet to address.

In the book Watney created that as a new unit instead of having to repeatedly state kiilowatt-hours per sol (martian day).

[trekky0623]

In the book Watney created that as a new unit instead of having to repeatedly state kiilowatt-hours per sol (martian day).

Given that Watney is writing all this down, and not speaking, surely kWh/sol is shorter than Spoiler

pirate-ninja?

It's been a while since I read it, so maybe he is speaking.

[Simon_Jester]

They're video or audio logs in the book, canonically, I think.

[Q99]

Saw it, loved it. This really was the best hard SF movie I've seen- and I do enjoy all the focus on problem solving.

That's a shame given that the science-y parts were what people were most excited about. Seems like if you're going to make a movie about this book, you shouldn't just make it another Hollywood sci-fi movie.

Oh, it's very science-y in the sense of "watching smart people put things together to solve problems." It doesn't talk the technical details of some of the stuff (a movies just not as good at that- though it does show people work through equations and do the math on a lot of matter), but this is some of the best science in a movie you'll ever see, and before they do almost everything the characters run the math.

Xkcd's description is bang-on. It is not 'another Hollywood sci-fi movie,' and everyone I've talk to who's seen/read both say it's a very good adaptation of the story.

This review by Howard Taylor is part of why I watched it.

[Adam Reynolds]

I just watched this again today and though of something random. Why didn't the crew tether themselves together when they were leaving? From my extremely limited knowledge, don't mountain climbers do this in certain cases?

While this obviously would have led to problems in terms of all of them going down rather than just Mark, it would have obviously avoided him getting left behind.

[Zeropoint]

Also, the model for the Hermes was freaking gorgeous.

It was/is, but I have a question about it. From the outside, we see the habitat section rotating to provide spin gravity. No problem there; a thing rotating around another thing is old news. From the inside, we see astronauts moving down the main passageway into a rotating four-way intersection from which they can climb "down" into one of the hab modules. It looks like an elegant, practical solution.

The thing is, I have a hard time reconciling the two views--what connects the front non-rotating half to the back non-rotating half? Surely the spinning section isn't the only thing connecting them? There's obviously no spine/keel running through the center of the rotating section, nor are there struts that go around the outside of it.

Am I missing something?