Karen LuJean Nyberg (born October 7, 1969) is an American mechanical engineer and NASA astronaut. Nyberg became the 50th woman in space on her first mission in 2008. Nyberg started her space career in 1991 and spent a total of 180 days in space in 2008 and 2013 (as a Mission Specialist on STS-124 and a Flight Engineer on Soyuz TMA-09M).