Soyuz launch vehicle umbilical towers

• Soyuz launch vehicle umbilical towers by pr1268 on 09 Apr, 2008 20:36
• What is the function/purpose of each of the umbilical towers connected to the Soyuz launch vehicle prior to launch?  Why two towers?  Thanks!
• #1 by edkyle99 on 09 Apr, 2008 21:13
• Quote

  pr1268 - 9/4/2008  3:36 PM
  
  What is the function/purpose of each of the umbilical towers connected to the Soyuz launch vehicle prior to launch?  Why two towers?  Thanks!

  
  The following links provide an interesting overview of the R-7 launch sites.
  
  http://suzymchale.com/kosmonavtka/rocklaunch.html
  http://suzymchale.com/kosmonavtka/images/r7launchpad.jpg
  
  The sites were originally designed to launch R-7 ICBM's, so they were designed to quickly handle an already horizontally-processed missile.  That helps explain the "why".  As for the "how", I seem to remember that one of the final two "tall" umbilical towers was called a "fueling mast" in some reports.  The komonavtka article only mentions that the masts provide power, fuel, pneumatics, gases, etc. (presumably to the upper stage and spacecraft).
  
   - Ed Kyle
• #2 by meiza on 09 Apr, 2008 23:19
• Umm, crew access?
• #3 by Mark Dave on 10 Apr, 2008 00:10
• Yep, the R7 pad diagram doesn't have the two large access gantries  for crew to enter the Soyuz.  
  
  
• #4 by pr1268 on 10 Apr, 2008 01:54
• Quote

  meiza - 9/4/2008  6:19 PM
  
  Umm, crew access?

  
  You mean the cosmonauts don't strap in when the LV is still horizontal, two days before launch, and ride to the launch pad on the railcar?
  
  (Just kidding - I'm laughing at my own stupidity for not noticing the absence of a conning tower in the recent TMA-12 launch video.)