Compilation of Assumptions
Environmental Assumptions
1.1.1 Given as part of the competition guidelines
- Robotic lander is delivered to the South Polar region of the moon (>75° S)
- Robotic lander rover either lands in or moves into a permanently shadowed crater where water ice is present within a meter of the surface.
- The excavator subsystem will collect at least 100kg of regolith, and the oxygen production/water extraction subsystem must process all of this 100kg within a one-month mission.
1.1.2 Additional assumptions made by LunarDREEM team
- Temperature in the permanently shadowed crater is constant at ~40K.
- Ambient pressure is a hard vacuum.
- Solar radiation has no appreciable effect on subsystems.
- The floor of the permanently shadowed crater is flat ground, with powdery dust to at least 1 meter.
- The regolith in the permanently shadowed crater has no more than 1% ice-water by weight (Based on data from the Clementine and Lunar Prospector probes, [Feldman, 2000])
The extraction of oxygen from iron-oxides in the polar lunar regolith is estimated to yield no more than 2% by weight Research indicates that approximately 4% can be extracted from lunar mare materials, while lunar highland materials offer around 1.2% Given that the lunar south pole is considered an intermediate region, a conservative estimate of 2% extraction is assumed.
- The average density of the lunar regolith is 3100 kg/m 3 [Heiken, 1991], so the 100 kg of regolith specified for this project has a volume of 032 m 3 , equivalent to a cube 32 cm on a side.
Mobility/Rover Assumptions
1.2.1 Given as part of the competition guidelines
- A rover the size of the Mars Exploration Rovers will carry the design team’s experiment package.
- The lander has ample volume available to meet the experiment requirements.
- Experiment packages should attempt to meet mass (50 kg) and power (100 W) constraints.
1.2.2 Additional assumptions made by LunarDREEM team
- “Experiment package” includes excavator subsystem, oxygen production/water extraction subsystem, bulk physical characteristics test chamber, and process efficiency measurements
- Experiment package is mounted on rover; rover provides mobility for all the subsystems (including excavation subsystem); rover mobility is dictated solely by mobility requirements for the Experiment Package.
- Rover can deliver the entire 100W continuous power to the Experiment Package when required
- Rover can “plant itself” to provide sufficient reaction force to counter excavation forces.
- No constraints on subsystem-rover interfacing; subsystems can be placed anywhere on the rover.
Control Assumptions
1.3.1 Given as part of the competition guidelines
-Real-time communications will be available on a continuous basis between the rover and Earth.
1.3.2 Additional assumptions made by LunarDREEM team
-Earth-based user control will not be limited by bandwidth availability.
-Earth-based control/oversight is available 24 hours a day throughout the entire mission.
Other Assumptions 2 Regolith Excavation System
Other assumptions specific to subsystem technologies are detailed separately in the following sections.
2 REGOLITH EXCAVATION, COLLECTION, AND DELIVERY SYSTEM
Excavation, Collection and Delivery System – an integrated system for the excavation and transfer of lunar regolith from the lunar surface to experiment test chambers.
The Excavation System consists of three key subsystems: the Excavator Subsystem for regolith collection, the Loading-Unloading Subsystem for transferring regolith to an oxygen production furnace or test chamber, and the Bulk Physical Characteristics Test Chamber for assessing the physical properties of lunar regolith This article outlines the objectives and design options for each subsystem, followed by a comprehensive evaluation of different Excavation System architectures A trade study is conducted to compare these architectures based on qualitative factors such as risk and complexity, leading to the proposal of a primary Excavation System architecture along with alternative options for further analysis.
Conceptual Design of Regolith Excavation, Collection and Delivery System
The Excavator Subsystem is essential for initial regolith interaction, tasked with collecting up to 100 kg of regolith from a depth of one meter within a month Its design must withstand the harsh lunar environment while preserving valuable volatiles and minimizing mass and power consumption Key objectives include risk reduction, simplicity in design, and effective mass flow control Risk is evaluated based on moving parts, environmental interfaces, and the subsystem's responsiveness to disturbances Simplicity is determined by the number of components and operational complexity, while mass flow controllability ensures precise movement and placement of regolith, crucial for mitigating lunar dust effects and facilitating testing processes.
