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February 28, 2009

The Nuclear Orion Home Run Shot, All Fallout Contained


The typical analysis of the nuclear Orion external pulse propulsion rocket is to use constant charges (bombs) every 1.1 seconds to launch with people inside who experience 4Gs or less.

Nuclear Orion can achieve launch costs of less than $1/kg and perhaps a tiny fraction of that. This is 1000 to 20,000 times cheaper than current costs.

UPDATE:
Rand Simberg at Transterrestrial has written up a response to the series of articles that have been written here in regards to nuclear Project Orion and the one shot contained fallout variant that has been presented here.

Rand points out his excellent article about how small space payloads can be made cheap if they are sent up frequently.

The 1,000 times cheaper number that I have quoted is cheaper than the Russian Dnepr converted ICBM cost of launch to Low Earth Orbit. I know of no space launch system that is launching more than 6 times per year now and I believe the peak might have been about 20 times in one year ever for one kind of rocket that was getting some economies of scale.

At the end of this article I noted that "Idealized chemical rockets with total economies of scale could achieve $50/kg." However, no one is doing this and Rand is hoping that Virgin Galactic or other new space launchers can build up to that level by doing thousands of sub-orbital flights and building up with technology and business to thousands of orbital flights.

This site analyzes past underground nuclear tests and geology and nuclear energy to kinetic energy to show how the one shot launch will work while containing fallout and not creating an EMP.
END UPDATE

How much would the pulse units cost? Pedersen gives the amazingly low figure of $10,000 to $40,000 per unit for the early Martin design; there is reason to think that $1 million is an upper limit [for the smaller charges]. Primarily from strength of materials considerations. Whereas the Shuttle might carry thirty tons of payload, the pulse vehicle would carry thousands. If one uses the extreme example of spending $5 billion to build a vehicle to lift 10,000 tons (or 20 million pounds) to orbit, the cost if spread over a single flight is $250 per pound, far cheaper than the accepted figure of $5,000 to $6,000 per pound for a Shuttle flight


Also, the system proposed here can just be a true nuclear bomb powered cannon. Not a chemical cannon launching nuclear bomb projectiles but a nuclear bomb powered cannon. So the projectiles and the launches do not have wait until we have working Orion ships to fire. We can just fire Orion like shells with cargo. We can use existing nuclear bombs from the existing arsenals. Ideally you would want to optimize with the more directional nuclear blasts (Casaba-Howitzer still mostly classified) Therefore initial costs and development would just be the containment launch facilty and adding the cheap filler part of the pulse charge that will be directed by the explosion. The nuclear bomb powered cannon is the simplest launch system. It has no development risk that can achieve $1/kg launch cost or less. The only new things being built are the fallout containment (which is a simple dome with a hole in the center and some kind of sliding door) and the shell which is a big simple metal shell.

Here we will look at containing the effects of handful or even one charge where all of the fallout can be contained.

Fallout and Typical Orion
The explosions for Orion that occur in the magnetosphere where the magnetic field lines lead back to earth is where fallout will come back down and be a problem.

We have already studied that reducing the fission component of any bomb and getting to higher fusion purity greatly reduces fallout and also a north pole launch reduces the fallout that returns to earth. Having a pile of conventional explosives for the first pulse also helps since the ground contact explosion is messier than the air bursts.


It would also seem best to send it up during a snow storm which would contain the fallout that coincides with a solar storm that flattens out the magnetosphere.

If you could not make the pure fusion bombs, which has not been done yet then another way to further reduce the radiation is for an unmanned high-G sprint start to a point outside the magnetosphere zone.

Another method is to use a large all chemical rocket that is able carry a smaller Orion into space where it is safe to light up the Orion.

The Toss and the Home Run shot
An unmanned Orion asteroid interceptor was designed. It would not need shock absorbers. Artillery arming, fusing, firing system for shells are regularly built to take 1000 Gs.

There was a three page paper: Nuclear explosive propelled Interceptor for deflecting objects on collision course with Earth. Johndale Solem, Los Alamos, proposed unmanned vehicle. No shock absorber or shielding. The pulse units were 25kg bombs of 2.5 kiloton yield for 100G acceleration of a 3.3 ton Orion. So an unmanned nuclear Orion can survive very high G forces. A single 25 kiloton yield would accelerate 3.3 tons to 1000Gs. A 2.5 megaton yield would accelerate 330 tons by 1000Gs. 25 megaton yield would accelerate 3,300 tons by 1000Gs. The highest acceleration had 0.4 seconds between charges so to get up to speed two or three charges might be needed to get 1.2 seconds of acceleration. Earth escape velocity is 11.2 km/s. 1000Gs is 9.8km/s**2. A structure can be built that can contain the fallout from one or a few bombs.

The tee up or toss. A toss would be to use a stack of chemical explosives to get the projectile moving a bit and clear of the ground when the nuclear charge goes off. A nuclear airburst has less fallout than a ground detonation. A tee-up would be to build a tower and have the projectile at the top and the nuclear charge at the proper distance below. Obviously the tower is utterly destroyed. Also, note that the initial charge or two would not count against any projectile or rocket cargo. It would always be outside.

We could also size the projectile so that we go at about 1.5 times the earth escape velocity so that it is a straight shot into the moon. The metal projectile designed to also survive the lunar impact. Ta da cheap cargo delivery to the moon.



Containing the Fallout


Please review the chart (click on pictures for a larger image) with the effects of different size nuclear explosions. Notice that the air eventually stops the nuclear explosion. The fireball stops after 1.1 kilometers because of air. The Orion tests showed that metal with ablative oil can be a few hundred feet away and not be damaged. The ablative oil vaporizes and takes care of the ultraviolet and soft x-rays. The metal has to be big enough to absorb the heat and not get to its melting temperature.

UPDATE:
The later articles that I have written indicate that an underground launch would contain most of the fallout and all of the blast. Any optional dome would be to capture any fallout that leaks from underground.
END UPDATE

You can build something bigger and relatively more flimsy or something smaller and tougher. The deciding factors are cost and cleanup and possibly maintenance.

Looking at the 10 megaton explosive the fireball radius is 1.1 kilometers. So something that is closer than that has to be able to withstand the fireball. We are talking about building Orion so we can make elongated Dome out of pusher plate material with a slathering of ablative coating on the inside. So contain it just like the pusher plate. It would need to be a few hundred meters wide. You would have a hole at the top for the Orion to pass through and doors that would slide into place to contain the fallout. Afterwards you clean up inside after things have settled and cooled.


Buckminster Fuller had designed geodesic domes that were 2 miles wide and 1 mile high. These would need to be able to withstand about 20-40 PSI. The materials exist to make such a structure.


A thin polymer film with thickness of 0.05 – 0.3 mm. The film is supported at this altitude by a small additional air pressure produced by ground ventilators. The film mass covered of 1 km**2 of ground area is M1 = 2×10**6 m**2 = 600 tons/km**2 and film cost is $60,000/km**2. Covering a diameter 20 km is 314 km**2. Area of semi-spherical dome is 628 km**2. The cost of Dome cover is 62.8 millions $US. The total cost of installation is about 30-90 million $US. There are large air supported strucures now of about 215 meters in diameter.


