History of Solar System formation and evolution hypotheses (we've known, of course, since 1965, that it doesn't), very slow, accelerated, and finally, daily rotation. He explained the differences between inner and outer planets and inner and outer moons through vortex behaviour. Mercury's eccentric orbit was explained by its recent expulsion from the Sun and Venus' slow rotation as its being in the "slow rotation phase", having been expelled second to last. The Tom Van Flandern model was first proposed in 1993 in the first edition of his book. In the revised version from 1999 and later, the original Solar System had 6 pairs of twin planets each fissioned
Venus Atmospheric Maneuverable Platform of a lenticular shape which would significantly simplify packing, deployment sequence and structural mass, but it would not cruise so efficiently. The vehicle concept was also presented in May 2017 as a proof-of-concept for exploration of other planets and moons of the Solar System with an atmosphere. The 2013 preliminary concept envisions a suite of instruments NASA calls the 'Venus Flagship Design Reference Mission' for a balloon. Its mass is estimated at 20 kg and would require 50 W of electrical power to operate. The notional intuments consist on: There are ongoing discussions about possible NASA participation in Russia's Venera-D