NASA’s Opportunity Mars rover has a tough assignment ahead - perhaps driving down into the large Victoria crater that it’s presently surveying.

But before “wheels down” into Victoria, a careful safety review that involves NASA Headquarters must conclude that the trip is doable. That’s the word from Steve Squyres, the principal investigator for the Mars rover project.

Just how safe will mean taking a new load of color stereo images to determine how steep the slopes are at the crater entrance ramp selected at “Duck Bay”, as well as getting a handle on the distribution of rock and soil on those slopes that could, quite literally, mean tough sledding for the robot.

If Opportunity gets a go-ahead to enter the crater, no telling how long the rover will spend there or how deep inside the feature it will go, Squyres told me.

What’s tricky is that assessing the lower slopes within Victoria can only be done once the rover is inside the crater.

“One key point about the possible entry at Victoria,” Squyres said, “is that we have no desire to make it a one-way trip! There’s an enormous amount of science still to be done out on the plains, both near Victoria and beyond. So if the decision is that it’s safe to go in, we’re going to do it, take care of business down there, and come back out again.”

Squyres added that if a wheel were to fail on the rover once inside the crater, it would probably not be possible for Earth controllers to steer Opportunity out again.

“A five-wheeled rover out on the plains, however, could do great science for a long time, and cover lots of distance. While we have no reason to expect a wheel failure on Opportunity, the failed right front wheel on Spirit [Opportunity's twin rover at Gusev crater] is a reminder that it can happen. So we’re not going to dawdle,” Squyres explained.