National Aeronautics and Space Administration

Glenn Research Center

Simulated Lunar Operations (SLOPE) Facility



The Space Mechanisms Simulated Lunar Operations (SLOPE) facility is a unique indoor, climate-controlled, confined terrain of lunar simulant for conducting traction and other terrain-characterizing testing that relate to future lunar vehicles. Facility provides a site to optimize surface mobility capability on Moon and Mars based on operational need.

Coupled with the Soils Design Laboratory based terramechanics modeling, measurements taken in the SLOPE facility can predict lunar tractability, which can be extended to Mars as well. With a level portion 12 m x 6 m, and coupled lift bed of 6 m x 4.7 m with up to 45 degree tilt angle, SLOPE is a unique indoor test bed for comparison characterization of wheels, tracks, or other mobility approaches.


  • 12m x 6m x 0.3m soil tank for large flat surface operations.
  • 6m x 5m x 0.3m adjustable tilting soil tank (0 to 45°) for sloped surface operations.
  • Dedicated wheel-test vehicle can be configured to 4×4 or 6×6 mode.
  • Portable Bevameter used to analyze the surface strength
  • of a terrain, which facilitates modeling of the terrain-machine interactions.
  • Drawbar pull rig applies controlled pull force to a test vehicle while wheel slip is recorded.

Research Projects

  • Exploration/ETDP/Human Robotics/In-Situ Resource Utilization (ISRU): Recreation of wheels uses on the Apollo lunar rover; develop and test advanced tire designs for lunar rovers; develop driving techniques to explore lunar craters and other steep slopes on moon surface; develop and validate terramechanics models

Potential Uses

  • Developing the sciences that will determine the geometry of the wheels, tracks, and tread patterns
  • Developing instrumentation and experimental methods to characterize the lunar terrain
  • Developing vehicle traction test methodologies.

Point of Contact: James Zakrajsek, 216-433-3968