Various concepts were evaluated to meet the Excavator Subsystem goals of extracting regolith from up to one meter below the lunar surface and collecting 100 kg of lunar regolith during a month-long mission These included innovative designs like vibrating wedges, vacuums, telescoping tubes, and electrostatic netting, alongside more conventional terrestrial systems such as backhoes, combines, treaded conveyor belts, and lifting drills Ultimately, terrestrial-based designs were preferred due to the inherent risks of the radical concepts, which depend on uncharacterized lunar environmental data and lack operational history Consequently, three Excavator Subsystem concepts rooted in terrestrial applications have been chosen for further investigation.
Drill, Treaded Conveyor Belt, and Backhoe Notional diagrams of the three excavator concept design options are shown in Figure 2.1
The Drill operates on the principle of the "Archimedes Screw," enabling vertical translation from the rover into the regolith As it rotates, the screw lifts regolith along its length while gradually pushing the drill housing deeper into the material, achieving a maximum depth of one meter The excavated regolith is expelled into a collection bin Although the Drill's length is fixed for one-meter depth, its diameter can be adjusted to gather up to 100 kg of regolith in one or multiple excavations While multiple excavations are less resource-intensive, they introduce greater operational complexity The Drill will be equipped with at least two essential control sensors: one for measuring angular velocity and another for tracking vertical position.
2.1.1.2.2 Excavator Concept 2: Treaded Conveyor Belt
The Treaded Conveyor Belt is a creative design most easily compared to the treaded track of a snowmobile.
The treaded conveyor belt operates using a motor that moves around two pulleys, enabling vertical and horizontal translation for increased excavation reach Positioned at the surface of the regolith, the conveyor belt scoops up small amounts of material as it moves, transporting the regolith to a collection bin Once emptied, the tread returns to scoop more regolith, while the entire system adjusts its position for the next excavation To ensure efficient operation, the treaded conveyor belt requires four essential control sensors: one for measuring x-displacement, another for y-displacement, a third for the angle of rotation at the rover's base, and a fourth to detect the scoops' contact with the ground.
The Backhoe is an innovative terrestrial design that mimics the motion of a human arm, enabling three-axis movement of its end-effector It features an actuator that rotates in both horizontal and vertical planes, akin to a human shoulder, connected to a middle actuator with vertical rotational capability, similar to an elbow This setup allows the final actuator to control the scoop's vertical movement, enabling it to reach any position within a specified radius around the shoulder attachment The scoop is designed to transport regolith from the lunar surface to a collection bin To function effectively, the Backhoe requires at least five control sensors: two for measuring x- and y-displacement, two for monitoring the rotational angles of the scoop and elbow, and one for detecting contact between the end-effector and the ground.
Concept 1: Drill Concept 2: Treaded Conveyor Belt Concept 3: Backhoe
Figure 2.1: Excavator Concepts (arrows indicate directions of motion)
The Loading-Unloading Subsystem is designed to efficiently load and unload regolith from an experiment chamber, such as a furnace, while closely interacting with the Excavator Subsystem as part of the Excavation System This subsystem aims to minimize mass and power consumption to adhere to mission constraints, reduce risks, and enhance simplicity for easier maintenance and support Furthermore, it is essential for the Loading-Unloading Subsystem to incorporate regolith mass measurement capabilities within the experiment chamber.
Three concepts are proposed for the Loading-Unloading Subsystem: Sliding Panels, Horizontal Piston, and Dual Irises Figures 2.2 – 2.4 show notional diagrams of these concepts.
2.1.2.2.1 Loading-Unloading Concept 1: Sliding Panels
In the initial stage, regolith is deposited into a container, which is then transferred to Stage 2a As the container progresses towards Stage 2a, the regolith starts to exit from the bottom, ultimately landing on a scale in Stage 2b for measurement.
