Nitpick "The Martian"

[peadar1987]

For one side, you are saying that the wind is nothing and you can walk without problem. For the other side was a event who cause considerable caos and it was in the news.

Somebody on the shore saw boats capsized (10 boats capsized out of 90+ over the course of a 90 minute race), the coastguard got an inaccurate report, thinking that all of the people in the event were in the water at the same time. Two people ended up in hospital, one with a banged head from a gybe, the other one with a back problem they had aggravated the day before, and decided to make use of the free hospital trip. 10 people were treated for mild hypothermia, which essentially meant being wrapped in a foil blanket and given a mug of tea.

You have 2 ways of lift, one is due the airfoil shape, and the other is just by angle toward the wind, like a normal kite (there is not airfoil shape there, also if it would, does not help in nothing).

45 degrees is an impossible angle to keep. The wind force is not constant and you still need to walk, and as I said, that position just help you to not tilt over.

Bending knees does not help for get equilibrium, something you really need.

I threw in 45 degrees because it was an easy number to work with, sine and cosine being the same. It shows that you aren't going to take flight by leaning over. If you use 5 degrees, you get an absolute maximum of 8.7% of the wind force lifting you, and a 1% reduction in drag. That's if all of your drag is bluff body drag, which is only true for very low windspeeds. For a windspeed of 40 knots, using your estimate for Cd, you still only get a drag force of 191N, or a lifting force of 16N. Negligible, really.

Bending your knees won't help get equilibrium, but your thighs will produce "downforce", cancelling out some of this lift.

Ok, this is what I am interested, because yeah, it may add considerable errors in my calculations.

That is just a function of CD with respect to Reynold, but I am not sure that is in Air.. I guess that graph is for water...

Reynolds number takes into account the kinematic viscosity of the fluid. The transition occurs at the same Reynolds number regardless of other factors, so long as you're using the same geometry conventions. The fluid doesn't matter as changing the fluid will change the Reynolds number.

reynolds and cd calculations is a nightmare, the only way to get a rought number is with special software and computer power, that is why the only good parameter is in a wind tunnel.

The only way to prove partially if you are right and in what porcentage, it is knowing real data on terminal velocity (last 300 meters to keep the air density constant) and then correlate those numbers with your new Cd estimation in case is turbulant.

The exact values will vary depending on the geometry and surface, but a smooth cylinder in subsonic flow, the laminar-turbulent transition will occur at the same Reynolds number. If anything, a human will have a higher Reynolds number, due to the more complex geometry and rougher surface.

Interestingly, when you plug the numbers for Mars into the equation, you get a kinematic viscosity ten times higher than that of earth's air, giving a speed of transition of 275m/s. Although that will be a maximum, it does seem to suggest that the Martian atmosphere with winds of 400 km/h will be operating in a broadly laminar regime, with the increased drag that implies. It makes things slightly less clear-cut, which I wasn't expecting, so kudos for pushing the point and making me do the maths. It means a 400km/hr wind on Mars will be more analogous to an 80kt wind on earth, which is extremely difficult to stand up in and walk against. I believe this video has windspeeds of 90-100 knots. I've seen clips from it before with the info, but I don't think it's included in this one:

[Brethern]

#1 I agree on. Especially since later in the book the effects of a storm are said to be mellow "because of the low air pressure" (I'm paraphrasing and this is from what I remember, so I might be wrong, but I know it irked me).

#2 Yes and no -- I'm pretty sure the discovery of perchlorates is very recent and wasn't known when Andy Weir wrote the book. Of course, it kills the plot as it is so it's not like he can retroactively fix that (unless there's a way to clean the soil)

#3 Water ice is found in some places, but not everywhere. So you can defend that by stating that it's not around where he is. Besides, you'll need to melt the ice (although the RTG can take care of that)

So I'', wondering. Mars has really big dust storms. Wouldn't it be possible for perchlorates to be in isolated deposits and only be spread due to the storm? I mean mars is a planet curiosity traveled what? twelve kilometers so far?

That's like aliens landing at one of the many naturally radioactive spots on earth and concluding the entire planet is like that.

[KerikBalm]

But the wind effect is considerable.. is not something to said "ohh how could the book being so wrong!!".

I love when books or movies have accurate physsics effects or even try to accomplish those. So not sure why you want so badly that his is wrong with their assumptions.

