A collection of engineers, astronauts and geologists have spent the past week testing out the Small Pressurized Rover in the 11th annual Desert RATS (Research and Technology Studies) field tests. Two teams of one astronaut and one geologist each have been driving the rover through the Arizona desert, trying it out in two different configurations. Concepts for a new generation of rovers, which astronauts will take with them when they return to the moon by 2020, are now being tested at sites around the country that have terrain similar to what might be encountered on the moon. One of these rover concepts is the Small Pressurized Rover, or SPR, that was unveiled in 2007. An SPR cabin prototype was then built and integrated with a rover chassis and completed for testing in 2008.

One configuration leaves the crew members free to get on and off the rover whenever they like, but they must wear spacesuits at all times to protect them from the lunar environment. The second configuration, the Small Pressurized Rover, or SPR, adds a module on top of the rover’s chassis that the crew can sit inside as they drive the vehicle, donning spacesuits whenever they want to get out.

NASA is testing a variety of lunar rover concepts that will help future astronauts explore the moon further than ever before, construct a long-term lunar base and conduct a wealth of science experiments. During the first use of such rovers on the Apollo missions, astronauts completed almost 20 traverses across the surface of the moon. With each successive mission, NASA improved the rovers’ capacity, increasing the number and duration of exploration missions astronauts could complete on the lunar surface.

For the first week of tests, the rover has been driven on day-long trips to determine how each configuration performed. These have been some of the longest drives the prototype has ever made, but next week the group will step it up another notch or two, by going on a three-day drive through the desert in the SPR to determine how it performs and whether it's comfortable enough for long-duration trips.

The Small Pressurized Rover involves working with the concept of a long-term lunar outpost in which NASA will need mobility systems for a range of activities. While some of these systems will perform unmanned tasks (think R2D2), the SPR concept could provide the astronauts’ main mode of transportation, and could also allow them the flexibility to work inside of it without the restrictions imposed by spacesuits. The adaptable vehicle features pivoting wheels that enable “crab style” movement to help the rover maneuver through difficult spots. Its cantilevered cockpit does not obstruct the driver’s visibility of the terrain ahead. Early concepts provide an exercise ergometer that allow crews to exercise while driving and simultaneously charge the vehicle’s batteries.

Each SPR consists of a Mobility Chassis and an SPR cabin module. The SPR could be delivered to the lunar surface as a pre-integrated unit or as separate elements. The cabin’s modular design enables it to be placed on a chassis. The Mobility Chassis can be configured in an unpressurized rover (UPR) configuration, with astronauts in spacesuits riding in rotating turrets and can also be used without the pressurized module. Astronauts may also ride in the turrets with the SPR in place, minimizing time for suit changes. The modular design will also allow attachment of various tools that may beneeded on a particular mission, such as winches, cable reels, backhoes and cranes.