## Friday, December 30, 2011

### New digital scale

Just picked up this digital scale, a 200 gram capacity .1 gram precision unit. There are many uses for this, but I mostly wanted it to help with the mixing of epoxy. It seems pretty good, calibrated well with 1 dollar bills (1 gram on the mark every time) and coins - a dime is supposed to be 2.27 grams give or take. Like any good scientist, I want to start weighing all kinds of things now. It would be interesting to weigh all of my D motors to check for any variations.

## Thursday, December 29, 2011

### Thermonuclear bomb physics package

I cannot confirm that this is a correct schematic for a modern fusion bomb, but it looks interesting enough to consider. Compare it to the actual image above.

## Wednesday, December 28, 2011

### The Hayden Letters

"In 1950, the Museum's Hayden Planetarium began accepting reservations for the first trip into space as part of a publicity campaign for its exhibition Conquest of Space. Letters poured in from around the world with requests to book trips to the Moon, Mars, Jupiter, and beyond, capturing the public's passion and curiosity for space exploration. View a selection of letters from enthusiastic would-be space travelers here."
At Flickr

## Tuesday, December 27, 2011

### Phobos Grunt will reenter atmosphere in about 2 weeks

That is not too shocking; we have been expecting this sad day for a while now. But the expected location of the landing is pretty interesting:

Freaking Afghanistan!

What happens when some of the most advanced technology (though perhaps not advanced enough) in the World lands in one of the most backward, ignorant countries in the World? Will they blame the jews this time, or perhaps some woman who was caught with her ankle showing?

## Monday, December 26, 2011

### KH-9 Hexagon - Declassified in Sept. 2011

Specifications

Data source: The Encyclopedia of US Spacecraft and NSSDC
Launch vehicle: Titan IIID/34D
Total weight: 11,400 kg (25,000 lb), with mapping camera 13,300 kg (29,000 lb)
Reentry weight: 5,330 kg (11,800 lb)
max. Diameter (main body): 3.05 m (120 in)
Length (with mapping camera): 16.21 m (638 in
Orbit: elliptical, 100 miles by 150 miles
Scanners: television, radio, and high resolution camera

Yahoo

Wiki

## Friday, December 23, 2011

### NASA video from ISS of comet and Earth

"International Space Station Commander Dan Burbank captured spectacular imagery of Comet Lovejoy as seen from about 240 miles above the Earth’s horizon on Wednesday, Dec. 21. Burbank described seeing the comet as “the most amazing thing I have ever seen in space,” in an interview with WDIV-TV in Detroit."

- NASA

### The full story of Stig-A from Armadillo Aerospace

"On Sunday morning, 4 December 2011, Armadillo Aerospace launched the tube rocket "Stiga" (aka STIG-A) to approximately 140,000 feet above sea level from Spaceport America. The rocket took just under 2 minutes to reach apogee and landed twelve and a half minutes after the launch. The landing point was 2.87 miles away from the launch pad and conveniently on a road, well within the 4.35 mile range established before the launch."

How great is this rocket? Only mach 2.87 and 140,000 feet! The efficiency of a slow burning rocket with active guidance is very clear. The rocket shut down more than 10 seconds early because it had passed a pre-arranged downrange distance. That is a great safety feature, and also means that it could have broken mach 3 and gotten closer to 200,000 feet if it burnt the tanks dry. (The last 10 seconds would, assuming no throttle or great loss in motor isp at high altitude, be the best 10 seconds of all.) In fact, with a bit of optimization, this rocket could carry payloads to space. That could be as simple as a slightly lighter air frame, a bit more fuel, or a better ISP.

This would be an idea booster stage to a dumb solid rocket motor, say a Q, if they are interested in getting payload to 500,000 feet + at some point. Lighting a Q at 90,000 feet and mach 2 would be more than enough to get 10kg of cameras to 500,000 feet. But that is just my gut reaction, always being obsessed with altitude. It is quite possible that they have other things in mind (such as larger payloads.)

