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RobertDyck

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From: Winnipeg, Canada

Registered: 2002-08-20

Posts: 7,813

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KO2 oxygen for spacesuits

Watched clips of a 1970 British TV show called UFO. Rather than a PLSS backpack, they had something that hooked over one shoulder. Could you make a PLSS that small? We would want regenerable technology for Mars, but the show was made before that was a consideration. How could you do it?

Russian Soyuz capsules use potassium superoxide (KO2).

Wikipedia: Potassium superoxide

Reactivity
Potassium superoxide is a strong oxidant, able to convert oxides into peroxides or molecular oxygen. Hydrolysis gives oxygen gas, hydrogen peroxide and potassium hydroxide:

    2 KO2 + 2 H2O → 2 KOH + H2O2 + O2

Potassium hydroxide (KOH) absorbing carbon dioxide produces carbonates:

    2 KOH + CO2 → K2CO3 + H2O
    KOH + CO2 → KHCO3

Combining these two reactions produces:

    4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2
    4 KO2 + 4 CO2 + 2 H2O → 4 KHCO3 + 3 O2

Applications
The Russian Space Agency has had success using potassium superoxide in chemical oxygen generators for its spacesuits and Soyuz spacecraft. KO2 has also been used in canisters for rebreathers for fire fighting and mine rescue work, but had limited use in scuba rebreathers because of its dangerously explosive reaction with water.

KO2 reacts with CO2 in the following reaction:

    4 KO2(s) + 2 CO2(g) → 2K2CO3(s) + 3O2(g)

Theoretically, 1 kg of KO2 absorbs 0.310 kg of CO2 while releasing 0.338 kg of O2. One mole of KO2 absorbs 0.5 moles of CO2 but releases only 0.75 moles of oxygen gas (O2) molecules.

Comparing to Apollo spacesuit PLSS
NASA Apollo project Space Suit(A7LB PGA)

Oxygen was supply from this System then keep astronaut's life for about seven hours continuously. 1.05 pound oxygen was housed in 46.6 square ibch tank with 900 psi.

One interesting feature of the Russian system is it removes CO2 and generates O2 in one device. The Apollo suit carried 1.05 lb O2 = 0.476272 kg. That would require 1.409 kg of KO2. A7L-B was rated for 7 hours of operation. Increasing to 1.8 kg would extend to 8 hours 56.5 minutes (8 hours plus reserve). One advantage of this system is the KO2 is at the same pressure as the suit, it doesn't require a 900 psi tank. That allows the canister to be lighter. You have to be careful with storage and handling; exposing KO2 to liquid water will produce a rapid vigorous reaction. Enough water would cause it to explode. But the TV show portrayed a military base, so they wouldn't be afraid of dangerous goods. Besides, Russians use it on Soyuz.

KO2 density is 2.14 g/cm³. Add some volume for air flow between granules. For 1.409 kg the volume would be 658.4 cm³. Note: 1 cm³ = 1 ml. Say double the volume for air between granules, so 1.3168 litres. An army style 1.3L canteen could hold that.

Obviously the suit on the show didn't bother with a cooling system. In real life, an MCP suit doesn't require anything more than a bottle of drinking water, but the show's suit doesn't look like MCP.

You know, PET (polyethylene terephthalate) has a service temperature range +150°C (302°F) to -70°C (-94°F). Put a plastic bag inside a 1 litre bottle, fill the bag with drinking water. The cap would have 2 hoses: drinking water from the bag, and return air from the helmet to the bottle outside the bag. Bursting pressure of a 2 litre pop bottle is 150 psi. At room temperature, pop is pressurized to 40 to 55 psi. With thermal insulation blanket around the standard pop bottle, that would provide drinking water.

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 17,313

Re: KO2 oxygen for spacesuits

For RobertDyck re new topic...

Thanks for creating this promising new topic....

Since humans release moisture into the air along with CO2, and since the Russians are using this system (KO2), the reaction of the water must not be a problem.

Could you show how the Russian system handles water?

Update at Noon+ local time: Recharging of KO2 cartridges may be possible in the expedition vehicle.  What is involved in recharging a cannister?

Thanks for opening this important topic! 

Reminder ... our newest member is interested in space suits.  It is possible you (RobertDyck) missed that, because with so much going on in the forum and elsewhere, a member can't possibly keep up with everything.

The name of the newest member is on display on the main page of the site (Index Display) .... He has been totally silent since joining. Perhaps a note from you via private email would encourage him to consider helping with the spacesuit segment of this project.

You are going to need to delegate responsibility to individuals, and eventually to thousands of people, just as was true for the Apollo Moon landings.

You've already got SpaceNut looking at magnetic shielding from ionized radiation, and others thinking about other segments of the overall project.

Adding a person who wants to focus on space suits (Mars suits included) would seem (to me at least) to be a logical progression.

