Accession Number : ADA307339

Title :   Evaluation of Self-Sealing Structures for Space Vehicle Application.

Descriptive Note : Contract rept.,

Corporate Author : NORTHROP CORP HAWTHORNE CA

Personal Author(s) : D'Anna, Philip J. ; Heitz, Roger M.

PDF Url : ADA307339

Report Date : MAY 1966

Pagination or Media Count : 85

Abstract : The concept of a self-sealing wall is investigated as a technique for ensuring the sealed integrity of pressurized space vehicle compartments in a micrometeorite environment. Experimental verification of the feasibility of this concept has been achieved with simulated space vehicle multi-sheet wall structures incorporating either mechanical, chemical or combined mechanical-chemical self-sealing techniques which were developed during the course of this investigation. Self-sealing capability of the candidate wall configurations has been established for a pressure differential of one atmosphere and three temperature conditions of the impact face sheet (R.T., -85 F and +300 F), by puncturing wall specimens with a 1/8-inch diameter steel sphere at impact velocities of 20,000 fps and above. However before effective self- sealing could be consistently achieved, at these higher impact velocities, it was necessary to develop impact damage control techniques for minimizing damage to the wall face sheets where sealing was to be effected. Two basic self-sealing wall configurations evolved from this investigation. One configuration, the 'Integral System Concept,' incorporates the self-sealing feature into the space between the inner and outer shell of an aluminum structural wall. In this concept, the sealing action is achieved at the outer shell where impact damage is minimal and sealing more easily effected. The other self-sealing wall configuration utilizes a 'Tile Concept' in which the self-sealing feature is incorporated into a nonmetallic open face tile which is then bonded to the inner shell of a double face sheet wall structure. In this concept, the sealing action is accomplished at the inner shell of the basic wall structure.

Descriptors :   *SPACECRAFT, *COMPOSITE MATERIALS, *SEALING COMPOUNDS, *SEALED SYSTEMS, VELOCITY, FIBERGLASS, SHOCK WAVES, ELASTOMERS, RUBBER, SHELLS(STRUCTURAL FORMS), IMPACT STRENGTH, TERMINAL BALLISTICS, ALUMINUM, EPOXY LAMINATES, WALLS, PRESSURIZATION, POLYURETHANE RESINS, TILES, FOAM, HONEYCOMB CORES, DAMAGE CONTROL, PHENOLIC PLASTICS, METEORITES.

Subject Categories : Adhesives, Seals and Binders
      Laminates and Composite Materials
      Unmanned Spacecraft
      Manned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE