On Oct. 12, 1964, the Soviet Union launched Voskhod 1, a 24-hour crewed mission that achieved several "firsts" for human spaceflight. On Oct. 12, 1964, the Soviet Union launched Voskhod 1, a 24-hour ...

Sudoku is a number-based puzzle game. The aim is to fill the 9×9 square grid using all of the numbers one to nine only once in each row and column, and within each of the smaller 3×3 grids. Players ...