I did say it was nitpicking...

http://dictionary.reference.com/browse/nitpick

verb (used without object)

1.to be excessively concerned with or critical of inconsequential details.

verb (used with object)

2.to criticize by focusing on inconsequential details.

noun

3.a carping, petty criticism.

The wind force would be substatial, but I don't think its enough to cause an abort.

We have had multiple rovers there, many may years, the only danger of the storms was coating the solar panels with dust.

Any mission to mars would be designed to tolerate that wind, and it wouldn't be too hard to design it like that.

Its somewhat plausible, but unlikely... the stupidity of congress would have to really infect NASA at all levels to produce a design that can't tolerate the martian dust storms, since we routinely encounter proportionately *much* stronger winds on Earth, and don't have much problems with them unless they get *much much much* stronger... like tornadoes and hurricanes.

Plus its coupled with the departure of the MAV *during the storm* while it was in danger of tipping (I guess we are to assume that the thrust vecotring saved it, and max Q isn't so bad on mars relative to earth, that the MAV can tolerate ascent in high winds

[AngelLestat]

Somebody on the shore saw boats capsized (10 boats capsized out of 90+ over the course of a 90 minute race), the coastguard got an inaccurate report, thinking that all of the people in the event were in the water at the same time. Two people ended up in hospital, one with a banged head from a gybe, the other one with a back problem they had aggravated the day before, and decided to make use of the free hospital trip. 10 people were treated for mild hypothermia, which essentially meant being wrapped in a foil blanket and given a mug of tea.

How cold is the water there?

Here in Buenos Aires, there is something call Pampero which happen many times by year, is a strong wind from SE that last only 5 min from 70kmh to 120kmh (40kts to 70kts), it is easy to recoignize by its cigar shape.

image1, image2, those distracted or who does not know.. they get cought because it happens too fast, almost like a shock wave. Destroys sails or windows/doors in houses that are not close.

The exact values will vary depending on the geometry and surface, but a smooth cylinder in subsonic flow, the laminar-turbulent transition will occur at the same Reynolds number. If anything, a human will have a higher Reynolds number, due to the more complex geometry and rougher surface.

Interestingly, when you plug the numbers for Mars into the equation, you get a kinematic viscosity ten times higher than that of earth's air, giving a speed of transition of 275m/s. Although that will be a maximum, it does seem to suggest that the Martian atmosphere with winds of 400 km/h will be operating in a broadly laminar regime, with the increased drag that implies. It makes things slightly less clear-cut, which I wasn't expecting, so kudos for pushing the point and making me do the maths. It means a 400km/hr wind on Mars will be more analogous to an 80kt wind on earth

Well that is not expected. What reynold number do you use for this? You calculate?

First I thought you were wrong.. But trying to find real data on reynolds numbers for mars, I found 2 papers who talk about wind turbines, because they have sense due how low is the R.N. there.

http://www.researchgate.net/publication/245526020_Low_Reynolds_Number_Vertical_Axis_Wind_Turbine_for_Mars

http://spectrum.library.concordia.ca/36176/1/low_reynolds_number.doc

It range from 5000 to 80000. I guess it depends on the shape from the vertical axis turbine. For spacesuit may be in the middle of that.

I believe this video has windspeeds of 90-100 knots. I've seen clips from it before with the info, but I don't think it's included in this one:

90 to 100 knots.. That is a F2 tornado, if it was that speed they would almost fly away, that is equal to 180kmh, 200kmh terminal velocity.

Or maybe you want to said 90kmh to 100kmh.

The wind force would be substatial, but I don't think its enough to cause an abort.

We have had multiple rovers there, many may years, the only danger of the storms was coating the solar panels with dust.

Any mission to mars would be designed to tolerate that wind, and it wouldn't be too hard to design it like that.

It seems the wind is not very strong so close to the ground. Also I dont think that a 400kmh wind is common on mars, it should be very strange..

Its somewhat plausible, but unlikely... the stupidity of congress would have to really infect NASA at all levels to produce a design that can't tolerate the martian dust storms, since we routinely encounter proportionately *much* stronger winds on Earth, and don't have much problems with them unless they get *much much much* stronger... like tornadoes and hurricanes.

