Map of the Pacific Ocean region with the Vandenberg launch site and French Polynesia noted. Photo: CIA

A Taurus rocket launch remains blocked over safety concerns with a tiny tropical island in the South Pacific Ocean and the U.S. Air Force doesn't know when the peculiar problem will be resolved, officials said Wednesday.

The Air Force, which manages the launch, had hoped the Orbital Sciences-built rocket with an experimental spy satellite aboard could be cleared for liftoff on Saturday from Vandenberg Air Force Base, Calif.

However, ongoing negotiations with the Tahitian government over the rocket's planned launch trajectory and threat posed to the French Polynesian island of Maria won't be completed in time to allow a weekend liftoff.

"Officials will continuing to aggressively to resolve the issue to ensure maximum safety for the upcoming launch," said Maj. John Cherry, spokesman at Vandenberg Air Force Base.

At the center of the controversy is the coconut-growing island of Maria. The island is located inside a 100-mile long and 30-mile wide stretch of the Pacific where the Taurus rocket's spent third stage is predicted to crash following launch.

The Tahitian government had granted a launch safety clearance but repealed the agreement last Friday citing that the island is now populated. Air Force officials say about 200 people live on the island.

When the rocket's trajectory to space was originally created, launch planners used Air Force maps and a United Nations database that incorrectly listed Maria as uninhabited.

Maria, located at 21.88 degrees South latitude and 136.33 degrees West longitude, is just one of 118 islands and atolls that make up French Polynesia, a territory of France.

Launch officials said Wednesday they could not easily tweak the launch timeline so the third stage could avoid the island.

The only options left are evacuating the island during the launch or reprogramming the Taurus' flight computer brain with a new trajectory.

The Air Force says a cost analysis will be performed of each option.

Oil platforms located offshore from Vandenberg are routinely cleared during rocket launches, giving a precedence for evacuating Maria. However, clearing an entire island and not missing any people would be difficult, the Air Force says.

An artist's concept of the MTI satellite the Taurus rocket will carry into space. Photo: Sandia National Laboratories

If a new trajectory has to be loaded into the Taurus computer, the rocket will have to be disassembled from its seaside launch platform, delaying the launch at least one month.

Although a new target launch date has not been set, the earliest the Taurus could fly is late next week. The reason is an unarmed Peacekeeper missile is slated for launch from Vandenberg early Wednesday morning.

The missile test will require support from the Western Range, which provides tracking, communications and safety services to all Vandenberg launches. The Range needs 48 to 72 hours between launches of different vehicles to reconfigure its systems.

The Air Force is also facing a mid-March deadline with the life of batteries installed aboard the Multispectral Thermal Imager satellite atop the Taurus rocket.

The MTI spacecraft is a research testbed for the U.S. Dept. of Energy's Office of Nonproliferation and National Security.

The satellite features a cryogenically-cooled telescope that will observe selected ground sites to test multispectral and thermal imaging. The new technologies, if they work, could be incorporated into futuristic spy satellites to detect facilities on Earth suspected of making nuclear or chemical weapons of mass destruction.