She’s Going to be a Stationary Platform

What’s a planetary scientist to do when a rover gets stuck in the sand after six years of exploration, is still working well, but can’t move anymore? You turn it into a stationary research platform. NASA’s Mars Exploration Rover Spirit has ended six years of roving in a sand pit and will now become a fixed science platform.  After it works itself into position to survive the Martian winter so that it can get more sunlight on its solar panels, the rover will ride out the severe weather and begin doing a class of science that can only be done by a freestanding set of instruments.

For example, Spirit is already studying tiny wobbles in the rotation of Mars over time. This allows scientists some valuable insight about the composition of the planet’s core. It’s not something that can be done overnight — it requires months of radio-tracking the motion of a point on the surface of Mars to calculate long-term motion with an accuracy of a few inches. And, since Spirit is now a “point” on the surface, it’s in a perfect position to do this work.  If Spirit continues working, it will help determine whether the core of Mars is liquid or solid — a question that is still unanswered.

Tools on the rover’s robotic arm can also study variations in the composition of nearby soil, which has been affected by water. And, as we do hear on Earth with fixed weather stations, the Spirit rover can monitor the weather and watch how the constant Martian winds move soil across the surface.

I think it’s a wonderful chapter in the rover’s life, which has been longer than anybody expected. It’s also a tribute to the folks at Jet Propulsion Laboratory who built it and continued to guide the rover around the planet until Spirit got stuck in a sandpit last year. A perfect example of making the best of what could have been a truly bad situation and coming out ahead!