Plus its coupled with the departure of the MAV *during the storm* while it was in danger of tipping (I guess we are to assume that the thrust vecotring saved it, and max Q isn't so bad on mars relative to earth, that the MAV can tolerate ascent in high winds

I have the theory that the real problem is NASA, not the goverment.

If is very unlikely to happen, I would vote for a NO.

It will be like design a probe to visit earth for first time, but we make it hurricane proff.. What is the point?

Other ships launch escape to orbit under the storm?

[peadar1987]

How cold is the water there?

You know what, I have no idea! I'd say probably about 10-12 celsius. I was trying my hardest not to go into it!

Here in Buenos Aires, there is something call Pampero which happen many times by year, is a strong wind from SE that last only 5 min from 70kmh to 120kmh (40kts to 70kts), it is easy to recoignize by its cigar shape.

image1, image2, those distracted or who does not know.. they get cought because it happens too fast, almost like a shock wave. Destroys sails or windows/doors in houses that are not close.

That's incredibly cool! This was the tail end of hurricane Bertha, so an unstable pressure gradient breeze. Baseline was about 30kts, with big squalls coming through with the fronts.

Well that is not expected. What reynold number do you use for this? You calculate?

First I thought you were wrong.. But trying to find real data on reynolds numbers for mars, I found 2 papers who talk about wind turbines, because they have sense due how low is the R.N. there.

http://www.researchgate.net/publication/245526020_Low_Reynolds_Number_Vertical_Axis_Wind_Turbine_for_Mars

http://spectrum.library.concordia.ca/36176/1/low_reynolds_number.doc

It range from 5000 to 80000. I guess it depends on the shape from the vertical axis turbine. For spacesuit may be in the middle of that.

I calculated using a fluid properties program I have for my PhD. Primary driver is the low kinematic viscosity of the Martian atmosphere (due to its low density), which will reduce the Reynolds number for a given wind speed. Nonetheless, for a given shape, the turbulent transition will still occur at the same Reynolds number, so I used 3*10^5, same as in the graph.

90 to 100 knots.. That is a F2 tornado, if it was that speed they would almost fly away, that is equal to 180kmh, 200kmh terminal velocity.

Or maybe you want to said 90kmh to 100kmh.

90-100 mph is what I remember, so closer to 80-90kts. You can look up videos of Mount Washington, some of them have windspeed information in them. They're among the few videos I've seen of people actually being dragged by the wind while standing up, so it gives a decent idea of the strength required.

[KerikBalm]

Other ships launch escape to orbit under the storm?

Not other ships... just the one ship... the only ship in roughly 3000 km...

He was left on Mars with no ride to space.

Then after the ascent vehicle made it to space, it rendevoused with a nuclear-ion propulsion ship with long term life support for the trip back to Earth.

So... he's left with a Mars Hab with supplies meant for a larger team for... 1(?) month... which meant they'd last him ~6 months. 2 rovers meant to carry humans, various other supplies.

There was another Mars Ascent vehicle was on the planet already, doing ISRU, in preparation for the next mars mission (which would use the same nuclear-ion ship to get the crew to/from mars)... but at a different location, very far away...

And thats basically where the book starts.

So they needed a plot device to get him left on Mars, with supplies -> an emergency abort.

I just don't think an emergency abort would happen due to the wind when the atmosphere is very very thin.

I think he could have used a different plot device that would be reasonable, but also seem like something that they could be excused for not planning for

[KerikBalm]

How cold is the water there?

Here in Buenos Aires, there is something call Pampero which happen many times by year, is a strong wind from SE that last only 5 min from 70kmh to 120kmh (40kts to 70kts), it is easy to recoignize by its cigar shape.

image1, image2, those distracted or who does not know.. they get cought because it happens too fast, almost like a shock wave. Destroys sails or windows/doors in houses that are not close.

That visually looks like the "morning glory" phenomenom that happens in Australia:

The description:

https://en.wikipedia.org/wiki/Morning_Glory_cloud

"The Morning Glory cloud is a rare meteorological phenomenon consisting of a low-level atmospheric solitary wave and associated cloud, occasionally observed in different locations around the world. The wave often occurs as an amplitude-ordered series of waves forming bands of roll clouds.

The southern part of the Gulf of Carpentaria in Northern Australia is the only known location where it can be predicted and observed on a more or less regular basis due to the configuration of land and sea in the area.

...

