An astronaut in a rocket...?

Question

An astronaut in a rocket moving at 0.4c toward the Sun finds himself halfway between Earth and the Sun. According to the astronaut, how far is he from Earth? In the frame of the Sun, the distance from Earth to the Sun is 1.5 1011 m.

Answer 1

√(1 - 0.4^2) = √(1 - 0.16) = √0.84
If he is indeed halfway he should observe
(7.5*10^10)/√0.84 =
81,831,708,838 m from Earth
(7.5*10^10)√0.84 =
68,738,635,424 m from the Sun

On the other hand if he perceives himself to be halfway, the above numbers would be reversed. Note, however, that in either case, the above numbers sum to 150,570,344,262 m. This discrepancy between observed and known actual distances should enable the astronaut to calculate his true position.