The regolith is processed in a furnace, after which the remaining waste is weighed before being disposed of Once the regolith is placed in the furnace, the container returns to its original position for reloading Two control sensors are essential for this operation; the first sensor verifies the regolith's presence in the initial bin, while the second ensures it is correctly positioned for entry into the furnace.
2.1.2.2.2 Loading-Unloading Concept 2: Horizontal Piston
Regolith is transported via a conveyor belt into a weighing bin before being processed in a furnace Once the furnace door opens, a piston pushes the bin inside, where processing occurs until completion Afterward, a grappling piston retrieves the bin, weighing it again before it exits through a trap door Meanwhile, a new bin is positioned to receive regolith from the conveyor belt The operation relies on three sensors: one for conveyor belt movement, another for measuring the regolith in the bin, and a third to confirm the bin's position for ejection.
2.1.2.2.3 Loading-Unloading Concept 3: Dual Iris
Regolith is first loaded onto the top iris for weighing before it is released into the furnace as the iris opens After processing, the waste regolith is weighed again, and the second iris opens to expel the regolith from the furnace and out of the system Each iris requires a sensor to detect the presence of regolith effectively.
2.1.3 Bulk Physical Characteristics Test Chamber
The Bulk Physical Characteristics Test Chamber is designed to assess the shear, yield, and strain (compaction) of lunar regolith obtained from the Excavator Subsystem This testing must be accomplished while adhering to mission constraints by minimizing mass and power consumption, reducing risk, enhancing simplicity, and ensuring ease of maintenance and support.
Three concepts are proposed for the Bulk Physical Characteristics Test Chamber: Compression Chamber,
The Rotary Bar and Thin Wire Pull concepts, illustrated in Figures 2.5 – 2.7, are designed to capture two key data types: voltage and displacement By analyzing voltage data, applied force and stress can be calculated, while displacement data is used to determine strain, which relates to compaction Yield strength is identified by creating a stress-strain curve to find the stress point at which elastic deformation ends This approach assumes that each regolith particle behaves similarly to atoms in a close-packed material, with size variations representing substitutional defects and voids indicating vacancy defects Yield occurs under stress due to dislocation movement, and friction between particles mirrors atomic bond interactions However, the model relies on specific conditions: the sample must be compressed to form a lattice structure, regolith particles need to be spherical, and other inter-particle forces like electrostatics must be considered Additionally, it does not address the potential fracturing of regolith particles under high stress.
The model, derived from NASA's educational brief "Mechanics of Granular Materials," involves a regolith sample placed in a split rectangular chamber, where it is compressed by a piston that also acts as the upper seal After achieving the desired compression, a motor induces a small displacement in the chamber, with the required voltage for this movement being recorded This measurement setup minimizes errors related to strain in the device, as the forces on the chamber walls are significantly lower than those needed to cause deformation However, the system faces a heightened risk of failure due to the abrasive nature of lunar regolith, which can compromise the seals of the many moving parts, potentially leading to incorrect system performance.
The Rotary Bar operates as a viscosity tester primarily for liquid materials, utilizing a cylindrical chamber where regolith is compressed by a piston against a rotating stiff bar connected to a rotary actuator As voltage is applied to the actuator's motor, the resulting spin of the bar indicates viscosity levels However, a significant challenge arises from the shear test, as forces on the bar increase along its length, leading to a non-uniform force distribution on the regolith Ongoing research aims to develop mathematical methods to compensate for this non-uniformity in data analysis.
2.1.3.2.3 Test Concept 3: Thin Wire Pull
Regolith is compressed in a rectangular chamber using a sealing piston, and a thin wire is then pulled through the sample with a linear actuator system to study how different orientations affect the material's characteristics However, this method poses significant risks, as the wire can fracture due to large forces and experiences varying normal forces depending on the chamber's orientation For instance, in a vertically oriented chamber, pulling the wire from the bottom to the top results in decreasing normal forces due to the diminishing weight of the regolith above it, leading to potential errors in the test results.
