Space Corps knife??

[rwponline]

What chores and functions might this space knife have to perform?

sal

For an EVA knife you'd want something with a serrated edge to cut through the beta cloth used pretty much everywhere exposed to space (a fireproof glass fiber cloth that can resist the UV and atomic oxygen present at orbital altitudes).

A blunt tip for a rescue/survival tool, or a pointed tip if you expect to get into 'glove-to-glove' combat in space.

One thing few people think about is that the suits (including the gloves) are pressurized. This means that to close your hand in a pressurized space suit glove you are fighting pressure until you relax your hand (allowing the glove to resume it's molded shape). For this reason, most EVA tools have very large diameter handles with aggressive ribs that don't require the hand to close much for a secure grip.

Materials are interesting too. Lots of anodized aluminum (gold color anodize for man-rated structure, clear for equipment rated), some stainless (though it's bad thermally), and beryllium copper for working around pure oxygen or other flammable materials (non-sparking).

For Intravehicular Activity (IVA), pretty much any knife that would be useful on the ground would be good up there, but I'd want a brightly colored handle to spot the opened knife floating my way (because I got busy and forgot to close it)...

-rwponline

[Doc Dan]

Bloke you are always in outer space. hahahaha! :D

[Bloke]

Bloke you are always in outer space. hahahaha! :D

[curlyhairedboy]

Cutting up Martian sushi?

sal

I can't wait for the day when "USA, Earth" becomes "Insert colony here, Mars".

[mark greenman]

In the book "Ghost Fleet," Sir Richard Branson and a team of Blackwater mercs take over the Chinese Space station with Tazers and Trench Knives.

So for that reason, plus the need to have the knife remain secure in hand even with a pressurized space glove on, a Jumpmaster with a D-ring trench knife handle would likely be ideal.

[bearfacedkiller]

[ZrowsN1s]

...

...this might Sting a bit.

[Spydersense]

...

...this might Sting a bit.

https://youtu.be/6zXDo4dL7SU

[JonLeBlanc]

-No cobalt in the blade steel (cobalt captures neutrons, emits beta and gamma radiation and turns into nickel)

You are confusing Cobalt 59, the natural, by far the most abundant and only stable cobalt isotope, with Cobalt 60, a synthetic radioactive isotope that has the property you mentioned. The cobalt extracted from ore used in knives is safe to use in high radiation environments.

I would think (but could be entirely wrong about this) that a blunt wharncliffe/sheepsfoot syle blade alà Rescue etc would be beneficial so as to avoid any puncturing cuts if the knife got away from an astronaut or if it were used by a suited astronaut outside the vehicle.

Regarding the radiation hazard of cobalt use, I believe Accutron is correct; cobalt-59 (natural cobalt) does absorb neutrons (especially fission spectrum neutrons, those produced in reactors) to produce cobalt-60, a prolific gammma emitter. From what I gather, the typical energy spectra of neutrons in space ranges from about .04eV to 10MeV, and that upper limit is about the same for a neutron flux produced in a reactor. So tl;dr yes natural cobalt-59 may very well be hazardous in space.

[SpyderEdgeForever]

Regarding the cobalt: There is alot of cobalt in metal rich asteroids in space.

Regarding the knife: With practically unlimited ultra high vacuum enviroment being all of outer space practically, and multiple sources of cheap and huge concentrated energy streams and micro gravity and zero gravity, you can make a host of new materials that would make normal steel seem like nothing. But then, what is "normal" steel?

A knife made from silicon or sapphire that is treated to be elastic and fracture tough would be far better than any steel alloy based knife, and would be much stronger and harder and could be given any color you want.

I would go with a Spyderco Endura with Shatter Proof Sapphire Blade Saber Ground.

The knife used in the above posted picture by the Harkonnen man is made of plasteel.

[Accutron]

Regarding the cobalt: There is alot of cobalt in metal rich asteroids in space.

Indeed there is. Unlike the Earth's crust, asteroids are enriched with Co-60, produced by continuous cosmic ray bombardment and solar radiation flux. When a space rock falls as a meteorite, Co-60 production ceases, at is no longer being exposed to significant amounts of cosmogenic radiation. Co-60 has a half-life of about 5.27 years, meaning that the majority of Co-60 found in a recently fallen meteorite was produced in the near past.

I'm not an astrophysicist or astrogeologist. My background is in electronics and engineering design. I don't know the isotope production rates involved, or how that translates to human tissue exposure. What I can say for sure is this: if you take a cobalt-containing knife on a spacewalk, the Co-59 in the blade will start turning into Co-60, and will later turn into stable Ni-60, altering the alloy composition. This cannot be of any benefit for either the astronaut or the knife.