Scaling up would not be that difficult. More material and larger ventilators. Plus before the Orion went up and set off charges you would under-inflate so when the extra-pressure came it would use up some of the force inflating the thin film cover. There would need to be some flap or cover to go over the exit. If it was cheaper one could pack up the big bag afterwards for processing as opposed to cleaning up on site.

With the fallout contained then it is possible to re-use the facility or the method for multiple clean launches.

The Explosion that Goes to Pusher Plate or Metal Containment
The Orion explosive charge has a nuclear bomb and propellant filler. The explosion is configured to send 85% of the force towards the pusher plate (or the projectile). The explosion compresses the propellant slab to 1/4 of its thickness. This expands as a jet of plasma at 150 km/sec (300,000 mph). 300 microseconds later the expanding propellant cools to 10,000 degrees (one electron volt). In another few hundred microseconds the cloud hits the pusher. For less than a millisecond the stagnating propellant reaches 100,000-120,000 degrees. In space the cloud would be invisible until it hits the plate and there is an intense white flash. The 15% of the force that is going to the walls of the containment will be going a bit further in the case where we have thick metal walls containing the remainder and the fallout.

The key was how opaque the ablative oil is. The more opaque the better it protects the plate (and the walls) 100,000 degrees is a good range for opacity. It is ultraviolet and soft x-ray. The more opaque the less the radiation eats into the surface. Then the pusher and the containment have to be large enough so that the heat can be absorbed without melting the whole mass of metal.

In the case of the home run shot. Even if some of the plate is eroded it does not matter because we only need to protect the cargo for the one hit and transport into space. After which we just need enough left so that cargo does not leak out.

Nuclear Bomb Powered Cannon
This mode of operation could start within 2-3 years. Just build the simple facility Dig a hole to blow up the bomb underground to contain the fallout. Requisition a nuclear bomb from one of the arsenals. Up to 150 kilotons for the first test, so that international discussions are optional [Threshold test ban that limits underground tests to 150 kilotons or less is the only ratified agreement in force]. Make a big metal projectile with ablative oil slathered on the bottom and tee it up. Talk a bit to the other nuclear nations, get some signoffs and light them up and start the space age. Get water, fuel, food, any hardened electronics and any other tough supplies up and available for the crews in chemical rockets to get.

Chemical fuel depots would be setup at the low cost of less than $1/kg. Supply depots as well. No chemical rocket would need to take any supplies that can take more than 1000Gs. Chemical rockets can take a lot more material about ten times more cheaply to low earth orbit than to geosynch. So the nuclear supply cannon would lower the cost of chemical rockets by over ten times by supplying fuel depots. You can also launch carbon nanotube tethers or other polymer tethers for space elevators. You can launch Uranium and metal and other materials to build Orion rockets in orbit or on the moon. You can launch certain thin film or polymer solar cell material (just have to make sure it is the kind of material that can take the strain and leave out the components and structure that cannot take the stress)

Also, the nuclear bomb powered cannon of simple projectiles can be located anywhere since there is no constraint to get the projectile out of the magnetosphere. You would never have a nuclear light up of the projectile.

You would need to size the projectile to reach orbital velocity with an extra margin for air resistance. Plus you would need some small propulsion at the top to circularize the orbit so that it did not still fall back down.

The Nuclear bomb cannon is so simple that it has almost no problematic failure modes. The initial shot - you know you are lighting up a nuclear bomb. If the bomb is a dud then the shot goes almost nowhere or falls short. You launch with a flight path over the ocean. You are slathering on the ablative oil before you light up. There is no pump issue for repeated shots. If the pusher plate has a problem, well you are launching supplies or hardened equipment so you may lose the payload. There would be no people lost as it is unmanned.

You have the benefit of taking one stockpiled nuclear bomb out of the stockpile for peaceful purposes. Plus there is benefit of starting a real space age.

FURTHER READING
Fallout and EMP analysis and pictures of Project Orion

Photos and video of project Orion and super-orion.

The history of above ground nuclear tests

United States 216 tests from 1945-1962 for a total of 153.8 megatons
U.S.S.R. 214 tests from 1949-1962 for a total of 281.6 megatons
United Kingdom 21 tests from 1952-1958 for a total of 10.8 megatons
France 46 tests from 1960-1974 for a total of 11.4 megatons
P.R.C. 23 tests from 1964-1980 for a total of 21.5 megatons
South Africa 1 test 1979 for 0.003 megatons

So would it be "crazy" to set off nuclear bombs even if ALL of the fallout was contained for purposes of starting a true space age. As opposed to the 500 bomb explosions that were done in the atmosphere before for geopolitical and military posturing.

Chemical space program deaths about 300 (astronauts and civilian

Deaths from nuclear weapon tests. No direct deaths. If that is what you are planning for then you are careful and make sure everyones stays out of harms way and you can for months and years in advance to contain the effects.

Laser array launch details. $2 Billion and five your program to get to 100MW sounding rocket.

Previous list of favorite space launch systems, with many not yet feasible. Even an Inertial Electostatic fusion [which does not work yet] single stage to orbit would have projected costs of $27/kg.

Space elevators which do not exist and might not work and are unlikely to be developed before 2030 have initial projected costs of $220/kg which would then fall possibly to $10/kg. Idealized chemical rockets with total economies of scale could achieve $50/kg.

This system is 10-50 times cheaper than idealized systems that might not work and would likely take decades to develop.

February 27, 2009

Charlie Stross Wrong About Space Colonization and Singularity

Charlie Stross has a 21st Century FAQ which tells people to forget about space colonization and the Singularity.

99.999% of the human species who will never get off the planet are concerned. There'll probably be a Mars expedition too. But barring fundamental biomedical breakthroughs, or physics/engineering breakthroughs that play hell with the laws of physics as currently understood, canned monkeys aren't going to Jupiter any time soon, never mind colonizing the universe.


He talks about taking 2.5 years to get out to Jupiter. He talks about concerns about radiation exposure and other medical issues for long flights at near zero gravity. He talks about the difficulty in protecting people in space in small space craft

Orion Lets You Go Fast and Big
The abandoned technology that can be used is nuclear powered Orion. Orion configurations can deliver 1000Gs of acceleration. So then it is a matter of dialing back the performance to what the current capabilities that are available for handling acceleration.

Orion scales up to 8 million ton ships.

We know we can send people into interplanetary space for several days (Apollo). We could easily make the trip to Mars in days and then onto to Jupiter in days. We could bring supplies, radiation protection in cargo that is equivalent to several great pyramids or how many loaded aircraft carriers equivalents.

It will be too bad if we did not develop this capability until for some reason we had screwed up the Earth by not using workable technology because of irrational fears.

All it takes if for people to awaken to the fact that Orion can be safe or to develop a near-earth (moon or orbital) deployment or construction or to develop a political correct version of nuclear rocket (IEC fusion space propulsion).

UDPATE:
This site analyzes past underground nuclear tests and geology and nuclear energy to kinetic energy to show how the one shot launch will work while containing fallout and not creating an EMP. Shows how leveraging existing geology and existing nuclear weapons and old research and tests shows how this can provide a multi-trillion jump start to the space age.

