AN INJECTION SYSTEM FOR ALLEVIATION OF RADIO BLACKOUT DURING RE-ENTRY

This report outlines method of creating a window for radio communication through a re-entry plasma sheath. The results of non-equilibrium numerical calculations illustrate that the injection of a coolant gas will reduce the plasma sheath temperature but will not reduce the free electron density or p...

Full description

Saved in:
Bibliographic Details
Main Authors: Good, R Earl, Rossi, Joseph J
Format: Report
Language:English
Subjects:
ATMOSPHERE ENTRY
ATTENUATION
BLACKOUT(PROPAGATION)
CARBON COMPOUNDS
COOLING
DISSOCIATION
ELECTRON DENSITY
ELECTRONS
ELECTROPHILIC GASES
FLUID FLOW
FLUORIDES
FLUORINE COMPOUNDS
GASES
INJECTION
JET FLOW
METHYL FLUORIDE
NITROGEN
NONEQUILIBRIUM FLOW
OXYGEN
Radio Communications
REDUCTION
REENTRY VEHICLES
SULFUR COMPOUNDS
SULFUR HEXAFLUORIDE
SUPERSONIC FLOW
TEMPERATURE
TEST VEHICLES
Unmanned Spacecraft
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This report outlines method of creating a window for radio communication through a re-entry plasma sheath. The results of non-equilibrium numerical calculations illustrate that the injection of a coolant gas will reduce the plasma sheath temperature but will not reduce the free electron density or plasma frequency. Plasma electron density can be reduced, however, by attachment to electrophilic gases. The chemical rates of attachment are computed; and criteria are developed which specify the amount of electrophilic gas required to reduce the electron density a specified amount in a given time. As a practical application, a gas injection system for the total alleviation of S-band blackout throughout the re-entry of a Trailblazer II vehicle would have a total charged weight of 3.4 lbs., a volume of 215 cubic inches, and would discharge 0.28 lbs. of SF(6) during re-entry. With a pulsed injection system, an even smaller system can be used.