EVA Development in Exploration-Driven Human Spaceflight

Since the Apollo program completed lunar surface operations in 1972, NASA astronauts have performed hundreds of Extravehicular Activities (EVAs) in support of Skylab, Space Shuttle and International Space Station missions. These EVAs were primarily driven by engineering objectives, such as the installation or repair of hardware. As a result, the tasks to be performed were generally well-constrained by the engineering of the hardware involved (barring, of course, unexpected hardware failures), and products guiding these EVAs were highly detailed and directive.

When astronauts return to the Moon, EVAs will include a significant component of scientific, discovery-based exploration. Mission planners will have knowledge of topography and large (>1m) features but cannot predict the nuances of terrain and geology that the astronauts will find on the lunar surface. The plan for Artemis EVAs must therefore enable sufficient flexibility to respond to the team’s evolving understanding of the lunar surface while keeping the astronaut crew safe. Thus, the Artemis missions require a paradigm shift in planning and execution of EVAs, from engineering-based, directed tasks to discovery-based scientific exploration. The human spaceflight community has been challenged to build on lessons learned from Apollo, merging 50 years of EVA experience with the planetary science community’s expertise, to prepare Artemis crews for success on the lunar surface.

NASA’s EVA Development Process must therefore evolve to incorporate, and facilitate, principles of scientific exploration. The current version of this process for Artemis has evolved through testing in field and virtual reality. In these tests, NASA Flight Operations Directorate (FOD) flight controllers integrate with Science Mission Directorate (SMD) science teams to develop and execute simulated lunar surface EVAs (e.g., JETT3, as in [1,2]). The tests span several months and encompass mapping, traverse planning, and traverse execution.

The Artemis EVA Development Process encompasses three primary phases: Science Preparation, Flight Operations Iteration, and Creation of Final Products (Fig. 1). Science Preparation and Flight Operations Iteration develops key information that will be needed by astronauts on the surface, including plans for the EVAs. In the last phase, Creation of Final Products, this information is formatted and approved for presentation to EVA astronauts and Flight Control Team members supporting the mission.