This article goes over a one shot variant of nuclear propulsion where all of the fallout can be contained.
END UPDATE






For the technology singularity, nanotechnology is developing at a rapid pace and cognitive enhancement via advanced brain computer interfaces is rapidly developing. Carbon nanotubes can interface to neurons and nanoparticles can wirelessly activate neurons. Carbon nanotubes are rapidly being developed into complex electronics and computers. Working neuroprostethics (brain enhancement modules) appear no more than two decades away and could even be here in 3-5 years and the computers that are interfaced could have have exaflops or zettaflops or more in 5-10 years.

The early clinical application will be to help people with brain damage like long term memory.

The non-clinical side is carrying around more powerful wearable computers with reality overlay displays and sensors for environment and communication with the wearer. Plus some other non-invasive connections.

Brain scale synaptic networks and other methods of human brain emulation are rapidly advancing.

Physical enhancement is already here with military exoskeletons.

Incredible HULC: Lockheed Exoskeleton Gives Superhuman Strength and Endurance to Soldiers Now



Human Universal Load Carrier (HULC) is based on a design from Berkeley Bionics of California, but Lockheed says they have enhanced the basic HULC.

Raytheon's rival XOS mechwarrior suit, which at last report still trails an inconvenient power cable to the nearest wall socket.

* Soldiers will be able to carry loads up to 200 pounds with minimal effort
* HULC uses four pounds of lithium polymer batteries will run the exoskeleton for an hour walking at 3mph, according to Lockheed. Speed marching at up to 7mph reduces this somewhat; a battery-draining "burst" at 10mph is the maximum speed
A soldier with a pack would normally go at 3 mph maximum and cover 10-12 miles in a day.
* Remote-controlled gun mounts weighing as little as 55lb are available, able to handle various kinds of normally tripod- or bipod-mounted heavy weapons
* there's an extended-endurance HULC fitted with a "silent" generator running on JP8 jet fuel. A tankful will run this suit for three days, marching eight hours per day
* HULC is basically a legs and body system only: there's no enhancement to the user's arms, though an over-shoulder frame can be fitted allowing a wearer to hoist heavy objects such as artilery shells with the aid of a lifting strop.

NOTE: Average humans walk 4 to 6 mph, but special operations soldiers are often expected to carry up to 150 pounds of supplies in their backpacks. 25mph speed with bionic boots (springing the step) would be covering almost a marathon distance in one hour.



The Lockheed Martin HULC page is here


HULC product card







The Berkeley Lower Extremity Exoskeleton is described here



Wired also has coverage.


Mars Express Configurations and Unmanned Kick, Coast Start for Nuclear Orion for 1% of Fallout or Less



The explosions for Orion that occur in the magnetosphere where the magnetic field lines lead back to earth is where fallout will come back down and be a problem.

We have already studied that reducing the fission component of any bomb and getting to higher fusion purity greatly reduces fallout and also a north pole launch reduces the fallout that returns to earth. Having a pile of conventional explosives for the first pulse also helps since the ground contact explosion is messier than the air bursts.

It would also seem best to send it up during a snow storm which would contain the fallout that coincides with a solar storm that flattens out the magnetosphere.

If you could not make the pure fusion bombs, which has not been done yet then another way to further reduce the radiation is for an unmanned high-G sprint start to a point outside the magnetosphere zone.




High-G Asteroid Interceptor


An unmanned Orion asteroid interceptor was designed. It would not need shock absorbers. Artillery arming, fusing, firing system for shells are regularly built to take 1000 Gs.

There was a three page paper: Nuclear explosive propelled Interceptor for deflecting objects on collision course with Earth. Johndale Solem, Los Alamos, proposed unmanned vehicle. No shock absorber or shielding. The pulse units were 25kg bombs of 2.5 kiloton yield.

Get to high velocities with only a few explosives and small shock absorbers or no shocks at all. Launch against a 100 meter chondritic asteroid coming at 25 km/sec. 1000 megatons if it hits. Launch when it is 15 million kilometers away and try to cause 10000km deflection. A minimal Orion weighing 3.3 tons with no warhead would do the job. 115 charges with a total of 288 kiloton yield. Launch to intercept in 5 hours. Ample time to launch a second if the first failed.



Sprinting out of the Magnetosphere
Notice the unmanned high acceleration configurations would reduce the number of charges to go through the atmosphere to about 1-3 charges. Instead of 200 charges to go to orbit with constant lower acceleration. Kick it hard with 3 or fewer 100G force acceleration charges. (charges would go off every half second for fast acceleration instead of 1.1 seconds for human safe acceleration).

It can head up at 100Gs. 980 m/s**2. So only 1-3 charges is enough to give escape velocity then coast. It is only a matter of containing the fallout from 1-3 low level charges. Plus 1-3 charges and that is it we have tens of thousands to millions of tons to start the space age.

Some of the Orion configurations were for 1000Gs of acceleration. At 100G's in 10 seconds it would be almost 50 kilometers up. 20 shots assuming one every 0.5 second. In 20 seconds it would be almost 200 kilometers up.

Some more charges could be used to slow the Orion for a rendezvous with human passengers and acceleration sensitive cargo. They could then fly anywhere in the solar system at a leisurely pace without concern about fallout.

Mars Express
Another aspect of the fast acceleration that is possible is that an unmanned Orion go from earth or earth orbit to Mars (decelerate at halfway) and get to Mars in under one day going at 100Gs if Mars and Earth are in the close approach. If the unmanned version was going at 1000Gs (which was a design that is possible), then Earth to Mars could be done in a few hours. At about 300Gs and you would be looking at a Mars Overnight package delivery.

Mars comes to about 50 million kilometers (36 million miles) of Earth on close orbital approach. This is just over three times the asteroid intercept scenario.

It is possible to get fit people to safely endure 30gs for one minute.

High acceleration compensation.

Equally important are some experimental protective techniques for increasing +Gz tolerance, currently under investigation. These methods include :

Pulsating G suits, synchronized to the electrocardiogram. This technique would provide a pulse superimposed on the systolic pulse, producing a higher systolic pressure at head level.

Optimization of physical fitness training procedures. This may allow a more forceful straining manoeuver with less fatigue.

Drugs to increase head level blood pressure on a short-term basis.


A liquid immersed and liquid breathing (special oxygen supplying liquid) person could sustain 15-80Gs. All air voids would need to have liquid. Ears, lungs etc... The liquid immersion and liquid breathing method has not been developed yet, but could work in theory and would increase the sustained acceleration tolerance to some higher level.

February 26, 2009

General Motors Admits to Working with EEStor

Denise Gray is GM’s director of advanced batteries and is principally involved in development of the Volt’s batteries. Denise spoke of General motors relationship with EEStor.

EEStor is one of those suppliers who often sends us information. We’re willing to evaluate what they have and provide information on what our portfolio of higher batteries needs are, so that as they hone in on their technology they recognize what that end game is all about.

So Yes, they are one of those suppliers that we frequently get information from.

So maybe one day we’ll see an EEStor-powered Chevrolet Volt?
Anything’s possible.






EEStor CEO Richard Weir has indicated he is working toward production "as soon as possible in 2009."

On January 9, 2008 EEStor publicly announced that Morton L. Topfer, a former vice chair of Dell, was rejoining the board. He had previously left in mid-2007 for reasons not publicly disclosed


Getting Closer to Curing Jerry's Kids, Labor Day Hangs in the Balance


University of Missouri scientist and his team have identified the location of the genetic material responsible for a molecular compound that is vital to curing the Muscular dystrophy (MD). The new advance will improve gene therapy strategies and they have turned muscle in mice with muscular dystrophy into regular muscle again.

