Q about suit cooling and endurance.

[kelvinzero]

<p>I read somewhere that the apollo suits expended water for cooling.</p><p>Did they actually release it into space? Is there an alternative that could allow longer durations or is it pretty much&nbsp;a fact of thermodynamics? If you do need to expend something, could we substitute oxygen for water since at least we can theoretically produce that from luna materials?</p>

 

[docm]

<p>NASA guys correct me if I'm wrong, but IIRC&nbsp;the A7L suit used a closed circuit water cooling unit in the form of long-johns with plastic pipes running through it.&nbsp; The heat was exchanged in the back packs Primary Life Support System&nbsp;where the heat&nbsp;was extracted,&nbsp;radiated to space then the water&nbsp;recirculated.&nbsp; </p><p>I don't think it was discharged, otherwise we'd have seen vapor all around the guys during their moon walks.</p> <div class="Discussion_UserSignature"> </div>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>NASA guys correct me if I'm wrong, but IIRC&nbsp;the A7L suit used a closed circuit water cooling unit in the form of long-johns with plastic pipes running through it.&nbsp; The heat was exchanged in the back packs Primary Life Support System&nbsp;where the heat&nbsp;was extracted,&nbsp;radiated to space then the water&nbsp;recirculated.&nbsp; I don't think it was discharged, otherwise we'd have seen vapor all around the guys during their moon walks. <br /> Posted by docm</DIV></p><p>Water is expended in all EVA suits, lunar, shuttle and Russian.&nbsp; It goes thru a subliminator to provide the cooling. &nbsp;&nbsp;</p>

 

[docm]

But is the water that carries the&nbsp;heat away from the sublimator the same as that in the cooling tubes or is it from a separate system? IOW is the sublimator plate porus and "charged" with water separate from the water in the cooling tubes?&nbsp; <div class="Discussion_UserSignature"> </div>

 

[Lancer525]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>NASA guys correct me if I'm wrong, but IIRC&nbsp;the A7L suit used a closed circuit water cooling unit in the form of long-johns with plastic pipes running through it.&nbsp; The heat was exchanged in the back packs Primary Life Support System&nbsp;where the heat&nbsp;was extracted,&nbsp;radiated to space then the water&nbsp;recirculated.&nbsp; I don't think it was discharged, otherwise we'd have seen vapor all around the guys during their moon walks. <br /> Posted by docm</DIV></p><p>&nbsp;But I have seen a photo of one of the guys on the moon with a cloud of vapor around him. It looked like a halo. I've been looking for that photo for years, but can't find it again. I know I've seen it, and it's from 15, 16, or 17.&nbsp; </p><p>Anyone?&nbsp;</p>