Precision cleaning of large complex structures. II

This paper is concerned with a program which has the objective to develop precision cleaning methods for the achievement of MIL-STD-1246A cleanliness levels on large complex structures. Increased spacecraft/payload cleanliness is needed as a result of technology advances and long-life reliability requirements for space systems. Cleaning techniques must, therefore, be devised to reduce particle concentrations and nonvolatile residue (NVR) to acceptable levels on large spacecraft structures and components. A description is given of results obtained from solvent wipe precision cleaning procedures for complex structures which were not readily cleaned by solvent flushing. Attention is given to the three phases involved in the approach to the project, the unhemmed polyester wipers, the solvent, precleaning, and the procedures of precision cleaning.