Weightlessness for only hours and deep space life sustainment

[Spacescifi]

Hours of weightless is... OK?:

 

This is related to real spaceflight and will rely on real solutions.

I saw one astronaut write something along the lines of, "We do not need a rotating centrifuge for gravity in space if your propulsion system is fast enough."

I know the expanse takes that idea and runs with it.

The astronaut went on to write that he would much rather have rotating stations at endpoints of travel.

His reason was that rotating structures are trouble waiting to happen, and trying to fix a rotating structure while it's rotating would be a nightmare. I almost think the astronaut has spacewalk PTSD.

In scifi, they have ways of getting across vast distances quickly. Like at a lightyear per hour of warp, dealing with weightlessness would not do nearly as much damage as our astronauts currently take. To Alpha Centauri that is what? A little over 4 hours of weightlessness?

Surely the human body could handle that without weakening the human body to the degree that months will do. What I am saying is that if it is only a matter of hours and not days of weightlessness, the human body should have no problem walking out of the spaceship on a planet. Granted they would feel heavy and be somewhat weaker, having had their bodies do the equivalent of absolutely nothing for hours, actually less than nothing since they did'nt even have gravity.

 

Life in zero g with no back-up:  The ISS is regularly resupplied with food and clothes. A deep space mission, whether with advanced scifi or near modern capabilties would both require the ship to be self sustaining.

Clothing: Gonna need to wash clothes somehow. Space wash machine anyone? 

Food: Plants. In space.

Meat: I know this is gonna have a LOT of issues, but I think either fish or insects are the easiest source of renewable fresh protein available for space.

Foodstuffs: Packaged food is a given, previous answers were about making fresh supplies.

Clothing again: Sheep in space anyone? Yeah, I know this is all types of wrong, but sheep wool people! Fresh clothing for a change! It would no doubt be considered animal cruelty, as the only way to keep the animal from urinating and pooping all over the ship would be with harness restraints and diapers. Also sedative when necessary.

 

What thoughts and solutions do you have on these two subjects?

Namely, is mere hours of weightlessness so weakening that a human could not stand on earth upon landing? And how would you solve the challenges presented with deep space self sustainment of life with no backup?

Edited May 21, 2019 by Spacescifi

[tomf]

The problem with your first point is we aren't anywhere close to having propulsion methods that could produce any significant acceleration for any significant time.

The best current engines with a mass ration of 95% could sustain 1g for about 13 minutes before running out of fuel.

A  NTR with ISP 800 could sustain nearly half an hour.

Whereas there are centrifugal designs we could build tomorrow.

[Flibble]

2 hours ago, Spacescifi said:

Clothing: Gonna need to wash clothes somehow. Space wash machine anyone? 

Food: Plants. In space.

Meat: I know this is gonna have a LOT of issues, but I think either fish or insects are the easiest source of renewable fresh protein available for space.

Foodstuffs: Packaged food is a given, previous answers were about making fresh supplies.

Clothing again: Sheep in space anyone? Yeah, I know this is all types of wrong, but sheep wool people! Fresh clothing for a change! It would no doubt be considered animal cruelty, as the only way to keep the animal from urinating and pooping all over the ship would be with harness restraints and diapers. Also sedative when necessary. 

Sure space washing machine is an option. I don't think you need gravity to wash things, water's high surface tension will make it cling to things. You can also just spin the drum to use centrifugal force to force the water into the clothes.

Food: Plants is the obvious solution. Or micro organisms like fungi.

Meat: Why bother? Plants are a more efficient way of getting protein. If animal protein is a requirement, insects are most efficient.

Clothing: Synthetic fibres, or plant based fibres (like cotton) are both a far better option than wool. Even silk would be easier to grow in microgravity.

[Spacescifi]

23 minutes ago, tomf said:

The problem with your first point is we aren't anywhere close to having propulsion methods that could produce any significant acceleration for any significant time.

The best current engines with a mass ration of 95% could sustain 1g for about 13 minutes before running out of fuel.

A  NTR with ISP 800 could sustain nearly half an hour.

Whereas there are centrifugal designs we could build tomorrow.

Yes I know. I think the astronaut was thinking... when we get there technologically, knowing full well we are not there yet.

As for centrifuge washing machines? They have the possibility of slowly spinning your entire spaceship.

When you have a centrifuge rotating, it is easy for it's force to be applied elsewhere on a spaceship unless you counter it with another centrifuge with the same mass load spinning in the opposite direction.

Centrifuges are actually finicky things in space because for every action there is a reaction.

 

Edited May 21, 2019 by Spacescifi
Fix

[Superfluous J]

20 minutes ago, Spacescifi said:

As for centrifuge washing machines? They have the possibility of slowly spinning your entire spaceship.

There are plenty of ways around that including spinning then the other way half the time.

[Flibble]

1 hour ago, 5thHorseman said:

There are plenty of ways around that including spinning then the other way half the time.

Indeed, washing machines tend to rotate both ways anyway as it mixes the clothing better.

[Nightside]

7 hours ago, Spacescifi said:

Clothing: Gonna need to wash clothes somehow. Space wash machine anyone? 

@Spacescifi clearly you are working on some ideas for a story. I'm very interested to learn more about this species that has mastered faster than light travel, yet can't get figure out how to keep a washing machine from spinning the ship out of control (I guess rotisserie chicken is off the menu too) and can't wait 4 hours until they haul up to port?

[Spacescifi]

21 minutes ago, Nightside said:

@Spacescifi clearly you are working on some ideas for a story. I'm very interested to learn more about this species that has mastered faster than light travel, yet can't get figure out how to keep a washing machine from spinning the ship out of control (I guess rotisserie chicken is off the menu too) and can't wait 4 hours until they haul up to port?

Yes and no.

Your comment. I am both interested in real solutions.  About dealing with living in zero g, and how much zero g the human body can take before coming back to earth is a real challenge. Using google did not help so far. But if I had to guess, I am guessing a week would do it.

That is like worse than being bedridden for a week on earth.

Edited May 21, 2019 by Spacescifi

[magnemoe]

5 hours ago, tomf said:

The problem with your first point is we aren't anywhere close to having propulsion methods that could produce any significant acceleration for any significant time.

The best current engines with a mass ration of 95% could sustain 1g for about 13 minutes before running out of fuel.

A  NTR with ISP 800 could sustain nearly half an hour.

Whereas there are centrifugal designs we could build tomorrow.

This, now even with an good hard scifi fusion engine you would still fase long time with cruise, but here it would be down to weeks or perhaps a couple months unless you go to the orth cloud or similar simply as going faster would start to dig into your mass ratio hard. 

[DDE]

Hours? You’re fussing about hours in zero-g, @Spacescifi? Right now, the solutions we look for are to counter the effects of years of zero-g. They are thus simply not relevant in the softer sci-fi settings.

It’s interesting that you just gloss over The Expanse. For true interplanetary flights, rather than brief hops within the Belt, they’d end up having acceleration gravity throughout most of the flight.

It’s also notable that, with accelerations developed by vehicles typically found in sci-fi, you’re not just looking at acceleration-induced gravity - you’re looking at your crew reduced to paste. Once you sit with a timer and some basic astronomy, you are looking at accelerations of many kilometers per second per second.

This means ubiquitous phlebotinum of “inertial dampeners”, which in turn can reasonably be expected to be a subform of artificial gravity. There’s no reason for a setting that handwaves typical sci-fi travel times to not handwave zero-g away.

Edited May 21, 2019 by DDE

[Flibble]

50 minutes ago, Spacescifi said:

Yes and no.

Your comment. I am both interested in real solutions.  About dealing with living in zero g, and how much zero g the human body can take before coming back to earth is a real challenge. Using google did not help so far. But if I had to guess, I am guessing a week would do it.

That is like worse than being bedridden for a week on earth.

The longest stay in space is 438 days. A week in space in nothing. It's not like being bedridden unless you're strapped into a pod unable to move.

6 minutes ago, DDE said:

Hours? You’re fussing about hours in zero-g, @Spacescifi? Right now, the solutions we look for are to counter the effects of years of zero-g. They are thus simply not relevant in the softer sci-fi settings.

It’s interesting that you just gloss over The Expanse. For true interplanetary flights, rather than brief hops within the Belt, they’d end up having acceleration gravity throughout most of the flight.

