This is not an addon but it is a pic of addon l am working on
the name is Earth Explorer Hydrogen Tanker
More about this spacecraft
it is used to refill the EE1 (Earth Explorer 1) my largest spacecraft design yet to be made in to an addon.
you dip it into a gas giant and colect a mass of Hydrogen and then you fire the Hydrogen into the reactor of the spacecraft.
SIZE. try greenland.
IÂ am planing to reless it next month