Even if there is a cure for MD, it is likely that there will still be telethon on labor day for remaining medical issues. Even if Jerry Lewis stopped hosting the show and the disease was cured, it is likey there would be some labor day medical fundraiser.

Muscular dystrophy, which affects approximately 250,000 people in the United States, occurs when damaged muscle tissue is replaced with fibrous, bony or fatty tissue and loses function. While scientists have identified one protein, dystrophin, as an important piece to curing the disease, another part of the mystery has eluded scientists for the past 14 years.

Duchenne muscular dystrophy (DMD), predominantly affecting males, is the most common type of muscular dystrophy. Patients with Duchenne muscular dystrophy have a gene mutation that disrupts the production of dystrophin. Absence of dystrophin starts a chain reaction that eventually leads to muscle cell degeneration and death.





While dystrophin is vital for muscle development, the protein also needs several "helpers" to maintain the muscle tissue. One of these "helper" molecular compounds is nNOS, which produces nitric oxide. This is important for muscles that are in use during high intensity movements, such as exercise.

Following the identification of the genetic material, Duan and his team created a series of new dystrophin genes. In their study, they used dystrophic mice to test the efficacy of these new genes. After genetically correcting the mice with the new dystrophin gene, Duan's team discovered that the missing nNOS was now restored in the dystrophic muscle. The mice that received the new gene did not experience muscle damage or fatigue following exercise.

"With this new discovery, we've solved a longstanding mystery of Duchenne Muscular Dystrophy," Duan said. "This will change the way we approach gene therapy for DMD patients in the future. With this study, we have finally found the genetic material that can fully restore all the functions required for correcting a dystrophic muscle and turning it into a normal muscle."


FURTHER READING
The MDA telethon

Research advances nanowire technology For Jumbo Displays Like the 120 Foot High NASDAQ Sign in Times Square



Researchers at Northeastern created a network of nanowires that can be scaled up more efficiently and cost-effectively to create displays such as the NASDAQ sign in New York City’s Times Square.

The seven-story NASDAQ sign is at the NASDAQ MarketSite at 4 Times Square on 43rd Street. The Nasdaq sign was unveiled in January 2000 and cost $37 million to build. The sign is 120 feet (36.6m) high. NASDAQ pays more than $2 million a year to lease the space for this sign.





Using Gallium nitride (GaN), a highly effective semiconductor material, the team created, for the first time, a horizontally aligned network of GaN nanowires, which are integral components in the development of electrical circuits in the nanoscale. GaN is currently used to create light-emitting diodes (LED) and blue and ultra-violet emitting lasers.

“Making devices that emit blue light and ultra-violet light is currently very expensive,” said Latika Menon, assistant professor of physics and co-author of the study. “The horizontal structure of the GaN nanowire network will result in a more cost-effective way to advance this technology.”

Electrodes allow for the flow of electricity between GaN nanowires and electrical wires, and the horizontal structure of the GaN nanowire networks are more easily attached to electrodes than vertical networks. In addition, the GaN nanowires have a cubic structure, with optical and transport properties that are more advanced than other nanowire structures, resulting in a more effective electrical circuit.

In terms of manufacturing, these horizontal network patterns can also be scaled up to large wafer sizes that are more compatible with the technology used to integrate them into new nanoelectronic devices. These devices connect nanotechnology and electronic devices to develop smaller and less costly manufacturing processes and products.



Small and Expensive Versus Big and Possibly Infrequent Space Launch

Hobby space and and Transterrestrial (Rand Simberg) are indicating that

A. because the current market for space payloads is small then no big dumb rockets should be built.

B. Some commenters say we can just leverage in space resources (ISRU - in space resource utilization) and make do with small payloads.

C. Another commenter said, if we could have built these systems back in the sixties, then we would have.

This relates back to the article on this site on big rockets that we are technically able to make.

1. I think the volume could be there if there was a good plan and objectives to seriously develop space (industrialize, colonize and develop energy). Go for 500 (simple chemical, space dragon) then 1000 ton heavy lift (gaseous core). Try to take some near earth asteroids and use them for material. Put up 500 or 1000 ton versions of bigelow inflated structures. For people in space, send up heavier structures with better radiation shielding and more supplies.

2. Bootstrapping with In space resources and small payloads makes all of the problems more complicated and takes longer. The systems have to be more clever to make the small and life stuff work. There has not actually been any leveraging of in space resources yet.

I see and blog about paper studies about in space resource utilization and making concrete on the moon, but I do not see actual hardware being put out there.






3. Orion stopped getting funding after the air force partnered with NASA and NASA would not step up for the budget for the next phase. There was probably also the political overlay but I will be getting hold of the 2002 book and looking at the historical record as to what killed what first.

Space Dragon had a NASA study which said that it would work, could be built and would provide the lower costs for payload. Space Dragon would be cheaper to develop than Ares or Direct 2.0. Why do we need another small lift system ?

Also, how long would take and how many launches to recover the costs of tens of billions for Ares and/or Direct 2.0 ?

How much would it cost to develop a dirt simple Big Dumb Booster ? Go big and go simple and develop the rocket for say $4 billion plus $500 million/yaer to maintain the operations and then each unit costs say $500 million or $1 billion and you can still have 5-10 big launches over how many years before you get up to the Ares development costs where it has not launched anything.

The Sea Dragon rocket would have been able to carry a payload of up to 550 metric tons into low earth orbit. Payload costs were estimated to be between $59 to $600 per kg, which is much less than today's launch costs. TRW conducted a program review and validated the design and its expected costs, apparently a surprise to NASA. However, budget pressures led to the closing of the Future Projects Branch, ending work on the super-heavy launchers they had proposed for a manned mission to Mars.


4. Where are the small lift systems that are getting all these "frequent launches" and getting the economic benefit of frequent launches ?

How often are 20 ton payloads launched ?
I am seeing about 30 scheduled launches, with about 1-6 for different launch systems. No one launch system is getting more than about 3 launches in a year.

What are the payloads that will be launched with Ares or Direct 2.0 ?
The payloads and projects for the Moon and Mars seemed to be predicated on the designed capabilities of Area or Direct 2.0. They are thinking small and designing small projects.

Many of the space based power projects hang up on the fact that $/kg costs are too high. Nothing gets started because the business case has no chicken or egg to get going. We can then say that there is no demand for low 4/kg.

We can go big, if we plan big and design big.

5. I understand that the reality is that there is no real over-arching primary goal to the space program. The proposals (Ares/Direct 2.0) are variations how do we keep the current people at NASA or at the companies that make the Delta, Atlas and Space Shuttle employed. The purpose of that is keep the senators and congressman that have the jobs and business in their space and district able to say see voters I am keeping NASA/Space jobs going. The satellites and exploration are in general just enough to show that this is all not completely pointless and the honest lower-level people are trying to achieve something (as much as they can) with their piece of the overall system.

ISS - dozens of launches. What was the real point ? How does it lead to any grand larger goal in space ?

Even if the current vision for the moon were funded and came off. What would be the final result ? Maybe a peak of a dozen people on the moon. How much in space resource utilization ? What would the next phase be able to build upon ? How it get to the next step up to more capability ?

