Vault Access Door
Multi-Stage Radiation Lock Door
The vault access door, technically designated as a multi-stage radiation lock door, is a 500 kg barrier assembly that provides robotic and personnel entry to the Lunar Ark vault while maintaining uninterrupted radiation shielding. To eliminate direct line-of-sight radiation pathways during ingress, the two-stage interlocked system employs a stepped labyrinth design fabricated from tungsten and high-density polyethylene composites set within a 316L stainless steel frame. Actuated by a non-hydraulic, sealed 200 W brushless direct-current drive, the mechanism uses sealed bearings to function across a 50-year design lifetime with a 100,000-hour mean time between failures.
Multi-stage radiation lock door providing personnel/robotic access to vault while maintaining shielding integrity even during entry.
Purpose
Multi-stage radiation lock door providing personnel/robotic access to vault while maintaining shielding integrity even during entry.
Context
Child of L2-RAD-VAULT within the Lunar Ark system
Principles
- ▸Stepped/labyrinth path prevents direct line-of-sight radiation paths
- ▸Door composition matches wall composition for equivalent shielding
- ▸Interlocked double-door system (one open at a time)
- ▸Hydraulic-equivalent powered drive (no hydraulics)
- ▸Failsafe: failed-closed default
Typical implementations
- ▸Nuclear facility radiation locks (terrestrial)
- ▸ISS airlock heritage design philosophy
- ▸Industrial radiation door designs
Lunar considerations
- ▸Robotic-only access (no crew normally)
- ▸Long-life mechanism with sealed bearings
- ▸Periodic interlock test
Specifications
Functional
| primary function | Multi-stage radiation lock door providing personnel/robotic access to vault while maintaining shielding integrity even during entry. |
| door mass kg | 500 |
| interlock stages | 2 |
Physical
| mass kg | 500 |
| materials | Tungsten/HDPE composite door, 316L SS frame, Sealed BLDC drive |
| vacuum compatibility | True |
Operational
| power consumption w | 200 |
| thermal range c | -40, 70 |
| lifetime years | 50 |
| mtbf hours | 100000 |
Interfaces
Provides
- Robotic access with shielding preserved
Requires
- Door operation power
- Drive motor (~200 W transient)
Cite this entry
Lunar Ark Codex. "Vault Access Door" (L3-RAD-VAULT-DOOR). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-RAD-VAULT-DOOR
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.