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In-situ Lunar Launch and Landing Pad Construction with Regolith-Thermoset Polymer Composite Materials
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.
In-situ Lunar Launch and Landing Pad Construction with Regolith-Thermoset Polymer Composite Materials
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. Though this has been a relatively successful approach, significant risks exist 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. Regolith-thermoset polymer composite materials were developed and evaluated for off Earth launch and landing pad applications. Performance under hot fire conditions was assessed for two simulated Starship lunar launch/landing environments, one targeting thermal conditions and the second targeting pressure conditions. Paver test articles were prepared at 20% and 11% polymer mass fractions. Sintered paver test articles were prepared with 20% polymer grouting filling the seams between pavers. Though significant erosion was experienced during the more extreme thermal testing conditions, all test articles successfully mitigated regolith ejecta from plume effects. A concept for preparing and emplacing the materials was developed and tested in laboratory conditions. The testing evaluated the feasibility of using twin and single screw extruder technology to mix, convey and deposit materials. Both the twin and single screw extruders were capable of processing and extruding the composite with a maximum of 90% mass fraction of regolith achieved by the twin screw extruder.A primary risk for application of regolith-thermoset polymer composites as lunar launch/landingpad is the mass of polymer required to be landed on the moon. Calculations were performed that show that a 100 m diameter, 0.025 m thick pad with polymer mass fraction of 15% will require a payload mass of 72 mt to the Lunar surface. This is below the planned Starship payload capacity to the lunar surface of 100 mt. The regolith-thermoset polymer composite based construction approach proved feasibility in three critical areas: performance under launch/landing conditions, demonstration of a mixing and depositing strategy, and fitting within the planned lunar payload capacity. It is recommended that materials and systems be developed to TRL 6 for a small-scale lunar demonstration of emplacement of a launch/landing pad via a CLPS mission to support Artemis Program roadmap gap closure activities.
Lunar Surface Operations: CSM Plane Change and Pre-launch - Lunar Surface - Part 3
The objectives of this slide presentation are: to describe the Command Service Module (CSM) plane change task, the prelaunch phase lunar module (LM) activities, and the prelaunch phase CSM activities.
Insitu Lunar Launch & Landing Pad Construction w/ Regolith and Thermoset Polymers
This CIF project is an extension of materials developed under a previous NASA Innovative Advanced Concepts (NIAC) project titled “Regolith Derived Heat Shield for Planetary Body Entry and Descent Systems with In-Situ Fabrication” by M. Hogue et al. (2012). Launch and landing pads are necessary to mitigate risks to lander/ascent vehicles, surface assets, and orbital assets from rocket plume ejected regolith. At this time, all launching and landing on the lunar surface will be on unprepared surface sites. Though this has been a successful approach for Apollo and other uncrewed missions, significant risks exist for the Artemis Program due to the increased thrust of the vehicles, presence of co-located assets, and potential surface level requirements for tall vehicles. This project developed a thermoset polymer–regolith composite material for use as a launch and landing pad. Test articles were prepared at 20% and 11% polymer mass percent (wt%) and tested under hot fire conditions that simulated large vehicle lunar launch/landing conditions. A minimum polymer wt% of 9% was achieved and both samples successfully mitigated regolith ejecta from plume effects. A concept for emplacing launch/landing pads was successfully tested in laboratory environments using a screw and barrel approach to mixing, conveying and depositing materials. It is recommended that materials and systems be developed to TRL 6 for a small-scale lunar demonstration of emplacement of a launch/landing pad via a Commercial Lunar Payload Services (CLPS) mission to support the Artemis Program.