The recovery worked well enough (damage was noticeable but not fatal) but the parachute systems are going to be redesigned in future. The drogue stage is based on a large ballute. Ballutes are ideal for high-mach conditions, but in this case the drogue was damaged, resulting in a high speed deployment for the main chute, also resulting in damage. For my 2 cents, I suggest a 6 ft rocketman kevlar 'chute or the 8 foot ballistic mach II 'chute for this purpose.

Source:
http://rocketdungeon.blogspot.com/

### High speed footage - Crossroads shot Baker

Note the initial hypersonic shockwave, a dark circle propagating through the water. This hydraulic shock, initially many miles per second, was powerful enough to crush the hulls of ships nearest to the blast.

## Tuesday, December 20, 2011

### Desorption-Assisted Sun Diver Missions

"Desorption-Assisted Sun Diver Missions

Gregory Benford1 and James Benford

Abstract.

Solar-driven sails which can also accelerate by "boil off" of coated materials offer new high-velocity missions. These can take advantage of high temperature characteristics of the sail by using the large solar flux at perihelion. For the near term use of beamed power, beam illumination at ~kW/cm2 in LEO can simulate conditions any solar grazer mission will experience to within 0.01 A.U. Sublimation (or desorption) thrust from LEO into interplanetary orbit can omit the several-year orbits conventional solar sails need to reach ~0.1 AU. A second "burn" at perihelion, the highest available orbital velocity in the inner solar system, and thus optimum point for a delta-V, then yields high velocities of ~50 km/s for >40 A.U. missions. The mission begins with deployment in Low Earth Orbit by conventional rocket. Then the launch begins, driven by a microwave beam (and much smaller solar photon thrust) from nearby in orbit. Beam heating makes a "paint" (polymer layer #1) desorp from the sail. Under this enhanced thrust, in repeated shots at.perihelion in steepening elliptical orbits, the sail attains ~15 km/s velocity, canceling most of its solar orbital velocity, and so can fall edge-on toward the sun immediately. (This is far faster than using solar pressure to spiral down, which takes years.) It approaches the sun edge-on, to minimize radiation pressure on it in the inward fall. At perihelion the spacecraft rotates to face the sun. Under intense sunlight ~20 times Earth insolation, the sail desorps away polymer #2, getting a ~50 km/s boost at its maximum (infall) velocity. It then sails away as a conventional, reflecting solar sail, with the final Aluminum layer revealed. Its final speed is after leaving the solar potential well is ~ 10 AU/year. Within ~5 years, it sails beyond Pluto, giving high velocity mapping of the outer solar system, the heliopause and interstellar medium."

Full paper here

### Tiny fan and coin vs current

"Single phase submicro brushless motor, made from rewound wristwatch coil wire and the A1442 speed controller ic chip. Magnet is .5mm x 1mm, smallest available, shaft from .007" music wire, hypodermic tubing for bearings. Propeller is 8 mm diameter, made from basswood."

"5 cents vs 200 amps"

## Sunday, December 18, 2011

### The Shadow - a water rocket built with HPR components

"This is the build log of our next rocket project called "The Shadow". This water rocket doesn't use PET bottles or FTC tubes as the basis for a pressure chamber. Many of the construction techniques are borrowed from the model rocketry world. Rather than scattering the development details of this rocket all over the flight log updates, we have decided to keep a dedicated page for this rocket's development. The flights of this rocket will still be in the regular flight log updates along with our regular development."

I would be interested to see just how fast and high a water rocket can go. For example, how about supersonic flight? Or a flight over two miles?

First posted over at The Rocket Dungeon where rocketry bloggers go to read rocketry blogs when they are not blogging.

## Saturday, December 17, 2011

### Photography of Nuclear Detonations - High Speed - Nuclear Explosion Induced Lightning

"This is an old Lookout Mountain Labs production which highlights some EG&G films of US nuclear weapons testing in Nevada and the Pacific during the 1950s.. Of special note are two views of the CASTLE BRAVO shot (I think) which show nuclear explosion induced lightning effects. Originally hosted on an MIT server. Color (cruddy). Length: ~11:33. Unrestored. Year unknown (probably mid to late 1950s). No sound. Not classified."