The Morning Glory is often accompanied by sudden wind squalls, intense low-level wind shear, a rapid increase in the vertical displacement of air parcels, and a sharp pressure jump at the surface.[5] Cloud is continuously formed at the leading edge while being eroded at the trailing edge.[4] Showers or thunderstorms may develop in its wake. In the front of the cloud, there is strong vertical motion that transports air up through the cloud and creates the rolling appearance, while the air in the middle and rear of the cloud becomes turbulent and sinks. The cloud quickly dissipates over land where the air is drier"

Of note:

"Morning Glory clouds can be observed from Burketown from late September to early November. The town attracts glider pilots intent on riding this phenomenon."

If this happens regularly near Buenos Aires... there is a tourism opprotunity... glider pilots would like a second location to try and fly in these things.

Edited July 2, 2015 by KerikBalm

[AngelLestat]

That's incredibly cool! This was the tail end of hurricane Bertha, so an unstable pressure gradient breeze. Baseline was about 30kts, with big squalls coming through with the fronts.

Ah bertha, I remember, is increidible that those low pressure center can reach so at north some times.. It seems that it took the race committee underguard.

I calculated using a fluid properties program I have for my PhD. Primary driver is the low kinematic viscosity of the Martian atmosphere (due to its low density), which will reduce the Reynolds number for a given wind speed. Nonetheless, for a given shape, the turbulent transition will still occur at the same Reynolds number, so I used 3*10^5, same as in the graph.

Cool. Some times I wish to have some of those fluid softwares and learn to use them, but just to play and test crazy ideas, but is not like I can get some real benefic from it

In that case, your number must be accurate enoght.

90-100 mph is what I remember, so closer to 80-90kts. You can look up videos of Mount Washington, some of them have windspeed information in them. They're among the few videos I've seen of people actually being dragged by the wind while standing up, so it gives a decent idea of the strength required.

Yeah, there are some places where winds are highly amplify. I visit one of those, the game was drop rough rocks over the cliff and see how they come back. Now there are signs to not do it, because you can harm other turist

Not other ships... just the one ship... the only ship in roughly 3000 km...

He was left on Mars with no ride to space.

Then after the ascent vehicle made it to space, it rendevoused with a nuclear-ion propulsion ship with long term life support for the trip back to Earth.

So... he's left with a Mars Hab with supplies meant for a larger team for... 1(?) month... which meant they'd last him ~6 months. 2 rovers meant to carry humans, various other supplies.

There was another Mars Ascent vehicle was on the planet already, doing ISRU, in preparation for the next mars mission (which would use the same nuclear-ion ship to get the crew to/from mars)... but at a different location, very far away...

And thats basically where the book starts.

Seems interesting, Maybe I will read it later if is good, because for sure the movie will skip a lot of science plot.

So they needed a plot device to get him left on Mars, with supplies -> an emergency abort.

I just don't think an emergency abort would happen due to the wind when the atmosphere is very very thin.

I think he could have used a different plot device that would be reasonable, but also seem like something that they could be excused for not planning for

Dunno, I cant think in any other possible plot which may be also fun to read/watch. In other mars movies, those plot are very syfy.

That visually looks like the "morning glory" phenomenom that happens in Australia:

wow... that looks cool, many of those cigar at equal distance.. that is really weird. It seems that they work similar to the Pampero taking into account the wind properties. I never see a Pampero from above. We dont have things very documented here

Of note:

"Morning Glory clouds can be observed from Burketown from late September to early November. The town attracts glider pilots intent on riding this phenomenon."

If this happens regularly near Buenos Aires... there is a tourism opprotunity... glider pilots would like a second location to try and fly in these things.

although the pampero happens often approx 7 times by year (mostly summers), it does not always had that particular shape, that shape is the pampero in its purest form, it happen 1 or 2 times by year with strong dry winds, and always some time after very long time north winds, I mistake before, It comes from SW (not SE), the basic properties are always the same, short time period, kinda shockwave. But then there are different types, wet (which behind brings rain clouds so the cigar is just the front).

The shape that I show, happen most often (not a rule) after the pampero leaves lands and is above water, like when you are in the middle of the river ("rio de la plata" estuary with more than 200 km width)

I took a time ago video with that shape in land. I need to find it..

