The "first light" ceremony for the Gran Telescopio Canarias, or GTC, under construction for seven years, is scheduled on Friday. The University of Florida -- which contributed $5 million to the project -- is the only U.S. institution with a stake in the massive telescope.

The roughly $175 million GTC is not yet complete. Only 12 of the 36 mirrors that will compose its 34.1-foot primary mirror have been installed, said Stan Dermott, chairman of the University of Florida astronomy department.

The rest of the mirrors are to be mounted this year. The telescope's grand opening with Spain's King Juan Carlos presiding is set for next summer. Only after that will scientific-quality observations begin, Dermott said.

Friday's test run will involve Prince Felipe, heir to the Spanish throne, training the telescope on Polaris, the North Star, for a ceremonial observation to be attended by about 300 people.

The Spanish government is the main owner of the GTC, with UF and two institutes in Mexico as partners.