TDRSS Battery Life Cycle Tests Interim Report

The design features of the tracking and data relay satellite system battery are described. Some of the life cycle tests performed on the battery are reported

Data correlation and analysis of arc tunnel and wind tunnel tests of RSI joints and gaps. Volume 1: Technical report

Heat transfer data measured in gaps typical of those under consideration for joints in space shuttle reusable surface insulation protection systems have been assimilated, analyzed and correlated. The data were obtained in four NASA facilities. Several types of gaps were investigated with emphasis on simple butt joints. Gap widths ranged from 0.07 to 0.7 cm and depths ranged from 1 to 6 cm. Laminar, transitional and turbulent boundary layer flows over the gap opening were investigated. Three-dimensional heating variations were observed within gaps in the absence of external flow pressure gradients. Heat transfer correlation equations were obtained for several of the tests. Thermal protection system performance with and without gaps was compared for a representative shuttle entry trajectory

Depositional and paragenetic controls on porosity development, upper Red River Formation, North Dakota

The upper Red River Formation in North Dakota comprises a subtidal/intertidal facies overlain by three evaporitic sequences of four lithologic units each, labeled P, R, and F in stratigraphic order. Four porosity zones are recognized in the upper Red River: the subtidal/ intertidal facies forms one porosity zone, and each evaporitic sequence contains another. Each unit in a sequence, as well as the sequence itself, is thinner and less widespread than its preceding counterpart. All strata are laterally continuous across the main part of the Williston basin in North Dakota, but, the porosity zones eventually disappear to the east as they approach the basin margin. Porosity within any given zone varies from one part of the basin to another, often within relatively short distances. The D porosity zone consists of two primary lithologic facies: a shallow subtidal burrowed mudstone and skeletal wackestone, and an impermeable, often laminated, black organic skeletal wackestone and packstone deposited in an intertidal or supratidal barred pond environment. Porosity in the subtidal burrowed facies is due to syndepositional dolomitization and later calcite solution and microfracturing. Maximum porosity values related to dolomitization and calcite dissolution occur in the burrowed horizons immediately above the impermeable organic units, which acted as barriers to interstitial fluid movement. Poor development of the organic units near the center of the basin perhaps accounts for sporadic porosity development in that area. The basal unit of each of the sequences overlying the 11D11 zone consists of open shelf bioturbated skeletal wackestone of characteristically low porosity. Porous, fine-grained, primary supratidal dolomite overlies the subtidal facies, and these units form the 11C, 11B, 11 and A porosity zones. A very thin argillaceous marker bed of non-calcareous shale completes each sequence. Porosity in the supratidal dolomite stems from intercrystalline voids and pinpoint porosity due to solution. Porosity in the upper three zones varies across the basin and is directly related to degree of exposure of the sediment in the supratidal environment, during which dolomitization occurred

Aerothermodynamic Assessment of Corrugated Panel Thermal Protection Systems

The feasibility of using corrugated panels as a thermal protection system for an advanced space transportation vehicle was investigated. The study consisted of two major tasks: development of improved correlations for wind tunnel heat transfer and pressure data to yield design techniques, and application of the design techniques to determine if corrugated panels have application future aerospace vehicles. A single-stage-to-orbit vehicle was used to assess advantages and aerothermodynamic penalties associated with use of such panels. In the correlation task, experimental turbulent heat transfer and pressure data obtained on corrugation roughened surfaces during wind tunnel testing were analyzed and compared with flat plate data. The correlations and data comparisons included the effects of a large range of geometric, inviscid flow, internal boundary layer, and bulk boundary layer parameters in supersonic and hypersonic flow

Modeling pN2 through Geological Time: Implications for Planetary Climates and Atmospheric Biosignatures

Nitrogen is a major nutrient for all life on Earth and could plausibly play a similar role in extraterrestrial biospheres. The major reservoir of nitrogen at Earth's surface is atmospheric N2, but recent studies have proposed that the size of this reservoir may have fluctuated significantly over the course of Earth's history with particularly low levels in the Neoarchean - presumably as a result of biological activity. We used a biogeochemical box model to test which conditions are necessary to cause large swings in atmospheric N2 pressure. Parameters for our model are constrained by observations of modern Earth and reconstructions of biomass burial and oxidative weathering in deep time. A 1-D climate model was used to model potential effects on atmospheric climate. In a second set of tests, we perturbed our box model to investigate which parameters have the greatest impact on the evolution of atmospheric pN2 and consider possible implications for nitrogen cycling on other planets. Our results suggest that (a) a high rate of biomass burial would have been needed in the Archean to draw down atmospheric pN2 to less than half modern levels, (b) the resulting effect on temperature could probably have been compensated by increasing solar luminosity and a mild increase in pCO2, and (c) atmospheric oxygenation could have initiated a stepwise pN2 rebound through oxidative weathering. In general, life appears to be necessary for significant atmospheric pN2 swings on Earth-like planets. Our results further support the idea that an exoplanetary atmosphere rich in both N2 and O2 is a signature of an oxygen-producing biosphere.Comment: 33 pages, 11 figures, 2 tables (includes appendix), published in Astrobiolog

Data correlation and analysis of arc tunnel and wind tunnel tests of RSI joints and gaps. Volume 2: Data base

Wind tunnel tests were conducted to determine the aerodynamic heating created by gaps in the reusable surface insulation (RSI) thermal protection system (TPS) for the space shuttle. The effects of various parameters of the RSI on convective heating characteristics are described. The wind tunnel tests provided a data base for accurate assessment of gap heating. Analysis and correlation of the data provide methods for predicting heating in the RSI gaps on the space shuttle

A study of leeside flow field heat transfer on Shuttle Orbiter configuration

A coupled inviscid and viscous theoretical solution of the flow about the entire configuration is the desirable and comprehensive approach to defining thermal environments about the space shuttle orbiter. Simplified methods for predicting entry heating on leeside surfaces of the orbiter are considered. Wind tunnel heat transfer and oil flow data at Mach 6 and 10 and Reynolds numbers ranging from 500,000 to 73 million were used to develop correlations for the wing upper surface and the top surface of the fuselage. These correlations were extrapolated to flight Reynolds number and compared with heating data obtained during the shuttle STS-2 reentry. Efforts directed toward the wing leeside surface resulted in an approach which generally agreed with the flight data. Heating predictions for the upper fuselage were less successful due to the extreme complexity of local flow interactions and the associated heating environment