Metro Exodus
68 Achievements
60-80h
GOG
Martian
Patch the Gasmask.
62.0%
How to unlock the Martian achievement in Metro Exodus - Definitive Guide
Shomberlon
TrueAchievements
TrueAchievements
If you miss the chance mentioned in busterfrosty's guide, you can get it out in the open world. If you wear your gasmask in combat, it'll begin to take damage. Eventually, you will see a hole in the glass in the bottom left corner. DO NOT take it to a workbench to fix, instead, wear it in an area that is toxic and requires the mask. You'll be given a prompt to fix the mask. Artyom will place a square of tape over the hole. Once the animation is complete the achievement will unlock.
1 Comment
Just take enough damage for a hole to form in the mask, hit LB. Simple as that.
By JMJimmy on 28 Apr 2021 20:03
DivineHitman047
TrueAchievements
TrueAchievements
For those, such as myself, that jumped right into Ranger Hardcore and dont know how to fix the mask. All you have to do is hit 
just like you would wipe your mask.
just like you would wipe your mask.
1 Comment
would be helpful to include when to do this, pressing LB just wipes the mask
By BLOOdREDkN7GHT on 22 Aug 2019 01:21
busterfrosty
TrueAchievements
TrueAchievements
Not sure if this is a set occurrence but I had gotten it at the end of The “Moscow” Level (1st level) right after I jumped on the 2nd train...you should see a prompt to repair the gas mask
Scotty
While wearing the Gasmask, when taking damage the Gasmask itself will also take damage and a visual of this will be on screen with a crack in the mask/screen. When this appears, if you're not playing on Ranger Hardcore, a message will appear on screen telling you to press 
to repair your mask as you will now be exposed to radioactive elements. Do this to put some sticky tape over the hole, unlocking the achievement.
to repair your mask as you will now be exposed to radioactive elements. Do this to put some sticky tape over the hole, unlocking the achievement.
mikem192
Whilst wearing your Gasmask during battle it will get damaged. Once the Gasmask has taken a certain amount of damage, a hole will appear on the left side of the screen so press 
to patch it.
to patch it.
AHybiS
stratege.ru
stratege.ru
This guide was translated automatically. Show original
during the first shootout we hit a gas mask, pressed 
seal the hole, and we have an achievement.
seal the hole, and we have an achievement.
Griffid3th
stratege.ru
stratege.ru
This guide was translated automatically. Show original
Always walk with a gas mask on (so that your enemies quickly break it), when a hole appears on the left of the screen, click on LB and get the achievement!