Evaluation of Dual-Launch Lunar Architectures Using the Mission Assessment Post Processor
The National Aeronautics and Space Administrations (NASA) Constellation Program is currently designing a new transportation system to replace the Space Shuttle, support human missions to both the International Space Station (ISS) and the Moon, and enable the eventual establishment of an outpost on the lunar surface. The present Constellation architecture is designed to meet nominal capability requirements and provide flexibility sufficient for handling a host of contingency scenarios including (but not limited to) launch delays at the Earth. This report summarizes a body of work performed in support of the Review of U.S. Human Space Flight Committee. It analyzes three lunar orbit rendezvous dual-launch architecture options which incorporate differing methodologies for mitigating the effects of launch delays at the Earth. NASA employed the recently-developed Mission Assessment Post Processor (MAPP) tool to quickly evaluate vehicle performance requirements for several candidate approaches for conducting human missions to the Moon. The MAPP tool enabled analysis of Earth perturbation effects and Earth-Moon geometry effects on the integrated vehicle performance as it varies over the 18.6-year lunar nodal cycle. Results are provided summarizing best-case and worst-case vehicle propellant requirements for each architecture option. Additionally, the associated vehicle payload mass requirements at launch are compared between each architecture and against those of the Constellation Program. The current Constellation Program architecture assumes that the Altair lunar lander and Earth Departure Stage (EDS) vehicles are launched on a heavy lift launch vehicle. The Orion Crew Exploration Vehicle (CEV) is separately launched on a smaller man-rated vehicle. This strategy relaxes man-rating requirements for the heavy lift launch vehicle and has the potential to significantly reduce the cost of the overall architecture over the operational lifetime of the program. The crew launch occurs first, four days prior to the optimal trans-lunar injection (TLI) departure window. This is done to allow for launch delays in the Altair/EDS launch. During this time, the Orion vehicle is required to conduct orbit maintenance while loitering in low Earth orbit (LEO). The alternative architectures presented aim to eliminate the need for costly orbit maintenance maneuvers while loitering in LEO. In all of the alternative architectures considered, it is assumed that the Altair and Orion vehicles are nominally launched 90 minutes apart, depart the Earth separately, and complete the rendezvous and docking sequence at the Moon. In this lunar orbit rendezvous (LOR) strategy, both the Altair and Orion vehicles will require separate EDS stages, and each will be required to perform lunar orbit insertion (LOI). This has the effect of balancing payload requirements between the two launch vehicles at the Earth. In this case, the overall payload mass is increased slightly, but the increased mission costs could potentially be offset by requiring the construction of two rockets similar in size and nature, unlike the current Constellation architecture. Three dual-launch architecture options with LOR were evaluated, which incorporate differing methodologies for mitigating the effects of launch delays at the Earth. Benefits and drawbacks of each of the dual-launch architecture options with LOR are discussed and the overall mission performance is compared with that of the existing Constellation Program lunar architecture.
In-situ Lunar Launch and Landing Pad Construction with Regolith-Thermoset Polymer Composite Materials
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Single launch lunar habitat derived from an NSTS external tank
A concept for using the spent external tank from a National Space Transportation System (NSTS) to derive a lunar habitat is described. The external tank is carried into low Earth orbit where the oxygen tank-intertank subassembly is separated from the hydrogen tank, berthed to Space Station Freedom and the subassembly outfitted as a 12-person lunar habitat using extravehicular activity (EVA) and intravehicular activity (IVA). A single launch of the NSTS orbiter can place the external tank in LEO, provide orbiter astronauts for disassembly of the external tank, and transport the required subsystem hardware for outfitting the lunar habitat. An estimate of the astronauts' EVA and IVA is provided. The liquid oxygen intertank modifications utilize existing structures and openings for man access without compromising the structural integrity of the tank. The modifications include installation of living quarters, instrumentation, and an airlock. Feasibility studies of the following additional systems include micrometeoroid and radiation protection, thermal control, environmental control and life support, and propulsion. The converted lunar habitat is designed for unmanned transport and autonomous soft landing on the lunar surface without need for site preparation. Lunar regolith is used to fill the micrometeoroid shield volume for radiation protection using a conveyer. The lunar habitat concept is considered to be feasible by the year 2000 with the concurrent development of a space transfer vehicle and a lunar lander for crew changeover and resupply.
On The Incorporation of Both Function-Driven Requirements and Topology Optimization in The Development of Lunar Launch & Landing Pads
In the design of additively manufactured structures, there can be a constant battle between focusing on function-driven design and topology optimization in an attempt to improve a products ability to meet all requirements. Function-driven optimization is defined as the process of identifying the best design parameters that satisfy project functionality requirements. Function-driven optimization is typically implemented by a designer(s) who, instead of computational limitations, has human bias for the input or inputs determined. On the other hand, topology optimization is defined as a mathematical method that optimizes material layout within a given design space, for a given set of loads, boundary conditions, and constraints with the goal of maximizing the performance of the system. In topology optimization, the work is defined by the limited mathematical inputs and computationally available goals/restraints. If not evaluated simultaneously, these two approaches can result in fundamentally different design concepts meant to address the same requirements. NASA’s Artemis program includes the development of a base camp near the lunar South Pole. After site selection is made, one of the first infrastructure elements needed will be a launch and landing pad (LLP). The construction of such a pad will prevent damage to nearby structures from plume-surface interaction (PSI) while also providing a stable platform for the lander. These benefits reduce the required distance between the established landing zones and other settlement infrastructure. In this paper, the authors evaluate the requirements associated with lunar LLP development, application of both functional and topological optimization techniques, methodologies to combine the two techniques, and potential impacts on final design of such a pad.
Launching lunar missions from Space Station Freedom
The relative orbital motion of Space Station Freedom and the moon places practical constraints on the timing of launch/return transfer trajectories. This paper describes the timing characteristics as well as the Delta-V variations over a representative cycle of launch/return opportunities. On average, the minimum-Delta-V transfer opportunities occur at intervals of 9 days. However, there is a significant nonuniform variation in this timing interval, as well as the minimum stay time at the moon, over the short cycle (51 days) and the long cycle (18.6 years). The advantage of three-impulse transfers for extending the launch window is also described.
