The former Jordanthorpe Comprehensive pupil was selected for the space mission after responding to a radio advertisement asking for applicants to be the first British astronaut.
She was selected ahead of 13,000 other applicants and the announcement was made live on ITV on November 25 1989.
Before flying, Sharman spent 18 months in intensive flight training in Star City.
The Soyuz TM-12 mission, which included Soviet cosmonauts Anatoly Artsebarsky and Sergei Krikalev, lasted eight days, most of that time spent at the Mir space station.
Sharman's tasks included medical and agricultural tests, photographing the British Isles, and participating in an unlicenced amateur radio hookup with British schoolchildren.
She was just 27 years and 11 months old when she went into space, making her (as of 2015) the sixth youngest of the 545 individuals who have flown in space.
Sharman has not returned to space, although she was one of three British candidates in the 1992 European Space Agency astronaut selection process and was on the shortlist of 25 applicants in 1998.
The 52-year-old spent the eight years following her mission to Mir self-employed, communicating science to the public.
Her autobiography, 'Seize the Moment', was published in 1993.
In 1997 she published a children's book, 'The Space Place'
She has presented radio and television programmes including for BBC Schools.
By 2011, she was working at the National Physical Laboratory as Group Leader of the Surface and Nanoanalysis Group.
Sharman became Operations Manager for the Department of Chemistry at Imperial College London in 2015. She still does outreach activities related to chemistry and her spaceflight, and was recently awarded an Honorary Fellowship from the British Science Association.
Today ( December 15 2015) Tim Peake becomes the first British astronaut to board the International Space Station.
For live updates on his mission - which launches at 11am today - click the link below.