I went through a phase in the 1970's and '80's when I adored Paolo Soleri. I was inspired by his vision of mile-high architecture, surrounded by vast swaths of nature. Somewhere along the way, Soleri forgot to explain how these mega-structures were going to obtain their energy.

I thought that the Orion trajectory upon return to Earth, like the Apollo missions, will go straight into re-entry. If there's an extension module:

"Pheromones" are widely suspected to be odorless. They are also the same chemicals from person to person. However, the detectable, conscious odor signature of people does vary from person to person. That scent has been shown to be related to a person's MHC genes, which are important in the immune system. We are…