Fig. 1: ATHLETE Rover with Brian Wilcox.

JPL leads a team that includes NASA's Johnson and Ames Centers, Stanford University, and Boeing to develop and demonstrate the ATHLETE (All-Terrain Hex-Legged Extra-Terrestrial Explorer) robotic vehicle. ATHLETE is capable of rolling over Apollo-like undulating terrain and "walking" over extremely rough or steep terrain so that robotic or human missions on the surface of the Moon can load, transport, manipulate, and deposit payloads to essentially any desired sites of interest.

The first version of the ATHLETE vehicle is under development and has the following characteristics:

• Greater than 4 m in diameter with more than 6 m reach
• Able to dock or mate with special-purpose devices, including a launchable/releasable grappling hook, refueling stations, excavation implements, and/or special end effectors
• 6-DOF legs for generalized robotic manipulation
• Large payload capacity of 450 kg per vehicle, with much more for multiple ATHLETE vehicles docked together

This system will exhibit the following capabilities:

• Able to move at 10 km/h over Apollo-like terrain (>100 times faster than Mars Exploration Rover (MER))
• Climb vertical steps of at least 70% of the maximum stowed dimension of the vehicle (>2x MER)
• Climb slopes of 35° on rock and 25° on soft sand
• Load, transport, manipulate, and deposit mock payloads in a useful fashion
• Be stowed and docked compactly for launch into an annular ring so that many vehicles can be efficiently stacked around a main payload on a single lander

The system is an Earth test-bed vehicle, controlled via an immersive user interface similar to that used for the MER mission. However, unlike the Mars usage, simulated Earth-Moon time delay will be used for operations.

Future planned improvements to the system will provide additional capabilities to:

• Self-deploy from compact storage on lunar landers
• Traverse almost any terrain, including vertical rock faces or sandy slopes at the angle of repose by using a launchable/releasable grappling hook
• Exhibit reliable autonomous footfall placement even on the roughest and steepest terrain
• Demonstrate a useful "voice and gesture" command mode to enable suited astronauts to interact with these vehicles

We seek to complete flight qualification of the key robotic components that enable this system as needed for a 10-year life (equatorial or polar) on the Moon, and to deliver a manufacturing analysis that shows the flight vehicles can be affordably manufactured in the quantities needed for Human Lunar Return.

By the end of this project, NASA will be able to confidently conduct an affordable lunar-surface flight experiment that demonstrates this technology on the Moon and subsequently uses it as part of the Human Lunar Return campaign to perform the needed robotic/human vehicle functions on the lunar surface.