US: Moonstruck

[Mr Awe]

There are, however, larger problems where the solution is just unknown. Boneloss. Huge problem with no known solution. An astronaut one month in zero G looses about as much bone as an elderly lady with osteporosis in a year. With an extended mission the boneloss becomes unaccaptle and the risk. The treadmills and exercise help with retaining muscle but, unfortunately not bone mass, which was hoped.

I don't think they've tried the centrifuge design, have they? Practically, I mean. I know it's common in fiction. I'm sure there are problems with that, but if it's effective at stopping bone loss then it puts the issue back into the realm of engineering.

There's radiation too.

That's just a matter of developing shielding which is light enough to lift. Engineering again.

You're right, there are engineering solutions. Both of those would add enormous cost. The radiation shielding might be unavoidable, especially a safe room for solar flares. Adding a centrifuge would be hugely impractical. The costs of doing both would make a mission impractical.

And, they are experimenting with medicine for boneloss but we're not really close to a solution. I used to work in a lab that researched muscle and bone retention in space. One of our zero G treadmills has flown on the shuttle. A medicine would be a great answer but we're not close to one.

Mr Awe

 

[Lindley]

Adding a centrifuge would be hugely impractical.

Any particular reason why? I mean, gyroscopes are pretty common flight instruments---I'm sure they've taken more than a few of those into space. Just make a big one.

 

[Docbrown777]

Why can't they just build a cylinder ship and then spin it to create artificial gravity so everyone can walk on the walls?

Seriously, overcoming the gravity and bone/muscle loss issue seems rather simple from my view.

 

[Maestro]

One of the things that we're not fully understanding as a thread is the market. We need to create a situation where the tech development is driven by the market. Otherwise, there isn't going to be much of a drive to develop things.

Putting a colony of humans, that includes private sector folks, is going to create a market to drive the technology we need to go to Mars, and then Io, and beyond. Right now, the only market force is "we should do that," and much like the "green" movement, "we should do that" just isn't enough.

 

[Mr Awe]

Adding a centrifuge would be hugely impractical.

Any particular reason why? I mean, gyroscopes are pretty common flight instruments---I'm sure they've taken more than a few of those into space. Just make a big one.

They need to add alot to handle it. They'd probably just spin the entire ship rather than adding a centrifuge. But, you've got to add a lot to make it work. It's just a cost thing relating to the added structure and weight. In addition to the added strains, generally the ship has to be larger so you have enough living space far enough away from the center of gravity to make it all work. The closer you get to the COG the less force you feel. So, you have to spread things out from a central point. Bigger equals more expensive.

It can be done and I suppose if the medicine doesn't pan out they may have to do it that way.

Mr Awe

 

[Mr Awe]

Why can't they just build a cylinder ship and then spin it to create artificial gravity so everyone can walk on the walls?

Seriously, overcoming the gravity and bone/muscle loss issue seems rather simple from my view.

It seems simple because you don't know what's involved. A cylinder would have to be large to work properly. Any ship using this design would be very noticeably larger and more complex than anything we've done so far.

It would probably be cheaper to solve the problem by reducing the exposure to the harmful conditions, zero G and radiation. That means faster rocket engines to produce a shorter flight duration. That's guess but I'd imagine that's true. They're working on new space drives but need time to perfect them.

Mr Awe

 

[Lindley]

Ah yes, size would be a limitation....

Well, I guess then the question becomes----do you have to build it in space to make it big enough? Or could you develop some kind of malleable yet super-strong material for the hull, such that it would simply "inflate" once it gets up there?

Frankly, more space on such a long trip seems like a good idea in general.....

 

[Mr Awe]

Well, I'm sure the astronauts wouldn't mind the extra space but the taxpayers may not be so happy picking up the tab for it! Inflateable spacecraft have been experimented with (on the ground). Who knows. Not sure how they'd deal with radiation in that scenario. But, again, it needs much, much more development.

 

[Meredith]

We need to send construction and mining robots along with ore processing and material construction equipment, all automated to the moon first.

Then send people back there and move them into already constructed huge safe lunar habitats.

 

[SeerSGB]

We need to send construction and mining robots along with ore processing and material construction equipment, all automated to the moon first.

Then send people back there and move them into already constructed huge safe lunar habitats.

Isn't that the plot to a bad sci-fi horror movie? Not saying it ins't a bad idea though, but first little accident and some poor 'bot will take the blame.

 

[RJDiogenes]

Yes, the experience is important but even before that, having the tested technology in hand is a prerequisite for gaining the experience. You've got the right idea but the wrong order of doing things. Tech first, then use it.

It's neither, actually. Obviously you need some tech first, but what really will drive development is practical usage and infrastructure. The first PCs came with some software, but it was increasingly common usage that spurred both technological and software development. We have the tech right now to get that process started with space travel and settlement.

Well, I guess then the question becomes----do you have to build it in space to make it big enough? Or could you develop some kind of malleable yet super-strong material for the hull, such that it would simply "inflate" once it gets up there?

This is the point of the tether experiments. Instead of a troublesome centrifuge or spinning the ship, you attach two separate modules to a tether and spin it around the common center of gravity.

We need to send construction and mining robots along with ore processing and material construction equipment, all automated to the moon first.

Then send people back there and move them into already constructed huge safe lunar habitats.

That would be great, but I think it would require a level of AI that we're not close to yet.

 

[SeerSGB]

Can't recall immeaditely, what's the comm time-lag from Earth to Moon? Cause I'm thinking remote control, or limited AI similar to what we use in Mars probe with a fail safe: encounter something not in the specs, stop, radio home and get the go no go.

 

[RJDiogenes]

That could work. I think the lag is 2 or 3 seconds.

 

[SeerSGB]

If most of the modules are prefab or "lego style", it'd make things more plug and play for the bots.

 

[RJDiogenes]

Yes, it's definitely the ore processing and material construction that's way beyond what we can currently manage.

 

[SeerSGB]

I thinking using something similar to the ISS modules to start, in landing capsule that cushions the landings-- again, taking a cue from the Mars probe program. We launch the sections up into a predetermined landing zone, they drop and the airbags deflate, tractor-bots move in or are packed with each section and drag it into place and mate it with the other segment.

It might work on a small, three or four segments, scale, just enough to test and prove the concept of long term habitation on the moon.

 

[Lindley]

Nuclear reactors on Earth use water for shielding. Any chance that could be used here too? Have two hulls, inner and outer, and fill the intermediate space with water?

I mean, you have to take lots of water along *anyway*, and it's easy to lift it to orbit in multiple trips if the amount is too heavy for one.....

Does Mars have a weak enough magnetic field for the radiation problem to be an issue on the surface there as well?

 

[SeerSGB]

Nuclear reactors on Earth use water for shielding. Any chance that could be used here too? Have two hulls, inner and outer, and fill the intermediate space with water?

I mean, you have to take lots of water along *anyway*, and it's easy to lift it to orbit in multiple trips if the amount is too heavy for one.....

Does Mars have a weak enough magnetic field for the radiation problem to be an issue on the surface there as well?

Well the question would be would the water be usable if it was used as a radiation barrier? I'm thinking probably not.

 

[Lindley]

One assumes with enough processing it could be. That is a good question though.

 

[SeerSGB]

I'm thinking if water was going to be the insulator of choice, a better way would be have as a layer of ice along the outer hull, that ways it shields both radiation and various smaller bits of debris. Water production could probably handled via fuel cells (think next gen to what we use in space now) and strict water reclamation procedures.