Marta Kristen

Kristen was born Birgit Annalisa Rusanen in Oslo, Norway, to a Finnish mother and a German soldier father who was killed during World War II. She spent her first years in an orphanage in Norway, and then was adopted in 1949 by an American couple from Detroit, Michigan, Harold Oliver Soderquist and Bertha, and renamed her Martha Annalise Soderquist. Her foster father was a of Professor of Education, at Wayne University, Detroit, Michigan. Marta also has an adopted brother which her foster parents adopted later.

Later, she moved to Los Angeles, California, with her family in 1959 when her father was on a sabbatical Marta remained there, with a guardian and is graduate of Santa Monica High School.

Knowing her Scandinavian heritage she adopted the more European sounded, "Marta" and used Marta Kristen as her stage name. She first appeared in a 1961 episode ("Bang! You're Dead") of Alfred Hitchcock Presents, alongside Billy Mumy, who would later co-star with Kristen in Lost in Space. Her first success in acting was the role of Lorelei in the 1965 movie Beach Blanket Bingo. She would later star in Lost in Space and make numerous guest appearances on television shows. When her daughter was born in 1969 she began making television commercials and eventually appeared in more than 40. She also made the occasional film appearance in movies such as Terminal Island (1973) and the cult science fiction film Battle Beyond the Stars (1980). In recent years she has starred in the 1998 television movie Lost in Space Forever and had a cameo role in the 1998 movie Lost in Space. She also appeared in the A&E Biography Jonathan Harris, Never Fear Smith Is Here in 2002. Kristen also provided voice work for the 2009 animated theatrical short The Bolt Who Screwed Christmas which also included voice work from her Lost in Space co-stars Harris, Mumy and Angela Cartwright.

Kristen's personal life has revolved around discovering her roots, caring for her daughter, and now caring for her granddaughter. On a trip to Finland in 1969, while still pregnant to her daughter Lora, she located her birth mother, Helmi Rusanen, and an older half-sister; and in 1997 she discovered a brother residing in Australia.

Kristen was married twice. Her first marriage was to Terry Treadwell, a psychologist, between 1964-1973, with whom had a daughter named Lora Alison Treadwell. She met her second husband, Kevin Kane, in 1974 and married in 18 November 1978. She and her husband lived in Santa Monica, California, with a pair of rescue dogs.

On May, 2016 announced on her Facebook page, that her husband Kevin Kane had died due to cancer.