Accession Number : ADA238159


Title :   Ablative Heat Shield Studies for NASA Mars/Earth Return Entry Vehicles


Descriptive Note : Master's thesis,


Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA


Personal Author(s) : Hamm, Michael K


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a238159.pdf


Report Date : Sep 1990


Pagination or Media Count : 121


Abstract : A material that behaves likes a glassy ablator on the surface, has a low thermal conductivity, is structurally tough, lightweight, and is in some sense reusable, would be desirable for the protective heat shield used on Earth entry vehicles. A material for this purpose has been developed that uses silicon dioxide (fused quartz) in a fibrous packed matrix, forming blocks which can behave as a glassy ablator on the surface when subject to very high surface heat fluxes. These fibrous silicon dioxide blocks are called Reusable Surface Insulation (RSI). The primary constituent of the RSI material is silicon dioxide, but may contain other compounds (e.g. alumina borosilicate) to affect the thermal and physical properties. The research performed in this thesis is to determine the ablative behavior of ceramic RSI materials in a hypersonic high enthalpy flow that is used to simulate entry into Earth atmosphere. Actual arc jet experiments were performed to measure mass loss, melt run off, and fiber collapse of these materials and compare the experimental results with predicted theoretical values. The tests were performed to ascertain if RSI type materials could be used for entry vehicles proposed in NASA Mars missions.


Descriptors :   *THERMAL PROPERTIES , MEASUREMENT , FIBERS , HIGH RATE , ATMOSPHERE ENTRY , PHYSICAL PROPERTIES , SILICON DIOXIDE , MATERIALS , INSULATION , MASS , GLASS , SURFACES , ALUMINUM OXIDES , THERMAL CONDUCTIVITY , LOW LEVEL , PROTECTIVE EQUIPMENT , SHIELDING , ARC JET ENGINES , HEAT SHIELDS , LOSSES , BEHAVIOR , FLOW , VEHICLES , VALUE , REUSABLE EQUIPMENT , ENTHALPY , BORON OXIDES , SILICATES , COLLAPSE , EARTH ATMOSPHERE , HYPERSONIC FLOW , ABLATIVE MATERIALS , ABLATION


Subject Categories : Ceramics, Refractories and Glass
      Unmanned Spacecraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE