These are the free-standing versions of the Saturn and Shuttle Launch Bases. They have a starting mass of 1t to allow them to be transported
by a wheeled or tracked vehicle. After positioning them on the launch pad, the mass can be switched to 2000t to keep them on the ground
when a powerful rocket's engines are started.  Driving a vehicle into physics range sometimes can cause a massive explosion to happen, as KSP
can be glitchy with large craft sitting on the pad or ground without a launch clamp holding them.

To use these versions, copy the two .mu files and the two .cfg files in the Extras/Saturn-Shuttle_Freestanding_Base 
into the ModularLaunchPads/Saturn_Shuttle folder.