Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2)

No abstract availabl

Tales from the Mars Science Laboratory Thermal Protection System Development (or, Try Not to Panic When Your Heatshield Material Disappears)

In 2012, the entry vehicle for the Mars Science Laboratory (MSL) mission was the largest and heaviest vehicle flown to another planet, designed to be able to withstand the largest heat fluxes in the Martian atmosphere ever attempted. The heatshield material that had been successfully used for all previous Mars missions had been baselined in the design, but during the development and qualification testing demonstrated catastrophic and unexplained failures. With only 10 months remaining before the original launch date, the TPS team led by NASA Ames designed and implemented a first-ever tiled, ablative heatshield. Highlights from MSL of the testing difficulties and innovations required to execute a new heatshield design will be presented, along with a sneak peak of the Mars 2020 mission

A Common Probe Design for Multiple Planetary Destinations

Atmospheric probes have been successfully flown to planets and moons in the solar system to conduct in-situ measurements. They include the Pioneer Venus multi-probes, the Galileo Jupiter probe, and Huygens probe. Probe mission concepts to five destinations, including Venus, Jupiter, Saturn, Uranus, and Neptune, have all utilized similar-shaped aeroshells and concept of operations, namely a 45 deg sphere cone shape with high density heatshield material and parachute system for extracting the descent vehicle from the aeroshell. Each concept designed its probe to meet specific mission requirements and to optimize mass, volume, and cost. At the 2017 IPPW, NASA Headquarters postulated that a common aero-shell design could be used successfully for multiple destinations and missions. This "common probe" design could even be assembled with multiple copies, properly stored, and made available for future NASA missions, potentially realizing savings in cost and schedule and reducing the risk of losing technologies and skills difficult to sustain over decades. Thus the NASA Planetary Science Division funded a study to investigate whether a common probe design could meet most, if not all, mission needs to the five planetary destinations with extreme entry environments. The Common Probe study involved four NASA Centers and addressed these issues, including constraints and inefficiencies that occur in specifying a common design.Study methodology: First, a notional payload of instruments for each destination was defined based on priority measurements from the Planetary Science Decadal Survey. Steep and shallow entry flight path angles (EFPA) were defined for each planet based on qualification and operational g-load limits for current, state-of-the-art instruments. Interplanetary trajectories were then identified for a bounding range of EFPA. Next, 3-DoF simulations for entry trajectories were run using the entry state vectors from the interplanetary trajectories. Aeroheating correlations were used to generate stagnation point convective and radiative heat flux profiles for several aeroshell shapes and entry masses. High fidelity thermal response models for various TPS materials were used to size stagnation point thicknesses, with margins based on previous studies. Backshell TPS masses were assumed based on scaled heat fluxes from the heatshield and also from previous mission concepts

Increasing Opioid Pain Pre-assessment and Reassessment Documentation Rate in Medical-Surgical Units

Problem The fifth vital sign, pain, requires proper pain management in hospital settings, often involving opioids with significant risks of adverse reactions. Appropriate pain assessment and management is vital to ensure safe medication administration and mitigate potential adverse reactions. Context This quality improvement (QI) project aimed to enhance opioid assessment and documentation rate above 90% compliance in two medical-surgical units, with a focus on bedside nurses. Nurses play a key role in administering and documenting pain assessments, a practice crucial to managing patient safety and effective pain management specific to opioid use. Intervention A baseline survey provided nurses’ understanding on compliance criteria and assessment timing. Interventions included visual reminders, informational posters, and instructions on how to access individual self-compliance reports. Measures A post-intervention survey assessed effectiveness and gathered feedback from nurses. April quarterly quality report data will be used to measure compliance rates for pain pre- and post-assessment documentation and compared with pre-intervention February quality report data. Alternatively, manual auditing of the electronic health record (EHR) for both units was performed to obtain preliminary post-intervention compliance data. Results Post-intervention results from April reports exhibited a decline of 7% in compliance rate for pre-assessment in unit A, but an increase by 0.5% for post-assessment documentation. Conversely, unit B displayed a 6.3% increase in pre-assessment documentation compliance and a 3.5% increase in post-assessment documentation rate. Conclusion Usage of visual aids to prompt pain assessment and reassessment documentation, coupled with enhanced nurse education on extracting self-compliance reports, have potential for enhancing nurse documentation compliance rates within medical-surgical units. Keywords: pain assessment, reassessment, documentation, medical-surgical, opioid

