[Atlas V] Centaur upper stage question

• [Atlas V] Centaur upper stage question by Kartoffelkuchen on 02 Jan, 2015 11:28
• Hi, I have a question regarding the Centaur upper stage of the Atlas V. On some images, you can see those, with a blue-green plane covered "bottles", on the bottom on the stage, near the engine. And on some images not. My question now is, what are those things? Are they removed before flight or why can't you see them sometimes? Or show the images different versions?
  http://www.capcomespace.net/dossiers/espace_US/lanceurs_US/atlas/ac203%20centaur%20SEC.jpg
  http://upload.wikimedia.org/wikipedia/commons/4/48/Centaur_upper_stage_lifted_up_to_put_on_the_first_stage_of_the_Atlas_V.jpg
  
  Thanks for help!
  
• #1 by Jim on 02 Jan, 2015 12:56
• They are helium and hydrazine bottles.  They have protective covers on them, that will be removed after the mate is completed.
  
  The one with 203 on it is actually an Atlas III Centaur.   One bottle for hydrazine and two for helium.
  The long tank on the Atlas V Centaur was just a larger helium.  It is for consolidating smaller bottles.  There still is/are bottle(s) on the other side.
• #2 by Kartoffelkuchen on 02 Jan, 2015 13:12
• Thanks Jim, that was what I wanted to know!