FURTHER READING
Sea Dragon - Why it would be Cheap
Remember - TRW validated the program and the costs
Also, the design and material is simple and should not have a large development cost.

To lower the cost of operation, the rocket itself was launched from the ocean, requiring little in the way of support systems. A large ballast tank system attached to the bottom of the first-stage engine bell was used to "hoist" the rocket vertical for launch. In this orientation the cargo at the top of the second stage was just above the waterline, making it easy to access. Truax had already experimented with this basic system in the Sea Bee and Sea Horse designs. To lower the cost of the rocket itself, he intended it to be build of inexpensive materials, specifically 8 mm steel sheeting. The rocket would be built at a sea-side shipbuilder and towed to sea for launch.

The first stage was to be powered by a single enormous 36 million kgf thrust engine burning RP-1 and liquid oxygen. The fuels were pushed into the engine by an external source of nitrogen gas, which provided a pressure of 32 atm for the RP-1 and 17 atm for the LOX, providing a total pressure in the engine of 20 atm (~300 psi) at takeoff. As the vehicle climbed the pressures dropped off, eventually burning out after 81 seconds. By this point the vehicle was 25 miles up and 20 miles downrange (40 km x 33 km), traveling at a speed of 4,000 mph (1.8 km/s). The normal mission profile expended the stage in a high-speed splashdown some 180 miles (290 km) downrange. Plans for stage recovery were studied as well.

The second stage was also equipped with a single very large engine, in this case a 6 million kgf thrust engine burning liquid hydrogen and LOX. Although also pressure-fed, in this case the nitrogen kept the system running at a constant lower pressure of 7 atm throughout the entire 260 second burn, at which point it was 230 km up and 940 km downrange. To improve performance, the engine featured an expanding engine bell, changing from 7:1 to 27:1 expansion as it climbed. The overall height of the rocket was shortened somewhat by making the "nose" of the first stage pointed, lying inside the second stage engine bell.

A typical launch sequence would start with the rocket being refurbished and mated to its cargo and ballast tanks on shore. The RP-1 and nitrogen would also be loaded at this point. The rocket would then be towed to a launch site, where the LOX and LH2 would be generated on-site using electrolysis, Truax suggested using a nuclear-powered aircraft carrier as a power supply during this phase. The ballast tanks, which also served as a cap and protection for the first stage engine bell, would then be filled with water, raising the rocket to vertical. Last minute checks could then be carried out, and the rocket launched.


Stem Cells for Universal Tissue and Replacement Organs


Stem cells on threads

1. Weaving stem cells into synthetic universal tissue (UK)

Embryonic stem cells can survive being spun into polymer threads – a technique that could be used to weave flexible synthetic tissues able to adapt to any transplant environment, say UK biophysicists. The approach could be a step towards the production of artificial organs. They are able weave stem cells into synthetic tissues.

There are a number of competing techniques for shaping living cells into custom-made tissue, including one based on inkjet printing, and another that uses air pressure to pull a cell solution into long threads.

That technology is able to weave networks of thread containing live brain cells without damaging them. Now, Suwan Jayasinghe's team at University College London has shown that a similar technique can be employed to create threads of embryonic stem cells. The group say this is the first time such cells have been printed using any technique.

The team use a technique called electrospraying, where two stainless steel needles, one inside the other, combine a stream of a viscous biodegradable polymer with a suspension of embryonic stem cells.

Applying a voltage to the needles charges the polymer and cells and they accelerate towards an "earthed" copper ring a short distance beneath, emerging as a single thin thread.


2. Bioscaffolds with blood flow networks have been made and blood, fat, and bone marrow grew. They are now able to make rejection free, three dimensional organ structures.

A novel approach to overcome organ construction obstacles using autologous explanted microcirculatory beds (EMBs) as bioscaffolds for engineering complex three-dimensional constructs. In this study, EMBs consisting of an afferent artery, capillary beds, efferent vein, and surrounding parenchymal tissue are explanted and maintained for 24 h ex vivo in a bioreactor that preserves EMB viability and function. Given the rapidly advancing field of stem cell biology, EMBs were subsequently seeded with three distinct stem cell populations, multipotent adult progenitor cells (MAPCs), and bone marrow and adipose tissue-derived mesenchymal stem cells (MSCs).







scientists from Stanford and New York University Langone Medical Center describe how they were able to use a "scaffolding" material extracted from the groin area of mice on which stem cells from blood, fat, and bone marrow grew. This advance clears two major hurdles to bioengineered replacement organs, namely a matrix on which stem cells can form a 3-dimensional organ and transplant rejection.


Synthetic tissue and better scaffolds for structure are step towards fully functional artificial organs. Another recent study showed how the artificial capillary networks needed to feed such organs could be grown using cotton candy at very low cost.

February 25, 2009

Nanotechnology and Technology Acceleration Buzz is Higher Because Actual Developments Are Showing Pessimists Were Wrong

J Storrs Hall has another excellent article, this one on validity of the molecular manufacturing vision and the usefulness of futurists in tough economic times. Josh states that the job of a futurist is to turn on the lights, to show what paths could actually lead to prosperity. I would say it is necessary to tap people on the shoulder and say big things are finally happening and the argument about what is or is not possible just got proven as possible. (H/t to nanowerk for many of these articles)

1. Carbon nanotubes connect neurons and are advancing to prosthetics for the brain. New work now considerably widens the perspectives of employing conductive nanomaterials for neuroengineering applications. It proposes carbon nanotubes not only as ideal probes for bidirectional interfaces in neuroprosthetics but also as nanotools to endogenously (re)engineer single-neuron excitability and network connectivity.

There are three fundamental obstacles to developing reliable neuroprosthetics: 1) stable interfacing of electromechanical devices with neural tissue, 2) understanding how to stimulate the neural tissue, and 3) understanding what signals to record from the neurons in order for the device to make an automatic and appropriate decision to stimulate. The new carbon nanotube-based interface technology discovered together with state of the art simulations of brain-machine interfaces is the key to developing all types of neuroprosthetics – sight, sound, smell, motion, vetoing epileptic attacks, spinal bypasses, as well as repairing and even enhancing cognitive functions.




Cultured rat hippocampal neuron grown on a layer of purified carbon nanotubes.

This goes with the other announcement of using light activated nanoparticles for a wireless brain interface












2. Pushing nanocrystal growth towards nanomanufacturing

Recent advance in seeded growth as the ultimate approach to producing metal nanocrystals with precisely controlled sizes, shapes, and compositions the necessary first step toward their use and assembly for large-scale applications.













3. DNA Nanotechnology goes 3D. DNA arrays assembled into a two dimensional hexagonal pattern, or a sheet, assemble further into multilayer stacks.



Unlike the formation of DNA crystals or DNA hydrogels, layer by layer assembly has an advantage as various layers can pack within three-dimensional structures, thereby providing different pore sizes for guest molecule incorporation.

There are a number of potential applications for this kind of research. One is the organization of inorganic materials on the DNA architecture, i.e. using DNA as scaffolds. Due to the multilayer packing of DNA sheets it is theoretically possible to position materials within the three dimensional framework of the DNA. The team was successful at visualizing and identifying three layers but they mention that they have also seen assemblies composed of more than three sheets.







