Space Suits: EMU, Orlan, Feitian, AxEMU and Wangyu

The suits

Seven Suits From Apollo to Artemis

Every crewed program has built its own; four are flying or flown, two are for the Moon.

Space suits
Suit	Program	Data point	Rated
A7L · NASA	Apollo, 1969-1972	12 men on the Moon; dust wore through outer layers in three days	Observed
EMU · NASA	Shuttle and ISS, since 1983	29.6 kPa pure oxygen; hours of prebreathe from the station's sea-level cabin	Observed
Orlan-MKS · Roscosmos	ISS	Rear entry; 40 kPa, so a shorter prebreathe	Observed
Feitian · CMSA	Shenzhou-7 and Tiangong, since 2008	China's EVA suit; Zhai Zhigang made the first Chinese spacewalk in it	Observed
SpaceX EVA suit	Polaris Dawn, 2024	First commercial spacewalk	Observed
AxEMU · Axiom Space	Artemis III	Lunar surface suit for NASA	Building
Wangyu · CMSA	Chinese crewed lunar landing	Lunar surface suit, named 2024	Building

Overhead

The Suit Sets the Overhead Multiplier

Hours of preparation, crossing and cleanup per hour outside run from 1.5 to 4.0 depending on three choices.

The three levers on suit overhead
Lever	Choice	Effect	Rated
Interface	Suitport instead of airlock	Cuts gas loss and dust carried inside	Modeled
Cabin pressure	Lower cabin nitrogen pressure	Shortens prebreathe; costs flammability margin and materials limits	Modeled
Excursion length	Longer excursions from a garage	Spreads the fixed cost of each crossing over more hours	Modeled

Prebreathe sits inside the multiplier. A suit at 29.6 kPa pure oxygen needs the nitrogen washed out of the body first, which takes hours from a sea-level cabin and minutes from a low-pressure one.

A six-month lunar tour needs about 1,750 hours of outside work across the whole site. At 2.5× overhead that is about 4,400 crew-hours, before any work is done inside.

The suit, specified

One Suit at an Industrial-Tempo Site

Rates are per hour outside, so they scale with the site total, not crew size.

One suit
Property	Figure	Note	Rated
Mass with portable life support	120-145 kg	About half is the backpack	Modeled
Electrical load	150-300 W	1-2 kWh per excursion; 8-15 kg of cells	Modeled
Cooling water, open-loop sublimator	0.55 kg per hour outside	Scales with site hours, not crew	Modeled
Metabolic oxygen	0.084 kg per hour outside	147 kg against 1,750 site hours	Modeled
CO₂ removal, lithium hydroxide	0.15-0.2 kg per hour outside	260-350 kg a tour	Modeled
CO₂ removal, vacuum-swing amine bed	No consumable	Vents to vacuum; Moon and free space only	Modeled
Dust-exposed moving interfaces	About 10 per suit	Shoulder and wrist bearings, glove and helmet disconnects, port seal	Modeled

Suits at the site
Measure	Figure	Note	Rated
Excursions a tour	About 292	1.6 a day across the site	Modeled
Suits landed	Six pressure units, plus a fitted inner layer per crew member	About 1 t for a crew of 10	Modeled
Cycles per suit per tour	About 49	Flight suits are refurbished every few tens of excursions	Modeled
Import instead of refurbish	12-15 suits a year	1.5-2 t of certification-heavy hardware	Modeled
Suit shop in the garage	25-40 m² of floor	Pressure test, bearing and seal service, soft goods, recertification	Modeled

Every suit passes its historical refurbishment interval about twice a tour, with no ground to send it back to. The site refurbishes suits at a bench in the garage, where suits are stored, or it imports a dozen or more a year.

Lithium hydroxide is the largest consumable after water, 260-350 kg a tour, and lithium is a permanent Earth import. A vacuum-swing amine bed consumes nothing on the Moon, but on Mars the 600 Pa carbon dioxide atmosphere leaves it almost no pressure ratio to work against a suit held under about 1 kPa of CO₂. Mars pays for its atmosphere here, in sorbent or in a compressor.

Fitted or common

The Line Between Fitted and Common Runs Through the Glove

A suit made to one person cannot be swapped like a spare part.

Fitted and common parts
Part	Class	Why	Rated
Pressure bladder and outer layers	Common	Pressure-bearing; swapped between crew	Modeled
Life-support backpack	Common	Consumable and serviceable	Modeled
Glove, outer	Common	Highest wear; a stock item	Modeled
Glove, inner, and sizing rings	Fitted	The only parts made to the person	Modeled

Everything pressure-bearing and everything consumable is common stock; only the sizing interface is fitted. One suit adds 30-60 part types to a site inventory of about 120 after commonality reduction.

Six suits carry about 60 dust-exposed interfaces against about 6,400 across a 160-unit robot fleet: 1% of the seal problem and all of the crew-safety problem. Replace-not-repair, the fleet's escape, is not available for suits. See Autonomy.

China

China Builds Its Own Suits for Orbit and the Moon

Feitian since 2008; Wangyu for the landing.

Chinese suits
Suit	Data point	Rated
Feitian · CMSA	First Chinese spacewalk, Shenzhou-7, 2008; routine EVAs from Tiangong since 2021	Observed
Wangyu · CMSA	Lunar surface suit for the Lanyue landing	Building

Contested

Deliberately Not Claimed

The load-bearing uncertainties, tagged with the confidence they actually earn.

Modeled

Suit service life at 49 cycles a tour is unknown. No suit is rated near that cadence; a ground testbed run at the site's ingress rate would settle it and the overhead multiplier together.

Modeled

No suit has worked a dusty surface for months. Apollo suits saw at most three EVAs each; abrasion rates over a six-month tour are extrapolated.

Modeled

Suitport hours are estimates. Suitports have been tested on the ground and on rovers in prototype; none has flown.

Record

Provenance and Data Sources

Confidence: Observed for flown, fielded or measured - Building for hardware and programs in development - Projected for announced plans - Modeled for original analysis
Status date: Q4 2026
Data: NASA EMU and A7L records; Roscosmos Orlan; Axiom Space; SpaceX Polaris Dawn
China: CMSA Feitian and Wangyu
Weakest link: Dust abrasion over a full tour