Generation of Requirements for Simulant Measurements

This document provides a formal, logical explanation of the parameters selected for the Figure of Merit algorithm used to evaluate lunar regolith simulant. The objectives, requirements, assumptions and analysis behind the parameters is provided. From NASA's objectives for lunar simulants a requirement is derived to verify and validate simulant performance versus lunar regolith. This requirement leads to a specification that comparative measurements be taken the same way on the regolith and the simulant. In turn this leads to a set of 9 criteria with which to evaluate comparative measurement. Many of the potential measurements of interest are not defensible under these criteria, for example many geotechnical properties of interest were not explicitly measured during Apollo and they can only be measured in situ on the Moon. A 2005 workshop identified 32 properties of major interest to users (Sibille Carpenter Schlagheck, and French, 2006). Virtually all of the properties are tightly constrained, though not predictable, if just four parameters are controlled. Three: composition, size and shape, are recognized as being definable at the particle level. The fourth, density, is a bulk property. In recent work a fifth parameter has been identified, which will need to be added to future releases of the Figure of Merit: spectroscopy

Lunar Simulants

Lunar simulants are terrestrial materials that mimic aspects of lunar regolith for testing of technology that would interact with lunar surface material. The goal of simulants is mission risk reduction by providing confidence, through testing with simulants, that a technology will perform as designed on the lunar surface. Lunar simulants are often used in education and outreach activities to increase public knowledge about lunar surface materials and to inspire the next generation of space explorers

3-D Printing in Zero-G ISS Technology Demonstration

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In Situ Manufacturing is a Necessary Part of Any Planetary Architecture

The key to any sustainable presence in space is the ability to manufacture necessary tools, parts, structures, spares, etc. in situ and on demand. Cost, volume, and up-mass constraints prohibit launching everything needed for long-duration or long-distance missions from Earth, including spare parts and replacement systems. There are many benefits to building items as-needed in situ using computer aided drafting (CAD) models and additive manufacturing technology: (1) Cost, up-mass, and volume savings for launch due to the ability to manufacture specific parts when needed. (2) CAD models can be generated on Earth and transmitted to the station or spacecraft, or they can be designed in situ for any task. Thus, multiple people in many locations can work on a single problem. (3) Items can be produced that will enhance the safety of crew and vehicles (e.g., latches or guards). (4) Items can be produced on-demand in a small amount of time (i.e., hours or days) compared to traditional manufacturing methods and, therefore, would not require the lengthy amount of time needed to machine the part from a solid block of material nor the wait time required if the part had to be launched from Earth. (5) Used and obsolete parts can be recycled into powder or wire feedstock for use in later manufacturing. (6) Ultimately, the ability to produce items as-needed will reduce mission risk, as one will have everything they need to fix a broken system or fashion a new part making it available on a more timely basis

Additive Construction: Using In-Situ Resources on Planetary Surfaces

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ISM In-Space Manufacturing

Develop and enable the technologies, materials, and processes required to provide affordable, sustainable on-demand manufacturing, recycling, and repair during Exploration Missions

On The Development of Additive Construction Technologies for Application to Development of Lunar/Martian Surface Structures Using In-Situ Materials

For long-duration missions on other planetary bodies, the use of in-situ materials will become increasingly critical. As man's presence on these bodies expands, so must the breadth of the structures required to accommodate them including habitats, laboratories, berms, radiation shielding for natural radiation and surface reactors, garages, solar storm shelters, greenhouses, etc. Planetary surface structure manufacturing and assembly technologies that incorporate in-situ resources provide options for autonomous, affordable, pre-positioned environments with radiation shielding features and protection from micrometeorites, exhaust plume debris, and other hazards. This is important because gamma and particle radiation constitute a serious but reducible threat to long-term survival of human beings, electronics, and other materials in space environments. Also, it is anticipated that surface structures will constitute the primary mass element of lunar or Martian launch requirements. The ability to use in-situ materials to construct these structures will provide a benefit in the reduction of up-mass that would otherwise make long-term Moon or Mars structures cost prohibitive. The ability to fabricate structures in situ brings with it the ability to repair these structures, which allows for self-sufficiency necessary for long-duration habitation. Previously, under the auspices of the MSFC In Situ Fabrication and Repair (ISFR) project and more recently, under the joint MSFC/KSC Additive Construction with Mobile Emplacement (ACME) project, the MSFC Surface Structures Group has been developing materials and construction technologies to support future planetary habitats with in situ resources. One such technology, known as Contour Crafting (additive construction), is shown in Figure 1, along with a typical structure fabricated using this technology. This paper will present the results to date of these efforts, including development of novel nozzle concepts for advanced layer deposition using the Contour Crafting process. This process, conceived initially for rapid development of cementitious structures on Earth, also lends itself exceptionally well to the automated fabrication of planetary surface structures using minimally processed regolith as aggregate, and imported binder material or binders developed from in situ materials. This process has been used successfully in the fabrication of construction elements using lunar regolith simulant and Mars regolith simulant, both with various binder materials. These binder materials have resulted from extensive evaluation and include both "imported" binder materials that might be launched from Earth as well as some binder materials that can theoretically also be derived from existing regolith materials. They were chosen to 1) reduce penetrating radiation as much as possible, primarily with hydrogen-bearing polymers, 2) attempt to provide an air-tight structure, 3) sufficiently mix and adsorb to regolith grains for strength, 4) maximize tolerance to day-night thermal cycling, 5) possibly increase electrical conductivity to dissipate any accumulated static charge, and 6) ease their application on planetary surfaces (specifically, the accommodation of reduced atmosphere and lack of heat sinks). Some of these materials have been tested with respect to radiation mitigation, micrometeorite resistance, and resistance to larger, slower-traveling pieces of regolith impinging on the surface, simulating nearby launch and landing activities. Conceptual designs for a Continuous Feedstock Delivery/Mixing System (CFDMS) will also be presented and future planned activities will be discussed as well

