NASA said it was determining the type of research a stationary Spirit could do in the future. For example, it could study the interior of Mars, monitor the weather and continue looking at the deposits uncovered by its wheels, a task it has already been performing.

A study of the planet's interior would use radio transmissions to measure wobble of the planet's axis of rotation, which is not feasible with a mobile rover, NASA said.

Getting the rover moving is still the first priority, NASA stated. In the past couple weeks, Spirit's right-front wheel, which had stopped operating in March 2006, showed signs of life this week by spinning slightly during one of the attempts to move the rover. The wheel however stopped later in another test and has not worked since.

Still, NASA scientists said movement of the right-front wheel for about 3.5 minutes was a surprise. It is not clear whether the wheel will work again, since it stopped during the final drive segment and it’s not clear whether extrication from the sand trap would be possible even with an operable right-front wheel, NASA said.