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This is a presentation prepared for 2021 ME/AE department seminar at KAIST. Overview of NASA’s Artemis program, Gateway, and the Power and Propulsion Element will be discussed. The focus of the talk will be the Hall thruster technology used in the PPE and my personal career path and life lessons.
To successfully implement the behavioral aspects required to select and screen for long-duration missions on the International Space Station and for Artemis Program lunar missions, a multi-phase process combining best practice elements from the fields of industrial-organizational psychology, operational psychology, aerospace psychology and aerospace psychiatry, are needed. Furthermore, this process should preferably be implemented by professionals with extensive experience in human spaceflight operations.
With the Artemis program, NASA isplanning longer stays on the surface, with more activities that have the potential to put the astronauts and equipment in contact with greater quantities of lunar dust. The success of these missions will depend on our understanding of material interactions with lunar dust and the development of ways to mitigate dust effects. This is particularly truein cases where exposure to dust will lead to failure of components, unacceptable loss of power or thermal control, unacceptable loss of visibility, or health issues.Optically transparent, sputter deposited,work function matching coatings are being developed at NASA Glenn Research Center to reduce adhesion of dust to windows, lenses and display panels by matching the minimum energy to remove an electron from the surface to that oflunar dust in order to reduce adhesion due to charge transfer. One of these work function matching coatings will be tested as part of Aegis Aerospace Inc.’s Regolith Adherence Characterization experiment going to the lunar surface on a Commercial Lunar Payload Services (CLPS) lander in 2023. Preparation of the work function matching coating and initial characterization prior to delivery for flight integration will be discussed.
The idea of a “digital twin” was born at NASA in the 1960s as a “living model” of the Apollo mission. In response to Apollo 13’s oxygen tank explosion and subsequent damage to the main engine, NASA employed multiple simulators to evaluate the failure and extended a physical model of the vehicle to include digital components. This “digital twin” was the first of its kind, allowing for a continuous ingestion of data to model the events leading to up to the accident for forensic analysis and exploration of next steps. Fast forward half a century and NASA, along with others in the aerospace community, continues to develop and utilize high-fidelity digital models of physical systems and components as well as the extreme environments in which they operate. NASA aims to travel further and stay longer in space as we realize the Artemis program, taking us from the moon to Mars by establishing a sustainable presence on the Moon to prepare for missions to Mars. We will no longer be able to rely on constant connectivity with an asset nor be in-the-loop for on-demand human intervention in the event of an anomaly. Further, the importance of digital twins is increasing as we seek alternatives for certification of structures so large that they cannot be fully evaluated in existing test facilities and autonomous systems that are not deterministic. The idea of a digital twin is not a new one. What is new is the scale, ordinality, and non-deterministic nature of the models that are critical to achieving NASA’s goals. Their number and autonomy from each other as well as the reference system is suggestive of a changing ecosystem, returning us the idea of a living model.
International Space Station as a Testbed for Exploration Environmental Control and Life Support Systems– 2022 StatusHuman exploration missions beyond low earth orbit, such as NASA’s Artemis Program, present significant challenges to spacecraft system design and supportability. A particularly challenging area is the Environmental Control and Life Support System (ECLSS) that maintains a habitable and life-sustaining environment for crewmembers. NASA is utilizing the experience gained from its current and prior spaceflight programs to mature life support technologies for exploration missions to deep space. The intent is to establish a portfolio of life support system capabilities with proven performance and reliability to enable human exploration missions and reduce risk to success of those missions. As a fully operational human-occupied platform in microgravity, the International Space Station (ISS) presents a unique opportunity to act as a testbed for exploration-class ECLSS, such that these systems may be tested, proven, and refined for eventual deployment on deep space human exploration missions. This paper will provide an updated status on the testbed development including hardware and ISS vehicle integration progress
