Tasks
Mission Phase
Tasks

Launch to LEO/CLO 60 Mars Surface Operations 484

Trans-Mars Injection 19 Mars Surface Ascent 29

Cruise to Mars 206 Trans-Earth Injection 10

Mars Orbit Injection 10 Cruise to Earth 204

Mars Orbit 13 Earth Approach 26

Mars Surface Descent 29 Earth Surface Descent 35

Total 1,125
We asked a highly-experienced mission planner, a scientist astronaut, and a high-ranking NASA scientist-manager to review and then comment on our Mars expedition task lists. The mission planner responded that the lists were comprehensive and recommended a few minor changes to MSO tasks based on the latest, unpublished mission plans (e.g., length of ladder, method for hoisting loads). The scientist manager responded that the lists were comprehensive and looked like “behind the scenes at The Martian,” referring to the 2015 feature film that portrayed a human expedition to Mars. The astronaut scientist responded that the lists were comprehensive, but there were too many task statements for SMEs to rate each one during the planned data-collection effort. The research team was encouraged by the experts’ review of our lists, but we were concerned about the astronaut’s comment. Based on our internal testing and feedback from the experts, we estimated that it would take between four and five hours to rate all 1,125 tasks, which, of course is too long to expect volunteers to devote to our study.
In response to the astronaut’s feedback, the research team decided to categorize the tasks within each mission phase according to similarity and then compose a statement that summarized the constituent tasks. This process resulted in a total of 158 summary task statements (representing the 1,125 tasks); for example, the 484 Mars Surface Operations tasks were reduced to 55 summary task statements and the 206 Cruise to Mars tasks were reduced to 27 summary statements. A summary statement and the corresponding EVA tasks from the MSO phase are reproduced, below.

Example of a Summary Task Statement and Constituent Tasks from the Master List

| Perform surface EVA physical functions on foot during Mars Surface Operations. |  |
| --- | --- |
|  | Carry incapacitated crew mate 20 meters to surface rover, manually while both are wearing surface EVA suits, to prepare for medical treatment. |
|  | Rise from prone position, using arms and legs while wearing surface EVA suit, to recover from fall on flat surface. |
|  | Rise from prone position, using arms and legs while wearing surface EVA suit, to recover from fall in loose regolith. |
|  | Bend over/stoop while wearing surface EVA suit to retrieve hand tool from planet surface. |
|  | Climb 3 meter ladder, manually while wearing surface EVA suit, to access Mars Surface Ascent Vehicle. |
|  | Adjust surface EVA suit controls, manually with gloved fingers, to operate mobile communications with Mars habitat personnel. |
|  | Adjust surface EVA suit controls, manually with gloved fingers, to optimize mobile life support system. |
|  | Carry harvested plant material from greenhouse to surface habitat galley, manually while wearing EVA suit, to prepare for crew consumption. |

Dig loose regolith from around surface rover wheel, manually using shovel while wearing surface EVA suit, to regain traction to proceed, a task performed by Mark Watney (Matt Damon) in The Martian (2015).