4. Building bottom up nanowalls

New work by a team of scientists in Korea demonstrates the position- and shape-controlled growth of nanoarchitectures using the selective growth of nanowalls with conventional lithography and catalyst-free metal organic vapor-phase epitaxy (MOVPE). This presents a significant advance towards the fabrication of artificial 1D and 2D nanomaterials as functional components in many integrated electronic and photonic devices.

The most exciting scientific core of their findings is the observation of selective formation of zinc oxide (ZnO) nanowalls along pattern edges on gallium nitride/silicon (GaN/Si) substrates, which enabled us to control nucleation sites to grow nanomaterials in specific positions.




5.
Using a process based on optical near-field effects, Lu and his team in UNL's Laser Assisted Nano-Engineering Lab created nanoscale devices based on connecting sharp-tipped electrodes with individually self-aligned carbon nanotubes. All locations with sharp tips can accommodate carbon nanotube growth. That means we can make multiple carbon nanotubes at a time and all of them will be self-aligned.

6. Kevlar has been reinforced with carbon nanotubes.

Kevlar-CNT composites show increases in all mechanical parameters of the nanocomposite material compared to the original Kevlar fibers, e.g.: Young’s modulus, from 115 to 207 GPa; strength, from 4.7 to 5.9 GPa; strain at break, from 4.0 to 5.4%; toughness, from 63 to 99 J/g. These improvements have been achieved at only 1 - 1.75 wt% of carbon nanotube content.


Carbon nanotubes are still expensive and only a few hundred tons are made per year so being able to use them to significantly strengthen cheaper material is a good commercial thing.

7. Nanotechnology lens for ultracompact photonic devices.

While nano-patterning of optically thick metallic films was theoretically proposed as an alternative to refractive lensing, scientists at Stanford University have now reported the first experimental demonstration of far-field lensing using a plasmonic slit array. [look far away at less the wavelength of the light]

The miniaturization of lenses, for example, has been essential in the development of modern solid-state image sensors and can also have important implications for other opto-electronic applications such as displays, solid state lighting, and potentially solar cells. The focusing capability of conventional, dielectric-based microlenses however deteriorates as their physical dimensions are reduced toward a single-wavelength scale. That's why scientists have begun exploring alternative approaches to refractive lensing.


7. Engineers use 'nano-origami' to build tiny electronic devices (3D MEMS and NEMS). MIT researchers folded a polymer sheet into one corner of a cube. The edge of each face is about 800 microns.



REVIEWING OTHER RECENT WORK
8. Self assembled memory is busting through what some expected was a 10-20 nanometer feature size barrier to 1-2 nanometers.

9. Room temperature single atom quantum dots

10. More durable and higher resolution nano-imprinting. It is working at 13 nanometer features and they seem confident about going to 1-2 nanometers.

11. Two Armed Nanorobotic Device Built from DNA: 100% Accurate Capture of Targeted Molecules

Chemists at New York University and China's Nanjing University have developed a two-armed nanorobotic device that can manipulate molecules within a device built from DNA. The device is described in the latest issue of the journal Nature Nanotechnology.


12. Cambridge is making longer lengths of super strong carbon nanotube rope. 9 GPa. Four times stronger than regular kevlar.

13. Stanford writes 35 bits per electron

In Praise of Large Payloads for Space by Joseph Friedlander Part 1

Hi, everybody this is Joseph Friedlander, in a guest article series on Nextbigfuture.

In this series I hope to discuss first some of the largest systems proposed to reach orbit with big payloads, and then why it’s a lot better (for equal cheapness) to have one big payload than say a million 30 kg payloads launched for a given project—and then some discussion of what those projects might be!

UPDATE: Pointers to critique and debate about this article.

The launch systems of huge size are
• LIBERTY SHIP
• ALDEBARAN
• SEA DRAGON
• ORION and SUPER-ORION



Without cheap prices per kilogram orbited and without huge mass throughput to space, the only business models so far that have made large-scale financial sense are data gathering and relay through satellites. This series will consider other business models as well.

• Brian has previously written of the LIBERTY SHIP, --1000 tons to orbit, 1000 tons coming back too—long life because huge weight margins with 29 km/ sec exhaust velocity of hydrogen and actually can retro down to decelerate, not burning via atmospheric braking, for far less stress on its reinforced ship-like structure—leading to long life.













Similar performance but much greater size both of ship and payload for the
• ALDEBARAN












The Aldebaran concept by Dandridge Cole, ca. 1960
Aldebaran vs Ocean Liner—50000 tons at takeoff

























Cost data on Aldebaran






60 million pounds (30000 tons to LEO or 45 million pounds 22,500 tons to lunar surface)

3000 isp (specific impulse) 29419.9 m/sec gas core reactor exhaust velocity
Could also be 22500 tons to a Near Earth Asteroid, since many of them have less delta-v than the 6-6.3 kilometers per second from Low Earth orbit to the Moon’s surface and the surface of Mars.

For comparison, delta-v for transferring from low-Earth orbit to rendezvous
with the Moon and Mars:
Moon: 6.0 km/s
Mars: 6.3 km/s
Delta V for many near earth asteroids by order of ease:

Delta V for many near earth asteroids by order of apparent size:

(H is the symbol of absolute magnitude, so a ranking by this makes dark large asteroids possibly underranked relative to true sizes, because they reflect less light and are dimmer as if small)

Delta V calculator for isp-m/sec conversions, mission analysis


pdf containing Cole’s design pictures and colonization ideas—also colony concepts by him and Kraft Ehricke

Paper by Kraft Ehricke

Wikipedia on Dandridge Cole, space visionary

Roy Scarfo’s artwork illustrating Dandridge Cole’s Macrolife concept of colonizing asteroids: (in his own words) the “Inside-out World,” the external view; the other of the set was the “Inside-out World,” the internal view.



Art by the great Roy Scarfo illustrating Dandridge Cole’s Concepts-- Philosophy Inc scans from Beyond Tomorrow (great out of print Cole Book, art by Roy Scarfo)]
Mention of Cole’s ideas about blow-molding molten asteroidal material to giant colony hulls-- the "nomadic pseudo-earth," as Cole and Cox called their conception, would be the hollowed out space inside a captured asteroid. The result would be a "gigantic geodesic interior chamber," created "in much the same way as a glassblower shapes a small solid lump of molten glass into a large empty bottle."

600 square miles of land in an asteroid--











Outside view—note the motors--












Also the unique lighting system without the vulnerable windows of O’Neill Colony designs—TWICE the land surface, too!



Notice that engines could be fitted on the colonized asteroid, as well as a mass driver for accelerating with man-tolerable G forces —over many kilometers small ships and capsules for delivery to Earth with but small effect on the massive colony’s trajectory.

5 Gs will accelerate to 3 km second over 60 seconds--- length determined by
.5 * (50 meters a second acceleration) * (number of seconds squared—to determine this, you divide desired final speed by tolerated acceleration so 3000/50=60 seconds)
.5 * 50 * 60 squared
25 * 3600 = 90 kilometers = length of accelerator—about 54 miles. Kind of like a rocket sled but can be propelled electrically or by other means.

Such an accelerator on the Moon could throw you to Earth or on a trajectory to Venus or Mars orbit.

