773 research outputs found

    Dual Mission Scenarios for the Human Lunar Campaign - Performance, Cost and Risk Benefits

    Get PDF
    Scenarios for human lunar operations with capabilities significantly beyond Constellation Program baseline missions are potentially feasible based on the concept of dual, sequential missions utilizing a common crew and a single Ares I/CEV (Crew Exploration Vehicle). For example, scenarios possible within the scope of baseline technology planning include outpost-based sortie missions and dual sortie missions. Top level cost benefits of these dual sortie scenarios may be estimated by comparison to the Constellation Program reference two-mission-per-year lunar campaign. The primary cost benefit is the accomplishment of Mission B with a "single launch solution" since no Ares I launch is required. Cumulative risk to the crew is lowered since crew exposure to launch risks and Earth return risks are reduced versus comparable Constellation Program reference two-mission-per-year scenarios. Payload-to-the-lunar-surface capability is substantially increased in the Mission B sortie as a result of additional propellant available for Lunar Lander #2 descent. This additional propellant is a result of EDS #2 transferring a smaller stack through trans-lunar injection and using remaining propellant to perform a portion of the lunar orbit insertion (LOI) maneuver. This paper describes these dual mission concepts, including cost, risk and performance benefits per lunar sortie site, and provides an initial feasibility assessment

    Schedule Risks Due to Delays in Advanced Technology Development

    Get PDF
    This paper discusses a methodology and modeling capability that probabilistically evaluates the likelihood and impacts of delays in advanced technology development prior to the start of design, development, test, and evaluation (DDT&E) of complex space systems. The challenges of understanding and modeling advanced technology development considerations are first outlined, followed by a discussion of the problem in the context of lunar surface architecture analysis. The current and planned methodologies to address the problem are then presented along with sample analyses and results. The methodology discussed herein provides decision-makers a thorough understanding of the schedule impacts resulting from the inclusion of various enabling advanced technology assumptions within system design

    Cis-Lunar Base Camp

    Get PDF
    Historically, when mounting expeditions into uncharted territories, explorers have established strategically positioned base camps to pre-position required equipment and consumables. These base camps are secure, safe positions from which expeditions can depart when conditions are favorable, at which technology and operations can be tested and validated, and facilitate timely access to more robust facilities in the event of an emergency. For human exploration missions into deep space, cis-lunar space is well suited to serve as such a base camp. The outer regions of cis-lunar space, such as the Earth-Moon Lagrange points, lie near the edge of Earth s gravity well, allowing equipment and consumables to be aggregated with easy access to deep space and to the lunar surface, as well as more distant destinations, such as near-Earth Asteroids (NEAs) and Mars and its moons. Several approaches to utilizing a cis-lunar base camp for sustainable human exploration, as well as some possible future applications are identified. The primary objective of the analysis presented in this paper is to identify options, show the macro trends, and provide information that can be used as a basis for more detailed mission development. Compared within are the high-level performance and cost of 15 preliminary cis-lunar exploration campaigns that establish the capability to conduct crewed missions of up to one year in duration, and then aggregate mass in cis-lunar space to facilitate an expedition from Cis-Lunar Base Camp. Launch vehicles, chemical propulsion stages, and electric propulsion stages are discussed and parametric sizing values are used to create architectures of in-space transportation elements that extend the existing in-space supply chain to cis-lunar space. The transportation options to cis-lunar space assessed vary in efficiency by almost 50%; from 0.16 to 0.68 kg of cargo in cis-lunar space for every kilogram of mass in Low Earth Orbit (LEO). For the 15 cases, 5-year campaign costs vary by only 15% from 0.36 to 0.51 on a normalized scale across all campaigns. Thus the development and first flight costs of assessed transportation options are similar. However, the cost of those options per flight beyond the initial operational capability varies by 70% from 0.3 to 1.0 on a normalized scale. The 10-year campaigns assessed begin to show the effect of this large range of cost beyond initial operational capability as they vary approximately 25% with values from 0.75 to 1.0 on the normalized campaign scale. Therefore, it is important to understand both the cost of implementation and first use as well as long term utilization. Finally, minimizing long term recurring costs is critical to the affordability of future human space exploration missions. Finally minimizing long term recurring costs is critical to the affordability of future human space exploration missions

    Innovative Technologies for Human Exploration: Opportunities for Partnerships and Leveraging Novel Technologies External to NASA

