Lunar Mission Pilot Case Studies
There is some evidence that the Moon may harbor water ice, deposited by comets or asteroids and preserved in the permanently shadowed portions of certain craters. One area of particular interest is Shackleton crater, which lies within a much larger crater called the South Pole - Aitken basin.
Water is not only essential for astronauts to drink, it can be electrolyzed to extract hydrogen, which is a good rocket fuel. NASA is very interested in determining whether significant stores of water ice exist on the Moon and, if so, whether a practical means can be developed to use it for future lunar fueling stations. Developing resources locally on the Moon or on other worlds (such as Mars in the more distant future) is known as "in situ resource utilization" or ISRU.
At the same time, NASA is considering various proposals for purely scientific investigations to be conducted on the Moon.
NASA's Exploration Systems Mission Directorate (Directorate Integration Office and Exploration Technology Development Program) selected the lunar exploration program as the domain for a series of studies to demonstrate the usefulness of START's methodology in helping NASA decision-makers determine how best to develop the capabilities needed for lunar exploration and scientific investigation. We believe these studies will be of interest to other directorates (e.g., Science Mission Directorate) and the Program Analysis and Evaluation office, and can reasonably be used to illustrate START's usefulness to the decision-making process throughout NASA.
Using the START tool
We used these studies as an opportunity to build START's new multipurpose software tool, which combines the best of the tools and methodologies we have applied to past tasks, and adds new capabilities. The tool is not meant to be an oracle dictating final answers, but rather an instrument to help decision-makers gather information and build a firm foundation for their decisions.
When conducting a study with the START tool, we perform the following steps:
- Identify the mission(s) to be accomplished and ask the decision-maker to assign relative weights to the missions (if more than one) and to provide any annual budget and workforce constraints that may apply.
- Work with the system architect to determine the activities and associated capabilities needed for the mission(s) and to assign requirements for each capability.
- Help technologists provide quantified information about each capability they seek to provide for the mission(s).
- Feed the above data into the START software tool and select the desired type of output (e.g., temporal investments by capability theme).
- Run the analysis and review the results with the sponsor.
- Test the sensitivity of the results to changes in the inputs if desired, make any desired adjustments to the input data and run the analysis again, repeating the process as many times as needed.
In the case of the Lunar Mission Pilot Case Studies, we began by identifying 9 possible component missions, some of which are alternate versions of each other:
- Lunar infrastructure (traveling to the Moon and back)
- Robotic prospecting precursor
- 7-day human-robot prospecting
- 14-day human-robot prospecting
- 42-day human-robot prospecting
- 7-day human-robot ISRU
- 14-day human-robot ISRU
- 42-day human-robot ISRU
- Non-polar human-robot ISRU
Lunar infrastructure must be done; traveling to and returning from the Moon is necessary in order for any of the other crewed missions to be accomplished.
The second mission, Robotic Prospecting Precursor, isn't quite in the same category. It would be possible to send astronauts to explore for lunar water without first sending robots to prepare the way, but as of the time of this study, that is not considered a prudent course of action. So this too, for purposes of our study, is considered a "must do" mission.
As the above list indicates, we divided the resource-exploitation campaign into two parts: prospecting (determining whether and where water ice is present) and ISRU (determining whether lunar water ice, if present, can be accessed and electrolyzed, and the resulting hydrogen stored until needed for fuel). For each of these two parts, we decided to perform analyses for alternate durations of 7 (NASA's nominal mission length), 14, and 42 days.
The final mission alternative in the above list, "non-polar ISRU mission," refers to the possibility that water ice may not be found in sufficient quantities at the lunar south pole. In that case, we assume that NASA would want to consider a mission to a lunar equatorial region to see whether a practical method can be developed to process the regolith (the fine dust and rubble that covers the Moon) to release the oxygen bound up in it.
The case studies
Our first study in this series has the primary purpose of demonstrating that START's new software tool can help NASA rapidly analyze multiple alternate budget scenarios. As an example task, it determined technology-investment recommendations, as a function of time, which would enable multiple missions under a number of potential budget, workforce and management constraints.
Our second study determined the relative value per investment dollar of two alternate Robotic Prospecting Precursor missions to the Moon, one of which would last 19 days and the other of which would run for nearly a year. This was the first START study to compare different mission architectures for the same goal, and to consider the entire life-cycle costs of the technology capabilities, rather than just their development costs to TRL 6.
Next, we expect to study the operations strategy for early missions at the lunar south pole in which astronauts at the rim of Shackleton crater work in conjunction with robotic partners. We'll study the role and activities of the various agents, such as humans in pressurized vehicles controlling robotic operations, humans performing extra-vehicular activities with robotic assistants, etc.
For more information, contact Charles Weisbin at Charles.R.Weisbin@jpl.nasa.gov
- Links to case studies: