With Spirit trapped in loose Martian soil since May 6th, engineers at NASA's Jet Propulsion Laboratory, in Pasadena, California, are working around the clock to mimic the conditions of the Mars Exploration Rover (MER) in their test facilities. Spirit and Opportunity are not the only MER components, as mission planners also built a third rover in case of emergencies. That robot is currently lying in a patch of soil similar in properties to that on Mars, and scientists are trying to figure out ways to get it out.

Once they figure out how to do that, they will attempt to recreate the same operations with Spirit. However, there is still a long way to go until then, MER Project Manager John Callas has recently said. First, the experts working on the simulation have to scan all the photos that the Martian rover sent back of its surroundings and to determine the exact composition of the soil. Then, there's the question of recreating it in such a manner that the results obtained back on Earth are also applicable to Spirit.

The engineers at JPL need to faithfully recreate the 12-degree slope the rover is on. They also need to adjust the properties of their soils to accurately match those of the Martian ground. For that, they have to combine numerous types of dirt and clay, in an attempt to get the correct consistency. The pictures Spirit sent back are not encouraging – the soil it's trapped in is very loose and of low consistency. In addition, the craft is caught up to its hubcaps in the ground, and any false attempt of releasing it could make it lodge itself even deeper into the ground.

Moreover, pictures sent back show that, under the rover, what appears to be a rock touches its underbelly. This poses an incredible threat to its chances of getting out of the sand, because, if the craft is stuck on it, then weight is lifted off its wheels, decreasing traction. Also, the wheels themselves could get damaged, and Spirit has already been short of one for about three years. This flaw has forced it to drive backwards for the larger part of its mission.

The engineers faced these challenges on another occasion, when Opportunity, currently trekking happily along on the other side of the Red Planet, became stuck in the sands of the Purgatory Dune. It took weeks to unstuck it, and experts believe that it may even take longer for Spirit, as a number of extra obstacles have to be surpassed. “If you set the belly on the ground, it's pretty much game over at that point. We suspect it's going to take a long time to get out of here,” Callas said, quoted by Space.