Throughout his stay on Mars, Watney keeps an extensive collection of video logs of his activities using the various cameras at his disposal. The Hab and Rover also have continuous monitoring systems. In the movie version, we often see the action from the perspective of these recording devices.

What happens to all this data at the end of the story? Did NASA receive it? Mark couldn't have physically taken it with him on the MAV, since he needed to reduce his weight as much as possible. (Unless his spacesuit has some kind of built-in data storage. Even then, he's never seen downloading the videos, or interacting with the data at all, really.)

His communication with NASA while on Mars happens via a makeshift setup using the Mars probe as a relay. It doesn't seem like it would have the bandwidth to continually upload the video feed, not to mention it's highly unlikely the process could be automated.

Supporting the above point, the movie consistently avoids showing NASA as seeing those videos during the events of the story. All they are going on is satellite imagery, text chat, and the occasional Pathfinder camera image.

Did the video logs reach Earth eventually? Or were they all left behind on Mars?

  • 2
    Is there an expanded universe for The Martian that can possibly address this question?
    – Buzz
    Dec 15, 2016 at 0:05
  • 2
    We don't know...
    – void_ptr
    Dec 15, 2016 at 0:37
  • 1
    Using near-future storage and compression, it seems likely that he could have carried the records on a microSD card or an even lighter successor format.
    – Politank-Z
    Dec 15, 2016 at 0:50
  • 3
    Several interviews with Andy Weir indicate that the video diary idea was deliberately chosen as a literary technique, putting the reader more intimately into the story than regular 3rd-person omniscient point of view. As @MikeJRamsey56 says, suspend your disbelief.
    – John Feltz
    Dec 15, 2016 at 1:45
  • 2
    I think they were more for his own sanity than anything else. Plus if NASA had discovered he had made them & perished there, they might have dedicated a mission to recover his remains and the videos at the same time. If he did not perish there, and remained nominally sane, he could relate the information in person. Dec 15, 2016 at 2:39

3 Answers 3


Actually, as I found in this answer here, and from Valorum's answer to this question. People surrounding this book and film can be pretty responsive to emails. So I emailed Andy Weir (I hope you don't mind me blacking out my name), but this was his reply: Andy Weir responds to my email stating that Mark uploaded his logs and transmitted them to Earth using the Ares 4 MAV.

So according to him, Mark uploads the logs and sends them using the Ares 4 Mav, although I have no recollection of that happening.

With regards to the movie...

We don't know
To elaborate, nowhere in the script from when Mark reaches the Schiaparelli Crater, to when the MAV takes off does he upload them or are they discussed.

TITLE: Sol 538
Mark stares at the camera with a look that says, “Oh jesus these JPL guys are gonna get me killed.”


Mark stands at the base of the MAV. He holds a large wrench in his hand, almost like a weapon.
As Mark stares up at the MAV with a gleam in his eyes...

Mark tears the acceleration chairs out of the cockpit.

WHUMP. One after another, the acceleration chairs hit the dirt in a pile. WHUMP.

Mark tears out the control panels. He’s having fun.

WHUMP. The controls hit the dirt. The pile is growing.

Mark waits in the airlock with a mess of stripped equipment.

The outside of the MAV now looks like the set of Sanford and Son. Mark wrenches one of the MAV’s hull panels free.

UP ABOVE: The nose airlock breaks free, and tumbles down towards camera, BLACKING OUT FRAME.

FROM BLACK, we FIND MARK. He’s sitting on a hill slope, surveying his handiwork.
The MAV has been TRANSFORMED. The whole front has been torn off. Hab canvas now covers it. Equipment litters the area all around us. Junkyard on Mars.
Mark just sits. Exhausted.

TITLE: Sol 560
Mark sits inside the makeshift pressurized tent. He tears open his last remaining ration pack: “Goodbye, Mars”
He eats in silence.

After that section the only mention of Mark on Mars is strapped into the MAV waiting to launch. As Santa said, the book uses written logs whereas the film uses video logs, and as Andy Weir's email references the book, we have to look at the film separately. However, Andy Weir tells us that the MAVs had high-bandwidth connection which would allow for video transmission nearly as well as text transmission, so the best we can do is to assume that Ridley Scott and Drew Goddard had similar intentions to Andy Weir, having Mark Watney send them back to Earth via the Ares 4 MAV.

  • Interesting. I just read through the end of the book from when Watney gets to the MAV. Although it mentions Watney storing his collected samples in a container near the launch area, nothing at all is mentioned regarding the logs (apart from him creating more).
    – user71418
    Dec 15, 2016 at 11:11
  • @Pᴇᴛᴇ, I thought the same, reading it this morning and last night (to make sure my question wasn't redundant), could it be possible that he'd written it and it got removed in editing and he forgot?
    – Edlothiad
    Dec 15, 2016 at 11:13
  • Or it could be on his online serialized version of the book, which I've not read.
    – user71418
    Dec 15, 2016 at 11:14
  • 1
    @Edlothiad Props for reaching out to Weir. I accept it is likely the text logs were uploaded via the MAV in the book. The fate of video logs can be assumed to be the same (since Mark had weeks to upload them once he arrives at the MAV, so bandwidth is not an issue). But I feel a definite answer would need to come directly from either the book or the movie.
    – Santa
    Dec 15, 2016 at 18:48
  • 1
    @Gallifreian, props to him for answering a couple hours later (too bad I'd fallen asleep already.
    – Edlothiad
    Dec 15, 2016 at 20:39

Someone asked this on Reddit, to no conclusion.

