From what I've read, back in the days when Josef Stalin was still dictator of the Soviet Union it was a crime to engage in mysticism. This was harsh for a country with mystical traditions reaching backwards for millenia. Stalin considered the seminary back in the days before he was a bank robber and then dictator. Russian scientists who had always had an aggressive interest in mysticism were encouraged in their research if they used strictly scientific methods. Psychic research advanced further, because of communism and Stalin, than it did anywhere except possibly Tibet and China.
Their name for the astral body was the Bioplasmic Body and some of their leading scientists researched it constantly. They said it was like an obedient superman. It was never born and it would never die. It can travel beyond light-speed into the speed of thought. It is indestructible and knows everything yet it will do anything it's owner asks. It's the ESP body. A 500 page technical manual was written about it's properties. For instance, it's 3/4 of an ounce and it leaves the physical body at the moment of death.
References:
Sheila Ostrander and Lynn Schroeder
Psychic Discoveries Behind the Iron Curtain,
Englewood Cliffs, New Jersey:
Prentice Hall, 1970.