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The combined anticipated trends of vehicle sharing (ride-hailing), automated control, and powertrain electrification are poised to disrupt the current paradigm of predominately owner-driven gasoline vehicles with low levels of utilization. Shared, automated, electric vehicle (SAEV) fleets offer the potential for lower cost and emissions and have garnered significant interest among the research community. While promising, unmanaged operation of these fleets may lead to unintended negative consequences. One potentially unintended consequence is a high quantity of SAEVs charging during peak demand hours on the electric grid, potentially increasing the required generation capacity. This research explores the flexibility associated with charging loads demanded by SAEV fleets in response to servicing personal mobility travel demands. Travel demand is synthesized in four major United States metropolitan areas: Detroit, MI; Austin, TX; Washington, DC; and Miami, FL.

An EVA simulation with a medical contingency scenario was conducted in 2006 with the NASA Haughton-Mars and EVA Physiology System and Performance Projects, to develop medical contingency management and evacuation techniques for planetary surface exploration. A rescue/evacuation system to allow two rescuer astronauts to evacuate one incapacitated astronaut was evaluated. The rescue system was utilized effectively to extract an injured astronaut up a slope of15-25° and into a surface mobility rover for transport to a simulated habitat for advanced medical care. Further research is recommended to evaluate the effects of reduced gravity and to develop synergies with other surface systems for carrying out the contingency procedures.

Sublimators have been used for heat rejection for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Some of the attractive features of sublimators are that they are compact, lightweight, and self-regulating. One of the drawbacks to previous designs has been sensitivity to non-volatile contamination in the feedwater, which can clog relatively small pores (∼3-µ6 μn) in the porous plates where ice forms and sublimates. The Contaminant Insensitive Sublimator (CIS) has been recently developed at NASA-JSC to be less sensitive to contaminants by using a larger pore size media (−350 um). Testing of a CIS Engineering Development Unit (EDU) has demonstrated good heat rejection performance. This paper describes testing that investigates different factors affecting efficient utilization of the feedwater.

Sublimators have been used for heat rejection in a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered to operate in a cyclical topping mode during low lunar orbit for Altair and possibly Orion, which represents a new mode of operation. This paper will investigate the feedwater utilization when a sublimator is used in this nontraditional manner. This paper includes testing efforts to date to investigate the Orbit-Averaged Feedwater Utilization (OAFU) for a sublimator.

In the design of a new space suit it is necessary to have requirements that define what mobility space suit joints should be capable of achieving in both a system and at the component level. NASA elected to divide mobility into its constituent parts -- range of motion (ROM) and torque -- in an effort to develop clean design requirements that limit subject performance bias and are easily verified. Unfortunately, the measurement of mobility can be difficult to obtain. Current technologies, such as the Vicon motion capture system, allow for the relatively easy benchmarking of range of motion (ROM) for a wide array of space suit systems. The ROM evaluations require subjects in the suit to accurately evaluate the ranges humans can achieve in the suit. However, when it comes to torque, there are significant challenges for both benchmarking current performance and writing requirements for future suits.

In applications that require space-suited crewmembers to traverse rough terrain, boot fit and mobility are of critical importance to the crewmember's overall performance capabilities. Current extravehicular activity (EVA) boot designs were developed for micro-gravity applications, and as such, incorporate only minimal mobility features. Recently three advanced space suit boot designs were evaluated at the National Aeronautics and Space Administration Johnson Space Center (NASA/JSC). The three designs included: 1) a modified Space Shuttle suit (Extravehicular Mobility Unit or EMU) boot, 2) the Modified Experiment Boot designed and fabricated by RD & PE Zvezda JSC, and 3) a boot designed and fabricated by the David Clark Company. Descriptions of each configuration and rationale for each boot design are presented.

Today’s electric vehicle (EV) owners charge their vehicles mostly at home and seldom use public direct current fast charger (DCFCs), reducing the need for a large deployment of DCFCs for private EV owners. However, due to the emerging interest among transportation network companies to operate EVs in their fleet, there is great potential for DCFCs to be highly utilized and become economically feasible in the future. This paper describes a heuristic algorithm to emulate operation of EVs within a hypothetical transportation network company fleet using a large global positioning system data set from Columbus, Ohio. DCFC requirements supporting operation of EVs are estimated using the Electric Vehicle Infrastructure Projection tool. Operation and installation costs were estimated using real-world data to assess the economic feasibility of the recommended fast charging stations.

Transportation vehicle and network system efficiency can be defined in two ways: 1) reduction of travel times across all the vehicles in the system, and 2) reduction in total energy consumed by all the vehicles in the system. The mechanisms to realize these efficiencies are treated as independent (i.e., vehicle and network domains) and, when combined, they have not been adequately studied to date. This research aims to integrate previously developed and published research on Predictive Optimal Energy Management Strategies (POEMS) and Intelligent Traffic Systems (ITS), to address the need for quantifying improvement in system efficiency resulting from simultaneous vehicle and network optimization. POEMS and ITS are partially independent methods which do not require each other to function but whose individual effectiveness may be affected by the presence of the other. In order to evaluate the system level efficiency improvements, the Mobility Energy Productivity (MEP) metric is used.