It’s also notable that, with accelerations developed by vehicles typically found in sci-fi, you’re not just looking at acceleration-induced gravity - you’re looking at your crew reduced to paste. Once you sit with a timer and some basic astronomy, you are looking at accelerations of many kilometers per second per second.

This means ubiquitous phlebotinum of “inertial dampeners”, which is turn can reasonably be expected to be a subform of artificial gravity. There’s no reason for a setting that handwaves typical sci-fi travel times to not handwave zero-g away.

I think paste is actually best case in some of these instances. If you have a ship that can go from basically stationary to light speed in a matter of seconds you're going to experience on the order of 10,000g acceleration. The crew will be a fine mist seeping through any gaps in the panelling of the back wall. Not to mention everything else in teh ship had better be bolted down very securely.

[Spacescifi]

22 minutes ago, DDE said:

Hours? You’re fussing about hours in zero-g, @Spacescifi? Right now, the solutions we look for are to counter the effects of years of zero-g. They are thus simply not relevant in the softer sci-fi settings.

It’s interesting that you just gloss over The Expanse. For true interplanetary flights, rather than brief hops within the Belt, they’d end up having acceleration gravity throughout most of the flight.

It’s also notable that, with accelerations developed by vehicles typically found in sci-fi, you’re not just looking at acceleration-induced gravity - you’re looking at your crew reduced to paste. Once you sit with a timer and some basic astronomy, you are looking at accelerations of many kilometers per second per second.

This means ubiquitous phlebotinum of “inertial dampeners”, which is turn can reasonably be expected to be a subform of artificial gravity. There’s no reason for a setting that handwaves typical sci-fi travel times to not handwave zero-g away.

Well there is.

What is warp? Moving space without moving. Ever played with kerbal's warp mod?

It allows you to get close to planets without accelerating, although you still have to accelerate once you drop out of warp, whether through gravity or using your engine to match velocities and actually land safely.

 

And thanks for clearing up the answers on zero g. One thing I do know is that eye pressure increases in weightlessness, so the eyes won't like it.

Still though, much better than years of weightlessness as you already mentioned.

Edited May 21, 2019 by Spacescifi

[kerbiloid]

8 hours ago, Spacescifi said:

"We do not need a rotating centrifuge for gravity in space if your propulsion system is fast enough." 

 

8 hours ago, Spacescifi said:

To Alpha Centauri that is what? A little over 4 hours of weightlessness?

http://nathangeffen.webfactional.com/spacetravel/spacetravel.php

3.5 years at 9.81 acceleration.

 

8 hours ago, Spacescifi said:

Clothing: Gonna need to wash clothes somehow. Space wash machine anyone?  

Grass skirts. Bast sandals. Grow in the greenhouse, require nothing. Totally green. Absolutely recyclable. Don't wash, add to compost.

Spoiler

 

8 hours ago, Spacescifi said:

Meat: I know this is gonna have a LOT of issues, but I think either fish or insects are the easiest source of renewable fresh protein available for space.

Fruit flies. Grow in the greenhouse and trash can, require nothing. Pigeon-sized, next to the reactor.

8 hours ago, Spacescifi said:

Foodstuffs: Packaged food is a given, previous answers were about making fresh supplies.

Flour. Rusk. The living classics -  Rumford's soup

Spoiler

 

8 hours ago, Spacescifi said:

Clothing again: Sheep in space anyone? Yeah, I know this is all types of wrong, but sheep wool people!

A spacesheep in a spaceship is too smelly. Better grass.

8 hours ago, Spacescifi said:

It would no doubt be considered animal cruelty, as the only way to keep the animal from urinating and pooping all over the ship would be with harness restraints and diapers.

Diapers spend material. Better a hose. And a rope on the neck, of course.

8 hours ago, Spacescifi said:

, is mere hours of weightlessness so weakening that a human could not stand on earth upon landing?

Depends on stomach. They can kneel.

[Spacescifi]

13 minutes ago, kerbiloid said:

 

http://nathangeffen.webfactional.com/spacetravel/spacetravel.php

3.5 years at 9.81 acceleration.

 

Grass skirts. Bast sandals. Grow in the greenhouse, require nothing. Totally green. Absolutely recyclable. Don't wash, add to compost.

  Hide contents

 

Fruit flies. Grow in the greenhouse and trash can, require nothing. Pigeon-sized, next to the reactor.