INTRODUCTION: Selection of medical devices for the Orion medical system is a complex task which is dependent on the current state of terrestrial technology. In this work we review the interplay between NASA requirements, constraints, and opportunities for synergy during the development of the Orion medical system. METHODS: The “plan to treat” list of conditions, and subsequently the medical resource list for the Orion Artemis II lunar flyby mission was completed using semi-quantitative methods. During this process, some medical resources were excluded to comply with mass and volume limits, while other resources applicable to multiple medical requirements were prioritized for inclusion. Choices were also examined considering NASA level of care standards for the Artemis design reference missions. As a means to optimize capabilities in spite of mass and volume constraints, ideas for integration of multiple devices into a single platform were explored, including a ‘hackathon’ challenge which was conducted to generate and evaluate concepts for combining medical devices into a single app-based mobile device (ultrasound, ECG, etc.). RESULTS: The Orion team identified 128 medical conditions that we “plan to treat”, with 139 unique medical resources to address these conditions, including 5 digital diagnostic devices (ECG, otoscope, stethoscope, pulse oximeter, and blood pressure monitor). During selection of these digital devices the team noted that miniaturized medical devices often use mobile device platforms (mHealth), some displaying and transmitting data exclusively via mobile device. Of the 5 initially selected devices, all are capable of mobile connection, one which cannot function without a mobile device (ECG). Furthermore, only one of these devices connects natively to a Windows platform, which is currently the only operating system available on Orion. DISCUSSION: Significant savings in mass and volume as well as training and usability improvements can be achieved by leveraging mHealth technologies. However, the platform presents significant challenges for deployment within the Artemis Program including lack of internet connectivity, incompatible operating systems, and radiation concerns. Each of these drawbacks are surmountable with investment in the supporting vehicle architecture, which may become necessary to support the technology trends seen in commercially available medical devices today. Objective: Learn about the opportunities and challenges of leveraging mHealth devices in the development of medical capabilities for austere environments. Learn about the constraints of the NASA spaceflight environment with regards to digital medical device integration.
NASA’s Artemis program has brought significant change to the agency’s human exploration strategy over the last several years. To better align with these policy changes, updates to several key ground rules and assumptions have been made to better support Strategic Analysis Cycle 2021 (SAC21). Of the changes, two in particular have had significant impact on the design of the Mars Ascent Vehicle (MAV): the desire for minimal surface infrastructure and reduced technology investments in support of initial human missions to Mars. As a result, recent designs for the MAV are based on a nitrogen tetroxide (NTO) and mono-methyl hydrazine (MMH) two stage propulsion system. The vehicle supports two crew members from the surface up to 84 hours nominally. This paper presents further details of the current MAV reference design used in NASA’s SAC21, including descriptions of the operations, configuration, subsystem design, and vehicle mass summary. Additional detail is also provided on rational that drove specific design changes since the last MAV concept, published in 2019.
As part of NASAs lunar exploration Artemis program, the agency is designing a Gateway to orbit8near the moon and provide long term support of a sustained lunar presence at the moon’s south pole.9The first element launched for the Gateway is the Co-Manifested Vehicle (CMV), comprised of the10Power and Propulsion Element (PPE) and Habitation and Lunar Outpost (HALO). The PPE Mission11Design team of McGuire & et. al (2021) has developed a Design Reference Mission (DRM) trajectory12for CMV’s Earth Orbit Raising (EOR) mission phase, which provides the vehicle’s 3 degrees of freedom13(DoF) trajectory information during the approximately yearlong spiral out from low Earth orbit and14into the lunar near-rectilinear halo orbit (NRHO). In tandem, the PPE GN&C team is developing a15high-fidelity and fine temporal resolution 6DoF model of the CMV spacecrafts GN&C performance16for delivery to the Gateway team; this work acts to bridge the gap between Mission Designs 3DoF17reference and detailed GN&Cs attitude simulation.
Lunar launch and landing pads are necessary to mitigate risks to lander/ascent vehicles and surrounding surface assets from rocket plume ejected regolith. The current state of the art of landing and launching from the lunar surface is to land/launch on unprepared regolith surfaces. Significant risks exist for the larger landers proposed for the Artemis Program due to higher thrust levels leading to increased ejecta and cratering, presence of co-located assets in the ejecta path, and potential strict surface levelness requirements for tall vehicles.
Introduction: A new era in lunar exploration has recently begun. Through NASA’s robotic Commercial Lunar Payload Services (CLPS) initiative, international and the human Artemis programs, multiple assets are being deployed to explore the Moon and at a rapid cadence. There will be a huge expanse in lunar surface exploration with mobility (e.g., rovers). Several missions are focused on collecting data for assessing lunar resources for potential In-Situ Resource Utilization (ISRU). With this expansion in exploration there will be a commensurate expansion in the volume and variety of data. Work has begun on establishing a measurement plan (i.e., what data is needed) for ISRU [1] but how to integrate these data into the broader Planetary Data Ecosystem (PDE) following FAIR (i.e., Findability, Accessibility, Interoperability, and Reuse) data practices has not been addressed. The VIPER team intends to engage this challenge.