As NASA is preparing to extend man's reach into space, it is expected that astronauts will be required to spend more and more time exposed to the hazards of performing Extra-Vehicular Activity (EVA). One of these hazards includes the risk of the space suit bladder being penetrated by hypervelocity micrometeoroid and orbital debris (MMOD) particles. Therefore, it has become increasingly important to investigate new ways to improve the protectiveness of the current Extravehicular Mobility Unit (EMU) against MMOD penetration. ILC Dover conducted a NASA funded study into identifying methods of improving the current EMU protection. The first part of this evaluation focused on identifying how to increase the EMU shielding, selecting materials to accomplish this, and testing these materials to determine the best lay-up combinations to integrate into the current thermal micrometeoroid garment (TMG) design.

The primary objectives of this study were to determine the factors that affect stability during locomotion in both lunar and martian gravity environments and to determine the criteria needed to enhance stability and traction. This study tested the effects of changing the speed of locomotion and the pattern of locomotion under three gravity conditions. The results showed that as the gravity level decreased, the amount of vertical and horizontal forces dropped significantly. The results also showed that there are some similarities across gravity levels with regard to changing the speed as well as the pattern of locomotion. In general, an increase in the speed resulted in an increase in the vertical and the horizontal forces. A change in the pattern of locomotion showed that even at reduced gravity, it will be more difficult to stop than compared to continue or start the motion.

The NASA Shuttle Extravehicular Mobility Unit (EMU) uses a non-regenerable absorbent to remove CO2 from an astronaut's breathing loop. A savings in launch weight, storage volume and life cycle cost may be achieved by incorporating a regenerable CO2 removal system into the EMU. This paper will discuss regenerable CO2 sorbents and their impact on the life support system of an EMU. The systems evaluated will be judged on their technical maturity, impact to the EMU, and impacts to space station and shuttle operation

The current Extravehicular Mobility Unit (EMU) system provides thermal control using a sublimator to reject both the heat produced by the astronaut's metabolic activity as well as the heat produced by the Portable Life Support Unit (PLSS). This sublimator vents up to eight pounds of water each Extravehicular Activity (EVA). If this load could be radiated to space, the amount of water that would need to be sublimated could be greatly reduced. There is enough surface area on the EMU that almost all of the heat can be rejected by radiation. Radiators, however, reject heat at a relatively constant rate, while the astronaut generates heat at a variable rate. To accommodate this variable heat load, NASA is developing a new freeze tolerant radiator where the tubes can selectively freeze to “turn down” the radiator and adjust to the heat rejection requirement. This radiator design significantly reduces the amount of expendable water needed for the sublimator.

Procedures that have been developed as part of the NASA JSC-sponsored pre-prototype Checkout, Servicing and Maintenance (COSM) program for pre- and post-EVA airlock operations are described. This paper addresses the accompanying pressure changes in the airlock and in the Advanced Extravehicular Mobility Unit (EMU). Additionally, the paper focuses on the components that are checked out, and includes the step-by-step sequences to be followed by the crew, the required screen displays and prompts that accompany each step, and a description of the automated processes that occur.

The Challenger 65 agricultural tractor combines the best features of current four wheel drive machines; speed, on-road mobility, and operator comfort with the well recognized advantages of track-type machines; tractive efficiency and reduced soil compaction.

Previous studies have shown that a multi-axis ankle joint accommodating abduction and adduction as well as ankle flexion/extension and rotation could be practically incorporated into a pressure suit. Several candidate configurations were manufactured and the performance of the enhanced ankle joints evaluated. Experience has suggested that these enhancements could be of significant benefit for planetary exploration missions requiring extensive walking over uneven terrain. During 1999, prototype pressure suit boots incorporating a multi-axis ankle joint configuration were manufactured. Their effect on balance stability and locomotion capabilities across slopes and over uneven surfaces in a pressurized spacesuit were evaluated in a series of 1-g experiments. This paper describes the enhanced test boots, the test procedure, and the results. Design refinements and further testing are recommended.

Ride hailing activity is rapidly increasing, largely due to the growth of transportation network companies such as Uber and Lyft. However, traditional taxi companies continue to represent an important mobility option for travelers. Columbus Yellow Cab, a taxi company in Columbus, Ohio, offers traditional line-of-sight hailing as well as digital hailing through a mobile app. Data from Columbus Yellow Cab was provided to the National Renewable Energy Laboratory to analyze the potential for taxi electrification. Columbus Yellow Cab data contained information describing both global positioning system trajectories and taxi meter information. The data spanned a period of 13 months, containing approximately 70 million global system positioning system points, 840 thousand trips, and 170 unique vehicles.

The emergence of connected and automated vehicles and smart cities technologies create the opportunity for new mobility modes and routing decision tools, among many others. To achieve maximum mobility and minimum energy consumption, it is critical to understand the energy cost of decisions and optimize accordingly. The Route Energy prediction model (RouteE) enables accurate estimation of energy consumption for a variety of vehicle types over trips or sub-trips where detailed drive cycle data are unavailable. Applications include vehicle route selection, energy accounting and optimization in transportation simulation, and corridor energy analyses, among others. The software is a Python package that includes a variety of pre-trained models from the National Renewable Energy Laboratory (NREL). However, RouteE also enables users to train custom models using their own data sets, making it a robust and valuable tool for both fast calculations and rigorous, data-rich research efforts.

The goal of the automated mobility platforms (AMPs) initiative is to raise the bar of service regarding equity and sustainability for public mobility systems that are crucial to large facilities, and doing so using electrified, energy efficient technology. Using airports as an example, the rapid growth in air travel demand has led to facility expansions and congested terminals, which directly impacts equity (e.g., increased challenges for Passengers with Reduced Mobility [PRMs]) and sustainability—both of which are important metrics often overlooked during the engineering design process.