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In this scene from the novel, 'The Martian', by Andy Weir, how does Mark Watney store hydrogen made from water in the tank?

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In this scene from the novel, 'The Martian', by Andy Weir, how does Mark Watney store hydrogen made from water in the tank?

How was MAV fuel plant able to make fuel using hydrogen so quickly in the end?How can Watney get so much hydrogen in the air?Does the Hermes aerobrake in Andy Weir's “The Martian”?Why does Mark Watney stop doing this in the garden?How did Mark Watney manufacture oxygen in The Martian?How does the oxygenator in The Martian split CO2 to make O2?Why did Mark Watney continuously create water in The Martian?The Martian - How were the ARESIII crew expected to get from Hermes to earth?In The Martian, how were the crew in the Hermes shielded from radiation?Why didn't Mark Watney lose all of his water when the hab exploded?

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This is the scene from chapter 25, where Watney describes how he had produced and stored hydrogen, which he produced by electrolysing water.

I need clarification of the bold part.

LOG ENTRY: SOL 529

I’m turning water into rocket fuel.

It’s easier than you’d think.

Separating hydrogen and oxygen only requires a couple of electrodes and some current. The problem is collecting the hydrogen. I don’t have any equipment for pulling hydrogen out of the air. The atmospheric regulator doesn’t even know how. The last time I had to get hydrogen out of the air (back when I turned the Hab into a bomb) I burned it to turn it into water. Obviously that would be counterproductive.

But NASA thought everything through and gave me a process. First, I disconnected the rover and trailer from each other. Then, while wearing my EVA suit, I depressurized the trailer and back-filled it with pure oxygen at one-fourth of an atmosphere. Then I opened a plastic box full of water and put a couple of electrodes in. That’s why I needed the atmosphere. Without it, the water would just boil immediately and I’d be hanging around in a steamy atmosphere.

The electrolysis separated the hydrogen and oxygen from each other. Now the trailer was full of even more oxygen and also hydrogen. Pretty dangerous, actually.

Then I fired up the atmospheric regulator. I know I just said it doesn’t recognize hydrogen, but it does know how to yank oxygen out of the air. I broke all the safeties and set it to pull 100 percent of the oxygen out. After it was done, all that was left in the trailer was hydrogen. That’s why I started out with an atmosphere of pure oxygen, so the regulator could separate it later.

Then I cycled the rover’s airlock with the inner door open. The airlock thought it was evacuating itself, but it was actually evacuating the whole trailer. The air was stored in the airlock’s holding tank. And there you have it, a tank of pure hydrogen.

According to my understanding, Watney is inside the trailer in an atmosphere of pure hydrogen. How, then, did he cycle the rover's airlock?

Which is the inner door he is talking about?

the-martian

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edited 8 hours ago

TheLethalCarrot

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2

1

This is the scene from chapter 25, where Watney describes how he had produced and stored hydrogen, which he produced by electrolysing water.

I need clarification of the bold part.

LOG ENTRY: SOL 529

I’m turning water into rocket fuel.

It’s easier than you’d think.

Separating hydrogen and oxygen only requires a couple of electrodes and some current. The problem is collecting the hydrogen. I don’t have any equipment for pulling hydrogen out of the air. The atmospheric regulator doesn’t even know how. The last time I had to get hydrogen out of the air (back when I turned the Hab into a bomb) I burned it to turn it into water. Obviously that would be counterproductive.

But NASA thought everything through and gave me a process. First, I disconnected the rover and trailer from each other. Then, while wearing my EVA suit, I depressurized the trailer and back-filled it with pure oxygen at one-fourth of an atmosphere. Then I opened a plastic box full of water and put a couple of electrodes in. That’s why I needed the atmosphere. Without it, the water would just boil immediately and I’d be hanging around in a steamy atmosphere.

The electrolysis separated the hydrogen and oxygen from each other. Now the trailer was full of even more oxygen and also hydrogen. Pretty dangerous, actually.