Edited July 2, 2015 by AngelLestat

[KerikBalm]

Well, I don't think anyone will be too upset by going a little off topic here:

that looks cool, many of those cigar at equal distance.. that is really weird

I think they often appear as just a single line, but also sometimes as multiple parallel ones... I don't know how frequent that is relative to the single ones

although the pampero happens often approx 7 times by year (mostly summers), it does not always had that particular shape, that shape is the pampero in its purest form,

The australian morning glory, according to wikipedia:

There are generally only a handful of well formed spectacular clouds during this period at Burketown. During the 2012 season there were only four to be seen from there, but quite a few ragged unspectacular cloud lines were seen.

I never see a Pampero from above.

I fly hanggliders (which are foot launched... and a reason that I may be carrying around an insturment to measure windspeed on top of a hill/mountain that may get very windy.. the strongest wind I've flown in is over 64 km/h... but anything over 50 is basically too strong to launch in.... but one can launch and have the windspeed increase... my glider can manage 120 kph airspeed, after all)... and after seeing some video... well, it looks so cool, that I'd definitely like to go fly one of those before I die.

It sounds like there are two places I can go to try and find them (although I think the on-site logistics favors australia)

I can't find the first youtube video I ever saw of these... it was just a series of pictures set to the song "hey, you, get off of my cloud"

Ahhh well...

I hope climate change doesn't cause these to stop forming/form less often

*edit* found it:

Apparently it starts with video, then just has still pictures

That was the first time I was informed about the morning glory clouds

Edited July 2, 2015 by KerikBalm

[PakledHostage]

If this happens regularly near Buenos Aires... there is a tourism opprotunity... glider pilots would like a second location to try and fly in these things.

I don't know about Buenos Aires, but Argentina has some awesome conditions for gliding. The world altitude record for sailplanes was set there, and the Perlan Project hopes to reach 90,000 feet there.

[GoSlash27]

2 points in the novel that bugged me:

#1 He was burning hydrazine in a closed ecosystem, which is extremely nasty stuff. Not like he could just crack a window and vent the fumes.

#2 When he rendezvoued with the rescue craft he had gotten within 30 m/sec of matching it's speed. That would mean he was within 30 m/sec of a trajectory back to Earth, which is implausible.

Best,

-Slashy

[Nothalogh]

That would mean he was within 30 m/sec of a trajectory back to Earth

Not exactly, the Hermes flies a continuous thrust trajectory, thus it's ballistic trajectory at martian flyby would not have taken it back to earth

[AngelLestat]

Well, I don't think anyone will be too upset by going a little off topic here:

It is your topic and we were only 3, but yeah, now more arrive, but allow me a final answer on this.

I think they often appear as just a single line, but also sometimes as multiple parallel ones... I don't know how frequent that is relative to the single ones.

Then it must be a very similar formation case, and I found another photo of pampero from a turist in Buenos Aires that show the same multiple cigars as the morning glory:

Here you can see some variances:

http://farm3.static.flickr.com/2127/2394774432_81546fc1fe_m.jpg

http://www.yachtmollymawk.com/wp-content/uploads/2014/02/17-December-pampero-in-Argentina.jpg

http://3.bp.blogspot.com/-3MuRP-_o_DY/UL1ALG19aJI/AAAAAAAAITw/DQ4e3Xea2to/s1600/DSC_0005.JPG

https://santiagodelrio.files.wordpress.com/2008/09/santiago-del-rio_corrientes-15.jpg?w=640&h=427

http://farm3.static.flickr.com/2274/2361256543_8248b02436_m.jpg

And looking for english articles I found that even Jules Verne wrote about the Pampero in one of his books, descripted with his own words.

http://www.weatheronline.co.uk/reports/wind/The-Pampero.htm

As you said, after so many years, we need to find if they survives to the climate change.

I fly hanggliders (which are foot launched... and a reason that I may be carrying around an insturment to measure windspeed on top of a hill/mountain that may get very windy.. the strongest wind I've flown in is over 64 km/h... but anything over 50 is basically too strong to launch in.... but one can launch and have the windspeed increase... my glider can manage 120 kph airspeed, after all)... and after seeing some video... well, it looks so cool, that I'd definitely like to go fly one of those before I die.

It sounds like there are two places I can go to try and find them (although I think the on-site logistics favors australia)

Ok, now I am jealous, heh, I will love to do that, but here in buenos aires you dont have any cliff to launch which makes it more expensive.

