Man, reading comments from the Musk Fluffers, they really have no fucking sense of history or different use cases. Let's begin here:
Gemini 6A would perform the first rendezvous of two spacecraft in orbit, using Gemini 7 as the target, though they would not dock. The crews also discussed the possibility of Stafford performing an EVA from 6A to 7, swapping places with Gemini 7 pilot Jim Lovell, but the commander of Gemini 7, Frank Borman, objected, pointing out that it would require Lovell to wear an uncomfortable EVA suit on a long-duration mission.
Even way back in '65, there were different suits, ah...suited for different mission objectives. There are a few kinds, in fact:
Intra-Vehicular Activity Suit
An Intra-vehicular Activity Suit is designed solely for use inside a spacecraft when crew members need protection from environmental hazards such as fire or loss of cabin pressure. They are lightweight and made of soft materials, allowing for ease of movement and comfort.
These suits do not have a life support system built-in as they are used in the pressurized environment of the spacecraft. Instead, they rely on the spacecraft's life support systems to provide air supply, temperature regulation, and pressure control.
Extra-Vehicular Activity Suit
An Extra-vehicular Activity Suit is designed specifically for use outside a spacecraft during spacewalks or EVAs. These suits must withstand extreme temperatures ranging from -250°F (-156°C) to 250°F (121°C), protect against radiation exposure, provide mobility in microgravity environments while providing essential life-support functions.
These suits have a self-contained life-support system that provides air supply, regulates temperature and pressure to keep astronauts safe while working outside the spacecraft's protective shell.
Planetary Surface EVA Suit
A Planetary Surface EVA suit is designed for missions where humans will explore planetary surfaces such as Moon or Mars. They need to provide protection against harsh environmental conditions like toxic dust particles or extreme temperature fluctuations.
These suits must be able to maintain an internal atmospheric pressure equivalent to Earth’s atmosphere while providing mobility over long distances on rough terrain. The suit design also includes features like radiation shielding layers and water recycling systems.
That's the general overview, and here are some specifics about the SpaceX Extra-Vehicular Activity suit and NASA's Extravehicular Mobility Unit, current version of which has been used over 25 years (of a piece with the newly announced Lunar item from Prada/Axiom, albeit from a different vendor):
The difference between SpaceX’s EVA suit and NASA’s EMU isn’t so much about aesthetic choices as it is the result of their respective functions, features, and history. At their core, each suit was engineered for different purposes. Also, both suits are at different stages of development, with the EMU being the result of decades of experience and refinements, with very specific mission requirements in mind.
On the other hand, the sleekness of SpaceX’s EVA suit is the result of being designed for short exposures to the rigors of space. You can find a parallel in the suits designed by NASA for the Gemini missions in the 1960s. They looked much sleeker than the suits used for Apollo, which required longer stays, where astronauts would be exposed to radiation and extreme changes in temperature.
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The EMU is bulky because it needs to be bulky. The heft reflects the need for extended life support, a comprehensive protection system, and multiple layers of insulation. Safety is the priority, and every element of the EMU was engineered with long-term survival in mind under extreme conditions. It’s like having a personal spaceship all around you.
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The EMU’s outermost skin is called Ortho-Fabric, which combines Kevlar, Nomex, and Gore-Tex. These materials are not only protective, but incredibly durable. Kevlar is used in bulletproof vests; it’s there to make sure the astronaut doesn’t get punctured by micrometeoroids or space debris. Nomex is a flame-resistant material, which may seem odd in space, but it’s vital in case the suit encounters superheated objects or malfunctions that create fire hazards. And Gore-Tex helps the suit to breathe, allowing moisture from the astronaut’s body to escape while blocking any external liquids. In total, the EMU uses 14 layers of material.
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SpaceX’s suit doesn’t use a heat exchange system; instead it uses phase-change materials, which releases or absorbs energy when it changes its state to heat or cool as the astronaut moves between sunlight and shadow. While these fabrics help regulate temperature without the need for dedicated cooling systems, it is not suitable for long spacewalks or hard work.
If SpaceX ever got a contract to develop a rugged suit like the (Ax)EMU, I'm betting it will also be pretty bulky. Maybe Elon doesn't fear micrometeoroids, lunar regolith, or radiation exposure? Yet anything that any contractor produces today will necessarily be built upon several decades of NASA's hard-won learning about the survival challenges of deep space.
Anyway, Artemis II is running a bit behind schedule, so who knows what will be in fashion when we finally return to the moon's surface...