I have never heard of nuclear lightning, but there is some great footage in this video that is new to me, including what is clearly lighting around the early fireball of test shot Ivy Mike. (At that time, it was by far the largest explosion ever.) Here is information about this lightning phenomenon:

"We report the results of a unique study of the lightning like phenomena that were seen to accompany the MIKE shot of operation IVY on October 31 1952. MIKE was a thermonuclear surface burst yielding 10.4 MT, which took place on Enewetak Atoll. During the period of approximately 10 ms after detonation, five discrete luminous channels were seen to start from the ground or sea surface at a distance of approximately 1 km from the burst point and to grow up into the clouds. We have reexamined the original photographic records of IVY-MIKE, obtaining effective brightnesses (optical powers per unit length) for the luminous channels at different altitudes as functions of time. The absolute calibration for the MIKE records was deduced by comparison with the photographic records of other events of that era, laboratory measurements of film sensitivity, and use of atmospheric transmission data taken just prior to the MIKE event. Errors in this analysis lead to an uncertainty of a factor of ~2 in the brightnesses of the luminous channels. In the laboratory we have used laser-guided electric discharges to create long (100 cm), arclike plasma channels to simulate the observed luminous channels and to allow determination of an empirical relation between the brightness of the channel and the electric current flowing in the channel.

These laboratory discharges had peak currents up to 100 kA and periods of ~2 ms. Spectroscopic analysis showed that the luminous channels consisted primarily of normal air plasma with typical ground-level contaminants. Photographic studies showed that these long-duration discharges are unstable to the m=1 magnetohydrodynamic (MHD) instability and become severely distorted in less than 1 ms. By direct comparison of the luminous channels seen at MIKE and the laboratory discharges, we deduce:(1) the peak current in the prominent (brightest) channel at MIKE was between 200 and 600 kA. Here the most likely value of the peak current was 250+/-50 kA, but potential systematic errors in the film calibration and the comparison of MIKE and laboratory data make higher currents possible. (2) The rapid decline in the brightness of the luminous channels seen at MIKE is caused by a combination of the effects of the MHD instability, which eventually leads to a broadening of the current-carrying channel, and channel cooling by turbulent convective mixing."

An empirical study of the nuclear explosion-induced lightning seen on IVY-MIKE - Journal of Geophysical Research, Volume 92, Issue D5, p. 5696-5712 - Colvin et. al.

http://glasstone.blogspot.com/

I cannot confirm, and honestly do not agree with many of the points in this blog. Like a certain aerospace blog, I find the posts very useful even if they are mixed evenly with a political agenda. To their credit, the agenda is never really denied. The author goes to great lengths to explain why the damage cased by nuclear blasts is actually minimal compared to what we have all come to expect from the media, government, liberals, or whomever. From years of research, I have found that sometimes the popular perception overstates the damage caused in a nuclear war, and sometimes the military and government underestimate it instead. Most interesting is the statement that attacks on urban areas would not result in a firestorm as in Hiroshima. I feel this ignores the amount of oil, natural gas, various other flammable liquids, and paper in an urban environment. Clearly a city-wide firestorm is unlikely. How could a fire spread across the hundreds of square km of a city like New York? But widespread fires of somewhat smaller-scale (yet still hugely damaging) would occur. Direct attacks on New York City would certainly damage and probably ignite the refinery oil-in system across the river in New Jersey, and possibly tankers in queue there. These fires wont kill many people, but they will have important ecological and climatological impacts.

I shudder to imagine the impact of a 100 kt attack on the Jamnagar Refinery in India, the largest in the World. Not only is such an attack more likely, due to well known problems with Pakistan, now on the verge of being taken over by Islamic terrorists, but it is also the kind of "local exchange" or "regional nuclear exchange" that can have global repercussions in climate. Cities in India are much closer to Hiroshima of 1945 than one would hope, and they are still candidates for widespread fire of very dirty fuels such as wood, coal, textiles, various oils and flammable liquids, and paper. The amount of smoke and ash created in a "local" war (with perhaps 25 detonations from each party) is staggering. There would be millions of kg of dust and ash produced as a result, not to mention fine soot particles that can be lofted into the upper atmosphere with larger detonations. I won't even get into the nitrogen oxides and ozone.

