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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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Advanced Sensor Concepts

The Advanced Sensor Concepts project was conducted under the Center Director's Discretionary Fund at the Marshall Space Flight Center. Its objective was to advance the technology originally developed for the Glovebox Integrated Microgravity Isolation Technology project. The objective of this effort was to develop and test several new motion sensors. To date, the investigators have invented seven new technologies during this endeavor and have conceived several others. The innovative basic sensor technology is an absolute position sensor. It employs only two active components, and it is simple, inexpensive, reliable, repeatable, lightweight, and relatively unobtrusive. Two sensors can be utilized in the same physical space to achieve redundancy. The sensor has micrometer positional accuracy and can be configured as a two- or three-dimensional sensor. The sensor technology has the potential to pioneer a new class of linear and rotary sensors. This sensor is the enabling technology for autonomous assembly of modular structures in space and on extraterrestrial locations.

Alhorn, D. C.↗

Standardized Action Modules for Humanoid Robot Control

Humanoid robots could reduce the risks of hazardous work by replacing humans in dangerous environments and they could be useful helpers in environments designed primarily for humans. Currently, no robot is capable enough to fulfill either of these roles for any practical application, and the Humanoid Project at the Jet Propulsion Laboratory's Bio-Inspired Technologies and Systems group is striving to change that. For this summer, our goal was to endow a Fujitsu HOAP 2 humanoid robot with the necessary intelligence and knowledge to autonomously assemble a cubical frame structure from tubular bars and corner joints. Performing such a complicated task requires that the robot have a robust control architecture that allows for a multitude of abilities and Operation modes. We have designed and implemented a modular control architecture that allows reusability of existing code and the integration of work by many team members into the larger control system while providing an easy way to implement later improvements. Such a control system has allowed us to achieve important milestones in the humanoid robot assembly task.

Csaszar, Ambrus↗

Planning the FUSE Mission Using the SOVA Algorithm

Three documents discuss the Sustainable Objective Valuation and Attainability (SOVA) algorithm and software as used to plan tasks (principally, scientific observations and associated maneuvers) for the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. SOVA is a means of managing risk in a complex system, based on a concept of computing the expected return value of a candidate ordered set of tasks as a product of pre-assigned task values and assessments of attainability made against qualitatively defined strategic objectives. For the FUSE mission, SOVA autonomously assembles a week-long schedule of target observations and associated maneuvers so as to maximize the expected scientific return value while keeping the satellite stable, managing the angular momentum of spacecraft attitude- control reaction wheels, and striving for other strategic objectives. A six-degree-of-freedom model of the spacecraft is used in simulating the tasks, and the attainability of a task is calculated at each step by use of strategic objectives as defined by use of fuzzy inference systems. SOVA utilizes a variant of a graph-search algorithm known as the A* search algorithm to assemble the tasks into a week-long target schedule, using the expected scientific return value to guide the search.

Lanzi, James↗

Archway for Radiation and Micrometeorite Occurrence Resistance

The environmental conditions of the Moon require mitigation if a long-term human presence is to be achieved for extended periods of time. Radiation, micrometeoroid impacts, high-velocity debris, and thermal cycling represent threats to crew, equipment, and facilities. For decades, local regolith has been suggested as a candidate material to use in the construction of protective barriers. A thickness of roughly 3m is sufficient protection from both direct and secondary radiation from cosmic rays and solar protons; this thickness is sufficient to reduce radiation exposure even during solar flares. NASA has previously identified a need for innovations that will support lunar habitats using lightweight structures because the reduction of structural mass translates directly into additional up and down mass capability that would facilitate additional logistics capacity and increased science return for all mission phases. The development of non-pressurized primary structures that have synergy with the development of pressurized structures is also of interest. The use of indigenous or in situ materials is also a well-known and active area of research that could drastically improve the practicality of human exploration beyond low-Earth orbit. The Archway for Radiation and Micrometeorite Occurrence Resistance (ARMOR) concept is a new, multifunctional structure that acts as radiation shielding and micrometeorite impact shielding for long-duration lunar surface protection of humans and equipment. ARMOR uses a combination of native regolith and a deployed membrane jacket to yield a multifunctional structure. ARMOR is a robust and modular system that can be autonomously assembled on-site prior to the first human surface arrival. The system provides protection by holding a sufficiently thick (3 m) archshaped shell of local regolith around a central cavity. The regolith is held in shape by an arch-shaped jacket made of strong but deployable material. No regolith processing is required. During the regolith filling process, an inflatable structure under the arch supports the mass of the regolith, but once regolith filling is complete the catenary arch formed by the regolith and the jacket becomes self-supporting and the inflatable can be deflated and removed. When complete, habitat modules and equipment can be moved into the protected cavity under the arch. ARMOR is a nearterm system that would provide a reliable and robust lightweight structure technology to support large lunar habitats, drastically lower launch mass, and improve efficient volume use, reducing launch costs.

Giersch, Louis R.↗

Baseline tests of an autonomous telerobotic system for assembly of space truss structures

Several proposed space missions include precision reflectors that are larger in diameter than any current or proposed launch vehicle. Most of these reflectors will require a truss structure to accurately position the reflector panels and these reflectors will likely require assembly in orbit. A research program has been conducted at the NASA Langley Research Center to develop the technology required for the robotic assembly of truss structures. The focus of this research has been on hardware concepts, computer software control systems, and operator interfaces necessary to perform supervised autonomous assembly. A special facility was developed and four assembly and disassembly tests of a 102-strut tetrahedral truss have been conducted. The test procedures were developed around traditional 'pick-and-place' robotic techniques that rely on positioning repeatability for successful operation. The data from two of the four tests were evaluated and are presented in this report. All operations in the tests were controlled by predefined sequences stored in a command file, and the operator intervened only when the system paused because of the failure of an actuator command. The tests were successful in identifying potential pitfalls in a telerobotic system, many of which would not have been readily anticipated or incurred through simulation studies. Addressing the total integrated task, instead of bench testing the component parts, forced all aspects of the task to be evaluated. Although the test results indicate that additional developments should be pursued, no problems were encountered that would preclude automated assembly in space as a viable construction method.

Rhodes, Marvin D.↗

Space station automation study. Volume 1: Executive summary. Autonomous systems and assembly

The space station automation study (SSAS) was to develop informed technical guidance for NASA personnel in the use of autonomy and autonomous systems to implement space station functions. The initial step taken by NASA in organizing the SSAS was to form and convene a panel of recognized expert technologists in automation, space sciences and aerospace engineering to produce a space station automation plan.

Source record↗

Space station automation study: Autonomous systems and assembly, volume 2

This final report, prepared by Martin Marietta Denver Aerospace, provides the technical results of their input to the Space Station Automation Study, the purpose of which is to develop informed technical guidance in the use of autonomous systems to implement space station functions, many of which can be programmed in advance and are well suited for automated systems.

Bradford, K. Z.↗

Hardware Systems and EDU Demonstration of the Tall Lunar Tower Project

The Tall Lunar Tower (TLT) project developed a robotic tower assembly system (RTAS) and TLT Truss engineering development units (EDUs) to perform a ground demonstration of supervised semi-autonomous robotic assembly of a truss-based tall tower. Truss structures provide exceptional strength-to-weight ratios for payload capabilities supporting large masses. On the lunar surface, tall towers are a critical structural system that will enable significant solar power generation by supporting vertical solar arrays and beyond-the-horizon communications at the lunar south pole, supporting the Artemis mission architecture, as well as a lunar economy. Tall towers, greater than 30-meters-tall, provide the elevation needed for more consistent solar power generation due to low inclination sunlight and deep shadowing from surface features on the lunar surface at the poles. The robotic structural assembly technologies developed for truss-based tall towers will also enable other large-scale functional lunar structures to be built, including launch plume deflectors, lunar safe havens for astronauts and assets, surface transportation for cargo, and other critical infrastructure. Robotic assembly of truss structures for lunar surface infrastructure is near-term enabling for future Artemis mission campaign and Moon to Mars Objectives needs for power and communication. The project team designed, fabricated, tested, and demonstrated the RTAS EDU by assembling a TLT Truss EDU in a laboratory environment. The hardware systems and the supervised semi-autonomous assembly process for a TLT assembled EDU design, along with descriptions of a hardware demonstration are presented.

In-space Assembly↗

Robotic Specialization in Autonomous Robotic Structural Assembly

Robotic in-space assembly of large space structures is a long-term NASA goal to reduce launch costs and enable larger scale missions. Recently, researchers have proposed using discrete lattice building blocks and co-designed robots to build high-performance, scalable primary structure for various on-orbit and surface applications. These robots would locomote on the lattice and work in teams to build and reconfigure building-blocks into functional structure. However, the most reliable and efficient robotic system architecture, characterized by the number of different robotic 'species' and the allocation of functionality between species, is an open question. To address this problem, we decompose the robotic building-block assembly task into functional primitives and, in simulation, study the performance of the the variety of possible resulting architectures. For a set consisting of five process types (move self, move block, move friend, align bock, fasten block), we describe a method of feature space exploration and ranking based on energy and reliability cost functions. The solution space is enumerated, filtered for unique solutions, and evaluated against energy and reliability cost functions for various simulated build sizes. We find that a 2 species system, dividing the five mentioned process types between one unit cell transport robot and one fastening robot, results in the lowest energy cost system, at some cost to reliability. This system enables fastening functionality to occupy the build front while reducing the need for that functional mass to travel back and forth from a feed station. Because the details of a robot design affect the weighting and final allocation of functionality, a sensitivity analysis was conducted to evaluate the effect of changing mass allocations on architecture performance. Future systems with additional functionalities such as repair, inspection, and others may use this process to analyze and determine alternative robot architectures.

