Mahr, Eric M. | Search NASA

NASA NTRS2019

Space Power Heritage Study Final Results

NASA space missions have long employed Radioisotope Power Systems (RPS) and solar-based power generation architectures. RPS have been used to enable or significantly enhance missions that venture deep into the solar system to distances from the sun which can make using solar architectures unfeasible and to areas where the sun is obscured due to shadows or atmospheric phenomena. The destination, however, is not the absolute factor of the determination of RPS or solar. This is highlighted by the Jupiter missions Galileo and Juno, which employed RPS and solar architectures, respectively. When baselining either RPS or solar architectures for a planetary mission, numerous factors must be considered, including scientific objectives, cost, schedule, and mass just to name a few. In an effort to better understand the decision-making process and provide insight for potential future missions, the NASA RPS Program Office tasked The Aerospace Corporation (Aerospace) to study historical missions that used RPS and solar architectures. Data was collected for a variety of RPS and solar missions to look for possible trends from the selected implementation. Additionally, mission case studies were developed based on interviews with mission personnel who were responsible for defining the power architecture of their mission. Informed by the data collected and case studies, two Measures of Effectiveness (MoEs) were produced: one based on cost of RPS versus solar, and one based on science mission cost effectiveness. The final results of this study have been captured in this briefing package which is available for full and open release. Additionally, a final report document also provides the same details of this package. This briefing package also includes an appendix which contains data not for public release which was used to provide detailed answers to questions raised during this study. The results of these inquiries are discussed in the report, but the proprietary data is not included. Finally, an executive summary package is also publicly available which was used to present the results of the study at the 2018 Aerospace Space Power Workshop.

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NASA NTRS2013

Assessing the Benefits of NASA Category 3, Low Cost Class C/D Missions

Category 3, Class C/D missions have the benefit of delivering worthwhile science at minimal cost which is increasingly important in NASA's constrained budget environment. Although higher cost Category 1 and 2 missions are necessary to achieve NASA's science objectives, Category 3 missions are shown to be an effective way to provide significant science return at a low cost. Category 3 missions, however, are often reviewed the same as the more risk averse Category 1 and 2 missions. Acknowledging that reviews are not the only aspect of a total engineering effort, reviews are still a significant concern for NASA programs. This can unnecessarily increase the cost and schedule of Category 3 missions. This paper quantifies the benefit and performance of Category 3 missions by looking at the cost vs. capability relative to Category 1 and 2 missions. Lessons learned from successful organizations that develop low cost Category 3, Class C/D missions are also investigated to help provide the basis for suggestions to streamline the review of NASA Category 3 missions.

Bitten, Robert E.↗