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Dirling, R. B., Jr.

Publications and source records attributed to Dirling, R. B., Jr..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Development of X-43A Mach 10 Leading Edges

The nose leading edge of the Hyper-X Mach 10 vehicle was orginally anticipated to reach temperatures near 4000 F at the leading-edge stagnation line. A SiC coated carbon/carbon (C/C) leading-edge material will not survive that extreme temperature for even a short duration single flight. To identify a suitable leading edge for the Mach 10 vehicle, arc-jet testing was performed on thirteen leading-edge segments fabricated from different material systems to evaluate their performance in a simulated flight environment. Hf, Zr, Si, and Ir based materials, in most cases as a coating on C/C, were included in the evaluation. Afterwards, MER, Tucson, AZ was selected as the supplier of the flight vehicle leading edges. The nose and the vertical and horizontal tail leading edges were fabricated out of a 3:1 biased high thermal conductivity C/C. The leading edges were coated with a three layer coating comprised of a SiC conversion of the top surface of the C/C, followed by a chemical vapor deposited layer of SiC, followed by a thin chemical vapor deposited layer of HfC. This paper will describe the fabrication of the Mach 10 C/C leading edges and the testing performed to validate performance.

Ohlhorst, Craig W.↗
NASA NTRS1984

Lightweight carbon-carbon thermal protection system for STARPROBE

This paper describes the preliminary design, development, and initial testing of prototype carbon-carbon components of the thermal protection system of the NASA STARPROBE spacecraft. The thermal protection system is designed to limit the spacecraft scientific instrument package to a maximum temperature of 55 C during the time of closest approach to the earth's sun when the peak radiative heating rate reaches 393 w/sq cm. The thermal protection system is comprised of a carbon-carbon thin shell primary shield and two carbon-carbon sandwich construction secondary shields which block reradiation from the primary shield to the spacecraft. These shields are joined and stiffened by carbon-carbon structural members and attached to the spacecraft with eight thin-walled carbon-carbon struts. Prototype parts of the principal components have been fabricated and will be tested in a solar radiative flux environment simulating peak mission values in late 1984.

Dirling, R. B., Jr.↗
NASA NTRS1982

Preliminary design of the thermal protection system for solar probe

A preliminary design of the thermal protection system for the NASA Solar Probe spacecraft is presented. As presently conceived, the spacecraft will be launched by the Space Shuttle on a Jovian swing-by trajectory and at perihelion approach to three solar radii of the surface of the Earth's sun. The system design satisfies maximum envelope, structural integrity, equipotential, and mass loss/contamination requirements by employing lightweight carbon-carbon emissive shields. The primary shield is a thin shell, 15.5-deg half-angle cone which absorbs direct solar flux at up to 10-deg off-nadir spacecraft pointing angles. Secondary shields of sandwich construction and low thickness-direction thermal conductivity are used to reduce the primary shield infrared radiation to the spacecraft payload.

Dirling, R. B., Jr.↗
NASA NTRS1979

Thermostructural design of a carbon-carbon heatshield for a Jovian entry

The thermostructural response of three candidate carbon-carbon composites for the Jovian entry probe heatshield was investigated. The analysis for the three materials, Sandia Felt, Carbitex 700, and SAI 4-D weave carbon-carbon was conducted using a dual finite element approach which involved heat conduction as well as the structural response. A receding boundary due to ablation and inertial loads encountered by the probe were included. Severe cracking, circumferential and radial, and interlaminar shear failure was observed during the radiative heating pulse for the Sandia Felt and Carbitex 700 materials, respectively. The 4-D weave material showed no failures over the entire entry.

White, M. J.↗
NASA NTRS1978

Jupiter probe heatshield configuration optimization

The effect of initial probe heatshield shape on the total probe mass loss during Jovian entry is considered. Modification of the aerothermal environment and probe entry trajectory due to changing probe heatshield shape is included in a computerized technique designed for rapid assessment of the effect of probe initial shape on heatshield mass loss. Results obtained indicate the importance of trajectory and heating distribution coupling with probe shape and mass change.

Dirling, R. B., Jr.↗