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Introduction
Published in Lauren Blackwell Landon, Kelley J. Slack, Eduardo Salas, Psychology and Human Performance in Space Programs, 2020
Kathryn E. Keeton, David Musson
And yet, this international partnership has successfully completed 58 Expedition missions to date (www.nasa.gov) despite ever increasing complexities in mission design and logistical considerations for the selection, training, and support of the astronaut crew. Here again we see the power of higher-order goals helping to align efforts from the international partners to make these expeditions possible. Specifically, we posit that the international partners’ ability to address these complexities is due to their ability to align both within teams (i.e., within complex individual national space agencies) and within the overarching multiteam system (MTS) (i.e., the international partnership at large) (Marks, DeChurch, Mathieu, Panzer, & Alonso, 2005). If supported, this alignment and focus on the higher-order goal will continue to be critical (both within each agency and within the overarching MTS) to future success of international spaceflight collaborations. This is particularly true when considering that longer-duration missions, such as to lunar stations or expeditions to the planet Mars, hold the potential for an exponential increase in complexity. For such missions, their future success will entail additional factors that must be considered including delayed communications between ground control and the flight crew, a paradigmatic shift for autonomous operations for the flight crews, and of course, additional physiological and psychological risks to the crew for deep space exploration.
Decoding Mission Design Problem for NTP Systems for Outer Planet Robotic Missions
Published in Nuclear Technology, 2022
Saroj Kumar, L. Dale Thomas, Jason T. Cassibry
Designing missions to outer planets is extremely challenging. Because of the large distances of these planetary bodies, the ∆V required for such missions is very high. To date, chemical propulsion systems have been the go-to choice for deep space exploration missions. However, its low propellant efficiency has also been a challenge toward designing a dedicated mission to Ice Giants without requiring a super heavy-lift launch vehicle.6 The highest-performing chemical propulsion engines are limited to a specific impulse of about 450 s, and only minute improvements can be expected.7 On the other hand, nuclear thermal propulsion (NTP) systems have already demonstrated a specific impulse of over 850 s during the Nuclear Engine for Rocket Vehicle Application (NERVA) program, and current engine designs have the potential to achieve a specific impulse of 900 s, i.e., about twice as efficient when compared with the best chemical propulsion engine.8 The limited ∆V capability of a chemical propulsion system and struggle against trip time and distance often necessitate the use of multiple gravity assist trajectories. The increased trip time due to gravity assist trajectories is directly proportional to the total cost of the mission life cycle, which can be a significant number for cost-capped planetary missions.9
Foreword Special issue on the Kilopower Project, Kilowatt Reactor Using Stirling TechnologY (KRUSTY) Test
Published in Nuclear Technology, 2020
In this issue, the introduction paper presents the goals of the Kilopower Project and the potential missions this reactor concept could serve in NASA. Kilopower was intended to serve both human exploration needs on planetary surfaces as well as science needs for deep-space exploration. The design work for the experiment by Poston and the power conversion development by Gibson present the pre-work required to perform the eventual KRUSTY test. A paper on regulatory analysis follows, to show the path used to gain approval of the proposed experiment. Then, the early zero-power critical experiments are presented by Sanchez and Grove. These experiments were essential data used to enhance model predictions prior to the high-temperature test. Next, Poston presents the three experiments (warm criticals) that increase the temperature in an incremental fashion prior to the final experiment. These experiments were used to achieve final regulatory approval of the final high-temperature experiment. The last paper by Poston presents the results of the steady-state and transient testing of the reactor at full power and at the design temperature. These results show that the reactor design and as-built experiment met all of the requirements that NASA had developed for the system.
Emergency strategy optimization for the environmental control system in manned spacecraft
Published in Engineering Optimization, 2018
Guoxiang Li, Liping Pang, Meng Liu, Yufeng Fang, Helin Zhang
Many researchers have studied the ECS running principles. Romani and Goes (2013) simulated the dynamic behaviour of cabin temperature and made suggestions about the temperature control stability. Jin, Hou, and Yang (2013) built an integrated simulation model of the ECS for a manned spacecraft, and analysed the ECS working performance. In this study, a non-regenerative LiOH assembly was used to remove carbon dioxide (CO2). A complete synopsis of the Apollo environmental control and life support system was set up in detail for system-level design and operational limits by Anderson and Martin (2005). Perry et al. (2015) developed and demonstrated an ARS suitable for deployment aboard deep-space exploration mission vehicles. Jones, Hodgson, and Kliss (2014) and Anderson and Stambaugh (2015) discussed the evolution of life support systems for deep space missions in detail.