Browsing by Author "Hanner, Charles"
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Item Design and Development of an EVA Assistance Roving Vehicle for Artemis and Beyond(50th International Conference on Environmental Systems, 7/12/2021) Akin, David; Hanner, Charles; Bolatto, Nicolas; Gribok, Daniil; Lachance, ZacharyIt seems logical that the Artemis program to return humans to the Moon should begin with capabilities at least equivalent to the last Apollo missions: specifically, a roving vehicle for crew transport. Given the intervening half-century, such a vehicle should also have advanced robotic capabilities to enhance and extend human exploration activities. Under support from the NASA Moon-to-Mars X-Hab program, the University of Maryland is developing such a robotic roving vehicle concept for Earth analog testing and evaluation. The approach taken is to design a vehicle for lunar use, then prototype the most similar vehicle possible for testing on Earth. Rather than a single vehicle for two EVA crew, probabilistic risk assessments indicated a greater utility for two vehicles designed for nominal single-person use, but each capable of carrying a second EVA crew in the event of a vehicle failure. This mitigates the Apollo-era stringent �walk-back� criteria, which limited both overall traverse distance and allowable exploration time at remote sites. Since human lunar landing systems are in preliminary design at this time, the UMd rover design was constrained to permit launching a pair on a single Commercial Lunar Payload Services (CLPS) landing mission, allowing the rovers to be pre-emplaced at the Artemis landing site before the arrival of the crew. The mobility system for the rover is designed to transport a 170 kg suited crew with 80 kg of exploration payload in nominal circumstances, and to additionally transport a second 170 kg crew as a contingency. The rover is designed for a top speed of 4 m/sec, �cruising� speed of 2.5 m/sec, with a 54 km range and peak slope capability of 30�. The paper covers design trades, prototype fabrication, and initial testing results in analog conditions with EVA simulation.Item Design, Fabrication, and Evaluation of the MX-D Spacesuit Simulator(2024 International Conference on Environmnetal Systems, 2024-07-21) Akin, David; Embrey, Meredith; Hanner, CharlesThis paper examines the use of spacesuit simulators for development and initial testing of technologies and architectures for advanced EVA systems, particularly pressure garments. By performing initial evaluation and operational testing in analogue environments, suit system enhancements can be assessed for continued development into pressurized suit systems, and possible extension to flight. The paper examines in detail the development and testing of the MX-D suit simulator system at the University of Maryland for this purpose. This system is designed to be a comparatively high-fidelity suit simulation, using various elements to replicate the bulk and restriction of current pressurized suits, while keeping the weight on the test subject representative of suit loads for the moon or Mars. The MX-D system is highly modular, facilitating easy change-out of prototype components to obtain direct comparisons of relative performance under identical circumstances, such as various shoulder or knee architectures. The MX-D has incorporated some elements of potential future suit architectures, such as chest-mounted battery packs allowing self-swapping and hot-swapping during an EVA, and the ability to use umbilical-supplied life support for a NIAC study. By adopting a separate �bubble� helmet rather than a torso-mounted hemispherical or ellipsoidal faceplate, helmets can be customized for specific experimental augmentations, such as an in-helmet data projection system, without impacting use of the rest of the suit. The system incorporates a thermoelectric cooling system for subject comfort with minimal impact on overall weight. Many suit elements are produced using additive manufacturing to allow rapid prototyping and testing of alternative designs, as well as simplifying development of variants such as suits optimized for underwater testing. The paper concludes with lessons learned to date from the MX-D development process, and discusses useful features for future suit simulators.Item Development and Testing of Crew Interfaces for an Advanced Unpressurized Exploration Rover(2023 International Conference on Environmental Systems, 2023-07-16) Hanner, Charles; Bolatto, Nicolas; Gribok, Daniil; Quizon, Spencer; Quintero, Rowan; Welfeld, Ian; Akin, DavidAlthough revolutionary in its impact on lunar exploration, the Apollo Lunar Roving Vehicle (LRV) had only rudimentary navigation capabilities, and crew controls were essentially limited to go/stop and turn right/turn left. After more than five decades, rovers supporting the Artemis program will have vastly increased capabilities, and a corresponding need for more detailed and complex crew interfaces. The VERTEX rover has been developed at the University of Maryland as an field test analogue of concepts such as the Lunar Terrain Vehicle, and incorporates advanced capabilities such as active suspension, variable deck height and angle, reconfigurable payload interfaces with multipurpose electronic interfaces, and advanced controls including teleoperation and autonomous driving modes. This paper details the development and human factors evaluation of controls, displays, and restraint systems for the VERTEX rover, based