5 ms·

I thought the martian was praised for generally being pretty on the money with the science content?

aqme28 9y ago
It has a couple problems. Like a windstorm that can tip their spacecraft and knocks a radar dish into the protagonist. But later, the atmosphere is so thin he doesn't need a nose on his rocket. Also there's no way you can grow that many potatoes on mars with a solar array that size.
- TeMPOraL 9y ago
  > Like a windstorm that can tip their spacecraft and knocks a radar dish into the protagonist. This is literally one of the two cases in which Andy explicitly said he used artistic license and departed from realism. The other one being super-efficient radiation shielding on Hermes which he didn't in any way explain in the book.
sjburt 9y ago
The Martian atmosphere is so thin that you'd be barely be able to feel hurricane-speed winds.
- TeMPOraL 9y ago
  That was one of the two things the author used artistic license on, the other one being unrealistically good radiation shielding on Hermes. The movie took at least one other liberty with science - they explicitly decided to ignore lower martian gravity, as they would make shots much more difficult/expensive, for (in their opinion) little added value.
sliken 9y ago
Except that living in fancy tents or traveling across the surface for weeks/months would result in death by radiation. Until mars gets a much larger atmosphere and a magnetic field living on the surface is going to require living under ground.
- WillPostForFood 9y ago
  Radiation is a real problem for people on Mars, but death after few weeks or months is overstating it. Increased cancer risk, for sure. https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzAzNi85NTkvb3JpZ2luYWwvUElBMTc2MDFfaXAuanBnPzEzOTI3NTc4MzE= https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1...
geekpowa 9y ago
KSP taught me that orbital intercept to rescue Watney was nosense. (The book was slightly more believable here). also the whole swing by Earth and head back at the last minute was wrong. Orbital intercepts between planets requires very precise timing and alignment. A transfer from Mars to Earth is never going to line up with an instant return transfer window back to Mars. On KSP itself, huge weakness for me in the game is that it is virtually unplayable stock. Absolute minimum you need to install a data providing mod like Kerbal Engineer Redux for both building rockets to quickly assess dVs and TWRs etc and in flight to help with figuring out burns etc. In stock you are reduced to having to use spreadsheets to build rockets and trying to land from visual clues only. The stock game badly needs something like KER. KAC is also helpful to quickly find transfer windows etc.
- CydeWeys 9y ago
  > A transfer from Mars to Earth is never going to line up with an instant return transfer window back to Mars. The whole point of the Hermes spacecraft as used in The Martian, though, is that it has a high specific impulse, low thrust ion drive, that runs continually during the entire orbit (using power from a reactor to do so). Andy Weir, the author, is a programmer, and he actually wrote a physics simulator to calculate the required orbit; see here: http://www.galactanet.com/martian/hermes.mp4 http://www.galactanet.com/martian/hermes.mp4 So it's definitely not a Hohmann transfer orbit since there is thrust applied throughout, and you are consequently reaching your destination faster than such a transfer would arrive. It ends up being a low thrust brachistochrone orbit. So anyway, the point is that, since you're continuously applying thrust anyway, you don't need perfect alignment, it just takes you longer if the alignment isn't correct. Andy Weir is a serious hard science fiction nerd, to the point that you can download the data that he simulated for these orbits and verify for yourself that they are in fact correct for the stated specifications of Hermes' ion drive. Totally agree with you that the Engineer plugin is absolutely essential for playing KSP, though. The game is so frustrating without that because there's so much trial and error with randomly flipping craft thanks to the new aero model if the TWR is off for any of your stages (and it will be until you've played awhile and developed an intuitive sense of what kind of rocket is reasonable -- a proficiency you won't likely reach if you didn't have Engineer from the beginning to help get you there).

It has a couple problems. Like a windstorm that can tip their spacecraft and knocks a radar dish into the protagonist. But later, the atmosphere is so thin he doesn't need a nose on his rocket. Also there's no way you can grow that many potatoes on mars with a solar array that size.

TeMPOraL 9y ago
> Like a windstorm that can tip their spacecraft and knocks a radar dish into the protagonist. This is literally one of the two cases in which Andy explicitly said he used artistic license and departed from realism. The other one being super-efficient radiation shielding on Hermes which he didn't in any way explain in the book.

sjburt 9y ago

The Martian atmosphere is so thin that you'd be barely be able to feel hurricane-speed winds.

TeMPOraL 9y ago
That was one of the two things the author used artistic license on, the other one being unrealistically good radiation shielding on Hermes. The movie took at least one other liberty with science - they explicitly decided to ignore lower martian gravity, as they would make shots much more difficult/expensive, for (in their opinion) little added value.

sliken 9y ago

Except that living in fancy tents or traveling across the surface for weeks/months would result in death by radiation. Until mars gets a much larger atmosphere and a magnetic field living on the surface is going to require living under ground.

WillPostForFood 9y ago
Radiation is a real problem for people on Mars, but death after few weeks or months is overstating it. Increased cancer risk, for sure. https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzAzNi85NTkvb3JpZ2luYWwvUElBMTc2MDFfaXAuanBnPzEzOTI3NTc4MzE= https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1...

geekpowa 9y ago

KSP taught me that orbital intercept to rescue Watney was nosense. (The book was slightly more believable here). also the whole swing by Earth and head back at the last minute was wrong. Orbital intercepts between planets requires very precise timing and alignment. A transfer from Mars to Earth is never going to line up with an instant return transfer window back to Mars. On KSP itself, huge weakness for me in the game is that it is virtually unplayable stock. Absolute minimum you need to install a data providing mod like Kerbal Engineer Redux for both building rockets to quickly assess dVs and TWRs etc and in flight to help with figuring out burns etc. In stock you are reduced to having to use spreadsheets to build rockets and trying to land from visual clues only. The stock game badly needs something like KER. KAC is also helpful to quickly find transfer windows etc.

CydeWeys 9y ago
> A transfer from Mars to Earth is never going to line up with an instant return transfer window back to Mars. The whole point of the Hermes spacecraft as used in The Martian, though, is that it has a high specific impulse, low thrust ion drive, that runs continually during the entire orbit (using power from a reactor to do so). Andy Weir, the author, is a programmer, and he actually wrote a physics simulator to calculate the required orbit; see here: http://www.galactanet.com/martian/hermes.mp4 http://www.galactanet.com/martian/hermes.mp4 So it's definitely not a Hohmann transfer orbit since there is thrust applied throughout, and you are consequently reaching your destination faster than such a transfer would arrive. It ends up being a low thrust brachistochrone orbit. So anyway, the point is that, since you're continuously applying thrust anyway, you don't need perfect alignment, it just takes you longer if the alignment isn't correct. Andy Weir is a serious hard science fiction nerd, to the point that you can download the data that he simulated for these orbits and verify for yourself that they are in fact correct for the stated specifications of Hermes' ion drive. Totally agree with you that the Engineer plugin is absolutely essential for playing KSP, though. The game is so frustrating without that because there's so much trial and error with randomly flipping craft thanks to the new aero model if the TWR is off for any of your stages (and it will be until you've played awhile and developed an intuitive sense of what kind of rocket is reasonable -- a proficiency you won't likely reach if you didn't have Engineer from the beginning to help get you there).