Application of Risk Informed Decision Making to Highly Reliable Three Dimensionally Woven Thermal Protection System for Mars Sample Return

The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

Variation in fast-start performance within a population of polyphenic bluegill (Lepomis macrochirus)

Bluegill sunfish Lepomis macrochirus exhibit intraspecific variation in their morphology and swimming performance based on habitat. The pelagic form has a relatively streamlined, fusiform body shape associated with greater steady-state swimming speed and energy economy. In contrast, littoral bluegill have deeper bodies with fins located farther from their center of mass to enhance maneuverability among littoral vegetation. Deeper body shapes have been associated with increased faststart performance to escape predators or capture prey. We hypothesized that littoral bluegill, which have a deeper body shape, would exhibit greater fast-start performance than pelagic bluegill. A total of 29 bluegill (16 littoral, 13 pelagic) were caught by hook and line, and their fast-start performance was analyzed from high-speed video recordings. Body shape appears to be a poor predictor of fast-start performance. Contrary to our expectations, pelagic bluegill had a significantly higher peak velocity, peak acceleration, and angular velocity compared to littoral bluegill. Pelagic bluegill living among larger predators and foraging on mobile prey may be exposed to selection pressures that favor increased fast-start performance. Integrated studies of internal morphology and physiology are needed to fully understand the relationship between morphology and performance in this population

High Velocity Impact Performance of a Dual Layer Thermal Protection System for the Mars Sample Return Earth Entry Vehicle

No abstract availabl

Thermal Testing of the Heatshield for Extreme Entry Environment Technology (HEEET) TPS

The testing of a thermal protection system (TPS) in multiple arc jets and laser facilities is critical not only to determine the ability of a material to withstand the harsh aerothermal environments but is also required to collect relevant data that allows construction of a thermal response model of the TPS for flight design. The present talk provides an overview of recent arcjet testing of the HEEET material, one of the families of materials from the 3D Woven TPS program, being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project

Enabling Entry Technologies for Ice Giant Missions

The highest priority science goals for Ice Giant missions are: 1) Interior structure of the Planet, and 2) Bulk composition that includes isotopes and noble gases. The interaction between the planetary interior and the atmosphere requires sustained global measurements. Noble gas and Isotope measurements require in situ measurement. Drag modulated aerocapture utilizing ADEPT offers more mass delivered to the Ice Giants than with propulsive orbit insertion. The Galileo Probe entered at a hot spot which created interpretation challenges. Juno is providing valuable orbital measurements, but without in situ measurements the story is incomplete. Planetary scientists interested in Ice Giant missions should perform mission design studies with these new Entry System technologies to assess the feasibility within the context of the international collaboration framework. A mission architecture that includes probe(s) along with an orbiting spacecraft can deploy the probes at the desired location while taking simultaneous measurements from orbit to provide invaluable data that can correlate both global and local measurements. Entry System Technologies currently being developed by NASA are poised to enable missions that position the Orbiter & Probes through drag modulated aerocapture (ADEPT), and HEEET enables the Probes to survive the extreme environments encountered for entry into the atmospheric interior

Enabling Entry Technologies for Ice Giant Missions

The proposed poster will highlight two NASA developed entry technologies that are enablers for Ice Giant Missions. They are: (1) Heat-shield for Extreme Entry Environment Technology (HEEET), and (2) Adaptable, Deployable, Entry, and Placement Technology (ADEPT), a mechanically deployable entry system. HEEET development is complete and is at TRL 6. HEEET is ready for Ice Giant in situ probe missions, and HEEET is an enabler for either direct ballistic entry or entry from Orbit. NASA plans to sustain the HEEET capability as it is needed for Venus, Saturn and higher speed sample return missions in addition to Ice Giant Missions. The emerging recognition among the scientific community that by delivering the probe from orbit will allow for simultaneous in-situ and orbital measurement can be enabled by aerocapture using ADEPT. The drag modulated aerocapture (DMA) with ADEPT is the simplest approach that can deliver an orbiter and probe together and without the significant penalty associated with propulsive insertion. Studies performed by JPL and NASA Ames teams point to this very promising possibility. Numerous DMA with ADEPT studies point to its applicability to small spacecraft missions as well as Ice Giant missions. The poster will present the current state of readiness of HEEET, ADEPT and DMA

Application of Risk Informed Decision Making to a Highly Reliable Three-Dimensionally Woven Thermal Protection System for Mars Sample Return

The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

Highly Reliable 3-Dimensional Woven Thermal Protection System for Mars Sample Return

No abstract availabl

Processing and Characterizing Alumina/Aluminum Composites with Tailored Microstructures Formed by Reactive Metal Penetration

In industry, the need to maximize energy efficiency depends on the availability of suitable advanced materials. Ceramic composites are exemplary materials for many advanced engineering applications because they exhibit good thermal stability, oxidation resistance and enhanced toughness. Presently, ceramic composite fabrication processes are costly, often requiring high temperatures and pressures to achieve reasonable densities. Our research is focused on developing a processing technique, that will allow production of alumina/aluminum composites using relatively low temperatures and without the application of an external force, thus reducing the processing costs. Our composites were formed using Reactive Metal Penetration (RMP), which is a process involving the reaction of molten Al with a dense ceramic preform. The result is a near net shape ceramic/metal composite with interpenetrating phases. The volume fraction of metal in the composites was varied by doping an aluminosilicate ceramic preform with silica. For this study we fabricated composites using pure mullite and mullite doped with 23 and 42 weight percent silica, yielding 18, 25, and 30 volume percent metal in the composites, respectively. Optical and Scanning Electron Microscopy were used to characterize the homogeneity and scale of the microstructure. The scale of the microstructure varied with preform composition, the reaction temperature and with secondary heat treatments. Four-point bend testing was used to evaluate the influence of microstructure on strength and reliability. During these studies a gradient in the microstructure was observed, which we further characterized using microhardness testing. Alumina/aluminum composites formed by RMP show higher toughness then monolithic alumina and have the potential for improved reliability when compared to monolithic ceramics