(th)

RobertDyck

Moderator

From: Winnipeg, Canada

Registered: 2002-08-20

Posts: 7,813

Website

Re: KO2 oxygen for spacesuits

Here's a question. PET is the polymer for plastic pop bottles. It's service temperature is +150°C to -70°C, embrittlement at -73°C. Spacesuit temperature in LEO is +120°C to -150°C. Mars surface can get below -80°C at night. You would want the water to remain above freezing so you could drink. But for safety should the polymer be something that can handle cold of Mars night? A safety valve could cut off the hoses should a leak occur. PCTFE can handle Mars cold, but that's an expensive custom bottle.

louis

Member

From: UK

Registered: 2008-03-24

Posts: 7,208

Re: KO2 oxygen for spacesuits

Sounds interesting. I suppose you need to ask about when you would need this oxygen supply. Presumably on an EVA - either task-orientated or for leisure. One could have a system where oxygen containers are dotted around the base area. So maybe you carry 3 separate containers and once one is used, you go to a robot vehicle which will carry fresh supplies. You can locate the vehicle by GPS. This would reduce the weight you need to carry. Something similar could be used even with exploration.  An explorer rover could have some smaller rovers attached that could carry oxygen supplies.

Watched clips of a 1970 British TV show called UFO. Rather than a PLSS backpack, they had something that hooked over one shoulder. Could you make a PLSS that small? We would want regenerable technology for Mars, but the show was made before that was a consideration. How could you do it?
https://i0.wp.com/gerryanderson.wpengin … =768%2C576

Russian Soyuz capsules use potassium superoxide (KO2).

Wikipedia: Potassium superoxide

Reactivity
Potassium superoxide is a strong oxidant, able to convert oxides into peroxides or molecular oxygen. Hydrolysis gives oxygen gas, hydrogen peroxide and potassium hydroxide:

    2 KO2 + 2 H2O → 2 KOH + H2O2 + O2

Potassium hydroxide (KOH) absorbing carbon dioxide produces carbonates:

    2 KOH + CO2 → K2CO3 + H2O
    KOH + CO2 → KHCO3

Combining these two reactions produces:

    4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2
    4 KO2 + 4 CO2 + 2 H2O → 4 KHCO3 + 3 O2

Applications
The Russian Space Agency has had success using potassium superoxide in chemical oxygen generators for its spacesuits and Soyuz spacecraft. KO2 has also been used in canisters for rebreathers for fire fighting and mine rescue work, but had limited use in scuba rebreathers because of its dangerously explosive reaction with water.

KO2 reacts with CO2 in the following reaction:

    4 KO2(s) + 2 CO2(g) → 2K2CO3(s) + 3O2(g)

Theoretically, 1 kg of KO2 absorbs 0.310 kg of CO2 while releasing 0.338 kg of O2. One mole of KO2 absorbs 0.5 moles of CO2 but releases only 0.75 moles of oxygen gas (O2) molecules.

Comparing to Apollo spacesuit PLSS
NASA Apollo project Space Suit(A7LB PGA)

Oxygen was supply from this System then keep astronaut's life for about seven hours continuously. 1.05 pound oxygen was housed in 46.6 square ibch tank with 900 psi.

One interesting feature of the Russian system is it removes CO2 and generates O2 in one device. The Apollo suit carried 1.05 lb O2 = 0.476272 kg. That would require 1.409 kg of KO2. A7L-B was rated for 7 hours of operation. Increasing to 1.8 kg would extend to 8 hours 56.5 minutes (8 hours plus reserve). One advantage of this system is the KO2 is at the same pressure as the suit, it doesn't require a 900 psi tank. That allows the canister to be lighter. You have to be careful with storage and handling; exposing KO2 to liquid water will produce a rapid vigorous reaction. Enough water would cause it to explode. But the TV show portrayed a military base, so they wouldn't be afraid of dangerous goods. Besides, Russians use it on Soyuz.

KO2 density is 2.14 g/cm³. Add some volume for air flow between granules. For 1.409 kg the volume would be 658.4 cm³. Note: 1 cm³ = 1 ml. Say double the volume for air between granules, so 1.3168 litres. An army style 1.3L canteen could hold that.

Obviously the suit on the show didn't bother with a cooling system. In real life, an MCP suit doesn't require anything more than a bottle of drinking water, but the show's suit doesn't look like MCP.

You know, PET (polyethylene terephthalate) has a service temperature range +150°C (302°F) to -70°C (-94°F). Put a plastic bag inside a 1 litre bottle, fill the bag with drinking water. The cap would have 2 hoses: drinking water from the bag, and return air from the helmet to the bottle outside the bag. Bursting pressure of a 2 litre pop bottle is 150 psi. At room temperature, pop is pressurized to 40 to 55 psi. With thermal insulation blanket around the standard pop bottle, that would provide drinking water.

---

Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

RobertDyck

Moderator

From: Winnipeg, Canada

Registered: 2002-08-20

Posts: 7,813

Website

Re: KO2 oxygen for spacesuits

I'm thinking of an emergency backup. In addition to the KO2 for primary oxygen, a bottle of oxygen for backup. Soyuz capsules have that, along with lithium hydroxide sized to go with the bottled oxygen. High Pressure COPV by MEYER
HDRX-005, capacity 0.5 litre, pressure 300 bar, 80 mm diameter x 190 mm long, bottle mass 0.42 kg, thread M18x1.5
This would hold 0.195 kg = 0.4299 pounds of O2. That would last 3 hours.

That's just a standard size. We could use an oxygen bottle 1/3 that size to provide 1 hour. But then again, how much oxygen you consume, and how much CO2 you produce, can vary.
The CO2 Scrubber in a Diver’s Rebreather

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,337

Re: KO2 oxygen for spacesuits

Robotic joints could make future space suits more comfortable
https://newatlas.com/space/robotic-join … mfortable/

another discussion

'MIT Mars Bio Suit'
https://newmars.com/forums/viewtopic.php?id=9529