Perhaps the quantities are too small over the life of the knife to be a serious concern. Still, when there are innumerable knife steels which contain only elements with a small neutron cross section, it seems like a reasonable precaution to avoid cobalt-containing steels.

[Doc Dan]

I personally think serrated H1 is the most practical material for the blade. I think it should be assembled in Golden, and be similar to the US Army Soldier Knife made by Victorinox with an Awl, flathead and phillips screw drivers, and etc. The main blade only needs to be one hand opening. The lock needs some thought, though. It needs to be capable of being operated with a gloved hand.

[ThePeacent]

button lock?

[Doc Dan]

Perhaps so, but with a very large button. A back lock with a large lock disengagement button would be good, too.

[SpyderEdgeForever]

I personally think serrated H1 is the most practical material for the blade. I think it should be assembled in Golden, and be similar to the US Army Soldier Knife made by Victorinox with an Awl, flathead and phillips screw drivers, and etc. The main blade only needs to be one hand opening. The lock needs some thought, though. It needs to be capable of being operated with a gloved hand.

You are a knife-design genius, Doc. I love this idea. Definitely H1. This would also satisfy the No-Cobalt rule as Accutron pointed out.

I guess N690Co Steel is out too because of the cobalt issue.

[The Meat man]

Here is my vote:

1) Some sort of good multi tool like the Leatherman Wave for onboard spacecraft without suits or gloves;

And 2) a fixed blade, H-1 SE knife like the Jumpmaster with a design optimized for use with awkward space gloves.

[emanuel]

I would think (but could be entirely wrong about this) that a blunt wharncliffe/sheepsfoot syle blade alà Rescue etc would be beneficial so as to avoid any puncturing cuts if the knife got away from an astronaut or if it were used by a suited astronaut outside the vehicle.

Regarding the radiation hazard of cobalt use, I believe Accutron is correct; cobalt-59 (natural cobalt) does absorb neutrons (especially fission spectrum neutrons, those produced in reactors) to produce cobalt-60, a prolific gammma emitter. From what I gather, the typical energy spectra of neutrons in space ranges from about .04eV to 10MeV, and that upper limit is about the same for a neutron flux produced in a reactor. So tl;dr yes natural cobalt-59 may very well be hazardous in space.

Guys, there is no "cobalt issue". You need slow neutrons (0.025 eV moving at 2.5km/s) in order to get them reliably captured by Cobalt 59. There are scientific papers on this subject. That's why cobalt 60 is rated as a synthetic element that does not have a natural source. The circumstances when and where it's produced naturaly are infime, and most high energy neutron sources will only get their neutrons captured in very specific and incredibly rare circumstances.
I repeat, you will long be dead before your knife has even hundreds of cobalt 60 atoms in it. There are other worries in space than your knife transmuting lol

@accutron, there is no cobalt 60 in measurable amounts in any meteorite ever found or collected, I couldn't find any source of what you stated to be true.

[Accutron]

@accutron, there is no cobalt 60 in measurable amounts in any meteorite ever found or collected, I couldn't find any source of what you stated to be true.

You must not have looked very hard.

https://ntrs.nasa.gov/search.jsp?R=19860022897

It's the third link down on Google when searching for "cobalt 60 meteorite" (no quotes). There are literally dozens of papers discussing cosmogenic Co-60 in meteorites.

[emanuel]

@accutron, there is no cobalt 60 in measurable amounts in any meteorite ever found or collected, I couldn't find any source of what you stated to be true.

You must not have looked very hard.

https://ntrs.nasa.gov/search.jsp?R=19860022897

It's the third link down on Google when searching for "cobalt 60 meteorite" (no quotes). There are literally dozens of papers discussing cosmogenic Co-60 in meteorites.

You are misinformed on this subject. The article you shared just proves my point... Even their high dpm/kgm values are LOWER than Earth background radiation.

Ok, let me explain again. Yes, no cobalt in actual measurable/impactful amounts. The article you linked says that the production of cobalt 60 is under 1 atom a minute for every GRAM of cobalt 59 in a meteorite, and slightly higher in specific types and densities.

On a macro scale, even if we maximize that production to the higher end of the autor's approximation, that's still insignificant and marginally higher than the rate you have in cobalt rich steel alloy here down on Earth. To put into perspective, you would need cubic KILOMETERS of space cobalt that reached a stable production / disintegration ratio, to make a cobalt 60 sewing needle.... Molar calculus, you can check yourself. I'll end this conversation here lol, most people don't probably care about this. Back to knives we go!

[legOFwhat?]

There is a joke to be had about "Tang" in here but for the life of me I can't find it..:)