Two parts with configurable diameter/height.
One part for 'Common Bulkhead' style upper-stages (Centaur, S-II, S-IVB)
One part for 'Split Tank' style upper stages (ICPS, HUS, EUS)

Features:

• Configurable tank geometry
  • Select the tank height
  • Select the intertank geometry
  • Select the mount geometry
• Includes RCS for attitude control / ullage, placement varies with mount
• Includes fuel-cell energy converters for a low-tech energy generation option
• Includes secondary top node for attaching other parts with procedural fairings (e.g. SC-B-SM), or payload fairing adapters (NYI)
• Allow swapping of fuel types

TODO:

• Need to add mount definitions to existing engine clusters