Regolith Excavation, Collection and Delivery System Architectures
An Excavation System Architecture consists of three key components: the Excavator Subsystem, the Loading-Unloading Subsystem, and the Bulk Physical Characteristics Test Chamber There are two approaches to selecting the architecture: one involves analyzing each subsystem's capabilities individually before combining them, while the other combines subsystem options into feasible architectures for a holistic analysis Due to overlapping objectives among subsystems, the latter method is often more effective It is essential that all subsystems minimize mass and power consumption to adhere to mission constraints, reduce risk, enhance simplicity, and facilitate maintenance Furthermore, the Excavator Subsystem plays a critical role in optimizing the control of mass flow to the other subsystems.
The design of Excavation System Architectures allows for 27 potential combinations based on three options for each subsystem; however, not all combinations are viable Each Excavator Subsystem can work with any Loading-Unloading Subsystem, but certain Bulk Physical Characteristics Test Chamber concepts align better with specific Loading-Unloading designs due to shape and orientation For instance, the Compression Chamber and Sliding Panel concepts feature a rectangular shape and vertical orientation, ensuring equal normal forces along the shear line and consistent force distribution from the container walls Conversely, the Rotary Bar concept, which is cylindrical and vertically oriented, pairs effectively with the Dual Iris Loading-Unloading Subsystem, also cylindrical and vertically oriented Lastly, the Wire Pull concept utilizes a horizontal orientation and rectangular shape, optimizing interaction with the Horizontal Piston concept while ensuring uniform contact with the regolith sample Although a cylindrical setup could work, it would introduce unnecessary complexity.
The nine feasible architectures presented for trade study are:
Architecture A: Drill + Sliding Panels + Compression Chamber
Architecture B: Drill + Horizontal Pistons + Wire Pull
Architecture C: Drill + Dual Iris + Rotary Bar
Architecture D: Treaded Conveyor Belt + Sliding Panels + Compression Chamber
Architecture E: Treaded Conveyor Belt + Horizontal Pistons + Wire Pull
Architecture F: Treaded Conveyor Belt + Dual Iris + Rotary Bar
Architecture G: Backhoe + Sliding Panels + Compression Chamber
Architecture H: Backhoe + Horizontal Pistons + Wire Pull
Architecture I: Backhoe + Dual Iris + Rotary Bar
Trade Studies and Methodology for Option Selection
2.3.1 Regolith Excavation, Collection and Delivery System Functional Properties
A trade study of nine Excavation System architectures identifies key functional properties that influence system objectives, aiming to minimize mass and power usage, reduce risk, enhance simplicity, facilitate maintenance and support, and optimize mass flow control from the Excavator Subsystem to other subsystems These properties encompass degrees of freedom, the number of moving parts in contact with regolith, the number of sensors, and the repeatability and accuracy of motion within the Excavator Subsystem Table 2.1 illustrates and justifies the connection between these objectives and the identified functional properties.
Related Concept Functional Properties Justification of Relationship
Freedom Degrees of freedom require actuated components, which add mass to the system
Freedom Degrees of freedom require actuated components, which require power
Decreasing the degrees of freedom decreases the number of actuated components, which reduces the risk that one of the actuated components will fail
Number of Moving Parts in Contact with Regolith
Decreasing the number of moving parts in contact witih lunar regolith reduces the probability that the abrasive lunar dust will damage an actuated component
More sensors mitigate risk by providing an increased opportunity to identify unexpected stimuli and disturbances and initiate contingency procedures to prevent damage to the system
Decreasing the degrees of freedom decreases the number of actuated components, which reduces the complexity associated with implementing the design and operating in the lunar environment
Number of Moving Parts in Contact with Regolith
Moving parts in contact with regolith must be shielded or otherwise made resistant to the abrasive lunar dust This increases the complexity associated with implementing the design.
Number of Sensors More sensors require increased control and processing complexity
Number of Sensors More sensors provide more data describing the state of the system.
