The existence of dark matter has been proven. The big question is what does it consist of? Is it formed by the same elements than the bright light reflecting one? How can we obtain a sample of it? Can dark matter constitute a risk for space travel and exploration?
These questions will puzzle astronomers and scientists until a sample of  dark matter is obtained #### in a laboratory on Earth.

Other questions rising about dark matter are whether it may constitue planets, satellites or other cosmic objects and whether it is subject to gravity and gravitation.

That much for dark matter.

As to the dark force, based in Newton's principle of action and reaction, this could  (theoretically) be the counterforce of gravitation that in some way is overcomming and prevailing over gravitation, possibly influenced by dark matter.

These are personnal ideas based on astrophysics and astronomy