For Questions That Don't Merit Their Own Thread

[kerbiloid]

  

31 minutes ago, magnemoe said:

Like this in freefall 

Like this in NASA dreams.

https://en.wikipedia.org/wiki/Suitport

Spoiler

Now imagine when (not "if") the first lunar traveller breaks a leg on the stones.
(Don't forget, they are there to drill and build, not just to carefully walk, like the apolloners did. This means inevitable traumas.)
How to pull him into the habitat through this hole without pulling off the damaged part?

Or how to pull in with broken spine or any other case of a horizontal patient.

Or what to do if the squared frame is damaged and can't match the airlock frame, so you can't pressurize the entrance..

So, they anyway need a normal airlock instead of this idiotic toy.
Because an airlock door is stronger and doesn't fall on rocks, and to just bring and put the broken comrade on the floor.

In this case they don't need to complicate the suit.

Also what if such man  falls on back, how should he stand up?
Should he be equipped with a wand and a hoola-hoop like in 1960s designs?

Upd.
Btw, interesting, what @Gargamel thinks about such case? (Iirc, he's a medic.)

Edited February 17, 2021 by kerbiloid

[magnemoe]

3 minutes ago, kerbiloid said:

  

Like this in NASA dreams.

https://en.wikipedia.org/wiki/Suitport

  Hide contents

Now imagine when (not "if") the first lunar traveller breaks a leg on the stones.
How to pull him into the habitat through this hole without pulling off the damaged part?

Or how to pull in with broken spine or any other case of a horizontal patient.

And what to do if the squared frame is damaged and can't match the airlock frame.

Yes most likely issue is problems with seal and locking. You would need an standard airlock anyway just to servicing the suits, emergencies or bring larger parts trough.  Guess you will use the airlock to get used to low pressure and pure oxygen too. For the rover I guess they would need to depressurize the cabin and enter, then pressurize. 
 

[Gargamel]

3 hours ago, kerbiloid said:

interesting, what @Gargamel thinks about such case? (Iirc, he's a medic.)

To be honest, there’s not much one can do first aid wise for a broken extremity while in a suit.    The suit itself should provide enough support to semi splint a bone till you can get out of the suit.   
 

As for getting out of the suit, there will either be a lot of screaming, or the copious administration of opiates.   

[kerbiloid]

37 minutes ago, Gargamel said:

To be honest, there’s not much one can do first aid wise for a broken extremity while in a suit.    The suit itself should provide enough support to semi splint a bone till you can get out of the suit.   

Yes, I mean they first have to extract the man from the shell before cook him.

On the Earth they can just cut the suit.

Edited February 17, 2021 by kerbiloid

[JoeSchmuckatelli]

7 hours ago, K^2 said:

That's going to be so ridiculously inefficient... I'm wondering if it makes sense to drag suits inside in the first place. Can't be that difficult to build an airlock that mates directly to the hatch on the back of the suit, can it? Seems like it'd be a much better option to just have the suits always stay on the outside.

That's not a bad idea - but would take a pretty big rework of the suits. 

 

Edit: @kerbiloidthanks for the info on suitport - had not seen this 

Having looked at it - I would make it a ton smaller and put it inside the first hatch - so that the astronaut is getting into and out of the suit while the lock is pressurized.  Doing it this way means that all you need is a good seal for dust - and not a whole 'lock on your back' apparatus 

Edited February 17, 2021 by JoeSchmuckatelli

[kerbiloid]

11 minutes ago, JoeSchmuckatelli said:

and put it inside the first hatch

Inside the airlock  chamber?
But the whole sense of this thing is to delimit the dusty and the clear sides.
So, by entering the airlock chamber he brings dust inside which makes the suitport useless.

[JoeSchmuckatelli]

41 minutes ago, kerbiloid said:

Inside the airlock  chamber?
But the whole sense of this thing is to delimit the dusty and the clear sides.
So, by entering the airlock chamber he brings dust inside which makes the suitport useless.

You have a special chamber that can pressurize around the suits - making it much safer for the astronaut to enter a suit with a much smaller / normal port - basically take what they drew for suitport and put a box around it.  Astronaut still enters the main part of the ship / inner lock station via the port in the back of the suit. The dust remains in the chamber.  Bonus - upon return to earth - more samples. 

 

One of the biggest things I've seen in suit design lately is greatly improved mobility.  The full suitport turtle back look like it will eliminate those advantages - so I'm suggesting a compromise.  Won't be perfect exclusion of regolith but will be miles ahead of what Apollo enjoyed 

Edited February 17, 2021 by JoeSchmuckatelli

[Gargamel]

Is there a LD50 value for water?

In particular, for drinking it.   

[JoeSchmuckatelli]

26 minutes ago, Gargamel said:

Is there a LD50 value for water?

In particular, for drinking it.   

90 g / kg

 

Median lethal dose - Wikipedia

 

Edited February 19, 2021 by JoeSchmuckatelli

[Gargamel]

53 minutes ago, JoeSchmuckatelli said:

90 g / kg

 

Median lethal dose - Wikipedia

 

Right.   Thanks to my intern research assistants @Vanamonde and @goldenpeach, we came up with the same number.   
 

Which after some minor rounding, comes out to about 6500 bottles of water for a 100kg person.  
 

Assuming you down a bottle in 30 seconds, that’s about 54 hours of constant drinking.   
 

That doesn’t make sense.   I’ve treated water toxicity patients before, and most of them start excreting the excess before It can build up too much.    Their kidneys get all pissy (ha punny!) and start trying to keep up.    If the rental system starts losing the race, it just gets dumped into one of the other system used to get rid of things, your lungs.  Then it’s not the water that kills you, it’s the drowning from the inside that gets you.  
 