Bernus, Borbala↗

Hardware Systems and EDU Demonstration of the Tall Lunar Tower Project

The Tall Lunar Tower (TLT) project developed a robotic tower assembly system (RTAS) and TLT Truss engineering development units (EDUs) to perform a ground demonstration of supervised semi-autonomous robotic assembly of a truss-based tall tower. Truss structures provide exceptional strength-to-weight ratios for payload capabilities supporting large masses. On the lunar surface, tall towers are a critical structural system that will enable significant solar power generation by supporting vertical solar arrays and beyond-the-horizon communications at the lunar south pole, supporting the Artemis mission architecture, as well as a lunar economy. Tall towers, greater than 30-meters-tall, provide the elevation needed for more consistent solar power generation due to low inclination sunlight and deep shadowing from surface features on the lunar surface at the poles. The robotic structural assembly technologies developed for truss-based tall towers will also enable other large-scale functional lunar structures to be built, including launch plume deflectors, lunar safe havens for astronauts and assets, surface transportation for cargo, and other critical infrastructure. Robotic assembly of truss structures for lunar surface infrastructure is near-term enabling for future Artemis mission campaign and Moon to Mars Objectives needs for power and communication. The project team designed, fabricated, tested, and demonstrated the RTAS EDU by assembling a TLT Truss EDU in a laboratory environment. The hardware systems and the supervised semi-autonomous assembly process for a TLT assembled EDU design, along with descriptions of a hardware demonstration are presented.

Lunar Infrastructure↗

State of the Profession Considerations: NASA Langley Research Center Capabilities / Technologies for Autonomous In-Space Assembly and Modular Persistent Assets

Successfully implementing OSAM into next generation revolutionary observatories requires integrating expertise and technologies in modular space structures, assembly operations, autonomy, and modeling/simulation. LaRC OSAM technologies/capabilities have been presented to inform the Planetary Science and Astrobiology Decadal Survey community of the robust and mature existing capability to support an OSAM based architecture for their next observatory. LaRC Structures and Assembly capabilities enable; a modular telescope architecture, high-performance structural modules, and robotic assembly techniques. LaRC Autonomy capabilities ensure that the robotic assembly will be accomplished in a safe and robust manner and only require humans in a supervisory role. The LaRC toolbox of Modeling and Simulation capabilities that is calibrated using module-level ground testing, will ensure that the performance of the fully assembled observatory, a very large zero-g system that will never be assembled/tested in a gravity environment, meets all performance requirements when it enters into service. Integrating all three LaRC capabilities and including embedded metrology, will enable servicing, repair, instrument upgrades (and/or replacement) while ensuring a very long lifetime for the observatory and providing a return-on-investment that is substantially greater than the initial cost. Further confidence will be achieved as OSAM technologies are validated in a new LaRC OSAM laboratory that allows large-scale collaborative testing of modular hardware, simulation software and algorithms, and autonomous agents.

Large space structures↗

FY22 Precision Assembled Space Structure) PASS Annual Review Presentation

Space Technology Mission Directorate, Game Changing Development Program: Precision Assembled Space Structure (PASS) annual review slides. PASS is an autonomous robotic assembly project with an emphasis on high-precision, high-performance large assembled structures.

Autonomous assembly↗

Inertial Transfer Concept for Autonomous In-Space Assembly

Rocket payload and fairing size have placed strict mass and volume limitations on single launch in-space structures. These limitations are what motivates In-Space Assembly (ISA)and where Inertial Transfer has potential to improve or augment ISA capabilities by utilizing an efficient multi-agent autonomous system to transport untethered payloads. Adoption of an inertial transfer approach significantly reduces system complexity, energy and time needed for assembly compared to conventional ISA capabilities, increasing the likelihood of early adoption for assembly. The Inertial Transfer concept is presented including autonomy capabilities, potential risks, and three system configurations. These configurations are based on the autonomous system’s available sensor coverage that tracks the payload’s state. Participating agents have well-defined roles, expectations, and assumptions in their physical organization and coordination of actions depending the mode of operation. The sensor information available to participating agents is considered as it affects the uncertainty in the estimated state and theactions required to capture the payload.

Multi-Agent↗

Inertial Transfer Concept for Autonomous In-Space Assembly

Rocket payload and fairing size have placed strict mass and volume limitations on single launch in-space structures. These limitations are what motivates In-Space Assembly (ISA) and where Inertial Transfer has potential to improve or augment ISA capabilities by utilizing a multiagent autonomous system to transport untethered payloads. The Inertial Transfer concept is presented including autonomy capabilities, potential risks, and three system configurations. These configurations are based on the autonomous system’s available sensor coverage that tracks the payload’s state. Participating agents have well-defined roles, expectations, and assumptions in their physical organization and coordination of actions depending the mode of operation. The sensor information available to participating agents is considered as it affects the uncertainty in the estimated state and the actions required to capture the payload.

Multi-Agent↗