This improves fault-detection and diagnoses critical to effective maintenance and support of the mission
The Excavator Subsystem plays a crucial role in effectively managing lunar dust by accurately containing and transporting regolith This precision enables the controlled placement of specific quantities of regolith within test chambers, which is essential for mitigating the adverse effects of lunar dust.
* applies to Excavator Subsystem only
Table 2.1: Relationship between Mission Objectives and Concept Functional Properties
In designing an Excavator System for the lunar environment, several unique functional properties must be considered, despite not being included in the initial conceptual trade study The method of power utilization—whether electric, pneumatic, or hydraulic—plays a crucial role in achieving simplicity While pneumatic and hydraulic systems are common on Earth, the moon's lack of atmosphere and extreme temperatures present significant challenges for these technologies Consequently, electric power emerges as the preferred solution, effectively addressing these lunar-specific issues.
Lubrication of moving parts is crucial for operational efficiency, but traditional viscous lubricants can solidify under extreme lunar temperatures, rendering them ineffective This solidification poses a risk of contaminating the regolith, which could compromise experiments aimed at analyzing its chemical composition and the efficiency of in-situ oxygen production To address these challenges, researchers are exploring alternatives to wet lubricants for the Excavator System's detailed design, particularly considering the impact of cyclic loads on performance.
The Excavation System plays a crucial role in minimizing mass, power consumption, and operational risk While utilizing multiple smaller excavations can extend operation time and increase the likelihood of component failure, it ultimately requires less mass and power compared to a single excavation This trade-off will be explored further in the preliminary design phase of the Excavation System Additionally, the modularity of the design is essential for risk reduction, allowing each subsystem to function independently For instance, if the Bulk Physical Characteristics Test Chamber experiences a failure, the Excavator Subsystem must still be capable of delivering regolith to other experiment chambers Ongoing research is focused on integrating effective modularity mechanisms into the preliminary design of the Excavation System.
2.3.2 Regolith Excavation, Collection and Delivery System Trade Study – Multiple Matrix Technique
The Excavation System Architecture trade study employs a multiple matrix method to systematically evaluate alternative options and synthesize architecture, ensuring alignment with overarching needs and objectives Initially, a relationship matrix (Matrix 1) was developed to connect the objectives with the concept functional properties outlined in Table 2.1 Subsequently, a second matrix (Matrix 2) was created to link specific functional properties to the Excavation System Architectures detailed in Section 2.2 By calculating a product-sum between these two matrices, the study assesses the effectiveness of each Excavation System Architecture in meeting the established objectives.
The initial relationship matrix (Matrix 1 in Table 2.2) illustrates the influence of functional properties on the objectives of the Excavator System, assigning a ranking to each functional property based on its impact on these objectives, using a scale of 1.
The scoring system ranges from 1 to 5, where a score of 5 indicates a very strong positive impact, while a score of 1 represents a very weak positive impact Cells linked to functional properties that either have a negative effect or no effect on objectives are left blank The relationship numbers in Matrix 1 align with the qualitative trends outlined in Table 2.1 Each objective is assigned an equal weight of 10, indicating its importance in the subsystem function; however, if a specific parameter like mass or power becomes critical, its weight can be adjusted accordingly Matrix 2 in Table 2.2 details the functional properties associated with each architecture, categorized by the number of degrees of freedom, moving parts in contact with regolith, and sensors Architectures are classified as having "Few," "Some," or "Many" sensors based on their average value and standard deviation, with those falling within one standard deviation categorized as "Few," those exceeding it as "Many," and all others as "Some."