Even if this is administered via IV, we still have to get over 1L per minute into this person/victim/water balloon.    That’s fast.   Like I’ve had to pressure infuse trauma victims with fluid just to keep their circulatory system from collapsing, and that infusion rate is nothing compared to this.   
 

This LD50 value makes no practical sense to me. 
 

(Thanks Joe  ) 

[Gargamel]

WAIT 

Math error detected 

 

it’s not 6500 bottles of water.    I had done 6.5 bottles per kg, not 6.5 kg / bottle.    That’s only 15 bottles.    
 

That doesn’t make any sense either.   For the exact opposite reasons as listed above. 

[kerbiloid]

Champions say (actually, don't anymore) ~10 l / client.

https://en.wikipedia.org/wiki/Water_intoxication

[monophonic]

44 minutes ago, Gargamel said:

This LD50 value makes no practical sense to me. 

Well, I followed the references from the wikipedia page. That value is measured on rats.

[Gargamel]

2 minutes ago, monophonic said:

Well, I followed the references from the wikipedia page. That value is measured on rats.

Well, that’s kind of the point of LD50 research.    You can’t just hand out random amounts of arsenic to school children to see how many die and when.  You have to use human analogs, and LD50 values are usually expressed in concentration levels.  
 

I just wondered if anybody had done the methodology to come up with LD50 numbers for water.    I have this mental picture of the researchers riding on the back of pigs, leaning on their heads, screaming “Drink Dammit!”  

[SOXBLOX]

LD50 of......water. *shakes head*

Only on the KSP forums...

Still, I'll avoid drinking more than 15 bottles. 

Edited February 19, 2021 by SOXBLOX

[kerbiloid]

8 hours ago, monophonic said:

That value is measured on rats.

+1

As the rat didn't wish to drink, they were holding its face underwater.

Edited February 19, 2021 by kerbiloid

[JoeSchmuckatelli]

7 hours ago, Gargamel said:

WAIT 

Math error detected 

 

it’s not 6500 bottles of water.    I had done 6.5 bottles per kg, not 6.5 kg / bottle.    That’s only 15 bottles.    
 

That doesn’t make any sense either.   For the exact opposite reasons as listed above. 

I know it's early - but your original 6,500 did not look right.   Neither does 15.  I used to drink 8-10 1qt canteens of water per day during intense summer training - and the risk was always flushing electrolytes.  So we ate a whole bunch, too.  

But that was also over the course of about 16 hours - with intense training in high heat and humidity; so all that water was being used & processed throughout the day. 

 

Take a 100 kg person. It would take 9000g of water to be toxic.  There are 29.57 g of water per ounce, and a 1 qt canteen is 32 oz.  That's about 946 g - so about 9 canteens. 

 

So - since the math works, but conflicts with my experience - the clear difference is in the rate of consumption!  If you don't give the body time to process, then you hit toxic conditions...  So you basically have to get a person to drink over 2 gallons immediately - and given that the human stomach is about 1/2 of that (2-4 l, max) - that is hard to do.  What becomes the risk, then is aspiration (aka drowning) which is why waterboarding (Chinese water torture) is so horrific. 

 

Edit - so back to 'experience' stories:  when it's cold, people want to eat, but not drink.  When it's hot you want to drink, but have a low appetite.  Not being mindful about what you eat and drink in extreme conditions can kill you.  I've seen Marines go down in summer as 'heat casualties' (heat exhaustion /stroke) despite drinking enough water - all because they were flushing their electrolytes (not eating enough).  I've also seen 'cold casualties' in the winter because people were not drinking enough. 

Edited February 19, 2021 by JoeSchmuckatelli

[Gargamel]

2 minutes ago, JoeSchmuckatelli said:

If you don't give the body time to process, then you hit toxic conditions...  So you basically have to get a person to drink over 2 gallons immediately - and given that the human stomach is about 1/2 of that (2-4 l, max) - that is hard to do.

But that's a physical trauma, not what LD50 is supposed to represent.   Hmmmph......

[JoeSchmuckatelli]

11 minutes ago, Gargamel said:

But that's a physical trauma, not what LD50 is supposed to represent.   Hmmmph......

That's kind of the point with the LD50 of water - because it is so required /easy to process and there are limits to consumption through natural methods - you rarely hear about water poisoning.  But bypass the stomach and dump 2 gallons into someone both intravenously (which you pointed out is also difficult) and by filling the stomach... Pretty sure you kill that person. 

 

Side note: there are easier ways. 

Edited February 19, 2021 by JoeSchmuckatelli

[kerbiloid]

46 minutes ago, Gargamel said:

But that's a physical trauma, not what LD50 is supposed to represent. 

A chemical one. Concentration of ions falls.

(At least, afair.)

Btw.
Why use an isotonic solution instead of just a distilled water?
Why salt pills?

Edited February 19, 2021 by kerbiloid

[Gargamel]

8 minutes ago, kerbiloid said:

Why use an isotonic solution instead of just a distilled water?

Because then we'd be looking at the LD50 of saline, not water. 

[adsii1970]

All that water drinking leads to a lot of peeing... just sayin'

[kerbiloid]

Just now, Gargamel said:

Because then we'd be looking at the LD50 of saline, not water. 

Excessive water decreases the saline ion concentration, affecting the chemistry.

Just now, adsii1970 said:

All that water drinking leads to a lot of peeing... just sayin'

Only first ten liters at once. Then no.

[VoidSquid]

 

[adsii1970]

@VoidSquid:

Yes, but I still love consuming it, especially when it is mixed with chlorogenic acids in their naturally occurring state as the Rubiaceae plant family, more specifically, the Coffea arabica plant. The berries release an awesome aroma when roasted and ground. Add them to hot boiling water through either a drip or peculated process to make make a great and natural energy beverage.