Lynda Oschin, wife of the late philanthropist Samuel Oschin, chairs the foundation that made the gift to the Air and Space Center at the California Science Center, the Los Angeles Times reported Thursday.
At Oschin's request, museum officials did not disclose the amount of the gift but termed it "transformational" for the free state-run museum adjacent to the University of Southern California.
"It's a huge boost," Science Center President Jeffrey N. Rudolph said. "It gives us enough money to ensure we can complete the architecture and exhibit design."
The Science Center has now raised nearly half the $200 million it needs to transport Endeavour from Florida, build a temporary hangar, and design and construct a permanent museum wing, to be called the Samuel Oschin Air and Space Center.
Samuel Oschin, who died in 2003, made his fortune at a savings and loan company and in real estate and was an avid fan of science, math and astronomy, the Times said.