Also as you see, there are times that the pampero carry heavy rain clouds which would not be very safe to ride them.

*edit* found it:

Apparently it starts with video, then just has still pictures

That was the first time I was informed about the morning glory clouds

It seems that they get benefic from the air stream on the clouds, is sad that nobody tries here, or they do but without sharing.

Looking that I found this which would be also amazing to use:

It also can be used with a tiny electric motor to those who has no cliff to launch.

Every time we are more close to the sky.

I don't know about Buenos Aires, but Argentina has some awesome conditions for gliding. The world altitude record for sailplanes was set there, and the Perlan Project hopes to reach 90,000 feet there.

Ah, that place is call Calafate, I imagine that they use thermals to rise over the montains (andes, fitz roy), then all the wind comming from chile, strikes in the Andes and rise, using that you can reach the jet stream which usually is always there, but not sure with what purpose or what are the properties of that Jet Stream.

[TythosEternal]

LOL, now you've gotten me confused... Are we nitpicking The Martian, or Seveneves? (http://forum.kerbalspaceprogram.com/threads/123033-Seveneves?p=1970646&viewfull=1#post1970646)

TL;DR: Hang gliders as launch vehicles

Edited July 3, 2015 by TythosEternal
Spelling, of course!

[Rune]

2 points in the novel that bugged me:

#1 He was burning hydrazine in a closed ecosystem, which is extremely nasty stuff. Not like he could just crack a window and vent the fumes.

#2 When he rendezvoued with the rescue craft he had gotten within 30 m/sec of matching it's speed. That would mean he was within 30 m/sec of a trajectory back to Earth, which is implausible.

Best,

-Slashy

Actually, the thing that really bugged me is what they did to get rid of the those last 30m/s... Plus the reason they were off with the launch in the first place. Yeah, the initial sandstorm was very dubious, but needing an aeroshell for liftoff from Mars is just as much a flight of fancy. And, you know, breaking a nuclear-powered manned ion spaceship in the thousand tonne range on a few hundreds of kilograms of compressed air at one bar...

I could accept a parallel-world Mars with a much thicker atmosphere as explaining away most of that, but that "emergency breaking maneuver"... how the hell did they move the humongous spacechip in time to point in the correct way? If they could move it, why the hell didn't they just use the RCS system to effect the change in velocity?

Rune. Yup, Weir got all his fluid dynamics wrong and played fast and loose with fuel requirements. But hey, it's still a very entertaining book.

[Brethern]

Actually, the thing that really bugged me is what they did to get rid of the those last 30m/s... Plus the reason they were off with the launch in the first place. Yeah, the initial sandstorm was very dubious, but needing an aeroshell for liftoff from Mars is just as much a flight of fancy. And, you know, breaking a nuclear-powered manned ion spaceship in the thousand tonne range on a few hundreds of kilograms of compressed air at one bar...

I could accept a parallel-world Mars with a much thicker atmosphere as explaining away most of that, but that "emergency breaking maneuver"... how the hell did they move the humongous spacechip in time to point in the correct way? If they could move it, why the hell didn't they just use the RCS system to effect the change in velocity?

Rune. Yup, Weir got all his fluid dynamics wrong and played fast and loose with fuel requirements. But hey, it's still a very entertaining book.

They did use the RCS to change their velocity, and just accept that in the future a ship can turn allot faster.

[KerikBalm]

Well, that part is simple enough to fix by simply adjusting the numbers.... suppose it was 3m/s instead of 30... (over 100 kph...).... now it seems more reasonable.... and still out of the range of the ion drives.

They were supposed to get the ship... what? 3mm/s/s?

That's 1,000 seconds/>16 minutes to kill relative velocity, then one needs to set up another intercept, and creep towards it... they didn't have time for that.

IIRC, the MAVs entire life support system had been thrown out, and all he had was the EVA suit.

But the sandstorm... well, you can always claim it was a super-sandstorm that was x% stronger than anything yet observed...

I guess its not really good to invoke a lavatube/skylight, since they weren't in the volcanic tharsis region.

Sandstorm to obscure vision + fall into a sinkhole/lavatube = he's lost and they don't know what happened.

Then throw in extra bad luck: meteors predicted to impact in their vicinity -> they GTFO.

