Every tourist needs a map, and Spirit, NASA’s Mars rover, is no exception.

When the 384-pound explorer rolls onto the Martian surface sometime during the next few days, it will know where to go thanks in part to Ohio State University scientists.

The map they are preparing is being readied from the panoramic photographs the rover took almost immediately after it smacked dead-on into Gusev Crater, where scientists will examine the geology and look for signs of water.

"We didn’t expect a panoramic a few hours after landing. That was incredible," said Rongxing Li, an OSU professor of geodetic science, a branch of mathematics concerned with locating points on Earth’s surface.

Li is in Pasadena for the next few months, working with a team of mapmakers.

The lander hit the surface of Mars late Saturday after a seven-month, 305 million-mile flight.

The successful landing — which involved slowing the craft with heat shields, a parachute, retro rockets and bouncing it to the surface inside a collection of air bags — is a good omen that Spirit’s twin sister, Opportunity, will land safely Jan. 24 on the opposite side of the planet.

Today, mission controllers will continue preparing the solarpowered Spirit for exploration.

"They’re very intent on making sure things got there OK. The engineering data takes priority," said Gay Hill, a NASA spokeswoman.

If all continues well, Li said, the golf cart-size explorer could be ordered to roll down a ramp and onto the surface of Mars as early as Wednesday.

The rover’s map is generated using a computer program developed by scientists at Ohio State and NASA’s Jet Propulsion Laboratory in Pasadena.

Researchers use the images from Spirit and compare them with satellite images produced by the Mars Global Surveyor satellite and with images the lander snapped during its descent.

These images will help plot the dips, bumps, gullies and rocks in the area.

The first images show the terrain within about 100 feet of the lander. A hill can be seen about a half-mile in the distance in some views.

Li said he was so excited on Sunday that he couldn’t sleep when he returned to his hotel. Instead, he went back to work.

The 45-year-old scientist said the data collected from Spirit is sent to the OSU campus, where researchers will prepare the map and send it back to the Jet Propulsion Lab.

"Our accuracy could be 99 percent," said Kaichang Di, a researcher working on the project in Columbus.

The final map will be a compilation created by maps made at Ohio State, the U.S. Geological Survey and the Jet Propulsion Lab.

Li said he studied maps of the 1997 Mars Pathfinder mission in which Sojourner — a tiny version of Spirit — explored its landing site. Those maps were thought to be off by as much as 10 percent.

Li said that can be greatly improved.

He and others are awaiting higher-resolution images to improve the map before Spirit is sent on its way. As Spirit moves around over the next three months, the map gradually will be enlarged and made more detailed.

Yesterday, NASA released a three-dimensional, black-andwhite panoramic picture of the bleak surface. Visitors were issued cardboard 3-D glasses to look at the 360-degree image.

"I feel like I’m at a bad ’50s Bmovie," mission manager Matt Wallace said as he watched a roomful of reporters take in the image.

Li said the mission staff was assembled in the control room as Spirit entered the planet’s thin carbon dioxide atmosphere Saturday.

"Most of us were silent. We were all in the same room, sweating," he said. Spirit communicated with Earth as it descended and then, after landing, went eerily quiet.

"Then there was no signal from the spacecraft and there was silence from well over 100 people, too," Li said.

Seven or eight minutes later, the signal reappeared.

"Wow, we did it," Li said.

Information from the Associated Press was used in this story.
mlafferty@dispatch.com