Matrix 2 also scores Excavator Subsystems according to repeatability/accuracy of motion The Drill is expected to provide the most controlled regolith excavation The threads of the drill will lift a specific quantity of regolith, and the regolith will remain contained inside the drill casing during transit to the next subsystem (score = 5) The Backhoe is expected to provide the least controlled excavation of regolith because it not trivial to scoop the same amount of regolith each time Also, the Backhoe does not contain the regolith during transfer to the next subsystem, resulting in an increased probability of depositing lunar dust on other rover systems (score = 1) Finally, the Conveyor Belt provides a medium amount of controllability as compared to the other two Excavator System concepts Less degrees of freedom of freedom provide less variability of motion than with a Backhoe, and the regolith is limited to travel along the conveyor belt (score
The entries in the Result Matrix (Matrix 3 in Table 2.2) are derived for each Excavation System architecture by multiplying the elements of row N in Matrix 1 with their corresponding weights from Matrix 2 The resulting products are summed to provide a relative assessment of how effectively each architecture meets the specified objectives The ranking metric is then determined by calculating the total points for each architecture and dividing it by the overall points in Matrix 3.
The trade study results are highest for the following four Excavation System Architectures:
Drill + Dual Iris + Rotary Bar
Drill + Horizontal Piston + Wire Pull
Treaded Conveyor Belt + Sliding Panels + Compression Chamber
Treaded Conveyor Belt + Dual Iris + Rotary Bar
2.3.3 Trade Study Implications and Future Design Methodologies
The preliminary design of the Excavator Subsystem will prioritize trade studies that evaluate the Drill and Treaded Conveyor Belt, focusing on a quantitative analysis of power and mass for various excavation scenarios This includes assessing the trade-offs between mass and power for both single and multiple excavations Additionally, scale models will be constructed and tested in the lab to validate the quantitative findings and ensure design operability For the Loading-Unloading Subsystem, the emphasis will be on a quantitative trade analysis of the leading concepts for the Drill and Conveyor Belt, specifically the Dual Iris and Sliding Panels, considering power, mass, geometry, and material options Furthermore, all proposed concepts for the Bulk Physical Characteristics Test Chamber will undergo small-scale laboratory experiments to confirm their validity before making a final selection.
Table 2.2: Relationship Matrix for Regolith Excavation, Collection and Delivery Trade Study
3 IN-SITU OXYGEN PRODUCTION SYSTEM
In-situ Oxygen Production System (ISOPS) – an integrated subsystem for both the production of oxygen and extraction of water from lunar regolith
3.1 High Level Oxygen ISOPS Architectures
3.1.1 Choosing the Process for an Oxygen Production Plant
The ISOPS initiative aims to validate oxygen production from lunar regolith throughout the mission, aligning with predictions from Earth-based experiments This technology demonstration sets the stage for utilizing in-situ resources to create consumables and propellant for future lunar exploration and potential Mars missions Over twenty methods for extracting oxygen from lunar soil have been proposed, with varying levels of development; four key processes—hydrothermal reduction, carbothermal reduction, molten silicate electrolysis, and vapor phase reduction—are particularly promising for large-scale oxygen production The processing temperatures, yields, and complexities of these methods are detailed in Table 3.1, with Taylor's complexity scoring ranging from 1 (many steps) to 10 (one step).
Table 3.1: Comparison of Oxygen Extraction Methods [data from Taylor, 1993]
Oxygen needs for a lunar base are estimated at 0.83 kg per person daily, necessitating the processing of 50 to 100 kilograms of regolith per person using hydrothermal reduction, which has a ~4% oxygen yield Although other methods are more efficient, hydrothermal reduction is favored for small-scale robotic demonstration missions due to its simplicity and lower processing temperatures, making it suitable for power-constrained environments Additionally, there is a robust dataset from laboratory experiments on hydrothermal reduction applied to lunar regolith, supporting its viability for such missions.
The lunar environment presents unique challenges for process validation, particularly due to the sintering of lunar regolith at temperatures exceeding 1050°C, which necessitates special mechanisms to prevent obstruction in processing equipment For the initial demonstration mission, it is advisable to avoid complications related to sintering While the final selection of a human-scale oxygen extraction process can be determined later, a hydrothermal-based demonstration mission is a pragmatic choice This mission will encompass not only the extraction process but also the excavation, collection, and handling of lunar regolith, as well as the collection and electrolysis of water in the high-temperature processing chamber and the subsequent storage of oxygen.
