The museum has been given a Pounds 15 million grant by the Wellcome Trust, and is so optimistic about receiving a further Pounds 24.5m of National Lottery money that an architect is to be appointed within a month.
The plan for the wing, which will be completed by 1999, was revealed at the Association for Science Education's annual meeting at the University of Reading last Saturday by its new honorary president, Sir Neil Cossons, director of the Science Museum.
He told the conference he wanted the new "Wellcome Wing" to serve science educators and that he wanted their views.
The intention is to always keep the new wing as up-to-date as possible. It will also have an IMAX theatre, where an extra-wide and deep screen seems to envelop viewers in sound and images, which will show science films. It will have permanent and temporary exhibitions, and the first areas to be developed will deal with biomedical and IT material.
Sir Neil told The TES he was "very hopeful" of the lottery cash, and believed the endorsement and support of the "redoubtable" Wellcome Trust would add weight to the bid. Work will begin as soon as the Heritage Lottery fund says yes.
However, he told the conference it was unfair that science centres - as opposed to museums - could not get funds from the Heritage Lottery, and had to rely on the Millennium fund. This meant they only had one shot at funding, and with applications totalling Pounds 200m to Pounds 300m to build science centres, many excellent proposals would lose out. The public demand for these hands-on places would thus not be met.
Sir Neil said public attitudes to science had changed in the past decade. "Science and technology are quite visibly moving from the twilight to the spotlight," he said. The scientific community had a new sense of being valued.
Developments in science were going to have a profound effect on the way the world operates in the future, but these could be important forces for good, rather than something to be feared, Sir Neil said.
He believed the public was ahead of many in the media and those who thought culture was only to do with literature and the arts. People recognised that to be a cultured person today, it was essential to have some knowledge of the main scientific topics of debate, such as artificial intelligence, biodiversity, fuzzy logic and cyberspace.