Browsing by Author "Bolatto, Nicolas"
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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 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 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 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.Item Model and Full-Scale Testing of Outfitting Approaches for Inflatable Habitats(51st International Conference on Environmental Systems, 7/10/2022) Bolatto, Nicolas; Merrill, Colby; Chawla, Ronak; Naylor, Olivia; Myers, Elizabeth; Akin, DavidInflatable habitats feature prominently in many future space program concepts, but generally there is little focus on how the system transitions from its newly inflated configuration to a fully operational system. The nearest flight analog was the Skylab �wet workshop� concept in the early 1970�s, which was rejected due to the length of time required to outfit an empty volume into a functional habitat. Under support from the NASA Moon to Mars X-Hab program, the University of Maryland has initiated an experimental study of outfitting inflatable habitats to an operational configuration. To keep the study manageable, the team adopted the basic Transhab configuration developed at NASA JSC. The pressure envelope would launch packaged around a central 3m diameter core, which takes all launch loads and contains all necessary systems and components. The envelope would inflate to an 8m diameter, and then be outfitted by moving selected components into the newly inflated volume. Potential agents include both human crew and robotic systems. While the systems were modeled in CAD, it was decided that the large number of potential operations and movement trajectories would be prohibitively difficult to evaluate using only computer graphics. For that reason, an approach was developed which used CAD, a 1/12 scale physical model, and full-scale segments of the habitat for evaluation purposes. The CAD model was used to derive the basic configuration of the central core, and to define major components such as crew compartments, movable and fixed equipment, and utilities including air handling, power, and data. Initial testing was done at 1/12 scale, including human and robotic figures, to consider strategies and test cases. Final testing was done with both humans and robots in the laboratory, and in neutral buoyancy to provide a microgravity environment. Results to date are presented, along with future plans.