Focusing on hydrothermal reduction, we have chosen task 4 as our specialization This processing system is also capable of extracting water ice from lunar regolith, addressing the needs of task 5 Essentially, hydrothermal reduction requires heating regolith to achieve its objectives.
High Level ISOPS Architectures
3.3.2The Effect Of Moist Hydrogen Gas On Process Efficiency Measurements
The electrolysis subsystem operates at approximately 21°C and standard pressure, introducing water vapor into the purged or recycled hydrogen flow, which leads to a loss of about 1.7% of the collected oxygen due to humidity This estimation is based on the assumption of a hydrogen flow that is either purged or dried and recycled, with a flow rate significantly higher than the minimum required Consequently, this may overstate the effect of moist hydrogen gas on process efficiency, indicating that there is no need to implement mechanisms for capturing and electrolyzing moisture from the hydrogen flow.
3.4 Control, Regulation, and Process Efficiency Measurement Sensors
The ISOPS system operates with two control sensors and three regulation sensors to ensure optimal performance One control sensor detects regolith in the Furnace to trigger heating, while another monitors water in the Electrolysis Subsystem to start electrolysis To maintain proper functioning, regulation sensors are essential for monitoring the processing temperature of the Furnace, the operating temperature of the Electrolysis Subsystem, and the Oxygen Collection Subsystem Additionally, three efficiency measurement sensors are required: a scale to weigh the regolith in the Furnace, a scale for the produced water, and a flow meter to quantify the collected oxygen.
Concept of Operations
The lunar rover will spend two weeks in a permanently shadowed crater collecting regolith and measuring its bulk physical characteristics, followed by an additional two weeks dedicated to processing the regolith to extract oxygen.
Excavating regolith requires four distinct mission phases: (1) Gather regolith, (2) Measure Bulk Physical
Characteristics of Regolith, (3) Load Regolith into Furnace, (4) Unload Processed Regolith from Furnace.
Processing regolith requires five distinct mission phases: (1) Heat Regolith, (2) Reduce Regolith, (3) Collect
Water electrolysis plays a crucial role in recycling hydrogen gas and collecting oxygen, forming the basis for mission scenarios that can be organized on a timeline These scenarios can be categorized into two main types: concurrent processing and sequential processing, as detailed in Section 3.1.2 Additionally, the figure below illustrates various methods for bulk or interspersed excavation of regolith, showcasing the practical applications of these processes.
The control flow diagram below outlines the essential procedures for excavating and processing regolith Arrows illustrate how each procedure initiates subsequent actions, without implying a specific sequence of operations Additionally, the dashed arrow represents the extra control flow involved when interspersed excavation is performed.
Figure 4.3: Control Flow Diagram of Excavation and Regolith Processing Procedures
Near real-time communication between Earth and the moon enables a combination of remote control and autonomous operations for lunar missions Remote operability is especially beneficial in unknown environments, as seen with the Excavator Subsystem, which will be remotely controlled to navigate around lunar rocks during excavation Conversely, autonomous operations are preferred for stable environments, allowing for automated regulation of systems such as the Furnace, Electrolysis Subsystem, and Oxygen Collection Subsystem temperatures.
The timeline depicted illustrates power consumption throughout the mission, based on the bulk excavation of lunar regolith It considers a processing architecture with a batch size of 10 kg, a processing duration of three hours, and a heating period of 24 hours.
Figure 4.4: Timeline of Power Consumption for Concept of Operations
The student team involved in the ISRU University Design Competition is part of the LunarDREEM project at MIT, which focuses on advancing space exploration by utilizing extraterrestrial resources Prior to the 2004-05 NASA ISRU competition announcement, LunarDREEM members were already engaged in lunar ISRU research and actively sharing their findings Their dedication to outreach is evident through various activities aimed at connecting with scientific, engineering, and public communities.