Going back to World War III, the risk of firestorm is a minor concern because a full-scale attack on a large city would physically destroy most of the city with between 3 and 15 warheads of 200 - 900 kt yield, in the instance of New York or Chicago. Not only would most buildings be damaged directly (all structures being exposed to at least one 200 kt blast at a distance of only a mile or two, followed by other blasts at greater distance) but the amount of fallout that is likely to occur after such a disaster will indeed render the urban area fatal to anyone who remains above-ground for days at the least. There is simply no way to deny this, and one can assume that anyone who has not escaped the city before or just after the blast, or who is not indoors (with intact windows and a supply of water) or underground will eventually die as a result of radiation exposure. Remember also that there will be no medical care, so LD/50 exposures will be bumped up to mostly fatal.

This is a complex topic and there are many different factors to consider. In reaction to the claim that nuclear weapons are not as deadly for civilians as expected, and are mostly a military weapon designed to target strategic forces of the enemy, I have to disagree. Nuclear weapons always have been and always will be a credible threat to civilians. Nuclear weapon strategy will never again work as a counter-force only strategy (even if, for a short time, it did.) It does little good to deny the fact that nuclear weapons are designed to kill as many civilians as possible, and in that they achieve the primary purpose of any large scale war; to destroy the social and economic structure of an enemy. Nuclear weapons achieve this in a simple way; by killing a vast number of individuals and destroying the infrastructure of their society. There is no reason to doubt the fact that a carefully executed nuclear strike would achieve this goal.

### Zooming in on the center of the galaxy

"This zoom sequence stars with a view of the Milky Way. We zoom in towards the crowded central region, in the constellation of Sagittarius (The Archer). By shifting to an infrared red view we see through the dusty clouds in this direction and get a close up view of the objects orbiting the supermassive black hole that lies at the centre of the Milky Way. The final views show the motion of a newly-discovered gas cloud that is falling rapidly towards the central black hole.

Credit:ESO/MPE/Nick Risinger (skysurvey.org)/VISTA/J. Emerson/Digitized Sky Survey 2"

### Comet Lovejoy survives a swing around the Sun

This is remarkable not only because of the intense amount of heat at .25 solar radii, but also because of the strong gravitational gradient involved. But there is no reason why a large object, made of ice and rubble, should not have a shot at surviving this flight. Imagine melting 10 meters of ice, for example, even with an acetylene welding torch. Clearly it takes time to get the job done. Additionally, the non-volatile solids may help insulate deeper collections of ice.

## Friday, December 16, 2011

### Mohr Rocket - Boosted dart system

"Engineer Ernst Mohr of Wuppertal, under the auspices of the German Rocket Society, developed a sounding rocket that was designed to reach altitudes of 50 km. A solid rocket motor with 7800 kgf would take the separable payload section to a speed of 1200 m/s. The booster had a diameter of 0.30 m, a length of 1.7 m, a total mass of 135 kg including 75 kg of solid propellant. The payload dart was 56 mm in diameter, 1.25 m long, and had a total mass of 15 kg.

Payload: 5.00 kg (11.00 lb) to a 50 km altitude.

Status: Retired 1959.
Gross mass: 150 kg (330 lb).
Height: 2.95 m (9.67 ft).
Diameter: 0.30 m (0.98 ft).
Thrust: 76.00 kN (17,085 lbf).
Apogee: 50 km (31 mi). " - Astronautix.com

I love the shape of that booster. It is obviously not a modern looking rocket, but for a boosted dart, the extra drag imposed by the stubby first stage is minimal, particularly if there is a fast burn.

## Wednesday, December 14, 2011

### More Rapatronic Camera Images of Nuclear Tests

"The rapatronic camera (a contraction of Rapid Action Electronic) is a high-speed camera capable of recording a still image with an exposure time as brief as 10 nanoseconds (billionths of a second).

The camera was developed by Harold Edgerton in the 1940s and was first used to photograph the rapidly-changing matter in nuclear explosions within milliseconds of ignition. To overcome the speed limitation of a conventional camera's mechanical shutter, the rapatronic camera uses two polarizing filters and a Kerr cell. The two filters are mounted with their polarization angles at 90° to each other, to block all incoming light. The Kerr cell between the filters, which changes the polarization plane of light passing through it depending on the level of voltage applied, acts as a shutter when it is energized at the right time for a very short amount of time, allowing the film to be properly exposed.

