Hi I am new and did not see a thread that dealt with this topic specifically, sorry if I overlooked it.
It seems like space exploration beyond NEO, possibly Mars, but definitely the Moon and other near earth objects could be done easily by combining resources and even using heavy lift vehicles currently in service. How difficult or inefficient would it be to to create a permanent/reusable, large capsule that could be sent to objects and returned to NEO to be refurbished and resupplied for a new trip? The vehicle could be assembled in space, like the ISS. The additional missions would then only require smaller Vehicles to ferry supplies and crew.
Even if you don't man rate the Delta Heavy, you would not have to send the crew up on a rocket that large.