Additive Construction with Mobile Emplacement (ACME) 3D Printing Structures with In-Situ Resources

No abstract availabl

Appropriate Simulants are a Requirement for Mars Surface Systems Technology Development

To date, there are two simulants for martian regolith: JSC Mars-1A, produced from palagonitic (weathered) basaltic tephra mined from the Pu'u Nene cinder cone in Hawaii [1] by commercial company Orbitec, and Mojave Mars Simulant (MMS), produced from Saddleback Basalt in the western Mojave desert by the Jet Propulsion Laboratory [2]. Until numerous recent orbiters, rovers, and landers were sent to Mars, weathered basalt was surmised to cover every inch of the martian landscape. All missions since Viking have disproven that the entire martian surface is weathered basalt. In fact, the outcrops, features, and surfaces that are significantly different from weathered basalt are too numerous to realistically count. There are gullies, evaporites, sand dunes, lake deposits, hydrothermal deposits, alluvium, etc. that indicate sedimentary and chemical processes. There is no one size fits all simulant. Each unique area requires its own simulant in order to test technologies and hardware, thereby reducing risk

3D Printing In Zero-G ISS Technology Demonstration

The National Aeronautics and Space Administration (NASA) has a long term strategy to fabricate components and equipment ondemand for manned missions to the Moon, Mars, and beyond. To support this strategy, NASA and Made in Space, Inc. are developing the 3D Printing In ZeroG payload as a Technology Demonstration for the International Space Station (ISS). The 3D Printing In ZeroG experiment ('3D Print') will be the first machine to perform 3D printing in space. The greater the distance from Earth and the longer the mission duration, the more difficult resupply becomes; this requires a change from the current spares, maintenance, repair, and hardware design model that has been used on the International Space Station (ISS) up until now. Given the extension of the ISS Program, which will inevitably result in replacement parts being required, the ISS is an ideal platform to begin changing the current model for resupply and repair to one that is more suitable for all exploration missions. 3D Printing, more formally known as Additive Manufacturing, is the method of building parts/objects/tools layerbylayer. The 3D Print experiment will use extrusionbased additive manufacturing, which involves building an object out of plastic deposited by a wirefeed via an extruder head. Parts can be printed from data files loaded on the device at launch, as well as additional files uplinked to the device while onorbit. The plastic extrusion additive manufacturing process is a lowenergy, lowmass solution to many common needs on board the ISS. The 3D Print payload will serve as the ideal first step to proving that process in space. It is unreasonable to expect NASA to launch large blocks of material from which parts or tools can be traditionally machined, and even more unreasonable to fly up multiple drill bits that would be required to machine parts from aerospacegrade materials such as titanium 64 alloy and Inconel. The technology to produce parts on demand, in space, offers unique design options that are not possible through traditional manufacturing methods while offering cost-effective, highprecision, lowunit ondemand manufacturing. Thus, Additive Manufacturing capabilities are the foundation of an advanced manufacturing in space roadmap. The 3D Printing In ZeroG experiment will demonstrate the capability of utilizing Additive Manufacturing technology in space. This will serve as the enabling first step to realizing an additive manufacturing, printondemand "machine shop" for longduration missions and sustaining human exploration of other planets, where there is extremely limited ability and availability of Earthbased logistics support. Simply put, Additive Manufacturing in space is a critical enabling technology for NASA. It will provide the capability to produce hardware ondemand, directly lowering cost and decreasing risk by having the exact part or tool needed in the time it takes to print. This capability will also provide the muchneeded solution to the cost, volume, and upmass constraints that prohibit launching everything needed for longduration or longdistance missions from Earth, including spare parts and replacement systems. A successful mission for the 3D Printing In ZeroG payload is the first step to demonstrate the capability of printing on orbit. The data gathered and lessons learned from this demonstration will be applied to the next generation of additive manufacturing technology on orbit. It is expected that Additive Manufacturing technology will quickly become a critical part of any mission's infrastructure