Question: How did Mark manage to make the hab last longer? He said he was in a hab designed to last 31 days.
jimba
24th Oct 2018
The Martian (2015)
Join the mailing list
Separate from membership, this is to get updates about mistakes in recent releases. Addresses are not passed on to any third party, and are used solely for direct communication from this site. You can unsubscribe at any time.
Check out the mistake & trivia books, on Kindle and in paperback.
Answer: It was designed to last a month with six occupants, but with only one the supplies would last a lot longer. As far as the structure itself, the "design" lifetimes are always conservative, as evidenced by the Mars rovers still running around Mars, such as Opportunity was designed to last at least 90 days, but is still ticking after 5000 days.
jimba
I thought that after 31 days the hab would run out of air.
Air for 31 days would assume they were using only canned air, and NASA included no extra for safety (like if they couldn't leave on time). Assuming they were using canned air, then with only one occupant the remaining air would last 6 times as long, so would still go well past the 31 day mark, though they were almost certainly using systems to recycle the air by scrubbing the CO2 so the air would last a lot longer. This is the same way air is handled in current NASA spacecraft. An offset though is we have a flame which is using oxygen at a greater rate than a person would, and plants that are also helping remove CO2 to produce oxygen, though the net of this would almost certainly be to have a higher oxygen use rate.
It's explained in greater detail in the book. There was a plentiful supply of oxygen for him to survive a long time, even using up some of it to produce water for the soil. The real risk was a potential build up of carbon dioxide, which would prevent the diffusion of carbon dioxide out of his blood and into his lungs.
He had an oxygenator in the Hab. That meant there was not a finite amount of oxygen.
Smokyoak