Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

Spacecraft in low Earth orbit (LEO) are subject to degradation in thermal and optical performance of components and materials
through interaction with atomic oxygen and vacuum ultraviolet radiation which are predominant in LEO. Due to the importance
of LEO durability and performance to manufacturers and users, an international test program for assessing the durability
of spacecraft materials and components was initiated. Initial tests consisted of exposure of samples representing a variety of thermal
control paints and multilayer insulation materials that have been used in space. Materials donated from various international
sources were tested alongside a material whose performance is well known such as Teflon FEP or Kapton H for multilayer insulation,
or Z-93-P for white thermal control paints. The optical, thermal or mass loss data generated during the test was then provided
to the participating material supplier. Data was not published unless the participant donating the material consented to publication.
This paper presents a description of the types of tests and facilities that have been used for the test program as well as some examples
of data that have been generated. The test program is intended to give spacecraft builders and users a better understanding
of degradation processes and effects to enable improved prediction of spacecraft performance.
Author
Far Ultraviolet Radiation; Oxygen Atoms; Spacecraft Components; Spacecraft Construction Materials; Orbital Space Tests;
Materials Tests
20000066596 Thiokol Propulsion, Brigham City, UT USA
Effective Adhesive Modulus Approach for Evaluation of Curing Stresses
Macon, David J., Thiokol Propulsion, USA; [2000]; 19p; In English
Contract(s)/Grant(s): NAS8-97238; Copyright; Avail: Issuing Activity
A study was performed to determine the most accurate approach for establishing a modulus value for measuring the curing
stress in an epoxy system. In this study, the curing stress for a number of epoxy systems was measured using the bimaterial beam
approach. The stress relaxation profile of the adhesive bonded to the metallic strip was compared to the relaxation profile of the
bulk adhesive. It was found that the shape of the relaxation curve was consistent for both samples. but that the magnitude of the
two curves differed. It is argued that the difference between the curves is a result of curing stress and that the long-term effective
modulus as measured from the bonded adhesive should be used to establish the curing stress.
Author
Adhesives; Adhesive Bonding; Evaluation; Curing; Stresses; Stress Relaxation
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PROPELLANTS AND FUELS
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20000064700 Thiokol Corp., Brigham City, UT USA
Reclaimation of Ammonium Perchlorate from Propellant Washout Water
Berntsen, Eric, Thiokol Corp., USA; [2000]; 5p; In English; Joint Ordnance Commanders Group (JOCG) and National Defense
Industrial Association (NDIA) 2000 Global Demilitarization Symposium and Exhibition, 15-18 May 2000, Coeur d’Alene, ID,
USA
Contract(s)/Grant(s): NAS8-38100; Copyright; Avail: Issuing Activity
Thiokol Propulsion has developed and is operating a process which treats and recovers Ammonium Perchlorate (AP) from
wash out water produced by Thiokols’ propellant removal facility. The system was designed to remove the dissolved AP from
the washout water by concentrating and precipitating the AP in an Evaporator. The evaporator processes the 10% AP solution at
22GPM and was designed to match the production rate of Thiokol’s propellant washout facility. The AP slurry produced in the
evaporator is dewatered by a centrifuge and is automatically loaded into 55-gallon drums for reuse at the rate of 1000 lbs./hr. Part
of the evaporator system includes equipment which sizes the AP crystals. The recovered AP is 99% pure and could be reused in
manufacturing new propellant. The end products of the process are crystalline AP and distilled water. The distilled water is
recycled and returned to the Thiokol’s propellant removal facility for reuse in washing out more propellant. The facility has been
operating for approximately one year and has recovered 830,000 pounds of AP, and has evaporated 988,000 gallons of AP washout
water. The facility was constructed using NASA and Thiokol funding. The Current contract is scheduled to be completed at the
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