In the source novel his logs are in text format, not video. At one point (after retrieving the Pathfinder) he makes an assertion that he should be more careful with his logs,

now that someone might actually read them

However, ultimate fate of his logs is left undisclosed in both media.

If you're asking about the films, then there is little chance he could take the logs with him. Logs seemed to be pretty HD (at least 720p), which would make them pretty bulky, disk space-wise. To take all of them home, he'd need a hard drive, which he couldn't store in his suit.

He did have USBs with crew's entertainment, but I imagine it would be insufficient to hold all of his logs.

And when you think about it, his logs only hold sentimental significance. Was he dead, NASA would try to rescue his logs (with his body) to collect information. But since they have a living Mark Watney, they could just ask whatever it is they're curios about (Potatoes? On Mars?!) directly to him (as pointed out by Andrew Thompson in comments).

  • 2
    I agree with this. I get the idea that Watney would have left the logs with whatever recording device he used (either in the Hab or the Rover) for members of the next mission to retrieve (if retrieval was part of the mission brief). He was pretty intent on surviving, so figured that he'd remember much of what he experienced to pass on to others (and typing stuff is a good aid for the memory as well as being a sanity crutch).
    – user71418
    Dec 15, 2016 at 7:30
  • @Pᴇᴛᴇ, if you look at my answer below, I suggested that to Andy Weir, and he says Mark uploaded his logs to Earth via the Ares IV MAV
    – Edlothiad
    Dec 15, 2016 at 11:11
  • @Edlothiad - Saw that, re-read the end of the book, I find no mention of this. I guess Andy could have intended this as an "off-screen" action though.
    – user71418
    Dec 15, 2016 at 11:12
  • I disagree about logs being insignificant. Just the recordings of a human living in a Mars habitat for a year and a half would be invaluable to NASA. They could study his behaviour and physiology in a much more objective manner than mere interviews could provide. It was an unscheduled, first of its kind experiment in long-term Mars settlement, and it wouldn't be repeated anytime soon. NASA would kill for that data.
    – Santa
    Dec 15, 2016 at 19:15
  • @Santa - I'm talking about the book. As they are portrayed in the book, they are not the type of reading NASA would appreciate. Mark doesn't share that much feelings; he rather uses his sarcasm. Dec 15, 2016 at 19:22

Ok so after watching the movie I dont remember if Mark actually ever holds the crew memory sticks in his hands on screen or not. (feel free to set me straight on this one) so I googled a bit and got redirected to Pineterest for stuff from the Martian set. Amongst the items are these 2 usb sticks.

Picture from Pinterest, all things "The Martian"

They look like they could hold 512 GB of data pretty easy. So I googled a bit more and found a link to Amazon where I was able to find a pretty small disk that could hold 512GB of data. (now remember these disks are able to hold more and more data every year. So if we go a few years in the future a USB stick like this one will prob be able to hold 1TB in a very few short years)

512GB Usb disk

So as an experiment, I took 1 video I have on my phone and tried to see what I could do with it. (Bear in mind that I'm a novice at this. Never had any reason to compress files before.)

starting point: 1080x1920, 673MB video, length 4 minutes 38 seconds

Using only 1 compression program (that I found in a YouTube video after I googled "compression") and 4 minutes of my time I got the video down.

ending point: 101MB video is still the same length and quality.

Now if I wanted to I could first render the video with some software and then use compression to get it further down in size if I knew that the size was a problem. but I managed to shave a CONSIDERABLE chunk of the video size in no time at all using 2016 technologies.

The movie is set in the year 2035, just under 20 years from now. It has all the NASA gimmicks and doo-hikies, so by 2035 I would imagine that you could very, very easily put a years worth of personal logs on a very small and portable USB disk without any kind of "technical" issues that we are facing today with current technology.

(This last part is a bit speculative and raises questions and what ifs so bear with me please.)

Who is to say that file size will even be a problem in 30 years time?


That the documents cant be compressed to a mere fraction of the "normal" video size while it is being recorded.

Mark is a genius for surviving so long on his own. Who is to say that he didn't find a way to send his logs back to earth somehow or to the ship returning for him at some point before he left base camp.

  • Considering every single gram counted, down to the last irrelevant bolt. It's unlikely they would've let him take a USB or two with him and if that was how they saved it (Which is wasn't as clarified in my answer above) they would've had him leave it for the next Ares Mission.
    – Edlothiad
    Dec 15, 2016 at 11:17
  • That is all good man. Ridley made the movie and in the movie there is no mention of what happened either. Also movie directors change stuff most times when interpreting a book into a movie. I was just demonstrating that is VERY possible to have large chunks of data compressed so space wouldn't be an issue. And considering that most of the internal workings of a USB stick is plastic and wires it couldn't weigh more than a few grams. Maybe less if NASA made em out of some kind of techno composites that are invented in the future. The movie is in 2035 so a ot of stuff can happen in 30 years.
    – Cherubel
    Dec 15, 2016 at 12:01
  • 1
    You're observations are interesting and you're very right. I just wanted to give my two cents. If making things smaller interests you, take a look at Moore's Law
    – Edlothiad
    Dec 15, 2016 at 12:31
  • @Edlothiad +1 on the answer and the link.
    – Cherubel
    Dec 15, 2016 at 12:42
  • A 512GB SSD in the MacBook Air I recently worked on is about two millimeters thick, and about the length/width of my thumb. I believe the newer ones have a terabyte in a similar shape and size. Picture: eshop.macsales.com/shop/ssd/owc/macbook-air/2013-2014-2015
    – WGroleau
    Dec 15, 2016 at 14:27

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