Why does Collins have less knobly bits attached to the front of his spacesuit?

Why does Aldrin have a red collar locking mechanism round his neck, whilst the other two are blue? Was Aldrin the designated red shirt for this mission?

Why does Aldrin have a gold attachment to one of his knobbly bits, whilst Armstrong has a blue one?

Why do they have “crotch flaps”? Surely not for… well, you know, whipping out the old docking module to write their names in the lunar dust.

Damnit, sorry. Can anyone re-post the image properly for me please?

I blame Hollywood. They were contracted to get it right, but there were so many errors. Running to time and budget, some were missed.

Collins because he didn’t need to leave the ship so no need to swop umbilicals. Crotch flaps so they could have a piss.

esselte said:

Damnit, sorry. Can anyone re-post the image properly for me please?

4,200px × 3,300px (scaled to 700px × 550px)

I divided 4200 by 6 and 3300 by 6

AwesomeO said:

Collins because he didn’t need to leave the ship so no need to swop umbilicals. Crotch flaps so they could have a piss.

Those are the obvious answers, but do they actually make sense?

I mean, at what point and for what reason would they actually have to swap umbilicals?

Aren’t the suits sealed units, except at the wrists and neck (and probably ankles) where they have metal clamps to ensure the integrity of the seal of the gloves, helmet and boots? If the crotch flaps genuinely are to let them urinate, how is it the suit sealed around this area? Is there a metal clamp underneath the visible flap?

Thanks CrazyNeutrino.

Collins suit is actually different to the other two in a large number of ways. It seems reasonable to assume that’s because he wasn’t actually going to the lunar surface, but what are the details involved?

esselte said:

AwesomeO said:

Collins because he didn’t need to leave the ship so no need to swop umbilicals. Crotch flaps so they could have a piss.

Those are the obvious answers, but do they actually make sense?

I mean, at what point and for what reason would they actually have to swap umbilicals?

Aren’t the suits sealed units, except at the wrists and neck (and probably ankles) where they have metal clamps to ensure the integrity of the seal of the gloves, helmet and boots? If the crotch flaps genuinely are to let them urinate, how is it the suit sealed around this area? Is there a metal clamp underneath the visible flap?

I imagine when they went away from the ships systems they would have to plug into the backpacks for air, cooling and communications. I have no idea how they sealed, maybe they didn’t and they had a slight leak and bottled air kept an over pressure. But the flap would have been to piss.

From another forum
I found it on the internet so it must be true.

The neck ring of the Apollo A7L suit was originally anodized blue in color. During use of the A7L suit, a design change was made to the vent port between the suit neck ring and the helmet. This change enlarged the vent port and slightly clocked its position on the neck ring. The color of the neck ring was changed from blue to red to make a clear distinction between the two vent port designs.

Thus an early (blue) A7L helmet would not get adequate vent flow on a later (red) neck ring suit and vise versa due to the changes in size and position of the vent port. A helmet with a blue neck ring will actually latch into a red suit neck ring but the vent ports will be misaligned. The first use of A7L suits with red neck rings was on the Apollo 11 mission. All subsequent A7L suits used the red neck rings as well as the A7LB suits.

The Apollo suit-side neck ring is actually made up of multiple parts, and all of them were initially anodized blue. When the vent port design change was made only the outer shell of the suit-side neck ring was changed in color from blue to red. All the other parts of the suit-side neck ring (with the exception of the suit-side vent port which was also changed from blue to red) remained blue. This is why the inside of a red suit-side neck ring is blue.

Further, the red neck rings included engraved wording stating that a red helmet neck ring should only be used with a red suit neck ring. Similar wording was on the red suit neck rings as well.

Crew photos were not necessarily taken with the crew wearing their flight spacesuit. Thus crew photos usually show a mix of neck ring colors as they used the suits that were available at the time of the photo.
In addition, crew training used whatever suits were available at the time. Only flight-day walk-out or in-flight photos will show what was actually used on the mission.

One additional note: In the Apollo 11 crew photo, only Collins is holding a helmet, both Armstrong and Aldrin are holding the LEVA without the helmets inside. The “red” color visible inside Armstrong’s LEVA is the interior of the LEVA shell which is red colored plastic.

From a quick look around, the crotch flap seems to be a simple protective cover for the entry/exit zip.

Question without notice.
Discounting insulation and radiation protection, how much of an astronauts body needs to be in a pressurised suit to survive vacuum? Would it be enough for the head and chest ?

maybe you’d end up one big hickie without the pressure protection.

Dropbear said:

Question without notice.
Discounting insulation and radiation protection, how much of an astronauts body needs to be in a pressurised suit to survive vacuum? Would it be enough for the head and chest ?

The whole kit & caboodle I’d imagine. It would presumably also be easier to make a suit that is evenly pressurised rather than just pressurised here and there.

Collins did a space-walk on the trip home to retrieve the film from the cameras outside of the orbiter.

Dropbear said:

Question without notice.
Discounting insulation and radiation protection, how much of an astronauts body needs to be in a pressurised suit to survive vacuum? Would it be enough for the head and chest ?

This is a question that has been puzzling me for a couple of years. So far as I can tell, only the head needs to be pressurised to avoid problems with boiling off of body fluids, particularly of saliva and around the eyes. But even there the pressurisation wouldn’t need to be full atmosphere. If the astronaut was breathing pure oxygen then you could drop the pressure to somewhere between 10% and 20% of Earth’s surface. Even at 10% the boiling point of water is 50 degrees Celsius, which is sufficiently above what would be a comfortable temperature to be deliberately avoided.

Some chest pressurisation would perhaps be a help to make breathing easier. The maximum lung pressure that most people can exert is 10% of Earth’s surface, so chest pressurisation wouldn’t necessarily need to be as strong as face pressure. Legs and arms don’t necessarily need any pressurisation at all.

Now let’s consider the source of the pressure. I like the idea of using stretched neoprene (ie a drysuit) to provide the necessary pressure. Just wear an undersized drysuit. That gives far better mobility to astronauts than standard spacesuits.

Now, as to cooling, most of the heat that we lose in normal life is through the skin, with perhaps 5% occurring through the lungs. But it doesn’t have to be that way. The greatest danger from overheating is brain damage (consider the damage caused by fever). If almost all of the heat loss is through the lungs then the body circulation results in the brain being cooler, which helps the brain to function better. To explain that better, the blood from the skin has to pass twice through the heart before it gets to the brain, but that from the lungs only passes once through the heart before reaching the brain or, to put that another way, the blood from the skin to the brain has to pass through the lungs on the way. To cool the lungs, simply use the adiabatic expansion of gas from a compressed oxygen source to do the cooling.

I would very much like to try out all this theory in a real vacuum chamber with a real drysuit.and oxygen tank.

I would have thought any breath held in the lungs would burst blood vessels pretty quick unless the chest was pressurised ?