76

That only looks like a heel! As shown here, it's a "foot restraint interface"! That said, it probably makes walking around in the training facilities a lot easier. Although that doesn't happen much - the EMUs are heavy. Source: JSC-19450 Rev. B Extravehicular Mobility Unit Systems Training Workbook This picture of a Manipulator Foot Restraint - ...


75

According to Chris Hadfield's answer during his Reddit AMA: "We have a squishy thing inside we jam our nose into while we clear our ears — we scratch our nose on that." The "squishy thing" is formally known as a Valsalva device (used by both astronauts and divers for equalizing pressure in their sinuses. (Thanks to Organic Marble's comment). In addition, ...


63

Are there failure modes that cause loss of pressure but not rapid, unplanned disassembly? Yes. The 3-man crew of Soyuz 11 died when a valve was jolted open, venting out all the cabin air supply. Soyuz was redesigned after that accident to carry two crew in pressure suits instead of 3 crew in shirtsleeves. (I believe they now carry three in pressure suits.) ...


51

There's no advantage to replacing the air with water. you're adding weight. you're adding resistance: when you move around, water will flow around the body and because you're proposing a thin layer of water, the flow is obstructed which means it takes energy to push the water around. you're replacing the air layer (which is a reasonably good thermal ...


50

Spacecraft and space suits do NOT generate a magnetic field for medical reasons. Any magnetic fields generated are side effects of using electric motors etc. The linked question on Skeptics thoroughly debunks the idea, noting that: Gagarin was not in "critical condition" after his flight; and, Any flights in LEO are well within Earth's magnetic field. ...


48

They're simply visual differences for identification. After Apollo 11, folks on the ground had a hard time finding photos of Armstrong on the moon. Most photos were taken by him and there was no obvious way to distinguish the two suits. After that stripes were added to the commander's suit for the remaining Apollo missions. As far as I'm aware, the ...


47

It's called, appropriately enough, the "sewn-on cuff checklist". Aldrin's tasks are in parentheses as shown by the (LMP) annotation at the top. It's a checklist of pretty much everything they were supposed to do on the surface, in NASA acronym-ese. Not just photography. Some examples: Set up the camera Preliminary checks Gather samples Inspect ...


41

Tom Jones talks about it some in his memoir "Skywalking" when he describes an EVA carried out on shuttle mission STS-98: Inside the airlock when it is pressurized Through the helmet shell, from the world outside the space suit, came a muted, sporadic tinkling sound, the result of minor collisions between our drifting tools and the airlock walls. ...


35

The outer pane is just a replaceable protection of the inner pane against scratches, dirt, and abrasion. The helmet on the suits for Artemis missions will also feature a quick-swap protective visor. The clear protective visor is a sacrifi­cial shield that protects the pressurized bubble from any wear and tear or dents and scratches from the abrasive ...


33

The SK-2 suit differed from the SK-1 suit mainly in the enclosure cut-out that took into account the specific features of a female body. The enclosure featured a decreased shoulder breadth, an increased hip girth and a decreased opening in the neck partition. In accordance with the decreased shoulder breath, the restraint system of shoulder joints was ...


32

If the suit would be useful, it has to be inflated. Which is definitively not how it looks like in images. If you could manage duct tape to hold the inner pressure for a moment without rupturing and/or leaking immediately, it would clearly help, but in the same moment, the "suit" would turn so stiff from pressure that it would be impossible to ...


31

The shuttle (and ISS) EMU (Extravehicular Mobility Unit) has a condensing heat exchanger as part of its ventilation loop. The condensate is stored, used for cooling, and the excess is drained after each EVA (Extravehicular Activity). Reference: Shuttle Crew Operations Manual: https://www.nasa.gov/centers/johnson/pdf/...


30

A space suit could be tested to double operating pressure. This test can be done in a vacuum or in air. For the stability of the suit, only the pressure difference between inside and outside is essential. To allow enough flexibility, the pressure difference (inside to outside) should be not greater than 0.2 to 0.4 bar. Breathing pure oxygen in the suit at ...


28

They tended to suffer painful fingernails in the Apollo days, in the Lunar Surface Journal Schmitt and Cernan gave a good description of this on several pages. There were also references made in the various technical debrief documents. The problem tended to arise from the fact that the gloves are pressurised, therefore stiff. The journal also links to a ...


26

...a thin layer of water that was held down by oxygen up at the head. "Held down" doesn't work so well in weightlessness. Water would move around inside the suit, climb up the astronaut's neck and put them in danger. This happened to ESA astronaut Luca Parmitano when doing a space walk at the ISS. See Space.com's Italian Astronaut Recounts Near-Drowning ...