The NASA Artemis Program plans to return humans to the Moon to stay. Extended human stays on the Moon will require substantial resources to sustain human presence over the long-term, requiring continuous supplies delivered from the Earth. However, if some of the resources were indigenously available, substantial logistical complexity and costs could be saved by “living off the land”, wherever possible. The LCROSS, LRO and other missions have confirmed the presence of resources such as volatiles in polar regions, so the next step is to understand the scientific nature and physical distribution of those candidate resources. Those local volatiles could be processed into propellants and human life-supporting needs, reducing risk of maintaining a permanent human presence on the Moon. The Volatiles Investigating Polar Exploration Resource (VIPER) is a surface mobility scientific platform, designed to spend ~100 days mapping and surveying four different Ice Stability Regions to understand the scientific nature and distribution of water and other volatiles. VIPER will also provide scientific mineralogical context of the lunar regolith, such as the presence of silicon and light metals in lunar regolith, providing a composite picture of resource availability and sustainment. This paper will discuss the latest development progress by the VIPER team, following our initial introduction to this mission at IAC2021. The VIPER team has passed both its NASA Preliminary Design Review (PDR) and Critical Design Reviews (CDR), and is now looking to performing significant testing of engineering units representing the design, prior to the team turning its attention to building the flight hardware. VIPER is managed within NASA’s Science Mission Directorate (SMD), utilizing the Commercial Lunar Payload Services (CLPS) delivery model with partner, Astrobotic, Inc.
The NASA Engineering and Safety Center (NESC) conducted an interdisciplinary study and workshop focusing on capabilities needed for crew health and safety on long-duration deep space expeditions in support of the Artemis Program and missions to Mars. The study focused on integration among four disciplines: 1) space weather monitoring and forecasting, 2) shielding technologies, 3) human health research, and 4) human factors engineering tools. An integrated risk assessment was performed to inform characteristics of mission architecture and capabilities needed for safe, long-duration human expeditions beyond low Earth orbit. This report contains the outcome of the NESC assessment.
Human exploration missions beyond low earth orbit, such as NASA’s Artemis Program, present significant challenges to spacecraft system design and supportability. A particularly challenging area is the Environmental Control and Life Support System (ECLSS) that maintains a habitable and life-sustaining environment for crewmembers. NASA is utilizing the experience gained from its current and prior spaceflight programs to mature life support technologies for exploration missions to deep space. The intent is to establish a portfolio of life support system capabilities with proven performance and reliability to enable human exploration missions and reduce risk to success of those missions. As a fully operational human-occupied platform in microgravity, the International Space Station (ISS) presents a unique opportunity to act as a testbed for exploration-class ECLSS, such that these systems may be tested, proven, and refined for eventual deployment on deep space human exploration missions. This paper will provide an updated status on the testbed development including hardware and ISS vehicle integration progress to date as well as future plans for efforts to design, select, build, test and fly Exploration ECLSS on the ISS.
NASA’s Artemis Program seeks not only to return humans to the Moon for the first time since the 1970’s but also to provide the technological basis for infrastructure that will enable permanent and expanding scientific and industrial exploitation of the Lunar surface. The primary purpose of this infrastructure is to generate and distribute power to a diverse and growing range of scientific and industrial assets, and the keys to success for this function are power management and control circuits that are highly reliable and maintainable for a decade of operation in the extreme thermal, radiation, and dust environment of the Lunar surface. While various combinations of wide band gap semiconductors, electronic devices, circuit topologies, and shielding schemes have been successfully developed for mission environments ranging from low Earth orbit to the Jovian system, power management technology has not been optimized to meet the full combination of mission requirements for the Lunar surface. To accomplish this, NASA requests the dedicated focus of the power electronics industry.
