There have been many women astronauts/cosmonauts in recent history. Have a look at the Women in Technology page. Also visit the NASA Aeronautics History page.
Without women in space, we would have no idea what the impact of the space environment upon female physiology is, and this is a vital set of data for the eventual human colonization/habitation of space. Beyond this unique contribution, we have Astronaut Shannon Lucid's spectacular extended stay in the MIR space station last year. As for the other women astronauts/cosmonauts, they performed just as professionally as did their male counterparts. Most were physicist or astronomer Mission Specialists.