A comparison of measured and theoretical predictions for STS ascent and entry sonic booms

Sonic boom measurements have been obtained during the flights of STS-1 through 5. During STS-1, 2, and 4, entry sonic boom measurements were obtained and ascent measurements were made on STS-5. The objectives of this measurement program were (1) to define the sonic boom characteristics of the Space Transportation System (STS), (2) provide a realistic assessment of the validity of xisting theoretical prediction techniques, and (3) establish a level of confidence for predicting future STS configuration sonic boom environments. Detail evaluation and reporting of the results of this program are in progress. This paper will address only the significant results, mainly those data obtained during the entry of STS-1 at Edwards Air Force Base (EAFB), and the ascent of STS-5 from Kennedy Space Center (KSC). The theoretical prediction technique employed in this analysis is the so called Thomas Program. This prediction technique is a semi-empirical method that required definition of the near field signatures, detailed trajectory characteristics, and the prevailing meteorological characteristics as an input. This analytical procedure then extrapolates the near field signatures from the flight altitude to an altitude consistent with each measurement location

A study of various synthetic routes to produce a halogen-labeled traction fluid

Several synthetic routes were studied for the synthesis of the compound 1, 1, 3-trimethyl-1, 3-dicyclohexyl-2 chloropropane. This halogen-labeled fluid would be of use in the study of high traction lubricants under elastohydrodynamic lubrication conditions using infrared emission spectroscopy. The synthetic routes included: dimerization of alpha-methylstyrene, methanol addition to alpha-methylstyrene, a Wittig reaction, and an organometallic approach. Because of steric hindrance and competing reactions, none of these routes were successful

Correlation of predicted and measured sonic boom characteristics from the reentry of STS-1 orbiter

Characteristics from sonic boom pressure signatures recorded at 11 locations during reentry of the Space Shuttle Orbiter Columbia are correlated with characteristics of wind tunnel signatures extrapolated from flight altitudes for Mach numbers ranging from 1.23 to 5.87. The flight pressure signature were recorded by microphones positioned at two levels near the descent groundtrack along the California corridor. The wind tunnel signatures used in theoretical predictions were measured using a 0.0041-scale model Orbiter. The mean difference between all measured and predicted overpressures is 12 percent from measured levels. With one exception, the flight signatures are very similar to theoretical n-waves

Apparatus for establishing flow of a fluid mass having a known velocity

An apparatus for establishing a flow of fluid mass, such as gas, having a known velocity is introduced. The apparatus is characterized by an hermetically sealed chamber conforming to a closed-loop configuration and including a throat and a plurality of axially displaceable pistons for sweeping through the throat a stream of gas including a core and an unsheared boundary layer. Within the throat there is a cylindrical coring body concentrically related to the throat for receiving the core, and a chamber surrounding the cylindrical body for drawing off the boundary layer, whereby the velocity of the core is liberated from the effects of the velocity of the boundary layer

Sanctions for E-Discovery Violations: By the Numbers

This Article reviews our comprehensive survey of written opinions from cases in federal courts prior to January 1, 2010, involving motions for sanctions relating to the discovery of electronically stored information (ESI) We analyzed each case for various factors, including date, court, type of case, sanctioning authority, sanctioned party, sanctioned misconduct, sanction type, sanctions to counsel, if any, and the protections provided from sanctions by Federal Rule of Civil Procedure 37(e) The survey identified 401 sanction cases and 230 sanction awards and showed that sanction motions and awards have increased over time, particularly in the last five years Sanctions against counsel are rare but are also increasing Sanction motions have been filed in all types of cases and in courts across the country Failure to produce ESI is the most common basis for sanctions Courts have used a variety of different rules, statutes, and powers to sanction parties for e-disco very violations, including Rule 37 and the inherent power of the court, and courts impose many different sanction types on e-discovery violators, including the severe sanctions of dismissal, default Judgment, adverse jury instructions, and sizeable monetary awards Rule 37(e) has not provided broad protection from such sanction

Sanctions for E-Discovery Violations: By the Numbers

This Article reviews our comprehensive survey of written opinions from cases in federal courts prior to January 1, 2010, involving motions for sanctions relating to the discovery of electronically stored information (ESI) We analyzed each case for various factors, including date, court, type of case, sanctioning authority, sanctioned party, sanctioned misconduct, sanction type, sanctions to counsel, if any, and the protections provided from sanctions by Federal Rule of Civil Procedure 37(e) The survey identified 401 sanction cases and 230 sanction awards and showed that sanction motions and awards have increased over time, particularly in the last five years Sanctions against counsel are rare but are also increasing Sanction motions have been filed in all types of cases and in courts across the country Failure to produce ESI is the most common basis for sanctions Courts have used a variety of different rules, statutes, and powers to sanction parties for e-disco very violations, including Rule 37 and the inherent power of the court, and courts impose many different sanction types on e-discovery violators, including the severe sanctions of dismissal, default Judgment, adverse jury instructions, and sizeable monetary awards Rule 37(e) has not provided broad protection from such sanction

Analysis of a spacecraft instrument ball bearing assembly lubricated by a perfluoroalkylether

An analysis of a spacecraft instrument ball bearing assembly, subjected to a scanning life test, was performed to determine the possible case of rotational problems involving these units aboard several satellites. The analysis indicated an ineffective transfer of a fluorinated liquid lubricant from a phenolic retainer to the bearing balls. Part of the analysis led to a novel HPLC separation method employing a fluorinated mobile phase in conjunction with silica based size exclusion columns

Preliminary sonic boom correlation of predicted and measured levels for STS-1 entry

A preliminary analysis correlating peaks from sonic boom pressure signatures recorded during the descent trajectory of the Orbiter Columbia, which landed in the dry lake bed at Edwards Air Force Base (EAFB), California, with measured wind tunnel signatures extrapolated from flight altitudes to the ground has been made for Mach numbers ranging from 1.3 to 6. The flight pressure signatures were recorded by microphones positioned at ground level near the groundtrack, whereas the wind tunnel signatures were measured during a test of a 0.0041-scale model Orbiter. The agreement between overpressure estimates based on wind tunnel data using preliminary flight trajectory data and oscillograph traces from ground measurements appears reasonable at this time for the range of Mach numbers considered. More detailed studies using final flight trajectory data and digitized ground measured data will be performed

Ferrographic analysis of wear particles from sliding elastohydrodynamic experiments

The Ferrograph was used to analyze wear debris generated in a sliding elastohydrodynamic contact. The amount of wear debris correlates well with the ratio of film thickness to composite surface roughness (A ratio). The general wear level parameter and the wear severity index yielded similar correlations with average A ratios. Essentially all the generated wear particles were of the normal rubbing wear type. The Ferrograph was more sensitive in detecting the wear debris than was the commonly used emission spectrograph

Ferrographic analysis of wear debris generated in a sliding elastohydrodynamic contact

The ferrograph was used to analyze wear debris generated in a sliding elastohydrodynamic contact. The amount of wear debris correlates well with the ratio of film thickness to composite surface roughness. Essentially all of the generated wear particles were of the normal rubbing wear type