    Get PDF
    Human spaceflight organizations have ambitious goals for expanding human presence throughout the solar system. To meet these goals, spaceflight organizations have to overcome complex technical challenges for human missions to Mars, Near Earth Asteroids, and other distant celestial bodies. Resolving these challenges requires considerable resources and technological innovations, such as advancements in human health and countermeasures for space environments; self-sustaining habitats; advanced power and propulsion systems; and information technologies. Today, government space agencies seek cooperative endeavors to reduce cost burdens, improve human exploration capabilities, and foster knowledge sharing among human spaceflight organizations. This paper looks at potential opportunities for partnerships and spin-ins from economic sectors outside the space industry. It highlights innovative technologies and breakthrough concepts that could have significant impacts on space exploration and identifies organizations throughout the broader economy that specialize in these technologies

    Innovative Technologies for Global Space Exploration

    Get PDF
    Under the direction of NASA's Exploration Systems Mission Directorate (ESMD), Directorate Integration Office (DIO), The Tauri Group with NASA's Technology Assessment and Integration Team (TAIT) completed several studies and white papers that identify novel technologies for human exploration. These studies provide technical inputs to space exploration roadmaps, identify potential organizations for exploration partnerships, and detail crosscutting technologies that may meet some of NASA's critical needs. These studies are supported by a relational database of more than 400 externally funded technologies relevant to current exploration challenges. The identified technologies can be integrated into existing and developing roadmaps to leverage external resources, thereby reducing the cost of space exploration. This approach to identifying potential spin-in technologies and partnerships could apply to other national space programs, as well as international and multi-government activities. This paper highlights innovative technologies and potential partnerships from economic sectors that historically are less connected to space exploration. It includes breakthrough concepts that could have a significant impact on space exploration and discusses the role of breakthrough concepts in technology planning. Technologies and partnerships are from NASA's Technology Horizons and Technology Frontiers game-changing and breakthrough technology reports as well as the External Government Technology Dataset, briefly described in the paper. The paper highlights example novel technologies that could be spun-in from government and commercial sources, including virtual worlds, synthetic biology, and human augmentation. It will consider how these technologies can impact space exploration and will discuss ongoing activities for planning and preparing them

    Technology Estimating: A Process to Determine the Cost and Schedule of Space Technology Research and Development

    Get PDF
    NASA is investing in new technologies that include 14 primary technology roadmap areas, and aeronautics. Understanding the cost for research and development of these technologies and the time it takes to increase the maturity of the technology is important to the support of the ongoing and future NASA missions. Overall, technology estimating may help provide guidance to technology investment strategies to help improve evaluation of technology affordability, and aid in decision support. The research provides a summary of the framework development of a Technology Estimating process where four technology roadmap areas were selected to be studied. The framework includes definition of terms, discussion for narrowing the focus from 14 NASA Technology Roadmap areas to four, and further refinement to include technologies, TRL range of 2 to 6. Included in this paper is a discussion to address the evaluation of 20 unique technology parameters that were initially identified, evaluated and then subsequently reduced for use in characterizing these technologies. A discussion of data acquisition effort and criteria established for data quality are provided. The findings obtained during the research included gaps identified, and a description of a spreadsheet-based estimating tool initiated as a part of the Technology Estimating process

    Gulf Coast Ticks (Amblyomma maculatum) and Rickettsia parkeri, United States

    Get PDF
    Geographic distribution of Rickettsia parkeri in its US tick vector, Amblyomma maculatum, was evaluated by PCR. R. parkeri was detected in ticks from Florida, Georgia, Kentucky, Mississippi, Oklahoma, and South Carolina, which suggests that A. maculatum may be responsible for additional cases of R. parkeri rickettsiosis throughout much of its US range

    Stair-specific algorithms for identification of touch-down and foot-off when descending or ascending a non-instrumented staircase.

    Get PDF
    yesThe present study introduces four event detection algorithms for defining touch-down and foot-off during stair descent and stair ascent using segmental kinematics. For stair descent, vertical velocity minima of the whole body center-of-mass was used to define touch-down, and foot-off was defined as the instant of trail limb peak knee flexion. For stair ascent, vertical velocity local minima of the lead-limb toe was used to define touch-down, and foot-off was defined as the local maxima in vertical displacement between the toe and pelvis. The performance of these algorithms was determined as the agreement in timings of kinematically derived events to those defined kinetically (ground reaction forces). Data were recorded while 17 young and 15 older adults completed stair descent and ascent trials over a four-step instrumented staircase. Trials were repeated for three stair riser height conditions (85 mm, 170 mm, and 255 mm). Kinematically derived touch-down and foot-off events showed good agreement (small 95% limits of agreement) with kinetically derived events for both young and older adults, across all riser heights, and for both ascent and descent. In addition, agreement metrics were better than those returned using existing kinematically derived event detection algorithms developed for overground gait. These results indicate that touch-down and foot-off during stair ascent and descent of non-instrumented staircases can be determined with acceptable precision using segmental kinematic data
    corecore