HRSI
Encyclopedia : H : HR : HRS : HRSI
High-temperature Reusable Surface Insulation (HRSI) is refractory ceramic material used as the basis of the heat shielding of the Space Shuttle. HRSI is refined from sand to form 99.8% (high purity) silica amorphous fibre. Raw HRSI must be combined with a silica-based binding agent & aqua before sintering.
Properties of HRSI
- Resilient to thermal shock - HRSI tiles can withstand a transition from an environment (1200 degrees Celsius) to full immersion in cold water without sustaining any structural damage.
- Rapid Heat Dissipation - The above sample could be handled with an ungloved hand seconds after immersion, even while the core of the tile still glowed red hot.
- Acoustic stress resilience - HRSI tiles can withstand acoustic levels of >165 dB without experiencing structural failure.
- Lack of strength/Porous - HRSI tiling is only 10% material, with the remaining 90% representing void (pores in the material). This form is the cause of the material's excellent refractory behaviour but leads to a lack of tensile strength. The material is also porous as a result.
HRSI is used in conjunction with stronger, waterproof materials in the Space Shuttle heatshielding to give a balance of strength & resistance to the high re-entry temperatures experienced in Earth's upper atmosphere.
HRSI is primarily designed to withstand transition from areas of extremely low temperature (the void of space, about -270 degrees Celsius) to the high temperatures of re-entry (caused by friction between the gases of the upper atmosphere & the hull of the Space Shuttle, typically around 1600 degrees Celsius).
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.