In the early 80s, CIA assigned an agent to investigate 'The Gateway Experience', Robert Monroe's program dedicated to explore and expand human consciousness, moving it outside the physical sphere so as to ultimately escape even the restrictions of time and space.

The program is a training system designed to bring enhanced strength, focus and coherence by synchronizing, at the same frequency, cerebral electrical waves between the left/right hemispheres of the brain. Some techniques learned: OBE, astral travel, remote viewing, self-healing.

After 20 years and millions invested in secrecy, CIA stated at the end of the program that "it works, but it is not reliable enough to finance".
Monroe's program still available to be purchased/downloaded online.

It has a lot of content, brings a new perspective and interesting techniques. Maybe I'll post more on another day to not overload information here.