ALBERT

Description: Hemolysis was induced in rats by the intravenous administration of phenylhydrazine, immune hemolytic serum and Tween 80. During the period of red cell destruction, which lasted for three to four days, there was a marked leukocytosis, neutrophilia and eosinophilia which also persisted for three to four days. With phenylhydrazine and Tween 80 there was an initial transitory eosinopenia; with immune serum there was an immediate eosinophilia. In contrast, anemia produced by cardiac hemorrhage was accompanied by a transient slight leukocytosis and eosinopenia. Within one day the white cell level returned to baseline levels, but eosinophilia appeared and persisted for two days. The injections of formaldehyde, ACTH, and saline, and cardiac puncture without bleeding caused a slight ephemeral leukocytosis and eosinopenia. The peripheral blood cell response observed during hemolysis occurred in the presence or absence of the adrenals, and with or without the administration of ACTH. It was concluded that hemolysis elicits a distinct pattern of cellular response in the peripheral blood which is not mediated through the adrenal cortex.

Description: The intravenous administration of phenylhydrazine caused a significantly greater destruction of red cells in adrenalectomized rats than in controls. Cortisone given to adrenalectomized rats prevented this increased destruction and maintained red cells at a level comparable to controls. ACTH almost completely prevented phenylhydrazine anemia in intact rats and the red cell level was significantly higher than that in intact rats which did not receive ACTH.

Description: 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-degree 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 International Planetary Probe Workshop (IPPW), NASA Headquarters postulated that a common aeroshell 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-degrees-of-freedom 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 Thermal Protection System (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. Presentation: We will present an overview of the study scope, highlights of the trade studies and design driver analyses, and the final recommendations of a common probe design and assembly. We will also indicate limitations that the common probe design may have for the different destinations. Finally, recommended qualification approaches for missions will be presented.

Description: With the gradual increase in robotic rover sophistication and the desire for humans to explore the solar system, the need for reentry systems to deliver large payloads into planetary atmospheres is looming. Heritage ablative Thermal Protection Systems (TPS) using Viking or Pathfinder era materials are at or near their performance limits and will be inadequate for many future missions. Significant advances in TPS materials technology are needed in order to enable susequent human exploration missions. This paper summarizes some recent progress at NASA in developing families of advanced rigid ablative TPS that could be used for thermal protection in planetary entry missions. In particular, the effort focuses on technologies required to land heavy masses on Mars to facilitate exploration.