Flour. Rusk. The living classics -  Rumford's soup

  Reveal hidden contents

 

A spacesheep in a spaceship is too smelly. Better grass.

Diapers spend material. Better a hose. And a rope on the neck, of course.

Depends on stomach. They can kneel.

 

This is somewhat comical but also true.

Some have even suggested just going naked in space, but that would be... icky.

In space sweat tends to adhere to the skin because of surface tension. With clothes on it pools up up under your clothes. Without clothes? You're going to be flinging sweat globules everytime you swing your arm, leg, or move fast.

Did I mention smelly?

Yet going green in space?  Going all low tech green in space is very ironic, which is what makes it hilarious. 

I once had a fictional alien race that bioengineered leaf form fitting suits, which evaporated sweat through the porous membranes so that it didn't pool up. Likewise the suits would be disposed of and also continually grown.

I like your solutions though because they are real and achievable.

Edited May 21, 2019 by Spacescifi

[mikegarrison]

Bottom line is that once you start inventing new physics it become your choice *which* new physics you invent. If you want to have FTL travel without artificial control of gravity, then that's your choice. For just a few hours of micro-gravity there is no need for clotheswashing or even toilets. Most people can "hold it" for that long, but you can also just have them wear diapers like real astronauts do.

Your major problem is likely to be space sickness. Four hours is not enough time to affect muscle conditioning or anything like that, but it's a long time to have the inner ear confused and thinking that it's been poisoned.

It's probably better to focus on your story and then retroactively invent the physics needed to make it happen. I think that's the way most good SF is written.

Edited May 21, 2019 by mikegarrison

[DDE]

4 hours ago, mikegarrison said:

Bottom line is that once you start inventing new physics it become your choice *which* new physics you invent. If you want to have FTL travel without artificial control of gravity, then that's your choice.

Judging by earlier threads, you shouldn't expect any consistent position on what rules aren't being broken. This is an attempt to bring minute elements of realism into a setting that's already gone extremely soft on the really big things.

Which is... pretty lopsided.

6 hours ago, Spacescifi said:

What is warp? Moving space without moving.

Not entirely.

6 hours ago, Spacescifi said:

It allows you to get close to planets without accelerating, although you still have to accelerate once you drop out of warp, whether through gravity or using your engine to match velocities and actually land safely.

Matching velocity in a reasonable timeframe brings us right back to the need for insane accelerations.

Especially when you go interstellar and slap anywhere between 10 and 100 km/s of velocity difference.

[Kerbart]

12 hours ago, Spacescifi said:

(...)

As for centrifuge washing machines? They have the possibility of slowly spinning your entire spaceship.

(...)

Centrifuges are actually finicky things in space because for every action there is a reaction.

Consider the mass of a drum full of clothes and water against the mass of the spaceship.

Consider the amount of time it takes to spin the centrifuge up to drying speed. 5s, 10s, maybe 30s?

How much angular velocity is that going to add to your ship? And remember, once the spin cycle ends it absorbs that angular velocity right back. As @5thHorseman mentions, have two spin cycles of equal length but opposite direction and the effect on the ship’s attitude might not be zero (the water is forced out unevenly between the two sessions) but it will be very, very little.

 

Centrifuges are far less finicky than people think because they’re inside a closed system. Making a ship rotate by continuously spinning a centrifuge is mechanically identical by carrying yourself up ten floors by pulling your bootstraps.

Speeding up and slowing down a centrifuge surely make the ship rotate in the opposite direction, but that’s the only time (which is also why gyro’s need to be reset every once in a while). Once your centrifuge is running at a constant rate, there’s no magic effect on the ship making it suddenly rotate more or less.

Edited May 21, 2019 by Kerbart

[mikegarrison]

24 minutes ago, DDE said:

Judging by earlier threads, you shouldn't expect any consistent position on what rules aren't being broken. This is an attempt to bring minute elements of realism into a setting that's already gone extremely soft on the really big things.

Which is... pretty lopsided.

We probably aren't the right forum to go into "how to write science fiction," but for the most part good science fiction is a) internally consistent with respect to science, and b) has a good story and characters. If the author wants to invent a way of moving between stars that involves about four hours of microgravity, then that's fine. I mean, think Babylon 5 where the Earth had jumpgates that moved them into hyperspace and between stars but didn't have any artificial gravity. In the same story, however, some of the older races *did* have artificial gravity.

