T
themanwithoutapast
Guest
I am aware that the ISS assembly sequence requires 4 ISS Truss segments to be launched BEFORE the actual launch of Node2, Columbus and Kibo.<br /><br />But just theoretically, although it has been put forward so many times that the above mentioned ISS modules can only be launched by the Shuttle, I just do not see a compelling reason for this. <br /><br />If we look at the Columbus module for instance, its mass when empty is 11 metric tons (and it is planned to have 9 tons additional equipment on board when launched). Its largest diameter is 4.4m. Now, to be clear, although it was built to be launched with the Space Shuttle, it is still in size and shape "just another ISS module" not different than Zarya or Zvezda that were both launched by a Proton. Thus equipped with a thruster for maneuvering and docking to the ISS, I am curious what the real obstacle for it being launched by an Ariane 5 or a Proton are. Am I missing something here?<br /><br />So if for some reason STS missions are reduced, how could it be practically done to launch Columbus, Kibo and beforehand Node2 (as well as maybe the Truss modules) by other launchcrafts (Ariane, Proton, Atlas)? And if possible to do part of the ISS assembly this way, could it not be that it would even be cheaper to finish up the ISS this way, rather than by Shuttle flights?<br /><br />