| Pressure | 3.7 psi / 25.5 kPa |
| Suit mass (1g) | 201 lb (system) |
| Life support (primary) | PLSS-6 nominal 6 hr |
| Life support (backup) | OPS 30 min |
| EVA duration | 6 hours |
| Program | Apollo |
| Agency | NASA |
| Manufacturer | ILC Industries + Hamilton Standard |
| First use | 1969 |
| Status | Retired |
| Donning / entry | Custom-fitted mid-entry configuration |
Mature lunar visor/thermal stack; improved PLSS-6; LCG; autonomous backpack
Apollo 11–14 lunar EVA
Spring-back too high for ideal exploration; hydration interface dust contamination risk
"Lunar EVA required not just survival but sustained human work capability"
Direct benchmark for lunar-surface productivity — Artemis programs reference this extensively
First US EVA physically exhausting and low-productivity despite suit functioning; glove productivity inadequate for task completion
→ Suit capability and worksite design must be developed together, not sequentially
Severe discomfort nicknamed 'crotch cutter' — fit and pressure-load path geometry produced painful localized loading
→ Localized contact loads can kill an otherwise promising concept. Pressure mapping and seat-interface studies are required
Unexpected arm growth when shoulder restraint cable failed; seized pulley caused overheating in crotch-thigh region
→ Critical restraint paths need redundancy or condition monitoring. Small mechanical hardware in pressure-load paths creates outsized crew risk
Numbness, bladder bunching, and palm-bar wear-through into hand across multiple crew members
→ Glove verification must include extended-use comfort and injury surveillance, not just pressure integrity and cold-object performance
Water entered Luca Parmitano's helmet during EVA — vision impaired, comms degraded, breathing compromised
→ Cooling-water management is a primary safety-critical function, not a nuisance issue. Contamination tolerance must be designed in from day one
"Established B.F. Goodrich as the lead US full-pressure suit contractor before Mercury existed"
"Parallel development track alongside Model O testing different mobility solutions"
"Naval and NASA pressure suit research tracks cross-pollinated significantly in this era"
