Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will:

According to Newton's Law of Universal Gravitation, every mass attracts every other mass with a force
$$F=G\frac{m_1{m}_2}{r^2}$$
. Even in "gravity-free" space (relative to a planet), the mutual gravitational attraction between the two astronauts will pull them toward each other.