Then I fired up the atmospheric regulator. I know I just said it doesn’t recognize hydrogen, but it does know how to yank oxygen out of the air. I broke all the safeties and set it to pull 100 percent of the oxygen out. After it was done, all that was left in the trailer was hydrogen. That’s why I started out with an atmosphere of pure oxygen, so the regulator could separate it later.

Then I cycled the rover’s airlock with the inner door open. The airlock thought it was evacuating itself, but it was actually evacuating the whole trailer. The air was stored in the airlock’s holding tank. And there you have it, a tank of pure hydrogen.

According to my understanding, Watney is inside the trailer in an atmosphere of pure hydrogen. How, then, did he cycle the rover's airlock?

Which is the inner door he is talking about?

the-martian

share|improve this question

edited 8 hours ago

TheLethalCarrot

80.7k3333 gold badges518518 silver badges555555 bronze badges

asked 9 hours ago

KshitijKshitij

1111 bronze badge

New contributor

Kshitij is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment
 | 

This is the scene from chapter 25, where Watney describes how he had produced and stored hydrogen, which he produced by electrolysing water.

I need clarification of the bold part.

LOG ENTRY: SOL 529

I’m turning water into rocket fuel.

It’s easier than you’d think.

Separating hydrogen and oxygen only requires a couple of electrodes and some current. The problem is collecting the hydrogen. I don’t have any equipment for pulling hydrogen out of the air. The atmospheric regulator doesn’t even know how. The last time I had to get hydrogen out of the air (back when I turned the Hab into a bomb) I burned it to turn it into water. Obviously that would be counterproductive.

But NASA thought everything through and gave me a process. First, I disconnected the rover and trailer from each other. Then, while wearing my EVA suit, I depressurized the trailer and back-filled it with pure oxygen at one-fourth of an atmosphere. Then I opened a plastic box full of water and put a couple of electrodes in. That’s why I needed the atmosphere. Without it, the water would just boil immediately and I’d be hanging around in a steamy atmosphere.

The electrolysis separated the hydrogen and oxygen from each other. Now the trailer was full of even more oxygen and also hydrogen. Pretty dangerous, actually.

Then I fired up the atmospheric regulator. I know I just said it doesn’t recognize hydrogen, but it does know how to yank oxygen out of the air. I broke all the safeties and set it to pull 100 percent of the oxygen out. After it was done, all that was left in the trailer was hydrogen. That’s why I started out with an atmosphere of pure oxygen, so the regulator could separate it later.

Then I cycled the rover’s airlock with the inner door open. The airlock thought it was evacuating itself, but it was actually evacuating the whole trailer. The air was stored in the airlock’s holding tank. And there you have it, a tank of pure hydrogen.

According to my understanding, Watney is inside the trailer in an atmosphere of pure hydrogen. How, then, did he cycle the rover's airlock?

Which is the inner door he is talking about?

the-martian

share|improve this question

edited 8 hours ago

TheLethalCarrot

80.7k3333 gold badges518518 silver badges555555 bronze badges

asked 9 hours ago

KshitijKshitij

1111 bronze badge

New contributor

Kshitij is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 8 hours ago

TheLethalCarrot

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asked 9 hours ago

KshitijKshitij

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Kshitij is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited 8 hours ago

TheLethalCarrot

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asked 9 hours ago

KshitijKshitij

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New contributor

Kshitij is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited 8 hours ago

TheLethalCarrot

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edited 8 hours ago

TheLethalCarrot

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asked 9 hours ago

KshitijKshitij

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asked 9 hours ago

KshitijKshitij

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1 Answer
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An airlock has an inner door and an outer door. The normal procedure is that you enter the airlock, close the inner door, depressurize the airlock chamber, open the outer and exit into vacuum. Same thing as in a submarine, except with vacuum instead of water.

Luckily for Watney, in the rover the pumps normally move air to a holding tank instead of the interior of the vehicle. So, when the airlock is full of hydrogen, he can pump it to the holding tank. When he does it with the inner door open, it pumps the whole atmosphere in the rover into the holding tank.

