54 research outputs found

    Resource Prospector: Evaluating the ISRU Potential of the Lunar Poles

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    Resource Prospector (RP) is a lunar volatiles prospecting mission being developed for potential flight in CY2021-2022. The mission includes a rover-borne payload that (1) can locate surface and near-subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith, and (3) demonstrate the form, extractability and usefulness of the materials. The primary mission goal for RP is to evaluate the In-Situ Resource Utilization (ISRU) potential of the lunar poles

    Tele-Operated Lunar Rover Navigation Using Lidar

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    Near real-time tele-operated driving on the lunar surface remains constrained by bandwidth and signal latency despite the Moon s relative proximity. As part of our work within NASA s Human-Robotic Systems Project (HRS), we have developed a stand-alone modular LIDAR based safeguarded tele-operation system of hardware, middleware, navigation software and user interface. The system has been installed and tested on two distinct NASA rovers-JSC s Centaur2 lunar rover prototype and ARC s KRex research rover- and tested over several kilometers of tele-operated driving at average sustained speeds of 0.15 - 0.25 m/s around rocks, slopes and simulated lunar craters using a deliberately constrained telemetry link. The navigation system builds onboard terrain and hazard maps, returning highest priority sections to the off-board operator as permitted by bandwidth availability. It also analyzes hazard maps onboard and can stop the vehicle prior to contacting hazards. It is robust to severe pose errors and uses a novel scan alignment algorithm to compensate for attitude and elevation errors

    Development of the Resource Prospector Planetary Rover

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    The Resource Prospector (RP) is an In-Situ Resource Utilization (ISRU) lunar rover mission under study by NASA. RP is planned to launch in 2020 to prospect for subsurface volatiles and to extract oxygen from lunar regolith. The mission will address several of NASA's "Strategic Knowledge Gaps" for lunar exploration. The mission will also address the Global Exploration Roadmap's strategic goal of using local resources for human exploration. The distribution of lunar subsurface volatiles drives the mission requirement for mobility. The spatial distribution is hypothesized to be governed by impact cratering with the top 0.5 m being patchy at scales of 100 m. The mixing time scale increases with depth (less frequent larger impacts). Consequently, increased mobility reduces the depth requirement for sampling. The target RP traverse will extend 1 km radially from the landing site to sample craters of varying sizes. Sampling craters with different ages will reveal possible volatile emplacement history. In 1 Ga, approximately 60-70 craters of 10 m diameter form per km2. Thus, the rover will need to sample at least ten of these craters, which may require a total traverse path length of 2-3 km. During 2014-2015, we developed an initial prototype rover for RP. The current design is a solar powered, four-wheeled vehicle, with hub motor drive, offset four wheel steering, and active suspension. Active suspension provides capabilities including changing vehicle ride height, traversing comparatively large obstacles, and controlling load on the wheels. All-wheel steering enables the vehicle to point arbitrarily while roving, e.g., to keep the solar array pointed at the sun while in motion. The offset steering combined with active suspension improves driving in soft soil. The rover's on-board software utilizes NASA's Core Flight Software, which is a reusable flight software environment. During 2015, we completed the initial rover software build, which provides low-level hardware interfaces, basic mobility control, waypoint driving, odometry, basic error checking, and camera services. Development of the prototype rover has enabled maturation of many of the subsystems to TRL 5. During the next year, we will conduct integrated testing of concepts of operation, navigation, and remote driving tools. In addition, we will perform environmental tests including radiation (avionics), thermal and thermal/vacuum (mechanisms), and gravity offload (mobility)

    Crew/Robot Coordinated Planetary EVA Operations at a Lunar Base Analog Site

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    Under the direction of NASA's Exploration Technology Development Program, robots and space suited subjects from several NASA centers recently completed a very successful demonstration of coordinated activities indicative of base camp operations on the lunar surface. For these activities, NASA chose a site near Meteor Crater, Arizona close to where Apollo Astronauts previously trained. The main scenario demonstrated crew returning from a planetary EVA (extra-vehicular activity) to a temporary base camp and entering a pressurized rover compartment while robots performed tasks in preparation for the next EVA. Scenario tasks included: rover operations under direct human control and autonomous modes, crew ingress and egress activities, autonomous robotic payload removal and stowage operations under both local control and remote control from Houston, and autonomous robotic navigation and inspection. In addition to the main scenario, participants had an opportunity to explore additional robotic operations: hill climbing, maneuvering heaving loads, gathering geo-logical samples, drilling, and tether operations. In this analog environment, the suited subjects and robots experienced high levels of dust, rough terrain, and harsh lighting

    The effectiveness of home versus community-based weight control programmes initiated soon after breast cancer diagnosis: a randomised controlled trial

