That was over 22 years ago in 1999.
Today she is 71, and has starred in 94 movies in total, 61 since Galaxy Quest was released.
In Galaxy Quest, I think Sigourney Weaver looks:
Galaxy Quest scores 6.9 out of 10 on The Movie Database.
Sigourney Weaver's first acting role was as 'Alvy's Date Outside Theatre' in Annie Hall, released in 1977 when she was 27.