L2-CRY-TANK CRITICAL PRESERVATION Level 2 · hardware

Cryogenic Storage Vessels

Cryogenic Dewar and Sample Containment System

The Cryogenic Dewar and Sample Containment System consists of vacuum-jacketed stainless steel 316L vessels housing biological samples from 6.7 million species at -196°C. Arranged across a minimum of four independent units for fault isolation, internal aluminum racks maintain temperature uniformity within ±1°C and provide 72 hours of passive holdover over a 100-year design life. On the Moon, ambient vacuum eliminates active jacket pumping, but the 1/6 g gravity alters liquid nitrogen distribution and boil-off dynamics. The system also requires seismic isolation against moonquakes and shielding against micrometeorite strikes on exposed vessel surfaces.

Vacuum-jacketed dewar vessels and internal sample rack systems providing the primary physical containment for 6.7 million species' biological samples at -196°C

Purpose

Provide mechanically robust, thermally isolated containment vessels that house sample racks, interface with active cooling systems, and enable robotic sample retrieval while maintaining ultra-stable cryogenic temperatures

Context

L2-CRY-TANK is the passive storage core. Multiple independent dewars provide fault isolation — a breach in one vessel does not compromise others. Internal sample racks are organized by species taxonomy with RFID-tagged positions. Each dewar interfaces with L2-CRY-COOL via cold buses and with L2-CRY-ISOL via vacuum jackets and MLI. Access ports enable robotic retrieval without significant thermal perturbation.

Principles

▸Vacuum-jacketed dewars minimize conductive and convective heat transfer
▸Multiple independent vessels provide fault isolation and partial-loss survivability
▸Internal cold buses distribute refrigeration uniformly across sample positions
▸Sample rack design must balance density against thermal uniformity and access
▸Dewar neck tubes are the primary parasitic heat leak path — optimized length/diameter ratio critical

Typical implementations

▸MVE HEco/XLC series biobank dewars (1,000-50,000 vial capacity)
▸Custom vacuum-jacketed vessels with internal cold bus (Brookhaven, CERN heritage)
▸Stainless steel 316L construction with electropolished inner surfaces
▸Aluminum sample racks with spring-loaded RFID cryovial holders

Lunar considerations

▸Lunar vacuum eliminates need for active vacuum pumping of jacket spaces
▸Reduced gravity (1/6 g) affects LN2 liquid distribution and boil-off patterns
▸Micrometeorite shielding required for any exposed vessel surfaces
▸Seismic isolation for moonquake protection of sample racks
▸Dewar fabrication on Earth — must survive launch vibration and lunar landing loads

Specifications

Functional

primary function	Contain and thermally protect biological samples in organized, retrievable storage
inputs	Refrigeration from L2-CRY-COOL via cold bus interfaces, LN2 from L2-CRY-LN2 for vapor-phase or liquid-phase backup cooling, Biological samples from L1-GEN via robotic insertion
outputs	Stable -196°C sample environment, Parasitic heat load to L2-CRY-COOL (defines cooling requirement), Sample position data to L2-CRY-INV
number of dewars	TBD (minimum 4 independent units for fault isolation)
total sample capacity	6.7M species across all vessel types
temperature uniformity c	±1°C across all sample positions within a dewar
passive holdover hours	72 hours without active cooling (LN2 thermal mass)
design life years	100

Physical

materials	Stainless steel 316L (inner and outer vessels), Aluminum 6061-T6 (sample racks, cold buses), Borosilicate glass (neck tube inserts), Getter materials (vacuum maintenance in jacket space)
internal temperature k	77
jacket vacuum torr	<1e-6
external	Lunar vault, temperature-controlled by L2-CRY-ISOL

Operational

power consumption w	50
thermal range c	-196, -180
lifetime years	100

Interfaces

Provides

→Genetic Archivesample_containmentcritical
Physical housing and thermal environment for all biological sample types
→Sample Inventory Managementrack_positionsessential
Organized, indexed sample positions with RFID interfaces for inventory tracking
→Cryo-Cooler Systemthermal_loadcritical
Parasitic heat leak defining the cooling requirement for active refrigeration

Requires

←Cryo-Cooler Systemrefrigerationcritical
Active cooling via cold bus to maintain -196°C against parasitic heat leaks
←Liquid Nitrogen Loopcryogencritical
LN2 for vapor-phase cooling and passive thermal backup reservoir
←Thermal Isolation Systemthermal_isolationcritical
Vacuum jackets, MLI, and vapor-cooled shields surrounding vessels
←Primary Structurestructuralcritical
Vault mounting, vibration isolation pads, micrometeorite shielding
←Robotic Operationsrobotic_accessessential
Robotic arms for sample insertion/retrieval through access ports