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    BackgroundBreast cancer diagnosis may be a teachable moment for lifestyle behaviour change and to prevent adjuvant therapy associated weight gain. We assessed the acceptability and effectiveness of two weight control programmes initiated soon after breast cancer diagnosis to reduce weight amongst overweight or obese women and prevent gains in normal-weight women.MethodsOverweight or obese (n?=?243) and normal weight (n?=?166) women were randomised to a three-month unsupervised home (home), a supervised community weight control programme (community) or to standard written advice (control). Primary end points were change in weight and body fat at 12 months. Secondary end points included change in insulin, cardiovascular risk markers, quality of life and cost-effectiveness of the programmes.ResultsForty-three percent of eligible women were recruited. Both programmes reduced weight and body fat: home vs. control mean (95% CI); weight ?2.3 (?3.5, ?1.0) kg, body fat ?1.6 (?2.6, ?0.7) kg, community vs. control; weight ?2.4 (?3.6, ?1.1) kg, body fat ?1.4 (?2.4, ?0.5) kg (all p?<?0.001). The community group increased physical activity, reduced insulin, cardiovascular disease risk markers, increased QOL and was cost-effective.ConclusionsThe programmes were equally effective for weight control, but the community programme had additional benefits.Clinical trial registrationISRCTN6857614

    Antiviral B cell memory in the absence of mature follicular dendritic cell networks and classical germinal centers in TNFR1-/- mice.

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    TNFR1-/- mice have been shown to lack networks of mature follicular dendritic cells (FDCs) and they do not form germinal centers. With nonreplicating Ags, IgG titers were inefficiently induced and not maintained. In this study, the neutralizing Ab response and the establishment of B cell memory in TNFR1-/- mice after infection with vesicular stomatitis virus (VSV) were analyzed histologically and functionally. Immunization with VSV-derived protein Ags without adjuvant induced only IgM but no IgG Abs in TNFR1-/- mice, whereas VSV glycoprotein emulsified in CFA or IFA induced IgM and IgG responses that were short-lived and of moderate titer. However, infection with live VSV induced excellent neutralizing IgM and IgG responses in TNFR1-/- mice, and adoptively transferable B cell memory was generated and persisted for more than 300 days. In contrast, IgG levels and Ab-forming cells in the bone marrow declined within 300 days by 90-95% compared with controls. These findings suggest that 1) increased Ag dose and time of Ag availability can substitute for FDC-stored Ab-complexed Ag in the induction of efficient IgG responses in TNFR1-/- mice devoid of classical germinal centers; 2) the induction and maintenance of adoptively transferable B cell memory can occur in the absence of Ag bound to mature FDCs; and 3) the long-term maintenance of elevated IgG titers is largely dependent on FDC-associated persisting Ag. However, about 5-10% of the Ab production remained in the absence of detectable persisting Ag in TNFR1-/- mice, probably either due to immature FDCs being partially functional and/or due to long-lived plasma cells

    Antiviral B cell memory in the absence of mature follicular dendritic cell networks and classical germinal centers in TNFR1-/- mice.

    No full text
    TNFR1-/- mice have been shown to lack networks of mature follicular dendritic cells (FDCs) and they do not form germinal centers. With nonreplicating Ags, IgG titers were inefficiently induced and not maintained. In this study, the neutralizing Ab response and the establishment of B cell memory in TNFR1-/- mice after infection with vesicular stomatitis virus (VSV) were analyzed histologically and functionally. Immunization with VSV-derived protein Ags without adjuvant induced only IgM but no IgG Abs in TNFR1-/- mice, whereas VSV glycoprotein emulsified in CFA or IFA induced IgM and IgG responses that were short-lived and of moderate titer. However, infection with live VSV induced excellent neutralizing IgM and IgG responses in TNFR1-/- mice, and adoptively transferable B cell memory was generated and persisted for more than 300 days. In contrast, IgG levels and Ab-forming cells in the bone marrow declined within 300 days by 90-95% compared with controls. These findings suggest that 1) increased Ag dose and time of Ag availability can substitute for FDC-stored Ab-complexed Ag in the induction of efficient IgG responses in TNFR1-/- mice devoid of classical germinal centers; 2) the induction and maintenance of adoptively transferable B cell memory can occur in the absence of Ag bound to mature FDCs; and 3) the long-term maintenance of elevated IgG titers is largely dependent on FDC-associated persisting Ag. However, about 5-10% of the Ab production remained in the absence of detectable persisting Ag in TNFR1-/- mice, probably either due to immature FDCs being partially functional and/or due to long-lived plasma cells

    Normal development and behaviour of mice lacking the neuronal cell-surface PrP protein

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    PrPC is a host protein anchored to the outer surface of neurons and to a lesser extent of lymphocytes and other cells. The transmissible agent (prion) responsible for scrapie is believed to be a modified form of PrPC. Mice homozygous for disrupted PrP genes have been generated. Surprisingly, they develop and behave normally for at least seven months, and no immunological defects are apparent. It is now feasible to determine whether mice devoid of PrPC can propagate prions and are susceptible to scrapie pathogenesis
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