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

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Ablators for Human and Robotic Exploration of the Moon, Mars and Beyond

When Apollo was designed to carry astronauts safely back from the Moon, at return speeds exceeding 11 km/s, it required development of a new lightweight ablative material to protect the capsule and crew from the intense heat of entry. Soon after the Apollo program, successful Mars Viking Lander missions employed a different and much lighter ablator in more benign entry conditions. On the other hand, the Pioneer-Venus and Galileo Probe missions that followed required yet another ablative system, to manage the extreme heating at those destinations, which was like flying a ballistic missile nose tip into a thermonuclear explosion. NASA had to invent a new heat-shield concept based on the rocket nozzle and ballistic missile ablative materials. In the mid 1990's, as the Science focus returned to Mars, advances in manufacturing, testing and materials technology led to innovative lightweight ablators that enabled comet and asteroid sample return missions and facilitated large lander missions such as MSL and Mars 2020. NASA's current plans for robotic and human exploration of the Moon, Mars and beyond introduce different constraints and new expectations for ablators. Human missions to Moon and Mars, sample return missions from Mars, and exploration of Uranus and Neptune, the two planets we are yet to explore, will require ablators that can withstand extreme environments, with verifiable robustness, and with raw materials and manufacturing approaches that are sustainable in the longer term. This talk will review the history of ablators as well as current ablative TPS development that addresses the requirements for future missions to Moon, Mars and beyond

The ecology of cancer

Neoplasia, the disease of multicellular organisms, is not only a major cause of human death worldwide but also affects numerous invertebrate and vertebrate species. Similar to other diseases, cancer is a significant physiological burden on the host and hence not only impacts the individual but also influences interindividual interactions, populations and consequently global ecosystems. Despite this, oncology and other biological sciences such as ecology and evolution have until very recently developed in relative isolation. To overcome this caveat, we draw parallel between invasive species and the metastatic cascade and provide an overview of the ecology of cancer at the scale of the organisms and the ecosystems of malignant cells (both at the micro- and macro-scales). We discuss the drivers of metastatic formations in the tissue environment and investigate how individuals respond to malignant growth and the impact of this response on populations. Finally, we provide potential avenues for applying evolutionary ecology principles to cancer prevention and to the development of novel treatment strategies