| タイトル | Large-Scale Liquid Hydrogen Testing of Variable Density Multilayer Insulation with a Foam Substrate |
| 本文（外部サイト） | http://hdl.handle.net/2060/20010063699 |
| 著者（英） | Martin, J. J.; Hastings, L. |
| 著者所属（英） | NASA Marshall Space Flight Center |
| 発行日 | 2001-06-01 |
| 言語 | eng |
| 内容記述 | The multipurpose hydrogen test bed (MHTB), with an 18-cu m liquid hydrogen tank, was used to evaluate a combination foam/multilayer combination insulation (MLI) concept. The foam element (Isofoam SS-1171) insulates during ground hold/ascent flight, and allowed a dry nitrogen purge as opposed to the more complex/heavy helium purge subsystem normally required. The 45-layer MLI was designed for an on-orbit storage period of 45 days. Unique WI features include a variable layer density, larger but fewer double-aluminized Mylar perforations for ascent to orbit venting, and a commercially established roll-wrap installation process that reduced assembly man-hours and resulted in a roust, virtually seamless MLI. Insulation performance was measured during three test series. The spray-on foam insulation (SOFI) successfully prevented purge gas liquefaction within the MLI and resulted in the expected ground hold heat leak of 63 W/sq m. The orbit hold tests resulted in heat leaks of 0.085 and 0.22 W/sq m with warm boundary temperatures of 164 and 305 K, respectively. Compared to the best previously measured performance with a traditional MLI system, a 41-percent heat leak reduction with 25 fewer MLI layers was achieved. The MHTB MLI heat leak is half that calculated for a constant layer density MLI. |
| NASA分類 | Composite Materials |
| レポートNO | NASA/TM-2001-211089
NAS 1.15:211089
M-1020 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/92843 |
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