That fallacy you point out in the first paragraph is sadly found in way too many papers related to clean energy and space exploration. Oh cool, look at all the atoms laying around! Let's ignore their energy levels and cook up some usecases....

In part I think it comes from the constant source of heat energy we're surrounded with on Earth. We're used to the idea of taking -300F materials and just allowing them to warm up. On Titan, that procedure subtracts from your minimal energy budget.

I don't disagree with your red flag, I do however note that there are other ways of getting electricity out of hydrocarbons without cracking water. Specifically a the use of fuel cells. If you feed methane to a Bloom Energy fuel cell after initially filling it with some liquid water, it will generate 250kW of power as long as you feed in methane.

That would be awesome for colonizing Titan!

http://www.bloomenergy.com/clean-energy/

But... where does it get the oxygen?

From the water using steam reforming as I understand it, which is recovered 100% when the cell is generating power. The only consumable ends up being the methane.

Looks like a standard solid oxide cell, going by their glitzy info page [1]. The water is used in reforming the methane but it's not a source of oxygen; that comes from the air.

[1] http://www.bloomenergy.com/fuel-cell/solid-oxide-fuel-cell-a...

You are correct sir. That kind of sucks then.

That first one is pretty funny, but perhaps we can assume the writers have enough science to realise the energy levels issue.

They may have omitted to say it, but I can imagine a fission power plant splitting water into H and O, which would be useful for a portable fuel source for flights, orbital launches, heating of suits and batteries, jetpacks, etc.

Yeah, they don't need hydrocarbon fuel, they're starting with energy from somewhere else anyway to initially make the oxygen. Just continue to use that energy source(possibly storing energy with hydrocarbons).

The 12mph collision would still be done in a space suit. Hopefully the space suit has a solid combination of rigidity and cushioning to protect against that level of fall. Sinking in to a memory foam and not being able to twist limbs or necks in to bad positions sounds good.

Also I always wonder why these articles gloss over the health issues related to low gravity. Thats not something we've figured out either. Astronauts lose a lot of bone density in space.

That is actually more solved than you think. [1]ARED is basically equivalent to free-weight training under Earth gravity. Many problems with exercise in space is that elastic materials provide different resistance depending on how far they are deformed, meaning muscles that are used more at the beginning of your rep are worked less than those you use near the end. ARED uses a piston under vacuum to provide constant resistance through the entire stroke. There was a video of it in action on the SmarterEveryDay youtube channel but I can't seem to find it, I'm not sure if one has actually made it up to the space station yet either.

[1]https://www.nasa.gov/mission_pages/station/research/experime...

Yeah I've seen videos about that, its useful to keep the decay at bay but its still in issue.

Also there is blindness, cardiovascular issues, and more. I hope they can figure out how to mitigate or remove these issues.

Colonising is different to visiting.

When visiting, changes (like in bone density) are bad, but can be monitored and taken into account when planning the mission duration.

When colonising, some permanent changes may be fine, since the change in environment is also permanent. If a colonist visited Earth, they would have to take into account the health issues caused by high gravity.

I agree that much more research is needed though; even if some physiological changes are acceptable for colonising, we should make damned sure we know what they are, and what the unacceptable changes are.

True but the brittleness still remains, smash too hard into something and your bone will crack.

Also theres blindness, cardiovascular, and other issues as well.

Definitely needs more research. Also makes me wonder about Elon's plans to bring people back, might not be possible after a certain length of stay on Mars.

And would it really be ok to walk around in methane in just a coat? Wouldn't your skin react?

The temperature is so cold that it would freeze your body if you were exposed, so you would still need an airtight seal. But the atmospheric pressure is high enough that you wouldn't need a bulky vacuum-proof pressurized spacesuit.

I'm thinking if the surface temperature were hundreds of degrees below, and the air were thick enough for conduction, that the suit would have to be a vacuum-insulation type of thing anyway?

No. Ambient-pressure-airtight is much easier than vacuum-airtight.

A drysuit for scuba diving is ambient-pressure airtight, basically just a neoprene coverall with sealed seams. It's easy to move around in.

But take away the external pressure, and you're in the middle of a 15 psi balloon,w which wants to be a sphere, not human-shaped. It becomes difficult to bend your limbs and fingers. Rotating a shoulder, neck, or wrist causes the suit to twist in like a party balloon. Anywhere the cross-section is not circular, it wants to be more circular.

You either need a hard shell suit, a tolerance for this difficulty, or a lot of engineering.

Come on. Ambient-pressure-200K-differential-airtight is nothing like a scuba suit.

wouldn't the same weak gravity imply less dense atmosphere to support wings, evening out?

Quantity reigns in this sense. E.g. Venus has a similar gravity as Earth (though a bit less), but the atmosphere is 93 times more dense at "sea level".

One of the theories for why Earth doesn't have a similarly dense atmosphere is because we have the Moon - a large gravitational body nearby strips away the atmosphere enough to prevent the endless buildup like Venus has.

Not necessarily. Titan's atmosphere is actually denser than Earth's. https://en.wikipedia.org/wiki/Atmosphere_of_Titan

Dense atmospheres also make it much easier to enter, descend, and land (EDL), since they can be used for drag parachutes and atmospheric braking.

The atmosphere on Mars by comparison is awful for landing spacecraft. It has just enough density to jumble the craft's trajectory, so vacuum-based EDL techniques similar to the moon landing are impossible, but it's too thin for atmospheric EDL systems similar to those used on Earth.

I wonder if it would also make it easier to exit--having dense atmosphere and low gravity. It might be possible to easily fly a rocket on the underbelly of a low-powered aircraft and launch it from the upper atmosphere.

Leaving the gravity well of a planet depends on delta-v needed to leave that gravity well, not just on getting high enough in the atmosphere. We can easily send balloons to 'space' on earth, but they don't have the speed to achieve escape velocity. Delta-v for Titan is around 2.6km/s (compared to 11.2 on Earth, and 5.0 on Mars).

Atmosphere (especially a dense one that causes drag and heating) makes achieving escape velocity harder, as you need to actually do it 'high up' where the atmosphere is not as dense, say from something similar to Low-Earth Orbit.

>Leaving the gravity well of a planet depends on delta-v needed to leave that gravity well, not just on getting high enough in the atmosphere.

I'm well aware of that, I think you didn't see what I was trying to say.

> as you need to actually do it 'high up' where the atmosphere is not as dense, say from something similar to Low-Earth Orbit.

That was actually the thought process behind it, not the problem with it. I will rephrase it:

On earth piggy-backing or ballooning a rocket to the upper atmosphere is not usually practical due to the ability to produce lift in the atmosphere relative to the size and weight of the rocket.

However, on Titan with a thick atmosphere, imagine flying one to the upper atmosphere which would take relatively little energy in a thick atmosphere with low gravity, thereby escaping much of the problem of atmospheric drag and using it to your benefit instead.

That's just the thought process, of course I don't of anyone that has done the math on the most efficient way to launch from Titan, yet.

That's an interesting thought, but I doubt it works. Density should go roughly like

    exp(-gravity * height)

Lesser gravity implies slower decrease of density with height. "Titan's lower gravity means that its atmosphere is far more extended than Earth's; even at a distance of 975 km, the Cassini spacecraft had to make adjustments to maintain a stable orbit against atmospheric drag." https://en.wikipedia.org/wiki/Atmosphere_of_Titan