June Lockhart (R) and Angela Cartwright in a scene from Lost in Space.

JUNE LOCKHART, who became the archetypal TV mom of the 1950s and 1960s with her roles on the campy sci-fi series Lost in Space and alongside a collie and a little boy on the family drama Lassie, died this week at age 100, her family announced on Saturday.

She died of natural causes at her home in Santa Monica, California, according to a spokesperson for the family.

Ms. Lockhart portrayed planet-hopping mom Maureen Robinson on producer Irwin Allen鈥檚 Lost in Space, which ran from 1965 to 1968 and was later very popular in syndication. From 1958 through 1964 she had played Ruth Martin, the mother of the young main character Timmy, on Lassie.

Lost in Space, which aired in the years leading to the first moon landing in 1969, adapted the castaway novel The Swiss Family Robinson to a space theme: a family is sent from Earth to colonize a distant planet but a stowaway sends the craft wildly off course.

Clad in a silvery space suit, Ms. Lockhart played the wife of the mission leader, portrayed by Guy Williams, whose three children, played by Billy Mumy, Angela Cartwright, and Marta Kristen, join in the journey.

The series started as a serious foray into science fiction but became sillier in the second and third seasons as it focused on Mumy鈥檚 youthful Will Robinson, buffoonish stowaway Dr. Smith (Jonathan Harris), and the show鈥檚 popular robot. At the first hint of trouble, the robot would exclaim, 鈥淒anger, Will Robinson!鈥

Ms. Lockhart fondly remembered the goofy 1968 episode titled 鈥淭he Great Vegetable Rebellion鈥 featuring a villainous carrot that plotted to turn the family into plants.

鈥淭he 鈥榁egetable Rebellion鈥 is definitely my favorite because we laughed so very hard through all of the shooting,鈥 Ms. Lockhart told the Chicago Sun-Times in 2004. 鈥淚n fact, Guy and I laughed so much and so often that we had to do take after take, which did not sit well with Irwin. So as punishment he wrote us out of the next two episodes. We got paid but we weren鈥檛 in them.鈥

Ms. Lockhart was born in New York on June 25, 1925. Her parents were actors 鈥 her father Gene Lockhart is best remembered as the judge in the 1947 holiday classic Miracle on 34th Street 鈥 and she made her film debut at age 12 alongside them in a 1938 version of A Christmas Carol.

As a young actor, she played supporting roles in major films including the 1944 Judy Garland movie Meet Me in St. Louis, one of the leading musicals of that decade, and starring roles in B movies like She-Wolf of London (1946).

She won a Tony Award in 1948 for her performance in the Broadway play For Love or Money and later was twice nominated for Emmy awards.

TIMMY鈥橲 MOTHER
Ms. Lockhart replaced Cloris Leachman as the adoptive mother of Timmy, played by Jon Provost, in the fifth season of the long-running series Lassie.

After Lost in Space, she played a doctor for the final two seasons of the sitcom Petticoat Junction and had a recurring role on the soap opera General Hospital.

Ms. Lockhart also had a small role in the 1998 big-budget film version of Lost in Space.

Ms. Lockhart, a space aficionado who attended NASA space shuttle launches, learned that despite all the rubbery monsters and far-fetched plot lines, Lost in Space inspired future astronauts.

鈥淚 spend a lot of time at NASA with the astronauts,鈥 she told the New Jersey newspaper The Record in 2002, 鈥渁nd to a man, or woman, they say that watching Lost in Space made them know what they wanted to do when they grew up. So when I鈥檓 down there, of course, they treat me like a duchess. It鈥檚 wonderful.鈥

After appearing on a quiz show in the 1950s with members of the White House press corps, she was given an open invitation to attend White House press briefings, and for many years did so.

During former actor Ronald Reagan鈥檚 presidency, she said he confessed to her his regret about a scene he played in a 1942 movie with her father in which Mr. Reagan鈥檚 character smashed a tomato filled with chocolate sauce into Gene Lockhart鈥檚 face.

鈥淭he president told me, 鈥業 felt bad I had to do that to your father because the idea of chocolate sauce and tomato sauce together is repulsive,鈥欌 she told the Chicago Tribune in 1987.

Ms. Lockhart married twice, with both marriages ending in divorce. 鈥 Reuters