UPPER ATMOSPHERE DENSITY OBTAINED FROM FALLING SPHERE DRAG MEASUREMENTS

Abstract

A density profile vs altitude from 95 to 130 km, obtained from drag measurements are made directly from within a falling sphere, is presented. The main sensors are linear accelerometers aligned to measure X, Y, Z components of acceleration of the sphere from which total drag is obtained. The method consists of ejecting an inflatable sphere somewhere between 80 and 100 km on the ascent of an Aerobee 150 rocket flight. From ejection, the sphere continues to approximately 250 km altitude on a trajectory which is, except for drag, a free-fall trajectory. The prediction of sphere drag coefficients with their estimated probable errors are given in the altitude range from 90 to 160 km. The telemetry record showing the drag forces used in calculating the density profile in the altitude range 95 to 130 km is shown. The sources of error in the calculated density are analyzed and tabulated. The calculated density in kilograms/cu m vs altitude in kilometers is compared with the ARDC Model Atmospheres of 1956, 1959, and 1961.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1962
Accession Number
AD0405736

Entities

People

  • F. S. Sherman
  • G. A. Faucher
  • R. W. Procunier

Organizations

  • Air Force Cambridge Research Laboratories

Tags

Communities of Interest

  • Sensors
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Accelerometers
  • Accuracy
  • Aerodynamic Drag
  • Air Force
  • Atmospheric Composition
  • Boundary Layer
  • Detectors
  • Equations
  • Flow
  • Mach Number
  • Measurement
  • Measuring Instruments
  • Reynolds Number
  • Telemetry
  • United States
  • Wind
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Space Exploration and Orbital Mechanics.