Andy Weir, who wrote the book, claims that he did considerable research to get the orbital mechanics correct. Fivedollargold was surprised how closely the film follows the novel. Several lines are quoted verbatim in the film.

It was a great movie! I listened to the audio book and the movie was true to the entire book. As to the orbital mechanics, Weir open sourced this while he was writing it. And several NASA scientists have verified the calculations since then. This should go on the list of objectivist movies. Yes, there are governments involved, but the individual chooses life and does the work necessary to live.

The interception was before the sling shot (I'm pretty sure)

To intercept, the low orbit craft was stripped down to bare essentials and still failed to do it's max when the cloth came off the nose and caused more drag than expected.

That caused the space craft to have to slow down in order to drop in orbit, and was still several meters too high.

We don't have enough info to calculate the speeds, either actual or relative for either craft. But it's the trajectories relative to each other and the relative speeds that are important. Yes, they're complicated calculations.

But I loved the movie, particularly after having read the book.

I posted this on a prior thread...I hope you do not mind my re-posting here. I really liked the movie, though I had to take the astrophysics on faith.

Uh - Warning: contains spoilers!

repost:
Wm and Ellen and I went to see The Martian yesterday evening. One of the things that is clear, upon reflecting upon movie, is the degree to which it is completely natural that geek culture owns all of the major characters. The single representative of ‘normals’ amongst the main cast is Annie Montrose, the NASA PR guru. In the same way that most shows now include a ‘token geek’ to act as a foil for the plot and represent how ‘out of it’ geeks are, Annie is the ‘token normal’ and holds the reverse role: she shows how lost most people would be amongst the brilliant eclectic geeks around her. The most wonderful scene that illustrates this was when the Council of Elrond was called, in the NASA Director’s office, and the Armani-clad Teddy Sanders, Director of NASA, immediately chimes in, "If this is the Council of Elrond, I want to be Glorfindel."; Annie Montrose is vastly puzzled but everyone else is quite comfortable with the metaphor.

The NASA Director was also played in a much more sympathetic fashion that in the book. I did miss the line (after Mitch Henderson, the Mission Commander, calls Teddy Sanders a coward for NAKing the Rich Purnell maneuver) where Teddy turns to Annie for moral support and (in the book) Annie says that she wished that Mitch had punched the Director out instead of just calling him the coward he is. (That was not in the movie; sigh.)

There was an interesting thread, also in the book but not so clear there as in the movie, of the scientists of the world being a subculture that transcended national boundaries. This is actually true, I think, but not often portrayed in such a subtle manner (true of music too).

While The Martian is quite reminiscent of the SF that we read as kids, where people go out into space and have wonderful adventures solving complex and dangerous problems, it is also a thoroughly modern movie. The distribution of race and gender is across the board in all roles, and the fact that a clueless Rastafarian astrophysicist is hailed as “a steely-eyed rocketman” by the Hermes crew is a good example of how careless of race and gender the plot is. (Even better, there is never an explanation for that message – because ‘of course you understand it’.) I was talking with a colleague at work a week or so ago, and we both had to adjust our identities to reading SF when we were young because there were no female (me) lead characters or black (him) lead characters in the books. This is SO not true for this movie! And it is not PC tokenism – these people obviously belong in the roles they inhabit.

It is important, crucially so, that you understand that there is NO Villain in this movie. Like the old SF novels, there is no one, twirling a waxed mustache, whom you must overcome as a plot element: it is an adventure of the spirit, and a triumph of intellect over the uncaring intransigence of the universe.

There needs to be a lot more movies like The Martian.

Jan

One of the best books I've read in recent years. Rife with science, math and humor. The movie came close to the mark and in spite of its Hollywood superficiality was worth watching.

I'm not an engineer, just a technician (one of the guys from whom engineers abscond with tools and the cheery phrase "I'll bring it right back!") so I can't comment on the feasibility of playing Catch The Skeet Astronaut, but the only annoyance I suffered in the movie - which I loved overall - is the whole hoary trope of the massive Mother Ship, as spacious and luxurious as a Malibu beach house. Up to the point where they showed that thing - with its vast living rooms, conference rooms, gymnasiums and... gymnasiums?!? - it was nicely linked to technological plausibility. But I read Zubrin's book, dammit!