Designing text-messaging (SMS) in HIV programs : ethics-framed recommendations from the field

Text messages (SMS) are being increasingly integrated into HIV programs across Southern Africa to improve patient adherence, linkage to care and provide psycho-social support. Careful attention needs to be paid to the design of SMS-based interventions for clients of HIV-care services to ensure that any potential harm, such as unwanted disclosure of HIV status, is minimized. In this article we propose a set of best practice recommendations to ensure that any SMS-based intervention considers ethical principles to safeguard safety, autonomy and confidentiality of its targeted HIV-positive beneficiaries. This analysis draws from our operational experience in Southern Africa in the design and conduct of mHealth interventions in the frame of HIV projects. The recommendations, framed in the context of the Belmont Report's three ethical pillars, may contribute to more safely operationalize any SMS service integrated into an HIV program if adopted by mHealth planners and implementers. We encourage actors to report on the ethical and methodological pathways followed when conducting SMS-based innovations to improve the wellbeing and quality provision of HIV-care for their targeted clients

Tales from the Mars Science Laboratory Thermal Protection System Development (or, Try Not to Panic When Your Heatshield Material Disappears)

In 2012, the entry vehicle for the Mars Science Laboratory (MSL) mission was the largest and heaviest vehicle flown to another planet, designed to be able to withstand the largest heat fluxes in the Martian atmosphere ever attempted. The heatshield material that had been successfully used for all previous Mars missions had been baselined in the design, but during the development and qualification testing demonstrated catastrophic and unexplained failures. With only 10 months remaining before the original launch date, the TPS team led by NASA Ames designed and implemented a first-ever tiled, ablative heatshield. Highlights from MSL of the testing difficulties and innovations required to execute a new heatshield design will be presented, along with a sneak peak of the Mars 2020 mission

Common Probe Design Study and Follow-On Activities

The Common Probe Study was funded by the NASA's Planetary Science Division in the Science Mission Directorate in 2018 to investigate the feasibility of a common aeroshell design for atmospheric probe missions at Venus, Jupiter, Saturn, Uranus, and Neptune. The study involved 4 NASA Centers: Ames Research Center, Goddard Space Flight Center, Langley Research Center, and the Jet Propulsion Laboratory. The common aeroshell design that was studied was a 400 kg, 1.5 m diameter, 45-degree sphere cone shape with a high density heatshield material (Heatshield for Extreme Entry Environments Technology, or HEEET) and a parachute system to extract the descent vehicle. This size of aeroshell could accommodate a descent vehicle of 0.75 m diameter, which could encompass both Tier 1 and Tier 2 science instruments at each of the 5 destinations. Study methodology: First, a notional payload of instruments for each destination was defined based on the top priority measurements indicated by the Planetary Science Decadal Survey. Steep and shallow entry flight path angles (EFPA) were defined for each planet based on qualification and operational g-load limits for current, state-of-the-art instruments. Interplanetary trajectories were then identified that bounded the EFPA range.Next, 3-DoF simulations for entry trajectories were run using the entry state vectors from the interplanetary trajectories. Conical ribbon parachutes were sized based on heatshield separation dynamics. Aero-heating correlations were used to generate stagnation point convective and radiative heat flux profiles. High fidelity thermal response models for various TPS materials were used to size stagnation point thicknesses, with margins based on previous studies. Backshell TPS masses were assumed based on scaled heat fluxes from the heatshield and also from previous mission concepts.Based on these analyses, we have found that the common design is applicable for atmospheric probe missions for 4 out of the 5 destinations. Because of the unique gravity well for Jupiter, the entry environments are more severe resulting in heat loads an order of magnitude higher than for the other destinations.The next step is to determine what follow-on activities NASA should engage in. A questionnaire for the atmospheric probe community has been developed, with a focus on what size of aeroshell should be further analyzed (smaller or same diameter), and what incentives would make using such an aeroshell, if assembled and available, desirable to mission proposers.Preliminary results from this questionnaire will be presented