26

It can be hard to see because it's on the front of the PLSS behind the astronaut's helmet. (NASA photo of Irwin on Apollo 15, I cropped it and added the arrow) Here's an exploded view showing the vent opening; the sublimator isn't labeled, but it's clearly the same device labeled in the image in the question. From Apollo EMU Experience Report, I added the ...


25

The suits used in the NBL are Class III "training only". The Display and Control Module (control panel on the chest), the life support backpack, and the SAFER self-rescue unit are mocked-up. Breathing air is supplied via an umbilical and bouyancy weigh-outs are added to the exterior of the suit. So: the soft goods (arms, legs, gloves, boots), the helmet, ...


24

For the ISS, the relevant bit of kit would be the Trace Contaminant Control System, which is part of the Air Revitalisation System. A Trace Contaminant Control System ensures that over 200 various trace chemical contaminants generated from material off-gassing and crew metabolic functions remain within allowable limits. A mass spectrometer measures the ...


23

From Retro Space Images's FaceBook post: Gene Cernan scratches the itch during an Apollo 17 training session at KSC.


23

I didn't know that during lunar day temperature is up to +100°C. That's how hot the lunar surface can get at the equator, about 2/3 of the way into the 2 week long lunar day. Those high temperatures were a concern; this is one of the reasons all of the Apollo landings took place within 12 to 48 hours after sunrise at the landing site. The lunar surface wasn'...


23

Intravehicular spacesuits are worn inside the cabin in case of emergencies, particularly during ascent and descent. The Mercury suits were manufactured by Goodrich. Nearly all other IV suits have been manufactured by the David Clark Company: Gemini, Apollo 1, Shuttle ejection seat suit, Shuttle LES, and Shuttle ACES (all an evolution of the Gemini design). ...


22

There is space for two full Extravehicular Mobility Units (EMUs), one short EMU, and two Orlan space suits (Russian equivalent to the EMU) aboard the ISS. They are stored in the Joint Airlock. Since the spacesuits are not part of the emergency plan, they do not store one for every astronaut (let alone a backup for each). Source: Answer by Robert Frost, ...


22

Well, an electric motor is arguably a 'pulsed magnetic device', as is a solenoid valve, but good ones try very hard to contain the fields to where they will do useful work. I suppose one could design a suit without any motors, and it may even have been done, but pumps, blowers and valves and such seem a sort of natural feature of a space craft life support ...


21

I think the device in question is described in US Patent 3,437,165 "VENTING DEVICE FOR PRESSURIZED SPACE SUIT HELMET" (filed Feb 27, 1967). It is possible that NASA did not file immediately for patent, especially when the port was eliminated. Hamilton Standard is listed as government employee on the patent form. The patent can be found in NTRS ...


20

The biggest issue was that the source of the liquid wasn't established and that it might have not been safe to drink, potentially causing bigger problems than Luca immediately faced. He did try to drink a bit of the fluid, and reported that it has an odd taste, so it was not his drinking water. They opted for immediate retreat back to the Quest airlock and ...


19

These are two microphones of the cosmonaut's headset (шлемофон - hat with headphones and microphones). Two microphones reserve each other. The ДЭМШ-microphone possessed considerable resistance to noise interference and selectivity to voice. For many decades, the ДЭМШ-microphone was installed in almost all Soviet military and professional civilian radio ...


19

From History of the Apollo Space Suit by the International Latex Corporation (ILC). PDF When setting up the suits in preparation for the extravehicular walk on the lunar surface, the astronauts attached oxygen hoses from the Lunar Module (both inlet and outlet) while at the same time attaching to the inlet and outlet hoses of the portable backpack. ...


18

The suit does not contain its own life support system. It is ventilated from a blower or, in case of a decompression, pressurized bottles within the spacecraft. It also does not have any meteoroid protection, and it tends to balloon when pressurized, restricting movement.


18

How about Willpower? Every Soldier learns to stand still at a parade or when they got to pledge loyalty. When I had my inauguration at the Austrian Military forces, we all had to stand still for quite some time (2-3 hours no nose or butt scratching) and it wasn't really a problem. Also, if you're concentrated on something serious (like doing work in a ...


18

Wikipedia says: As an example, during the Apollo 12 commander's first EVA (of 3 hrs, 44 minutes), 4.75 lb of feedwater were sublimated, and this dissipated 894.4 Btu / hr. That's 2.154 kg of water over 224 minutes, or 10g/min, or 0.16g/s. Water vapor is invisible to the naked eye (2, 3). What you see e.g. when boiling water is not the water vapor itself,...


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