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Large-scale liquid hydrogen testing of variable density multilayer insulation with a foam substrate
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hastings, L. Martin, J. J. |
| Copyright Year | 2001 |
| Description | 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. |
| File Size | 4744020 |
| Page Count | 90 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20010063699 |
| Archival Resource Key | ark:/13960/t9b61hv83 |
| Language | English |
| Publisher Date | 2001-06-01 |
| Access Restriction | Open |
| Subject Keyword | Composite Materials Foams Cryogenic Fluid Storage Condensing Mylar Trademark Liquid Hydrogen Multilayer Insulation Substrates Drying Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