Seriously - assuming a laissez-faire revolution and a hundred years or so of prosperity, abundance and privatization, a spacecraft of that size and opulence would be feasible, but by then you'd have split-level condos all over Mars anyway. So they could've toned down the Hermes craft to something a little more realistic and a little less Kubrick. A good real-world model to work off of would be the ISS - every square inch is dedicated to some specific purpose. No vast expanses of empty floor space, no lounge-benches along the walls, and the vacuum outside is about as absolute as it gets, so the picture windows would have to be a bit smaller.

Another thing I didn't care for was the lack of subtlety in foreshadowing. I forget the exact wording, but at one point just after they discover that Watney is alive, one of the guys back on Earth says "He'll have to make that food stretch for x period of time if he wants to survive - and that's barring any catastrophes."

Ahem! Cue catastrophe. An entire section of the hab facility blows itself to smithereens within seconds of that statement, and there go the potatoes. So... 'could've been a little less paint-by-numbers in spots.

But overall it was an excellent, nicely-detailed space-survival tale that placed reason in the driver's seat.

I just watched the movie and enjoyed it. It's one of the best space movies I've seen. It does have some dramatic exaggerations of physics, but I expect that out of Hollywood anyway.

1) The atmospheric density on Mars is very low. While dust storms can dramatically minimize visibility, the aerodynamic force exerted by the dusty wind is too low to blow an astronaut away.

2) Any pre-positioned Mars Ascent Vehicle (MAV) that can easily be toppled over by a windy Martian dust storm (not!) would not be able to stay in its spot for long periods of time, to support a launch-on-demand capability for Martian astronauts.

3) The Hermes flyby of Mars, while rescuing the Martian astronaut, is completely wrong on orbital mechanics. The MAV reaches a low orbit around Mars. The Hermes allegedly cannot decelerate to enter Martian orbit and must simply fly by the planet, while attempting a rendezvous with the Martian astronaut from the MAV. The flyby orbital speed would have been too fast to attempt this. For the orbital speeds to be that close for that long of time, the Hermes would have entered Martian orbit, in an elliptical orbit. Of course, I have not read the book, so perhaps the movie's depiction of the MAV low orbit is wrong. Perhaps the book's MAV orbit was highly elliptical but slightly insufficient to leave Mars' gravity well, with the low point (perigee) achieving a maximum velocity just below escape velocity. But even with this assumption, the Hermes would have entered Martian orbit in a similar highly elliptical orbit.

All that being said, Hollywood usually butchers the Laws of Physics far worse on most movies. So, as long as you don't let the exaggerations detract from the dramatic story, you can enjoy it immensely...

While I can't speak to your specific question about the speed of the ISC, I can say that absolutely loved the film. On our way home, I suggested to my wife that the author must have been in some way inspired by Rand. The movie damn near answers the question, "What would it be like if we took everyone from the Gulch, and threw them into a space odyssey? And, while we're at it, what if we just left out all the bad guys too? Wouldn't that be fun?" Yes. Yes it would be, and it was.

I haven't yet read the book, but it's now on my list of must-reads.

Faster than a fish on a bicycle?

I loved the book. The author, Andy Weir is a software engineer and actually wrote software to calculate the orbits of the mission so I'm inclined to believe it is practical. It's certainly beyond my skills to check it but his blog he started it on was popular with tech people and it isn't one of the things he says is wrong.

It is one of the best books I've read in years, it's amazing that the hard science works so well -- and translates to the screen in a script full of dialog direct from the book.

It's rare that you see a movie made from a book you love that lives up to it, but in this case I think it's a little better. The book ends sooner and I like having the storm and takeoff at the beginning rather than as a flashback.

Reading the book I was amazed to find my eyes tearing up when reading the Pathfinder bootlog!

I never watched the film; It turned me off the instant I watched the trailer.

The first lines were :
"Every Human Being has a basic instinct to help each other out....We pool money to help a hiker lost in the mountains or victims of disasters....This instinct is found in every culture.....without exception."

EXCELLENT... Minimally Editing should get an Academy Award. Very well done.