Alternative to space suits

[Ken Fabian]

Wouldn't a small capsule - that has external arm/gloves - be more practical for working in free fall than a space suit with legs? Seems like legs are mostly not used on space walks and having space suits with them adds complications that serve no real purpose. You could pull your arms back inside a capsule and scratch your bum - do all those necessary things like eat, drink, piss, blow your nose or wipe off sweat. Also you could have access to the essential hardware, in case. A capsule wouldn't have to have a lot of internal space. It would also be possible to have mechanical grabbers and tools operated by internal controls. Any designs for such a thing out there?

[swansont]

Whenever you exert a force or torque there is a reaction force or torque. If you aren't properly anchored, you will be pushed or spun as a result. We don't notice this much on the earth where we have a normal force of many hundred newtons already present, but this is missing in space. Being able to put your feet where you need to, and have the tactile feedback it includes, is probably necessary for some of the work that is done.

 

[Ken Fabian]

Swansont - I was thinking gyroscopic stabilisers for maintaining orientation - I would expect space suits to have those too - as well as grabbers of some kind to anchor with and give resistance to work against.  I don't doubt there would be situations where booted feet would work or spaces would be too tight for even a smallish capsule - not that suits aren't bulky and awkward too - but wondered if it may be a requirement for being able to operate inside a space vessel, if only for emergencies, that has a real necessity for legs. Yet most outside work wouldn't need legs and working for long periods ought be easier and more comfortable in a "pod" or capsule, even if it's only just enough room to pull arms back in and deal with body's needs.

[Raider5678]

1 hour ago, Ken Fabian said:

Swansont - I was thinking gyroscopic stabilisers for maintaining orientation - I would expect space suits to have those too - as well as grabbers of some kind to anchor with and give resistance to work against.  I don't doubt there would be situations where booted feet would work or spaces would be too tight for even a smallish capsule - not that suits aren't bulky and awkward too - but wondered if it may be a requirement for being able to operate inside a space vessel, if only for emergencies, that has a real necessity for legs. Yet most outside work wouldn't need legs and working for long periods ought be easier and more comfortable in a "pod" or capsule, even if it's only just enough room to pull arms back in and deal with body's needs.

A space suit allows more maneuverability.

Climbing alongside a craft with a ladder, getting back in, etc.

[Ken Fabian]

I don't think an astronaut would use feet as well as hands on a ladder (why a ladder at all?) in zero gee - and I'm not suggesting a capsule that is much more massive than a space suit, that could not be pulled around by hands. But would much movement be done physically like that? I would think micro jets would handle most movements and do so more easily than clambering around. I read somewhere that most manual tasks in zero gee take about 2.5 times as long as in gravity - just on the basis of efficiency of movement jetting around would beat clambering.

[swansont]

13 hours ago, Ken Fabian said:

I don't think an astronaut would use feet as well as hands on a ladder (why a ladder at all?) in zero gee

There's the issue of letting go and then drifting off into space forever...

Quote

But would much movement be done physically like that? I would think micro jets would handle most movements and do so more easily than clambering around. I read somewhere that most manual tasks in zero gee take about 2.5 times as long as in gravity - just on the basis of efficiency of movement jetting around would beat clambering.

Micro jets means additional bulk, since you need to carry the propulsion hardware as well as fuel.

[Phi for All]

There is also a need to reduce the risk of creating debris which I don't think this alternative addresses adequately. More metal on metal, "grabbers", etc, mean more risk of small bits breaking off to create problems for this craft and every other piece of equipment we have in orbit. And you can't use a vacuum cleaner on space debris.

[StringJunky]

1 minute ago, Phi for All said:

There is also a need to reduce the risk of creating debris which I don't think this alternative addresses adequately. More metal on metal, "grabbers", etc, mean more risk of small bits breaking off to create problems for this craft and every other piece of equipment we have in orbit. And you can't use a vacuum cleaner on space debris.

But... but... they're called 'vacuum cleaners'. 

[Phi for All]

1 minute ago, StringJunky said:

But... but... they're called 'vacuum cleaners'. 

But vacuums don't need cleaning.

Vacuum cleaners are like hot water heaters. 

[StringJunky]

Just now, Phi for All said:

But vacuums don't need cleaning.

Vacuum cleaners are like hot water heaters. 

Yeah.

[Ken Fabian]

5 hours ago, swansont said:

There's the issue of letting go and then drifting off into space forever...

Being able to work safely without holding on - and without a permanent tether - seems like a necessary threshold for serious construction work in space; much too limiting of work potential otherwise. I don't see that booted feet are that much use for holding on anyway.

5 hours ago, swansont said:

Micro jets means additional bulk, since you need to carry the propulsion hardware as well as fuel.

NASA added them to space suits (Manned Manoeuvring Units) , although they discontinued using them, because of that drifting off issue I suppose. I don't think the issues are insurmountable, whether with single person "capsules" or space suits.

I still think that anything less than independent movement will limit a space worker's efficiency and effectiveness - and given the high costs of getting them there as well as the innate difficulties of working in zero gee anything that improved their effectiveness is surely important.

2 hours ago, Phi for All said:

There is also a need to reduce the risk of creating debris which I don't think this alternative addresses adequately. More metal on metal, "grabbers", etc, mean more risk of small bits breaking off to create problems for this craft and every other piece of equipment we have in orbit. And you can't use a vacuum cleaner on space debris.

Easily avoided - use soft jawed grabbers. Although I do wonder if serious in-space construction work would be best done within some kind of enclosed safety barrier, to prevent both workers and materials drifting away.

Edited January 19, 2018 by Ken Fabian
punctuation