Browsing by Author "Lachance, Zachary"
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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 Development of an Autonomous Umbilical Tending System for Rover-Supported Surface EVAs(51st International Conference on Environmental Systems, 7/10/2022) Bolatto, Nicolas; Fink, Robert; Martin, Joshua; Lachance, Zachary; Vishnoi, Rahul; Akin, DavidFor surface extravehicular activities, no parameter is more impactful on the design of spacesuits than the "weight on the back," or the weight of the suit system that must be supported by the astronaut under gravity. The portable life support system (PLSS) alone has nearly doubled the weight on the astronaut historically, significantly increasing the exertion required to conduct manned surface activities and drastically curtailing the range of motion of the astronaut due to the movement of the center of mass rearwards and upwards. Both of these negatively affect EVA performance of astronauts; as a result, the capability to offload an astronaut's PLSS would be of great benefit to future EVA operations. The University of Maryland Space Systems Laboratory has been investigating one potential solution to this via its "BioBot" concept, supported by the NASA NIAC program. The overall concept is of a rover carrying the life support system for the EVA crew and supplying consumables via umbilicals. This paper will focus on the critical technology to make this approach viable: the umbilical-handling robot and its associated rover-mounted life support hardware. The robotic manipulator must support both its own weight and that of the umbilical, while keeping close enough to the EVA crew to eliminate the need for additional slack which could snag the umbilical on surface features. This paper details the design of the umbilical-handling robot, which must function as an Earth analog system for human factors testing, and the designs of the umbilical, suit disconnect, and Earth analog life support system. Additionally, this paper describes the sensors and algorithms for smoothly blended motion between the manipulator and the rover, as well as the design implications for the astronaut-following rover itself. Test results to date are also presented and future design modifications discussed.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.