Note on language: 'Cycle' here means 'automated sequence of operations'. In a washing machine you have a rinse cycle, which means alternately filling with cold water then spinning a few times.

share|improve this answer

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the answer. But I understand what an airlock and an airlock's cycle is. My actual doubt is how could Watney operate the rover's airlock when he was inside the trailer? And does the inner door he refers to belong to the trailer's airlock, or to the rover's airlock? For the present I have assumed that there is a misprint in the novel, as that seems most likely. The correct version should be, "Then I cycled the trailer's airlock...". That would explain everything. But am I somehow wrong in assuming that it's a misprint?
  
  – Kshitij
  4 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kshitij I see what you mean now. Yes, looks like a typo.
  
  – richardb
  4 hours ago
  

  
  
  
  

add a comment
 | 

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3

An airlock has an inner door and an outer door. The normal procedure is that you enter the airlock, close the inner door, depressurize the airlock chamber, open the outer and exit into vacuum. Same thing as in a submarine, except with vacuum instead of water.

Luckily for Watney, in the rover the pumps normally move air to a holding tank instead of the interior of the vehicle. So, when the airlock is full of hydrogen, he can pump it to the holding tank. When he does it with the inner door open, it pumps the whole atmosphere in the rover into the holding tank.

Note on language: 'Cycle' here means 'automated sequence of operations'. In a washing machine you have a rinse cycle, which means alternately filling with cold water then spinning a few times.

share|improve this answer

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the answer. But I understand what an airlock and an airlock's cycle is. My actual doubt is how could Watney operate the rover's airlock when he was inside the trailer? And does the inner door he refers to belong to the trailer's airlock, or to the rover's airlock? For the present I have assumed that there is a misprint in the novel, as that seems most likely. The correct version should be, "Then I cycled the trailer's airlock...". That would explain everything. But am I somehow wrong in assuming that it's a misprint?
  
  – Kshitij
  4 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kshitij I see what you mean now. Yes, looks like a typo.
  
  – richardb
  4 hours ago
  

  
  
  
  

add a comment
 | 

3

An airlock has an inner door and an outer door. The normal procedure is that you enter the airlock, close the inner door, depressurize the airlock chamber, open the outer and exit into vacuum. Same thing as in a submarine, except with vacuum instead of water.

Luckily for Watney, in the rover the pumps normally move air to a holding tank instead of the interior of the vehicle. So, when the airlock is full of hydrogen, he can pump it to the holding tank. When he does it with the inner door open, it pumps the whole atmosphere in the rover into the holding tank.

Note on language: 'Cycle' here means 'automated sequence of operations'. In a washing machine you have a rinse cycle, which means alternately filling with cold water then spinning a few times.

share|improve this answer

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the answer. But I understand what an airlock and an airlock's cycle is. My actual doubt is how could Watney operate the rover's airlock when he was inside the trailer? And does the inner door he refers to belong to the trailer's airlock, or to the rover's airlock? For the present I have assumed that there is a misprint in the novel, as that seems most likely. The correct version should be, "Then I cycled the trailer's airlock...". That would explain everything. But am I somehow wrong in assuming that it's a misprint?
  
  – Kshitij
  4 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kshitij I see what you mean now. Yes, looks like a typo.
  
  – richardb
  4 hours ago
  

  
  
  
  

add a comment
 | 

An airlock has an inner door and an outer door. The normal procedure is that you enter the airlock, close the inner door, depressurize the airlock chamber, open the outer and exit into vacuum. Same thing as in a submarine, except with vacuum instead of water.

Luckily for Watney, in the rover the pumps normally move air to a holding tank instead of the interior of the vehicle. So, when the airlock is full of hydrogen, he can pump it to the holding tank. When he does it with the inner door open, it pumps the whole atmosphere in the rover into the holding tank.

Note on language: 'Cycle' here means 'automated sequence of operations'. In a washing machine you have a rinse cycle, which means alternately filling with cold water then spinning a few times.

share|improve this answer

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

share|improve this answer

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges

answered 5 hours ago

richardbrichardb

47733 silver badges77 bronze badges