The LunarDREEM project team attended the Space Frontier Foundation's fifth-annual "Return to the Moon" conference in Las Vegas from July 16-18, 2004, where they engaged with leaders in the international lunar exploration community During the event, they presented preliminary findings on a lunar robotic mission that utilizes in-situ produced oxygen as a propellant, enabling a single lander to visit multiple sites on the Moon.
At the SpaceVision2004 Conference at MIT from November 11-14, student team members showcased an outreach poster for the ISRU Design Competition This marked their first poster session, where they detailed the competition's challenges, design options, and trade study methodology The team garnered positive feedback from attendees across government, industry, and academia, while also igniting enthusiasm among fellow students for their competition efforts.
Members of the design competition team involved in the LunarDREEM project from June to August 2004 will present their research paper at the 1st Space Exploration Conference in Orlando, Florida, from January 30 to February 1 Sponsored by NASA’s Exploration Systems Mission Directorate, their paper was one of only 52 selected from 675 submissions, highlighting its competitive merit This conference offers the team a valuable platform to share their design competition progress, engage with the space community, and promote interest in lunar in-situ resource utilization (ISRU) activities.
The student team is developing a LunarDREEM ISRU Design Competition website aimed at engaging a broader student audience, featuring dedicated sections for K-8, 9-12, and university students The K-8 section will offer a general overview of In-Situ Resource Utilization (ISRU) and lunar applications, along with simplified visuals of the team's system designs The high school section will delve into technical details of the competition, incorporating relevant chemistry and physics concepts, while introducing trade studies and design methodologies For university students, the website will present in-depth information on the team's progress, assumptions, and calculations, alongside links to other university teams and NASA's ISRU resources The LunarDREEM team is committed to launching the website according to the competition timeline.
The LunarDREEM team, supported by the Massachusetts Space Grant, will showcase their work at the Massachusetts Space Day event at the Boston Museum of Science in Fall 2005, targeting several hundred high school students They will collaborate with museum staff to create a temporary exhibit featuring their excavator apparatus and educational materials highlighting the significance of In-Situ Resource Utilization (ISRU) for future space exploration Emphasizing that the project was entirely student-led, the exhibit aims to inspire young attendees Additionally, the LunarDREEM team will present their work as part of the 16.S26 Freshman Seminar series at MIT in late April or early May.
“Modern Space Science and Engineering”
The LunarDREEM student team aims to adapt K-8 and 9-12 website content into concise lesson plans for local grade-school and high-school students Supported by the Massachusetts Space Grant Consortium, which backs initiatives like the Science Club for Girls and middle school Rocket Clubs, the team will present their material in local schools Additionally, discussions have begun with the MIT/IGNITE program, known for creating classroom content and offering lecturers to Cambridge public schools, to further enhance their educational outreach.
MIT/IGNITE/Cambridge Educational Outreach:
The IGNITE Foundation, Inc is a recognized 501(c)(3) organization dedicated to creating collaborative educational enrichment programs, with a primary focus on math, science, and technology, inspired by 'NASA type' missions By highlighting the advantages of aerospace technology, we aim to address the critical need for support in these fields In partnership with the LunarDREEM Proposal team at MIT, we plan to enhance our outreach initiatives to achieve a significant impact, beginning with two elementary schools in the Cambridge Public School District, Haggerty and Tobin, aligning with the objectives of the LunarDREEM Design Project and NASA student proposal.
IGNITE has formed partnerships with various organizations that align with its initiatives and has identified experienced presenters in the fields of space and science from the education community This project will feature two speakers who will visit selected schools over a six-month period Alongside guest speaker programs, thematic support will be offered through enrichment materials to enhance project-based curricula developed by district teachers Additionally, a teacher-training workshop and a related after-school program will be provided to further support educational goals.
The lunar content area will explore the phases of the moon and their connection to the Sun, Earth, and Moon relationship, as well as the moon's influence on weather and tides It will cover the history of both manned and unmanned missions to the moon, highlighting the contributions of astronomers throughout history and linking global folklore Additionally, the article will delve into the challenges of living on the moon and emphasize the importance of "living off the land" in extraterrestrial environments.