On an asteroid it could throw you (depending on the asteroid) back to Earth orbit with net payload in a retro capsule built from materials on the asteroid itself. Theoretically as long as you have a locating device, it can reenter and float in the ocean, it can be as cheap as a sewer pipe—it’s up that’s expensive in space, not necessarily down. And with cheap downward shipments you can make money back. In other words, exports would pay for the program over time.



Asteroid with linear motor












SEA DRAGON 550 tons to low earth orbit
More Robert Truax data on Sea dragon and other vehicles (sea launched a Truax specialty—why pay for a launch pad?)

Look at the size of that thing—yet it is the smallest payload of any non-NASA system considered here—“only” 550 tons—because it uses regular chemical rockets, not nuclear. Note that Sea Dragon above could have orbited a preassembled equivalent to the 227 ton International Space Station-- and years of supplies in one whack, and a heavier cheaper version at that—under $1 billion versus $100 billion. More on mission architectures later in the series…



Saturn 5 to same scale as Sea Dragon. Saturn 5 on the right












I believe NASA should drop this Ares 1 and Ares 5 nonsense.

The proposed Ares I configuration has been criticized on several grounds. The production of a launch vehicle in the 25 tonnes (55,000 lb) payload class can be seen as direct competition with existing vehicles such as the Boeing Delta IV-Heavy. It can be argued that lower costs and improved safety are likely to result from the use of an existing vehicle, since it would have lower development costs, a proven track record, and would benefit from a higher flight rate…



a superior for less version would be the Direct scenario











The key program risk, according to DIRECT, is that NASA's Ares I is already over-budget, late and is lacking in performance, so when serious funding is required for the much larger and more expensive Ares V, Congress is not likely to be impressed. The risk is that Congress may pull the budgetary plug on the Heavy Lift effort before it is complete. This would leave NASA with a very expensive, yet small, Ares I launcher and no heavy-lift capability to enable any Lunar or Martian exploration programs in the future, but even Direct is still too expensive (but if Congress
is determined to save the Shuttle industrial base, it is a better way than the Ares vehicles) rather, for cheapest spaceflight, if NASA is really determined to build a non nuclear system-- build the Sea Dragon – for reasons to be stated later in this series but revolving around lower cost of development and per kilogram to orbit-- (the fact that from orbit with enough mass to play with radically cheaper spaceships are possible—of which more anon.)

• PROJECT ORION, which Brian has covered extensively on this site:
here and here and other articles.

Many have focused on the 40 meter diameter 4000 ton Orion but this is one concept that scales so well that the bigger (within reason) the better.



The Super-Orion we will consider here is the 8 million ton model. This alas is not 8 million tons to orbit but rather an extrapolation of the 4000-ton model—1/4 each payload, structure, pusher plate, and bomb units (fuel/reaction mass)
So in this case 2 million tons of each. Note that in most cases nearly all the ship and pusher mass would be usable in some way as construction materials or at least as shielding or reaction mass. So 2 million tons of payload, and 2 million tons of ship/station/base (the ISS is 227,267 kg as of last report) so the equivalent of 8800 International Space Stations—This implies the ability to drop colonies, outposts and miner’s settlements throughout a given area. Imagine a flight around Jupiter, stopping at each of the 61 moons (or multiple sites on the biggest ones) and putting a colony of 1000 people (including a small medical center) at each one. Resources could be identified and mined, all in one mission, and a trading economy set up in the Jupiter system. But more on mission scenarios later.

It is superfluous to talk about the Super-Orion or indeed the regular Orion without touching on the issue of nuclear contamination.

The problem about launching bomb-propelled ships anywhere in the magnetosphere, is that the thermonuclear bomb debris comes down to Earth, captured and sucked in along magnetic lines of force. Therefore you really want a polar exit through the doughnut holes of Earth’s magnetic field to escape velocity, then go to your desired target at a great distance.



There are other tricks that may be useful to limit fallout, but the key thing is minimizing the fission fraction of each bomb.
With a standard 5 Kiloton primary of a B-61 nuclear bomb,

(Using the Russian trick of NO sparkplug in the secondary, used for that 30 KT incremental Peaceful Nuclear Explosion sealed secondary unit of theirs –presumably at a considerable tritium cost, as in a neutron bomb--) you could get 99.9% fusion, better than 98% for Tsar Bomba.

So the total fission product fallout for 1000 bombs would be on the order of 5 megatons which is one bomb test in the old days of 1952-63.

If you could further mess with the design you might be able to get the total fission down to 1 megaton. The problem is keeping the units affordable (Tritium is $30000 a gram) and you need about $90000 worth for each primary, and who knows how much for each fission free secondary.

All of this totally neglects the problems of messing with a known to work primary configuration which would take many now banned weapons tests to recertify (one reason why DOE keeps 5000 old pits at Pantex for a ‘rainy day!’)

As for developing from scratch a new primary, it seems unlikely the people objecting to fallout would rejoice in new low yield primary development—historically they never have.

As Brian has written, Orion's propulsion units would be inert material such as polyethylene, or boron salts, used to transmit the force of the propulsion unit's detonation to the Orion's pusher plate, and absorb neutrons to minimize fallout

--that is to stopping neutron activation of Nitrogen-17 to become Carbon 14 which is not good for living things. It can directly become part of nucleus- DNA (DNA) in a given cell. It will be flushed out over time but meanwhile there is exposure. That is why you want to stop it before it starts, and boron very probably will do that. This was an idea by Freeman Dyson.

There remains the problem of tritium contamination.

Tritium Units where 1 TU is defined as the ratio of 1 tritium atom to 10**18 hydrogen atoms. As noted earlier, nuclear weapons testing, primarily in the high-latitude regions of the Northern Hemisphere, throughout the late 1950’s and early 1960’s introduced large amounts of tritium into the atmosphere, especially the stratosphere. Before these nuclear tests, there were only about 3 to 4 kilograms of tritium on the Earth’s surface; but these amounts rose by 2 or 3 orders of magnitude during the post-test period.

Lets just say that in the peak year 1963 of Tritium contamination, Kodak had to take precautions against slightly clouding the film when they made it according to a story I heard.

Each megaton of fusion is said to put out 1.5 kg of byproduct tritium, unrecoverable and dilute. Obviously you want to immobilize that.

I believe that bizarre as it sounds the best thing to do is take off in the largest polar blizzard of the winter so things are immobilized near the ground in the snow (where they can decay in peace). It is a mark of the power of the Super-Orion that you can plan to take off in any weather with absolute impunity- the weather has to be afraid of Super-Orion, not the other way around!

I am just remembering the reference to Antarctica Control in the 1979 movie Alien. That makes sense (Southern Ocean in storm into polar radiation doughnut exit hole) so you fly up the South Pole from the Southern Ocean. You tow to there from the shipyard.

The rule of thumb I am working on is that if a 4000 ton regular Orion uses one thousand 5 kiloton charges, then a 2250 times heavier Super Orion— (off the cuff design consistent with known facts) might approximate--
9 million tons gross weight
-2 million tons payload
-2 million tons structure
-2 million tons pusher plate
-3 million tons pulse units/charges (about 4 tons of bomb with about 3000 tons of plasma-generating and support material to be energized making up just one single working charge for a Super-Orion with the mass of a Saturn V! Per unit!)
(and you will be using 1000 of these to Earth escape velocity.)

