IntenseDebate - hkeithhenson

4 years ago @ The Space Review: essa... - The Space Review: Refl... · 0 replies · +4 points

I know this is only a review, but even for a review, it is short on specifics. I would love to know what markets people are now considering.

4 years ago @ The Space Review: essa... - The Space Review: What... · 0 replies · +11 points

Ion engines or related high exhaust engines could use the same fuel mass to raise the orbit high enough that it would take several centuries to decay back to the atmosphere.

It is, after all, a historical object by this time. Hmm. I would if the ISS could be designated a National Historic Landmark? That would make it legally hard to destroy.

4 years ago @ The Space Review: essa... - The Space Review: Clos... · 9 replies · +1 points

Excellent article. I would go a little further than Robert though. I don't think there is a commercial case for humans on the moon at all I spent ten years working on the economics of power satellites. You can't build power satellites in low radiation LEO because they get hit by space junk on the way out to GEO. Going above the junk does not work with humans because of radiation. So if we are going to build power satellites at all, it will take robots and/or teleoperation. For those who want to go into soon, this is a bitter pill. (it was for me.)

The same is true for the lunar surface. Can anyone think of a task on the moon that a robot can't do?

Now, eventually, the robots will build us O'Neill cylinders and shielded space vehicles to get there. But not soon.

4 years ago @ The Space Review: essa... - The Space Review: If w... · 0 replies · +3 points

My problem with any human presence on the moon is that none of the schemes I have seen are about primary production. (Primary is like mining or farming, it's not service like moving satellites around.) O'Neill proposed using the moon for materials. He had the minimum number of people on the moon to service the mass driver.

For a small fraction of what landing people would cost, we could put robots on the moon and prospect for water.

5 years ago @ The Space Review: essa... - The Space Review: Why ... · 1 reply · +2 points

To mousethatroared and Steve Graber.

I have thought about this for many years and do not have a workable solution to the space junk problem (other than going above it). There are obvious ways such as GW scale lasers to evaporate the junk. The problem is that such devices are unavoidably ways to destroy space assets. That is prohibited by treaty.. Cost is another consideration, the cleanup cost I expect would run a large multiple of the cost of a power satellite. This probably makes the entire power satellite project too expensive.

If you have ideas on cleaning up the space junk, please share them.

5 years ago @ The Space Review: essa... - The Space Review: Why ... · 1 reply · +4 points

Power satellites are harder than you might expect.

The space junk makes it very difficult to build power satellites in LEO and move them under their own power to GEO. If we put the construction site above the junk, then the radiation (bottom of the lower Van Allen belt) is too high for humans to be outside more than minutes.

On top of this, there is radio interference to consider. There has been discussion of these problems on the Google group Power satellite economics.

5 years ago @ The Space Review: essa... - The Space Review: Revi... · 0 replies · +3 points

"China has many smart scientists and engineers"

With 3 times the US population, they will eventually have 3 times (or more) the number of engineers and scientists. Further, the population average IQ is about 7 or 8 points higher than the US/EU average. How this came about is fairly well understood, though it is not politically correct. See the last two pages here: http://faculty.econ.ucdavis.edu/faculty/gclark/pa...

5 years ago @ The Space Review: essa... - The Space Review: Wher... · 1 reply · +3 points

Mars doesn't have much of an atmosphere, but what it does have has carbon. On the moon, where are you going to get carbon?

5 years ago @ The Space Review: essa... - The Space Review: The ... · 2 replies · +5 points

Giulio, I am sympathetic but the examples you gave do not seem to make sense.

"Despite their name, rare-earth elements are – with the exception of the radioactive promethium – relatively plentiful in Earth's crust, with cerium being the 25th most abundant element at 68 parts per million, more abundant than copper." https://en.wikipedia.org/wiki/Rare-earth_element

"Much speculation has been made over the possibility of helium-3 as a future energy source. Unlike most other nuclear fusion reactions, the fusion of helium-3 atoms releases large amounts of energy without causing the surrounding material to become radioactive. However, the temperatures required to achieve helium-3 fusion reactions are much higher than in traditional fusion reactions," https://en.wikipedia.org/wiki/Helium-3

I have looked for something from space to sell since 1975. The only near term thing that looks possible is energy, SBSP. Thermal power satellites can use water from the moon (if it makes sense.) If you take a somewhat longer view, it might be possible to extract gold and platinum group metals from solid chunks of metal such as 1982 DA. https://htyp.org/Mining_Asteroids

5 years ago @ The Space Review: essa... - The Space Review: Not ... · 1 reply · +8 points

I mostly agree with Al, though writers on this subject don't understand what drives human populations into wars or inhibits them from going to war. (Stone age evolution shaped human genetics to go to war when the future looked bleak. We still have this trait, but it can be kept in the "off-state" by steady or improving income per capita, though being attacked is an alternate means of a population going into "war-mode."

The only person I know about who examined the vulnerability of a space colony to nuclear weapons is Alexis Gilliland. In _Long Shot for Rosinante_, a space colony out in the asteroids is attacked by a one-megaton semi-sentient missile. Dated, but the trilogy is still well worth reading.

it's hard to say if humans will *ever* do space colonies. The time frame for them overlaps with the estimates for the singularity. If that happens, and it is hard to see how it might be avoided, human nature could change in fundamenal ways including a population collapse as people upload into simulations. I wrote about this in The Clinic Seed and here: https://web.archive.org/web/20121130232045/http:/...

Trying to anticipate the future is a bitch.

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