SANTA FE, N.M. — Spaceport America, which was built with nearly quarter of a billion dollars in taxpayer money, is taking out a $21 million loan to build two visitor centers in southern New Mexico.

Gov. Susana Martinez and other members of the state board of finance voted unanimously Wednesday to let the Spaceport Authority seek the private loans for the centers, despite concerns the state could be left holding the tab.

The spaceport's $209 million budget two years ago had some $15 million targeted for the visitor centers. But that shrunk as other expenses mounted, including an appropriation of $7 million to extend the runway at the request of anchor tenant Virgin Galactic. State funds were used to design the buildings and buy land, but the authority needs a loan to build them, officials said.

Spaceport officials said they have several banks interested in financing the projects, and a loan could be secured in about 30 days. Construction could begin soon after that.

"We are thrilled," Executive Director Christine Anderson told the Albuquerque Journal after the meeting. "This was critical for the success of our business model."

She said the centers are a crucial element for drawing visitors to the spaceport, where Richard Branson's Virgin Galactic plans to take tourists into space for $200,000 a head. Virgin Galactic has said those flights could begin by the end of this year.

But the spaceport's business model also relies on an anticipated 200,000 annual visitors to the spaceport, which will feature a variety of space-related attractions for families.

Anderson said the spaceport authority will pay back the loan using revenue from visitor fees and an annual licensing fee from a third-party vendor that will operate the centers. Some board members expressed concern that the state could be forced to pay back the loan if the visitor numbers prove to be overly optimistic.

One of the visitor centers would be built at Spaceport America itself. A smaller one would be built off Interstate 25 near Truth or Consequences. From there, visitors would be shuttled about 30 miles to the spaceport.