Super Orion would take say one thousand 10-12 megaton charges. This is roughly equivalent to a W-53 bomb. or about half of a W-41 bomb

Note that these are not regular bombs but pulse devices with attached reaction mass to be energized and directed in a fan cone of not more than 22.5 degrees dispersal.

That is efficient fusion of around 120-140 kg of D-D or rather more 160-180 kg Li6D. That is to escape velocity, more for the home trip. So a few hundred tons of fusion fuel. Note the pulse units are 3 million kilograms, but the expensive parts are actually ‘small’ in mass. Note also that a few thousand tons heated to many tens of thousands of degrees will eat up megatons of energy—because it radiates by the fourth power of the temperature difference. (Just to melt rock, it would melt a perhaps a few million tons per bomb) Again, this bracketing logically puts us in the several to 20 megaton range. Between a W-38 and a W-41 but 5kt maximum fission content, please!

This also means that the 8 million ton Orion “only” has 2 million tons of payload. You’d need a 32+ million ton Orion for 8 million tons of pure payload.
Still one hundred thousand 20 ton Shuttle or Ariane V kind of payloads isn’t bad.

G. Harry Stine once wrote that a large thermonuclear device detonated in the geostationary arc would create trapped radiation that could destroy every satellite there, so you definitely want the Super-Orion to avoid that flight path!

This ends Part 1. In future parts we shall consider what we might do with such wonder ships…

Solid State Drives Cheaper, 100 times Faster than SAN Hard Disk Arrays

The Enterprise solid state storage disruption is happening now.

Enterprise solid-state drives typically offer much better performance than even the fastest hard-disk drives. Fusion-io claims that its IoDrive improves storage performance by as much as 1,000 times over traditional disk arrays while operating at a fraction of the power and at a tenth of the total cost of ownership.

Solid state drive companies want to do to enterprise storage what the Nvidia graphic cards did to the Graphic Workstation companies in the nineties.

How will Fusion-io's solid-state drives change all of this? "We have the ability to put five and soon 10 terabytes within a standard 4U server," he said. "In the near future we will be announcing a card which holds two of our I/O memory modules, therefore doubling the capacity but also the performance per slot," Flynn explained.

"We are not replacing a 15K-rpm disk drive," Flynn said. (Hard-disk drives spinning at 15,000 revolutions per minute hard disk drives are the highest-performance disk drives used in enterprise servers.) "We are miniaturizing an entire (storage area network) of multiple drives by making it out of silicon. While a 15K-rpm drive may cost $2 to $3 per gigabyte, a high-performance SAN costs $50 per gigabyte and up--built from those same HDDs, mind you," he said. "Our ioDrives are made up of chips that cost only $2 to $4 per gigabyte, but when we integrate them into a miniaturized silicon SAN, we charge $30 per gigabyte."






Faster IO: Enterprise SSDs process 100 times the number of IOPS per watt as a typical 15K 2.5-inch server hard disk drive.

Enterprises solid-state drives consume less than 25 percent of the power of a 15K hard-disk drive.

Because enterprise solid-state drives are a relatively new technology, reliability is crucial. Fusion-io offers a technology called "Flashback" protection--extra chips that can jump in to take over immediately if there is a failure.

Here are some more specifics Flynn offered. Currently, Fusion-io can achieve just shy of 1 terabyte of storage by using three 320GB cards. "We're doubling density per module and doubling the number of modules per card so we're going to have 1.3TB on a single PCI Express card," he said.

"We'll be able to address 90 percent of the databases with a single drop-in card. Most databases are less than 1TB in size," he said.


How to Think Like A Quantum Computer Programmer

Matt Hastings writes in an understandable way about adiabatic quantum computer algorithms. The last half of this article describes the question and answer analysis that Matt Hastings uses to try and create a useful algorithm for quantum computing. Adiabatic Quantum Computers are the kind of computer that Dwave systems of vancouver is trying to make. Dwave systems is at 128 qubits now and could be at 2048 by the end of the 2009.

This summary goes over two brief introductory paragraphs of how quantum computers and the sub-type of adiabatic quantum computers work. Next the question and answer analysis is provided with minimal math. You still need to know something about computer algorithms and how fast computers can solve problems. Some pointers exponential time means problems rapidly become to big to solve. Polynomial time means that useful problems can be solved in reasonable time.

How General Quantum Computing Works
There are many proposals for doing quantum computing. But basically all of them involve the following sequence of steps: you initialize a system to some quantum state, you evolve it under some Hamiltonian (which may be time-dependent), and then you measure something to get your answer. If you think about the usual gate model of quantum computing, you can imagine producing the effect of each of those 2-qubit gates by acting for a short time with a Hamiltonian that acts just on those two qubits (in fact, that is how it would actually have to be done in practice). If you think about measurement based quantum computing, there are in fact many measurement steps in between, not just one at the end, but all of those intervening measurement steps could be modeled by Hamiltonian dynamics in some larger Hilbert space. So, everything in quantum computing is just create a state, evolve, and then measure.


How Adiabatic Quantum Computing Works a Little Differently

Adiabatic quantum computing is a special case of this. In adiabatic quantum computing you again evolve the system under a time-dependent Hamiltonian, H(t) , but you have two further constraints. First, your initial state is the ground state of H(0). Next, the Hamiltonian changes very slowly in time, so that for all times your H(t) quantum state remains close to the ground state of H(t) .

It has also been shown by Aharonov et. al. that such a linear interpolation (adjusting the simple Adiabatic formula with a function) is computationally as powerful as the gate model.







Questions and Answers from the Analysis: Thinking like a Quantum Computing Programmer
Question: Can we make adiabatic quantum computation with a large spectral gap (of order 1)?
Partial Answer: Immediately, we realize that this will imply that we follow a “long path” in parameter space if we want to do anything useful.

Answer: Everything that can be done with an order unity spectral gap in one dimension can be done on a classical computer in polynomial time.

Answer: We need to have a polynomially long path, and we need to work in more than one dimension.

Question: Are there any interesting algorithms based on such a long path. Is there any reason to believe that this will allow us to get nontrivial results?

Partials Answer: not only is it possible, but that this possibility in fact already is well known [topological quantum computeing]

Question: Topological quantum computing can be realized as adiabatic evolution: add some terms to the Hamiltonian which favor producing defects, and then slowly change those terms to drag the defects, and braid them. However, topological quantum computing relies on a highly degenerate ground state. Is it possible to do this “long path” adiabatic quantum computing with a unique ground state and a spectral gap of order 1?

Answer: Don’t know. Maybe. I thought for a short time about whether one could at least come up with a Grover algorithm [Faster than Classical Database searching] that worked this way, but didn’t get anywhere. Perhaps instead of linearly interpolating one could imagine changing in a position-dependent way. Maybe one could choose some long random path in parameter space.


FURTHER READING
Topological quantum computers for beginners

Topological approaches to fault tolerance seem especially promising.


So more stable and more fault tolerant than other kinds of quantum computers.

Topological quantum computing at wikipedia

A topological quantum computer is a theoretical quantum computer that employs two-dimensional quasiparticles called anyons, whose world lines cross over one another to form braids in a three-dimensional spacetime (i.e., one temporal plus two spatial dimensions). These braids form the logic gates that make up the computer. The advantage of a quantum computer based on quantum braids over using trapped quantum particles is that the former is much more stable.