Launching the MAV in winds strong enough to tip it over.... dubious.

Feel free to suggest an alternate plot device to get him stranded on mars with supplies.

[SomeGuy12]

Feel free to suggest an alternate plot device to get him stranded on mars with supplies.

It doesn't have to be complicated. A shoddy oxygen tank on the mars ascent vehicle explodes and a piece of the exploding wreckage hits the hab module. That depressurizes it, killing all the astronauts but one. Another piece hits the main radio antenna aimed at earth. Our hero patches the leak in the dome and is now basically in the situation he started in in the books.

[peadar1987]

It doesn't have to be complicated. A shoddy oxygen tank on the mars ascent vehicle explodes and a piece of the exploding wreckage hits the hab module. That depressurizes it, killing all the astronauts but one. Another piece hits the main radio antenna aimed at earth. Our hero patches the leak in the dome and is now basically in the situation he started in in the books.

Only all his friends are dead, ruining the happy ending, Hermes is empty, which means no Rich Purnell manoeuvre, and no qualified pilot on hand to remotely launch the MAV. Food now isn't so much of a problem, because Watney has a ready supply of meat. Each of his friends can feed him for about about 6 weeks to a month, more if he rations himself, so with five of them, he can probably buy an entire year, during which he grows and stockpiles potatoes, and creates a much bigger window for an unrushed resupply probe to reach him.

It turns the whole thing into a very different story.

[Brethern]

It doesn't have to be complicated. A shoddy oxygen tank on the mars ascent vehicle explodes and a piece of the exploding wreckage hits the hab module. That depressurizes it, killing all the astronauts but one. Another piece hits the main radio antenna aimed at earth. Our hero patches the leak in the dome and is now basically in the situation he started in in the books.

So apollo 13 again?

Try again and make it interesting.

[RainDreamer]

The story place more focus on the human vs nature aspects rather than humans do things wrong. NASA has been portrayed as being quite competent in what they do in the book, except for the rushed launch. The plot device that stranded our astronaut has to be something that can't be blamed on human - it has to be an 'act of god'

[-Velocity-]

I found the probability of the Pathfinder's electronics still being operational to the degree they were in the book (essentially, only one thing was broken, IIRC) completely unbelievable. The thing goes through regular cycles of 100+ degrees C- frequently more, and would have been experiencing that about once a day for like 50 years. There's no way in hell that differential CTEs wouldn't have destroyed its electronics (also, it probably have had all its memory destroyed/erased/corrupted, though I'm not sure what kind of memory they used on it).

Of course the opening storm with powerful winds was not believable.

Also, I'm struggling to remember everything here- but there was a scene where he sort of blew up his hab by exhaling too much oxygen into its hydrogen-filled atmosphere from which he had removed the oxygen. IIRC, after that the problem was magically solved, as if all the hydrogen had been burned up. That would only have happened if the oxygen+hydrogen had waited till there was an oxygen excess- but that's unlikely, you can ignite hydrogen and oxygen at far below or above a 2:1 H2 to O2 ratio. Anyway, I think I had another problem with that scene, but I can't remember exactly.

Edited July 5, 2015 by |Velocity|

[SomeGuy12]

So apollo 13 again?

The goal was a realistic event that could result in the same scenario as the book. Since an exploding oxygen tank ruining your day is clearly possible, it meets the realism test.

[Brethern]

The goal was a realistic event that could result in the same scenario as the book. Since an exploding oxygen tank ruining your day is clearly possible, it meets the realism test.

And you have any idea just how badly NASA would have to drop the ball for that to happen again?

The only way that would happen is if a craft as poorly designed as the apollo spacecraft was used.

[peadar1987]

The goal was a realistic event that could result in the same scenario as the book. Since an exploding oxygen tank ruining your day is clearly possible, it meets the realism test.

Except it wouldn't be the same scenario as the book:

Only all his friends are dead, ruining the happy ending, Hermes is empty, which means no Rich Purnell manoeuvre, and no qualified pilot on hand to remotely launch the MAV. Food now isn't so much of a problem, because Watney has a ready supply of meat. Each of his friends can feed him for about about 6 weeks to a month, more if he rations himself, so with five of them, he can probably buy an entire year, during which he grows and stockpiles potatoes, and creates a much bigger window for an unrushed resupply probe to reach him.

It turns the whole thing into a very different story.