I'll also point out that at no time in Babylon 5 did they ever talk about how to use the toilet or whether they were wearing diapers in their fighter ships. Basically, it wasn't important to the story so they ignored it.

[Spacescifi]

38 minutes ago, mikegarrison said:

We probably aren't the right forum to go into "how to write science fiction," but for the most part good science fiction is a) internally consistent with respect to science, and b) has a good story and characters. If the author wants to invent a way of moving between stars that involves about four hours of microgravity, then that's fine. I mean, think Babylon 5 where the Earth had jumpgates that moved them into hyperspace and between stars but didn't have any artificial gravity. In the same story, however, some of the older races *did* have artificial gravity.

I'll also point out that at no time in Babylon 5 did they ever talk about how to use the toilet or whether they were wearing diapers in their fighter ships. Basically, it wasn't important to the story so they ignored it.

Why I am doing it is because I can, and I find weightlness an immersive thing that most of us won't experience. So leaving it in will be an educational experience for anyone who wants to experience it without actually going.

I want to not only entertain, but educate about space travel realities with my scifi.

That is why fictional tech is not nearly as important to me as dealing with specific real life issues in space.

Really, that is the only way I can put my space knowledge to use, other than writing purely educational books, which I would find less entertaining.

Thanks for the answers all of you. Quite informative.

Edited May 21, 2019 by Spacescifi

[AngrybobH]

Micro gravity for hours would probably have no appreciable effect on humans. Days is space can a bit jarring to some but a week or two can start bone decalcification and other effects. I imagine that some people would experience an uneasy feeling after some hours in micro G when getting back to a gravity-all-the-time environment. Though, I do believe it would be quite short lived. NASA has done quite a bit of study on this and is currently running a study on the ISS. Valeri Polyakov spent the longest consecutive time in space (438 days) and probably poked and prodded for some time. Info on this is readily available.

As far as food goes, vegetarianism is a perfectly good solution. plants do grow in micro G. Clothing can be either synthetic or organic. Synthetic fibers can be made from plant material and most clothes could be recyclable. Also, why wash clothes with water? why not dry clean, no tumbling or spinning required.

[mikegarrison]

3 hours ago, AngrybobH said:

Also, why wash clothes with water? why not dry clean, no tumbling or spinning required.

You want to be really careful with what kind of volatile chemicals you introduce into a small, closed circuit environment. Water is completely non-toxic and doesn't give off sickening fumes.

Anyway, dry cleaning does involve tumbling and spinning. It just uses different liquids other than water. It's not actually "dry".

Edited May 22, 2019 by mikegarrison

[kerbiloid]

12 hours ago, mikegarrison said:

did they ever talk about how to use the toilet or whether they were wearing diapers

In Planetes did.

11 hours ago, AngrybobH said:

plants do grow in micro G.

Algae even have no idea what is G.

P.S.
If they produce enough organics to eat, they probably can produce enough cellulose for clothes and napkins.
Then no washing or cleaning, just kill it with fire, and reuse the water and the carbon dioxide.

Edited May 22, 2019 by kerbiloid

[DDE]

3 hours ago, kerbiloid said:

In Planetes did.

The “refresher” on the Millennium Falcon has a long history of disappearing and reappearing depending on who’s drawing the cross-section.

11 hours ago, mikegarrison said:

Anyway, dry cleaning does involve tumbling and spinning. It just uses different liquids other than water. It's not actually "dry".

I hear KhimMash have been working on CO2-based “dry” cleaning for space applications.

15 hours ago, Spacescifi said:

Why I am doing it is because I can

[kerbiloid]

Or just do not let your suit get dirty.

Spoiler

 

 

Edited May 22, 2019 by kerbiloid

[Spacescifi]

1 hour ago, DDE said:

The “refresher” on the Millennium Falcon has a long history of disappearing and reappearing depending on who’s drawing the cross-section.

I hear KhimMash have been working on CO2-based “dry” cleaning for space applications.

 

Hmm... being that I intend to do it for fiction and not for reals... I tend to also think I should by default.

The heart wants what it wants, and it wants weightlessness to be a factor in space travel. At least fictionally.