Materials/Seals and adhesives
Seals and adhesives
seals-adhesivesWhat this is
Seals, O-rings, adhesives, tapes and potting compounds.
They hold things together and keep gas in. Cold stiffens them, vacuum makes them outgas, and failures here can be mission-ending.
Types
Pick a type to see its materials.
| Type | Materials | Ranking |
|---|---|---|
| Elastomers and O-rings | 1 | — |
| Adhesives | 1 | — |
| Tapes | none yet | — |
| Potting compounds | none yet | — |
What matters
The measurements we use to compare seals and adhesives. Each one has a standard test and a direction: is higher or lower better?
| Measurement | Better when | How it is tested |
|---|---|---|
| Outgassing, total mass loss (TML)Mass lost in vacuum that can fog optics | lower | ASTM E595 |
| Outgassing, condensable (CVCM)Vapor that recondenses on cold surfaces | lower | ASTM E595 |
| Flammability (crewed vehicles)Whether a flame spreads upward | higher | NASA-STD-6001 Test 1 |
| Maximum service temperatureHottest it can work long term | higher | Material-specific |
| Minimum service temperatureColdest before it turns brittle or stops working | lower | Glass transition, ductile-to-brittle tests |
| Gas permeabilityHow much gas leaks through the wall | lower | Material-specific |
| Toxic offgassing (crewed vehicles)Harmful gases released into cabin air | lower | NASA-STD-6001 Test 7 |
| Dust abrasion wearSurface lost to regolith grit | lower | Abrasion tests with simulants |