For a film-like sequence of high-speed photographs, as used in the photography of nuclear and thermonuclear tests, arrays of up to 12 cameras were deployed, with each camera carefully timed to record a different time frame." Wiki

### Helium balloon from California to Mediterranian

The California Near Space Project launches conventional high altitude flights, as well as long range attempts (where the balloon travels at lower altitudes for long durations.) It appears that the latest launch is still going strong, now south of Italy. You can track flight K6RPT-11 here.

Some of the high altitude flights, those that end in a balloon burst at altitude due to expansion and UV degradation of the rubber, have gone into the upper 120,000 foot range. As always, this kind of performance gets me thinking about rockoons again. An N 10,000 at 100,000 feet would probably be good enough for a camera payload to space. But that is going to take quite a few balloons to get the job done. (Or a zero pressure balloon of massive size.)

## Tuesday, December 13, 2011

### Stratolaunch - the largest airplane ever

"Stratolaunch Systems is pioneering innovative solutions to revolutionize space transportation. Watch the video or visit http://www.stratolaunch.com to learn more."

It looks like a large Pegasus. The real question is the cost per launch, and they really need to get it down to a few million per launch. (At 15,000 lbs payload, I would like to see $5,000,000 per launch, compared to$30,000,000 per Pegasus at 1,000 lbs payload.) Short of a drastic decrease in price, or increase in launch rate, this type of complexity and the serious limitations imposed make it hard to justify. As always, the best solution is probably the big dumb rocket way with solid propellant in the booster stage. Reusable rockets, SSTO systems, or hybrid systems like this tend to cost too much money. The Shuttle is a key example of that problem.

This jet is unable to carry a rocket bigger than about 500,000 lbs. Will it impart enough additional altitude and forward velocity to make that worthwhile? Or are you (as is often the case) just better off going with a 1,000,000 lbs rocket from the ground?

## Monday, December 12, 2011

### Visitors from around the World

This page, initially only a modest side project, has taken over most of my blogging time. High Power Rocketry has a daily post rate of greater than one, and is closing in on 1,000 posts. Most of the readers are from North America, but a significant number are from other parts of the World. Here are the visitors from other nations during the past 12 months:

United Kingdom 5,382
Germany 4,675
Australia 2,913
France 2,024
Russia 1,885
Netherlands 1,450
India 844
Brazil 698

### Phobos Grunt update

The almost inevitable end is near: Phobos grunt will be destroyed upon reentry as seen in this artist rendition. But questions remain - will Russia try again? When will humans recover a sample from the Mars system?

December 8, 2011

Dear Colleagues,

As you may already know, the launch of the Phobos-Soil spacecraft was a failure. On November 8, 2011 the spacecraft was put into the near Earth orbit, however, the booster did not turn on, and, therefore, the spacecraft did not manage to change this initial orbit and transfer to the interplanetary trajectory. The reason of this failure has not been determined yet.

Immediately after this unpredictable event all forces of the mission control team were concentrated in order to attempt to establish communication with the spacecraft. Several foreign organizations, in particular, ESOC-ESA, DSN-JPL-NASA, NORAD-STRATCOM, numerous amateur observers tracked the spacecraft to establish communication with it and determine parameters of the orbit, its orientation and attitude. However, despite people being at work 24 / 7 since the launch, all these attempts have not yield any satisfactory results. We are grateful to our foreign colleagues, who provided us with every list of information about the spacecraft which was crucial at the time.

Currently, the spacecraft is rotating [tumbling] at the near Earth orbit, lowering every day, and we expect that it is to entry the atmosphere in several weeks. Lavochkin Association specialists will continue their attempts to establish connection with the spacecraft and send commands until the very end of its existence. We are working nevertheless on the issue of re-entry and probability of where and which fragments may hit the ground (if any). There is a sensitive matter that one of the scientific instruments (Messbauer spectrometer) contains radioactive material Co-57. However, the amount of Co-57 is about few (less than 10) micrograms, so that, according to our evaluations, no significant problems are is anticipated.