Overview of the MEDLI Project

The Mars Science Laboratory Entry, Descent, and Landing Instrumentation (MEDLI) Project's objectives are to measure aerothermal environments, sub-surface heatshield material response, vehicle orientation, and atmospheric density for the atmospheric entry and descent phases of the Mars Science Laboratory (MSL) entry vehicle. The flight science objectives of MEDLI directly address the largest uncertainties in the ability to design and validate a robust Mars entry system, including aerothermal, aerodynamic and atmosphere models, and thermal protection system (TPS) design. The instrumentation suite will be installed in the heatshield of the MSL entry vehicle. The acquired data will support future Mars entry and aerocapture missions by providing measured atmospheric data to validate Mars atmosphere models and clarify the design margins for future Mars missions. MEDLI thermocouple and recession sensor data will significantly improve the understanding of aeroheating and TPS performance uncertainties for future missions. MEDLI pressure data will permit more accurate trajectory reconstruction, as well as separation of aerodynamic and atmospheric uncertainties in the hypersonic and supersonic regimes. This paper provides an overview of the project including the instrumentation design, system architecture, and expected measurement response

Aerothermal Design of a Common Probe for Multiple Planetary Destinations

Estimate the mass of the Thermal Protection System (TPS) for a single design construct of an atmospheric entry probe with a rigid aeroshell, which could be used at five destinations, i.e. Venus, Saturn, Uranus, Neptune, and perhaps, Jupiter. The entry mass of the probe is 400 kg with a ballistic coefficient of 216 kg/m2. Process: The 3DoF trajectory simulation program Traj, coupled with the TPS response program FIAT was used for simulation and design. The assumed atmospheric models were VIRA (Venus-GRAM) for Venus, the Julianne Moses' model for Saturn, a NASA Ames engineering model for Uranus, Neptune-GRAM for Neptune, and Galileo Probe (Al Seiff's) result for Jupiter

G-quadruplex DNA and the Regulation of Human Telomere Accessibility

Human telomeres are nucleoprotein structures that cap the ends of chromosomes, preventing them from degradation. In normal cells, they are shortened due to the end replication problem. However, most cancer cells overcome this inherent growth limitation by upregulating telomerase, an enzyme that elongates telomeres to yield an immortal phenotype. The remaining cancerous cells immortalize by activating the alternative telomerelengthening pathway (ALT). Thus, treatments that directly target the telomere could disrupt both mechanisms the cancer cell employs for unlimited proliferation. The telomere overhang is G-rich DNA that spontaneously folds into a G-quadruplex. In vitro, the G-quadruplex structure has been shown to inhibit telomere extension by telomerase, making it an attractive potential therapeutic target. However, G-quadruplex capping properties and regulatory roles are still poorly understood. In this study, we used a FRET-based assay to probe the stability and accessibility of the G-quadruplex. We examined the folding behavior of variable telomeric repeat lengths (4- 8). Accessibility of the G-quadruplex was measured by the rate of quadruplex unfolding after the addition of complementary DNA, ALT pathway proteins, and telomerase. These measurements revealed a distinct periodic pattern of overhang accessibility where DNA and protein binding is limited for multiples of four TTAGGG repeats, whereas five to seven repeats are more accessible (7>6>5). Contrastingly, POT1, a telomere-specific binding protein, showed accessibility independent of the number of repeats. These results demonstrate the role of G-quadruplexes as physical impedances to the binding of telomere associated proteins and as critical regulatory structures for theOpe