Karen LuJean Nyberg (born October 7, 1969) is an American mechanical engineer and retired NASA astronaut.

[2] Nyberg graduated summa cum laude with a bachelor's degree in mechanical engineering from the University of North Dakota in 1994.

After two years of training and evaluation she qualified as a mission specialist and was assigned for technical duties in the Astronaut Office Station Operations Branch.

In July 2006, Nyberg took part in NEEMO 10, a deep-sea training and simulation exercise at the Aquarius underwater laboratory to help NASA prepare for the return of astronauts to the Moon and crewed missions to Mars.

On the 50th anniversary on June 16, 2013, of Vostok 6, the first spaceshot by a woman, Valentina Tereshkova, Nyberg was one of only two women then in space, the other being Chinese astronaut Wang Yaping aboard the Tiangong-1 on the Shenzhou 10 mission.

[9] Stuffed animals are often taken to space, for sentimental purposes but also because they are good zero-gravity indicators: they start to float when entering the orbit.

Her recreational interests include running, sewing, drawing and painting, backpacking, piano, and spending time with her family.