At present, the next steps of the Russian space science program on the Solar system exploration are being discussed. In accordance with the current plans, the next missions are Luna-Glob and Luna-Resource. As another possible additional step, at the moment ROSCOSMOS, ESA and NASA are discussing the collaboration on the ExoMars and Russian Mars-NET missions. Moreover, the Russian Academy of Sciences would like to prepare a new mission to Phobos. However, no decision has not been taken yet.

We would like to express our deep gratitude to You and all the scientists and specialists for collaboration on the Phobos-Soil Mission, preparation of scientific instruments and provision of ground support. We are deeply sorry about the failure of the Phobos-Soil Mission. We hope in future to continue our collaboration on space science projects.

Director, Space Research Institute
Chair, Solar system exploration Board

P.S. Please, convey this letter to members of your team. Thank you.

### The Whirlpool Galaxy

A composite image of the Whirlpool Galaxy (also known as M51). The green image is from the Hubble Space Telescope and shows the optical wavelength. The submillimetre light detected by SCUBA-2 is shown in red (850 microns) and blue (450 microns). The Whirlpool Galaxy lies at an estimated distance of 31 million light years from Earth in the constellation Canes Venatici Credit: JAC / UBC / Nasa

## Sunday, December 11, 2011

### Nuclear fireballs, rope-tricks, and isothermal spheres

Many of these images were taken with rapatronic cameras.

## Friday, December 9, 2011

### Shake table testing of JWST mirrors under various vibration stresses

"The James Webb Space Telescope will experience intense forces as it launches into space. To ensure that the different parts of the observatory won't suffer damage during this stage of the mission, engineers shake them rigorously. These two- to three-week-long vibration tests are performed on each of Webb's 18 primary mirror segments and the secondary, tertiary, and fine-steering mirrors. Engineers test the mirror's optics before and after each vibration test to confirm that the simulated launch left the mirror surface unscathed, without deformation or structural changes."

## Wednesday, December 7, 2011

### Armadillo Aerospace launches "Stig-a" to near space

"The launch of Armadillo Aerospace's reusable suborbital sounding rocket Stiga. Fueled by liquid oxygen and denatured ethanol, the rocket reached close to 140,000 feet above sea level."

What a great flight this is! And the footage is particularly nice. It is cool to see just how little drag the rocket experiences at apogee. The 'chute came out and barely caught any air.

I think the rocket is called Stig, and this is Stig model A. If I am wrong, please correct me. A bunch of other sources keep calling it "Stiga" as in the title for this video.

### 'Mythbusters' cannonball busts through house

"Strangely, it missed the trash cans, tore through a cinder-block wall, bounced its merry way down a hillside, barreled 700 yards through a suburban California neighborhood, smashed through the front door of a house, bounced up the stairs of the house and, without knocking, penetrated a bedroom door where a man, woman, and child were sleeping.

They were only woken after the cannonball had passed through. There was a little rubble and dust.

Was it done? Of course not. The cannonball then bounced its way out through the wall of the house, crossed a road, smashed a few tiles that were carelessly lying around on the roof of another house and finally took a seat inside the Gill family's Toyota Sienna, which they had thoughtlessly parked in the driveway of their home."

Cnet

Mythbusters has always been a bit of a tease show, light on science, but generally they are safe to a fault. It is hard to imagine how this cannonball could have maintained enough inertia to do so much damage.

## Monday, December 5, 2011

### NASA losing one astronaut every two months

Commander of final shuttle mission to leave nasa

And why should they stay? Under the, as the French say, craptastic space leadership of President Obama, manned space exploration from America has basically been forced in a 5 - 7 year dead zone. No American space missions of any import should be expected in that time. It would not be shocking to see 10 - 15 years elapse before any really ambitious steps are made forward to deep space. And all this in the 2010s, 40 years after the plans for deep space missions were worked out and the capability to make good on the missions was first available. There is no greater indication of our failure to innovate and inspire than the decline of NASA. You can eat your seed corn this year, and eat well, but you will surely starve next year. The NASA budget should be pegged to 1% of the federal budget. That alone would get us manned asteroid and Mars missions. There are plenty of reasons to hate Nixon (the war on drugs and for-profit medicine are two hallmarks that liberals like myself see right off the bat) but the worst thing he ever did was drastically cut funding for NASA at a time when the agency had just pulled off the greatest single achievement in human history. Because you know, once they do that, why would you want to see what they can do next?