on both laboratory and field testing. While advanced robotic systems are often controlled from graphical user interfaces including touch screens, the extremes of lighting on the lunar surface and effects of regolith on pressure suit gloves drive designers to greater use of discrete and dedicated control interfaces and single-function displays easy to read in both bright sunshine and darkness. Extensive human factors testing was performed to examine potential layouts for the comparatively large number of discrete displays and controls, without impacting rover ingress/egress in spacesuits. Display and control layouts are also inherently impacted by crew seating and restraints, and a focused effort was made to move beyond the unsatisfactory simple seat belts of the Apollo LRV to restraint systems which are easier to engage and release in a spacesuit. The seat design itself is strongly driven by the portable life support system, and the VERTEX seat system was optimized to accommodate a number of different backpack designs and sizes to support external test objectives.Item Development and Testing of the BioBot EVA Support System(51st International Conference on Environmental Systems, 7/10/2022) Hanner, Charles; Bolatto, Nicolas; Martin, Joshua; Gribok, Daniil; Akin, DavidWith the resumption of human lunar exploration and plans for eventual Mars landings, extravehicular activities (EVAs) in gravitational environments will again become a primary focus. Geological exploration in early missions will require daily EVAs, rather than the roughly monthly sorties on International Space Station. Even in the reduced gravity of the Moon, EVA system weight on the crew will be the predominant factor in crew performance, fatigue, and safety; the largest single item of which is the weight of the portable life support system. Under NASA NIAC sponsorship, the University of Maryland has been investigating the �BioBot� concept, using a highly capable rover to accompany each EVA crew, carrying their life support system and supplying necessary consumables via a robotically-tended umbilical. During the NIAC Phase 2 effort, a prototype BioBot system has been developed to explore the concept of remotely-tended life support. Field testing accomplished to date includes extended simulated geological traverses performed both with BioBot and with a simulated �conventional� EVA backpack-mounted PLSS. These tests examine the trade-off between decreased on-suit life support weight and increased untethered activity duration in geological and base-servicing scenarios, as early studies have shown the desirability of giving the crew the option to disconnect from the umbilical and perform short traverses untethered from BioBot. This paper presents an overview of the BioBot concept and results from field testing to date, including specifics of the component systems: the rover itself, capable of traversing any terrain suitable for walking in EVA; a robotic umbilical tending system; a spacesuit simulator capable of interfacing to the umbilical, but with some onboard life support to support independent operations as needed; and the sensors, algorithms, and software to provide robust and safe autonomous robotic operations in the vicinity of an EVA crew.Item Experimental Investigation of Minimum Cabin Sizes at Varying Gravity Levels(51st International Conference on Environmental Systems, 7/10/2022) Lachance, Zachary; Akin, David; Hanner, Charles; Bolatto, NicolasThe return to the development of near-term human exploration missions beyond low Earth orbit has necessitated renewed investigation of low size, low mass, and cost-effective human spacecraft. However, very little experimental data on the effects of smaller cabin sizes on crew performance exists, and that which does is mainly focused on micro-gravity habitation in low Earth orbit and thus not directly extensible to the Moon or Mars. The focus of this research is to experimentally analyze the impact of reducing habitat size on crew performance to determine the minimum effective habitat volume for future manned spacecraft. This paper summarizes ongoing research being conducted by the University of Maryland Space Systems Laboratory with support from the NASA X-Hab program to investigate minimum effective habitat and spacecraft sizing, as well as results and conclusions to date for crew effectiveness within restricted cabin volumes under short-term, high-workload testing conditions. Utilizing modular resizable habitat mockups, tests in habitats ranging from 5 to 25 m3 were conducted in simulated micro, Lunar, and Martian gravities through underwater testing with body-segmented ballasting, as well as a surface Earth-gravity control. The impact of size and configuration on crew effectiveness was measured by timed habitat translations, which are compared along with qualitative data to arrive at spacecraft sizing conclusions. While the underwater environment prevents long-duration studies, thus not allowing for analysis of the psychological impacts of smaller habitat sizes, the short-term, high-workload human effectiveness in varying gravity environments provides new insights into the sizing of future manned spacecraft designs.Item Experimental Investigation of Minimum Required Cabin Sizing in Varying Gravity Levels(50th International Conference on Environmental Systems, 7/12/2021) Akin, David; Lachance, Zachary; Hanner, CharlesWith the renewed emphasis on near-term human exploration beyond low Earth orbit, there is a reemphasized priority on