I remember only the last patr of this movie. There are some scientists (maybe astronauts) from different nations (maybe USA and URSS) that only at the end of the movie decide to work together instead against each other (as I think was asked by their respective leaders).
At the end of the movie there are their shoulder flags on the ground, in the sand.
This could be from 1990 to 2000, more or less.
I'm sure this is not "2010", "Red Planet", nor "Mission to Mars".