The accumulation of Lunar dust on various surfaces is the subject of much recent study, yet is still poorly understood. Recent plans to return humans to the Moon as part of the Artemis program mean that the presence of robust infrastructure to support a permanent human presence is inevitable. Power supply systems, such as Radioisotope Thermoelectric Generators are a likely part of that infrastructure, but require radiative thermal dissipation through a series of radiator fins to function effectively. In this work, the results of a parametric study of the impact on radiator efficiency due to various quantities and types of lunar dust simulants are presented, determining that the impact from low levels of lunar dust accumulation is not significantly detrimental to the efficiency of Multi-Mission Radioisotope Thermoelectric Generator performance in a vacuum, but increased fidelity of data would improve these findings.
Through the NASA Artemis program, a new era of space exploration will serve to lead humanity towards sustained lunar exploration in preparation for the next giant leap-human exploration of Mars. These crewed spacecraft and habitats will require more automation and autonomy to support these complex missions. Crew size will be small and therefore a more efficient command and control input method is desired. Speech recognition along with visual or auditory feedback is an alternative, providing an extra pair of hands and eyes for the crew. Yet, speech recognition demands a highly integrated development approach to ensure a successful system implementation. To ensure the voice control application is developed correctly will require a Human Systems Integration (HSI) approach. This paper provides an insight into the development of a speech/voice control application for a spacecraft system that encompasses automation and autonomy through an HSI approach. Results of the voice control experiment of the Space Shuttle camera system are provided as lessons learned about using voice control on a spacecraft. Limitations and challenges of the technology are addressed as well as how HSI along with Human Readiness Level can help successfully develop voice control command and control systems.
NASA is set to embark on the next era of human space exploration on the Artemis program. An eventual goal of the program is to maintain a human presence on the lunar surface. With such a goal comes the challenge of providing durable infrastructure that is suitable for the Moon and utilizes in-situ resources. Bringing materials form Earth poses a financial burden and increased safety concern. The composition of the lunar soil makes it advantageous to create a geopolymer concrete material. The lunar regolith can be used in the as found condition on the lunar surface and most of the mixing solution can be extracted form the regolith. It is envisioned than any concrete infrastructure would make use of additive manufacturing techniques with a temporary controlled environment enclosure to mitigate the harsh lunar conditions. Data is needed to benchmark how the material behaves once exposed to such an extreme environment so structural failures are mitigated.
NASA is embarking on a new and exciting era of human exploration to the Moon and its vicinity. As part of the Artemis program, NASA is developing the lunar Gateway, an orbiting platform in Near Rectilinear Halo Orbit (NRHO) about the Moon. The first two elements of the Gateway will be launched in 2024 and will be transferred from a high Earth orbit to the NRHO via the use of Solar Electric Propulsion (SEP). The SEP system is located on the Power and Propulsion Element (PPE) which will provide up to 60 kW of power. Aerojet Rocketdyne is developing the 12 kW flight Hall thrusters to be used for transferring the PPE and the Habitat and Logistics Outpost (HALO) module to NRHO. Work is continuing on the development testing, and these results will be described in the paper. The project has also recently completed its critical design review and is transitioning to the fabrication of the three flight thrusters. The 12 kW Hall thrusters are being developed under the NASA Advanced Electric Propulsion System (AEPS) program. As part of the AEPS program, AR built two Engineering Test Unit (ETU) Hall thrusters based on the NASA HERMeS engine and conducted a series of tests to validate the design. One series of tests focused on environments and functional testing, while the other series was mainly focused on long duration test blocks. Results from these tests were used to compare with NASA data from the HERMeS thruster. The comparison of the test results showed no change to the critical performance and lifetime parameters, which enabled the next phase of the program to proceed. Currently testing is continuing on the Engineering Development Units (EDU) as part of the flight qualification activities. The successful completion of the CDR serves as the starting point for the flight thruster fabrication, which is now underway to support the launch of the Gateway modules in 2024. The development and qualification of the AEPS 12 kW Hall thrusters is proceeding well. As the program completes CDR and transitions into flight builds of the three 12 kW Hall thrusters that will be used to transfer the combined PPE and HALO stack to the NRHO, the results of the development testing are reviewed in this presentation, and a status of the program and future plans is provided. The launch of the two Gateway modules and the transfer of this large payload to cislunar orbit will mark a significant milestone in electric propulsion, as it will demonstrate the ability of SEP to transfer very large payloads over great distances. This establishes the precedent that could lead to cargo transfers from the Earth to the Moon or even to Mars using SEP.