## Sunday, December 4, 2011

If you like what you see, click here to see the rest of HPR.

## Thursday, December 1, 2011

### Schwerer gustav and dora railway siege guns

Close to 10,000 people have visited this post, making it by far the most popular. Over 100 views today alone! If you were searching for this topic, please leave a comment and let us know what you are working on.

### MSL Parachute Test

This is a huge 'chute that will apparently take the entire payload (minus heat-shield) from the end of the ballistic entry sequence, to before the operation of the skycrane system. I keep thinking this would go great with a S motor project. Maybe a full scale V2?

## Wednesday, November 30, 2011

### Ultralight nano metal material

"Ultralight (<10 milligrams per cubic centimeter) cellular materials are desirable for thermal insulation; battery electrodes; catalyst supports; and acoustic, vibration, or shock energy damping. We present ultralight materials based on periodic hollow-tube microlattices. These materials are fabricated by starting with a template formed by self-propagating photopolymer waveguide prototyping, coating the template by electroless nickel plating, and subsequently etching away the template. The resulting metallic microlattices exhibit densities ρ ≥ 0.9 milligram per cubic centimeter, complete recovery after compression exceeding 50% strain, and energy absorption similar to elastomers. Young’s modulus E scales with density as E ~ ρ2, in contrast to the E ~ ρ3 scaling observed for ultralight aerogels and carbon nanotube foams with stochastic architecture. We attribute these properties to structural hierarchy at the nanometer, micrometer, and millimeter scales."

Science Mag

## Monday, November 28, 2011

### Visitors to Mars

And now we can add MSL to the list:

### The square kilometer array

This will be one of the most important leaps in astronomy to date. Sadly the USA was not even a serious contender for hosting this project, as we continue to fall behind in high technology and science. It is worth mentioning that a similar, highly ambitious project was planned here called "Cyclops" way back in 1971. It goes without saying that funding never arrived.

## Sunday, November 27, 2011

### Beer in (near) space

Meh, every balloon flight that goes up without a rocket is a waste :)

### Amateur astronomer captures disk around distant star

This is a very challenging thing to do, particularly with a 10 inch reflecting telescope. Impressive indeed!

## Thursday, November 24, 2011

### Fourth generation nuclear weapons

"The fourth chapter is devoted to fourth generation nuclear weapons. These new fission or fusion explosives could have yields in the range of 1 to 100 ton equivalents of TNT, i.e., in the gap which today separates conventional weapons from nuclear weapons. These relatively low-yield nuclear explosives would not qualify as weapons of \emph{mass} destruction. Seven physical processes which could be used to make such low-yield nuclear weapons, or to make compact non-fission triggers for large scale thermonuclear explosions, are investigated in detail: subcritical fission-burn, magnetic compression, superheavy elements, antimatter, nuclear isomers, metallic hydrogen and superlasers (i.e., ultrapowerful lasers with intensities higher than 1019 W/cm2).

The conclusion stresses that considerable research is underway in all five nuclear-weapon States (as well as in several other major industrialized States such as Germany and Japan) on ICF and on many physical processes that provide the scientific basis necessary to develop fourth generation nuclear weapons. Substantial progress has been made in the past few years on all these processes, and the construction of large ICF microexplosion facilities in both nuclear-weapon and non-nuclear-weapon States is giving the arms race a fresh boost. The world runs the risk that certain countries will equip themselves directly with fourth generation nuclear weapons, bypassing the acquisition of previous generations of nuclear weapons."

Nuclear Weapon Archive

And if you can read with a heavy grain of salt, here is some extreme speculation on what various future nuclear technologies may bring including nuclear shaped charges:

Physics Forum Keep in mind that several posts here fall into the realm of pseudo-science.