the timely and cost-effective development of human spacecraft to support the planned missions. While smaller systems are less expensive to develop, there is little or no experimental data on the impact of smaller habitats on human performance. What data exists is primarily from microgravity experience; there is no meaningful flight data on crew performance in restricted volumes for operations on the Moon or Mars. This paper summarizes ongoing research in the University of Maryland Space Systems Laboratory under the support of the NASA X-Hab program to experimentally investigate the minimum effective cabin sizing and layout for critical elements of the space architecture, including launch and entry vehicles, surface ascent/descent vehicles, on-orbit and surface habitats, and pressurized rovers. Through the design and development of a modular resizable habitat mockup, tests of crew operations including nominal mission operations, maintenance and repair tasks, logistics management, and food preparation are assessed as a function of cabin volume, length/diameter ratio, and horizontal vs. vertical orientation of the cylindrical pressure vessels. Tests focus on various configurations with habitable volumes between 5 and 22 cubic meters, and crew sizes ranging from 2-4. While initial plans included significant laboratory testing, dealing with safety restrictions due to the COVID epidemic has caused a change to almost entirely underwater testing, which allows the use of body segment ballasting to simulate microgravity, lunar, and Mars gravity levels. While the use of the underwater simulation environment precludes long-duration studies such as those performed in analogue field sites, the ability to repeat activities in varying habitat configurations at differing gravitations provides new insight into future spacecraft cabin/habitat design.Item Experimental Investigation of Vertical Translation Design Commonality Across Differing Gravitation Levels(48th International Conference on Environmental Systems, 2018-07-08) Carpenter, Lemuel; Hanner, Charles; Akin, DavidCurrent knowledge of human habitation in partial-gravity is limited to six brief sorties to the lunar surface. As interest in human exploration and longer-term habitation of the Moon and Mars increases, methods must be created to better understand how to design a living environment for humans in differing gravity levels. This paper presents the results of recent studies at the University of Maryland on human accessibility between different floors of a habitat in various gravity levels, based on the use of body segment parameter ballasting in the underwater environment to represent the gravitational force on each body segment in ascending and descending ladders and staircases. This has culminated in the development of a dedicated test apparatus which allows full reconfiguration of the angle and tread spacing on staircases, and can be used both underwater and in the laboratory environment. Test subjects ascend and descend the ladder at various gravity conditions to determine the effect of differing apparent gravity levels, with data collected on both performance and gaits as measured by motion capture systems. Extensions to this work are proposed that focus on part-task simulations such as servicing and repair of equipment racks, and focused studies on the habitat design implications of rotating habitats for artificial gravity.Item Initial Testing and Evaluation of the BioBot EVA Support System(2024 International Conference on Environmnetal Systems, 2024-07-21) Hanner, Charles; Bolatto, Nicolas; Akin, DavidCurrent concepts for the Artemis personal life support system (PLSS) for lunar exploration are trending towards twice the weight as that used during Apollo. While the Artemis PLSS will be superior in many respects, the additional weight on the astronaut�s back will hamper the widespread use of EVA required to make the Artemis program a success in terms of both science and public engagement. Under the NASA Innovative Advanced Concepts (NIAC) program, the University of Maryland is developing and field testing the �BioBot� concept for extended EVA support. In this concept, a highly capable rover accompanies each EVA crew, carrying the bulk of their life support on the rover and supplying consumables to the astronaut via an umbilical tended by an autonomous manipulator system. This scenario places a number of technical demands on the individual BioBot components, such as rover trafficability comparable to the suited crew walking, autonomous crew tracking and umbilical manipulation, and limited on-back life support systems for independent mobility at will with simple and highly reliable mate/demate of the umbilical from the suit in the field. The baseline of two single-person rovers allows dedicated support of each crew, but also allows both crew to return on the functional vehicle following a rover failure, thus alleviating the onerous �walkback� criteria of a single two-person rover. BioBot was designed for deployment of both rovers on a single CLPS lander during the early phases of Artemis, with each rover having a 10-meter umbilical-tending manipulator. The prototype system developed at the UMD Space Systems Laboratory is limited to a 5-meter arm due to the requirement for analogue field testing in Earth gravity. This paper details the development and field-testing of BioBot, from localized testing on the UMD campus to full system simulated geologically focused EVA activity in analogue field sites.