Around 1980 the L5 Society defeated the Moon Treaty. Personal experience, got to testify before Congress.

I can see it now, student with a ring of rubber fingers signing in a mess of students to a video lecture.

The model M I am typing on is a Unicomp built 3/31/99, got it direct from Unicomp less than a year ago after my former model M finally died. It's directly plugged in, but there are PS2 to USB adapters that work fine. My wife has one and she types 120 wpm.

On another list someone asked me to explain the press release. Here is my try.

Hypersonic engines are up against hard physics. The ram air heats so much in the inlet that it's hard for combustion to add much energy to make it go faster out the back.

The idea behind the SABRE engines is to cool the ram air before it is compressed. The heat exchanger to do this is what the press release is all about. With not much more than a ton of mass, it sucks 400 MW of heat out of the incoming air, dropping the temperature from 1500 C to -150 C in a few inches of heat exchanger that looks much like fabric because the tubes are so tiny.

The engine cycle also uses the temperature difference between the ram air and the LH2 to run the compressor. It takes close to 2/5th of the energy from burning hydrogen to liquefy it. The engines recover much of this by running a helium turbine on the temperature difference between the ram air and the liquid hydrogen flow to the engines. The turbine powers the compressor stage that raises the pressure of the -150 C air to rocket chamber pressure.

The design is extremely clever thermodynamics which also avoids most of the metallurgical problems of high temperature. Fabricating the air to helium heat exchanger was a very hard task. They have miles of tiny tubing, tens of thousands of brazed joints and they don't leak!

Using these engines and breathing air, the vehicle reaches 26 km and about a quarter of the velocity to orbit giving an equivalent exhaust velocity (back calculate from hydrogen consumption) of 9 km/s. That's twice as good as the space shuttle main engines. It is expected to go into orbit with 15 tons of payload out of 300 or 5% even though the rest of the acceleration is on internal oxygen that only gives 4.5 km/s exhaust velocity.

Leaving out the oxygen and using big propulsion lasers to heat hydrogen reaction mass, such a vehicle would get 25% of takeoff mass to LEO, reducing the already low cost by a factor of 5. That's enough to change the economics of power satellites from being too expensive to consider to a cost substantially less expensive than any fossil fuel.

But try explaining any of this in a press release.

There seems to be a way around the whole climate/energy problem.

Power satellites have long been dismissed because of the high cost of lifting parts to GEO.

But if you build just one with expensive conventional rockets and equip it with propulsion lasers, the cost to get the parts up for enough to end the use of fossil fuels goes to under $100/kg and the cost of power to under 2 cents per kWh.

At that price, the oil companies can make all the synthetic, carbon neutral gasoline they want for a dollar a gallon.

If you want to know more, ask, especially if you know someone who could lead a hundred billion dollar project. hkeithhenson@gmail.com

I have bisected bugs, horizontally.

When I was in college the place we lived in had an infestation of 2 inch cockroaches.

Used to kill them with wax bullets.

Shoot at the floor at a low angle a few inches in front of the bug and the spray of wax would cut them in half.

Often the bottom half would run off and leave the top half.

Gasoline has about 40 kWh/gal of energy in it. So if the process takes no more than 100 kWh to produce a gallon, then the energy cost is a dollar a gallon per cent of cost per kWh.

So penny a kWh power will provide dollar a gallon synthetic gasoline. (Plus capital cost for the plants of perhaps 10%).

http://www.htyp.org/dollar_a_gallon_gasoline

I think I know how to get the cost of power down into the 1-2 cents per kWh level. It involves power satellites and laser propulsion to get the cost of lifting parts to GEO down. If you want to know more ask. hkeithhenson@gmail.com The previous iteration is here. http://www.theoildrum.com/node/7898

It is worth considering why riots are so easy to set off in that part of the world.

I expect that the poor economic conditions are more of a factor than the particular flavor of religion.

I tied wars into evolutionary psychology in "Evolutionary Psychology, Memes and the Origin of War." It is certainly predictable from the economic prospects of a population.

I think we already know how to solve the energy problem. Power satellites are the obvious answer except the cost of lifting parts to GEO is too high.

Beamed power propulsion will get the cost down to under $100/kg, a point at which power is under two cents per kWh and synthetic fuels on off peak power cost around a dollar a gallon.

The trick is to build one power sat with conventional rockets and use it to power GW class propulsion lasers to bring up parts for thousands of power sats. The growth potential is high enough that a real effort could end the use of fossil fuels in a decade. And not by reducing energy use or shivering in the dark, but by undercutting the cost of fossil fuels with carbon neutral synthetics. http://www.htyp.org/dollar_a_gallon_gasoline

Since WW II the west has lived in a remarkable era.

The history of humans, most of it in the stone age, has been one of nearly continuous war. What shut it off for us?

I have run a rough model of how the psychological mechanisms that turn bad economic prospects into wars. It turns out that the advantage for genes is around 37% for attempting to kill neighboring tribes compared to starving as the result of population growth followed by a weather glitch. (For the genes, the downside of going to war is limited because the young women--who also carried the genes--were normally considered booty and incorporated as wives into the winning tribe.)

It also turned out that there was an even larger disadvantage for the genes if the prospects were for good times. So genes built highly sensitive "behavior switches" in the stone age.

I.e., bad economic prospects switch on the mechanisms that eventually lead to wars.

As long as the economic growth is higher than the population growth, the psychological mechanisms for wars stay off.

More if you Google for "Evolutionary psychology, memes, and the origin of war."

The basic physics says beamed energy is a good idea.

Beamed energy lets you get about twice the exhaust velocity you can get with the best chemical fuels.

That changes the mass ratio from 7.4 (to LEO with best chemical) to 3.

That's the difference between 13.5% structure, engines and payload to 33% The minimum for reusable is thought to be around 15%, so the payload fraction goes from -1.5% to perhaps 18% of take off mass.

Keith Henson

Does anyone know if Steve has considered cryonic suspension?

Does he even know about it?

Everyone is either in the experimental group (those who are suspended) or the control group (everyone else).

I would sure like Steve to be in the experimental group. http://www.merkle.com/cryo/

Besides, I think he would rather interested in how Apple does over the next 50-100 years (maybe even less depending on how fast things develop).

"Investing in nuclear power plants and research is not now and will never be cost effective."

Suppose (It's possible) that biological research made humans completely immune to the effects of radiation.

Would that make nuclear power plants cost effective?

There are two ways I know of to collect dilute solar energy that might be economic, i.e., lower than the price of coal.

First is over 40 years old, go into space and beam energy down as microwaves. .

Zero gravity and no wind means the collecting structures can be far lighter than anything on earth. They are still way too expensive to haul up by current or projected developments in chemical rockets. The cost must come down by a factor of 200 for current rockets and a factor of 40 for the projected cost of the Falcon Heavy. $100 per kg is what's needed..

That looks possible (at 500,000 tons per year) by using partly air breathing vehicles for the first stage and beamed energy (lasers) for the second. Details here: http://www.theoildrum.com/node/7898.

The second way is to float the collectors at 20 km where you can avoid clouds and the cosine effect by pointing a 2 km parabolic reflector at the sun. This works as far north as Stockholm. You bring the energy down in a 50 meter diameter light pipe, convert to heat which can be efficiently stored at high temperature.

Based on materials cost, the investment looks to be around $1.2 B/GW and the power cost between one and two cents per kWh. The storage system (35,000 cubic meters of firebrick) costs a tenth of a cent per kWh. I worked on this for a year and a half. We found no showstoppers, but the engineering detail got beyond what could be done with a small unpaid team. More here www.stratosolar.com