Birgit Annalisa Rusanen, later known as Marta Kristen, was born on February 26, 1945, in Oslo, Norway, to a Finnish mother and a German soldier who was killed during World War II.
Marta was only two months old when she was left in an orphanage, and in 1949, Dr. and Mrs. Harold Soderquist of Detroit, Michigan adopted her and brought her to America, renaming her Martha Soderquist.
In 1959, the family moved to Los Angeles, and Marta attended Santa Monica High School for a year before graduating from Hollywood Professional School.
Producer/director James B. Harris discovered Marta and arranged for her to get an agent, leading to her booking for TV programs such as Alfred Hitchcock Presents and The Loretta Young Show.
In 1963, Marta met a graduate student and married him six months later, and her career took off, with her most notable role being "Judy Robinson" in Lost in Space.
However, the show did not meet expectations, and Marta later reflected on the experience, saying, "The show had so much promise. When it started to be silly, we all began to look at each other and say, 'We're in an episode with talking vegetables?' Five years of the Actors Studio, and I'm doing this?"
Offscreen, Marta tried to find her roots, and it wasn't until 1969, when she was pregnant with her first child and traveling alone through Europe, that she was able to find her biological mother in Finland and meet her older sister for the first time.
Marta returned to the USA and gave birth to her daughter Laura, and she concentrated on raising her daughter, appearing in over 40 TV commercials instead of pursuing television or film roles.
Marta and her first husband divorced in 1973, and she met Kevin Kane, an attorney, in 1974, marrying him until his death in 2016.
Marta has remained moderately active in TV and movies, even appearing in the big-screen version of Lost in Space in 1998, and she discovered more family members in 1997, including a younger brother in Australia and a sister in Finland.
Throughout her life, Marta has prioritized her family, and in an interview, she revealed that she was "co-parenting my daughter's child, Lena. I used to do a lot of theater and traveled a lot. But those things are out of the picture for the next couple of years".