Advanced Materials Testing for Lunar Landing & Launch Pad Construction
Five candidate lunar landing and launch pad candidate materials were evaluated in relevant Oxygen/Methane rocket engine plume environment exposure tests. The performance trends were modeled, observed, measured (to the extent possible), and testing results were evaluated. A total of fifteen high temperature plume tests were performed in two test campaigns: five in December 2020 and ten in March 2021. The results indicate that several of the selected materials are promising for future consideration in designing and building lunar landing and launch pads, although further development work is needed for all of them.
Development of space launch facilities.
Manned lunar launch area site selection and planning, considering safety hazards, spaceport zoning, instrumentation, interference control, community relations, etc
Lunar base launch and landing facility conceptual design, 2nd edition
This report documents the Lunar Base Launch and Landing Facility Conceptual Design study. The purpose of this study was to examine the requirements for launch and landing facilities for early lunar bases and to prepare conceptual designs for some of these facilities. The emphasis of this study is on the facilities needed from the first manned landing until permanent occupancy. Surface characteristics and flight vehicle interactions are described, and various facility operations are related. Specific recommendations for equipment, facilities, and evolutionary planning are made, and effects of different aspects of lunar development scenarios on facilities and operations are detailed. Finally, for a given scenario, a specific conceptual design is developed and presented.
Lunar surface vehicle model competition
During Fall and Winter quarters, Georgia Tech's School of Mechanical Engineering students designed machines and devices related to Lunar Base construction tasks. These include joint projects with Textile Engineering students. Topics studied included lunar environment simulator via drop tower technology, lunar rated fasteners, lunar habitat shelter, design of a lunar surface trenching machine, lunar support system, lunar worksite illumination (daytime), lunar regolith bagging system, sunlight diffusing tent for lunar worksite, service apparatus for lunar launch vehicles, lunar communication/power cables and teleoperated deployment machine, lunar regolith bag collection and emplacement device, soil stabilization mat for lunar launch/landing site, lunar rated fastening systems for robotic implementation, lunar surface cable/conduit and automated deployment system, lunar regolith bagging system, and lunar rated fasteners and fastening systems. A special topics team of five Spring quarter students designed and constructed a remotely controlled crane implement for the SKITTER model.
Results of MODIS Band-to-Band Registration Characterization Using On-Orbit Lunar Observations
Since launch, lunar observations have been made regularly by both Terra and Aqua MODIS and used for a number of sensor calibration and characterization related applications, including radiometric stability monitoring, spatial characterization, optical leak and electronic cross-talk characterization, and calibration inter-comparison. MODIS has 36 spectral bands with a total of 490 individual detectors. They are located on four focal plane assemblies (FPA). This paper focuses on the use of MODIS lunar observations to characterize its band-to-band registration (BBR). In addition to BBR, the approach developed by the MODIS Characterization Support Team (MCST) can be used to characterize MODIS detector-to-detector registration (DDR). Long-term BBR results developed from this approach are presented and compared with that derived from a unique on-board calibrator (OBC). Results show that on-orbit changes of BBR have been very small for both Terra and Aqua MODIS and this approach can be applied to other remote sensing instruments.
On obtaining lunar mission launch opportunities
A general procedure for predicting launch opportunities for the RAE-B lunar orbiter mission is presented. It is shown that knowledge of the earth-moon distance and lunar phase and declination are sufficient to determine launch periods consistent with present mission constraints and to approximately predict launch, transfer, and arrival parameters such as park orbit coast time, the possiblity of shadows in all phases of the mission, arrival energy, and the amount of sunlit orbit time in the lunar orbit. Constraints on RAE-B include bounds on the spin axis-sun angle in the translunar trajectory, an upper limit on the arrival energy, and a minimum time for sunlight duration in lunar orbits are being considered for the mission. Comparisons are made of relevant parameters for the two cases. The general features of launch, transfer, and arrival parameters are discussed and are shown to be a function of lunar declination, flight time, and launch azimuth.
Lunar Landing & Launch Pads
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Lunar base launch and landing facilities conceptual design
The purpose of this study was to perform a first look at the requirements for launch and landing facilities for early lunar bases and to prepared conceptual designs for some of these facilities. The emphasis of the study is on the facilities needed from the first manned landing until permanent occupancy, the Phase 2 lunar base. Factors including surface characteristics, navigation system, engine blast effects, and expected surface operations are used to develop landing pad designs, and definitions fo various other elements of the launch and landing facilities. Finally, the dependence of the use of these elements and the evolution of the facilities are established.