Officials at the Discovery Museum of Sacramento (DMS) are still looking for investors to get the Powerhouse Science Center project off the ground.
Due to the lack of progress, the opening of the new centre has been pushed back until at least 2013.
A site has yet to be officially chosen, although DMS has identified the historic P&E Power Station on the banks of the Sacramento River as the ideal location for the new science centre.
Plans for Powerhouse Science Center include large exhibition galleries, a planetarium and a new a Challenger Learning Center - an educational facility exploring the NASA space shuttle programme, which is named in the honour of the 1986 Challenger shuttle tragedy.
A spokesperson for the project said: "The Powerhouse Science Center will feature generous exhibit space for current and traveling exhibits as well as a newly expanded and updated Planetarium & Challenger Learning Center.
"Movies, laser shows, and astronomy programs, a café with outdoor seating and more will be part of the centre."
