Today marks a major chapter in the continued growth of electric carmaker Tesla Motors with the official ceremony to mark its takeover of the former NUMMI plant, which closed in April after 25 years as a joint venture between General Motors and Toyota.

Sen. Dianne Feinstein, D-Calif., and Tesla founder and CEO Elon Musk will participate in a short ceremony at 3 p.m. where a tarp will be removed, revealing the new Tesla Motors plant logo on the front of the building that faces the busy Nimitz Freeway in Fremont.

The plant has two years of outfitting ahead of it before the first Tesla sedan rolls off the assembly line in the middle of 2012. NUMMI only recently completed liquidating equipment that Toyota did not want for its other plants.

Tesla said it spent $17 million to buy assets it can use to produce its aluminum body vehicle, ranging from equipment carts to hydraulic presses. That's on top of the $42 million spent to purchase the sprawling plant and the land beneath it. Communications manager Khobi Brooklyn said the equipment was in "great condition."

Gilbert Passin, Tesla's vice president of manufacturing, is in charge of converting the facility to meet Tesla's needs. He is in the process of evaluating the kind of assembly machines and technology that will be installed at the plant. Some of the existing equipment will be modified because, unlike NUMMI's steel bodies, Tesla will use aluminum.

The Tesla factories has a skeleton crew of about 70 on site versus the 4700 that NUMMI employed. Among the 70 are about 30 managers hired from NUMMI. Passin expects that Tesla will operate with 450 to 500 employees, including management, engineers and assembly line team members. Hiring is still about a year away.

Tesla is only using about five to 10 percent of the total facility and it will operate only one shift to start. Some areas, such as stamping (where doors, roofs and hoods are made from rolls of aluminum), will remain as they were under NUMMI.

Passin says he's under pressure to deliver a fully operational plant on a tight schedule. From now to the end of the year, he will be working on the plant's layout. Next year, installation of equipment will begin. Some of it may be robotic and intelligent machines that use visual cues to install such things as window glass.

Toward the end of 2011, Tesla will begin automatic mode testing and start hiring.

We'll have more on this developing story later today on line and on ABC7 News at 5 and 6. In the meantime, take a look at the accompanying slideshow of a few photos taken inside the Tesla plant today.