Oct 152013
 

For some pretty reasonable reasons, 3D printing of metal components lags a bit behind that of polymers. The best metal components I’ve seen look pretty rough, while some high-end plastic parts are optically smooth. Still, progress is being made:

Amaze project aims to take 3D printing ‘into metal age’

Tungsten alloy components that can withstand temperatures of 3,000C were unveiled at Amaze’s launch on Tuesday at London’s Science Museum.

Tungsten. Yow. Lots of rockets use tungsten alloys in the throats due to the hardness and heat resistance of the metal. But manufacturing tungsten components is amazingly difficult for those same reasons. If these 3D tungsten parts of are adequate strength and smoothness, there just might be a revolution in small rocket engines.

I wonder if 3D printing can make tungsten components that have silver mixed in. Back when I worked on booster sep motors for the Shuttle at UTC, NASA became interested in tungsten throat inserts that were “silver infiltrated.” By mixing silver in with the tungsten, the thermal conductivity of the tungsten could be substantially improved. And while tungsten can take a hell of a lot of heat, it will merrily melt if brought to the combustion temperature of mundane solid propellants. By increasing the thermal conductivity, hot-spots in the tungsten can be smoothed out. The result would be a more survivable – and more reusable, thus cheaper –  throat insert. This might not be of much value for a, say, Sidewinder air-to-air missile… but it might be pretty good for a Sidewinder model rocket using high-end amateur rocket motors.

 Posted by at 11:42 am
Oct 142013
 

What you call a “slow news day:”

Converted Ballistic Missiles Could Launch Aid to Disaster Zones

Before anyone gets too worked up, this idea springs not from some tax-dollar-spewing government think-tank, but from a grad student in Tokyo.

The idea: a natural disaster strikes the Middle of Nowhere. Ships will take forever to get there; planes can’t. So… put medicine, electrical generators, whatever, onto the fronts of decommissioned ICBMs and launch into the disaster zone. Supplies can be on-site in an hour or less. One one hand… sure, you could do that. On the other hand… ah… no.

1) Launching ICBMs can make other nations twitchy.

2) ICBMs, even decommissioned ones, are *expensive* and the payloads are small.

3) How good is your targetting? And is a generator falling out of the sky what the people on the ground really need?

4) Airplanes can be there in a few hours. If they can’t land – rough terrain, no runways, etc. – they can always do the Berlin Air Lift Candy Bomber thing and chuck relief supplies out the back under parachute.

Personally, my biggest issue is #2. Unless your Intercontenental Ballistic Package Delivery System is kept in a state of constant readiness – and that’ll cost a lot – it’s going to take a long time to get it ready to launch. So ICBMs just seem a poor choice here. However… there is a forthcoming alternative: rocketplanes.

The likes of XCOR’s “Lynx” suborbital rocketplane will, if it works out, turn out to be a vehicle with performance that at least kinda-sorta approximates ICBMs, and will by definition be kept in a virtually constant state of readiness, and will by definition be relatively cheap. Lynx is rather small, of course, and on its own couldn’t carry much very far; but put an upper stage on it, as XCOR plans to do, and you can put a payload into orbit… or halfway across the planet. Does this make economic and logistical sense? Well… still, probably “no.” But I think it makes less un-sense than expending an ICBM. And Lynx will, hopefully, be just the first, small generation; follow-on craft will be bigger and more capable. I can imagine that a successful suborbital tourism rocketplane might lead to a 737-sized suborbital transport rocketplane, carrying a few dozen passengers across oceans in a matter of minutes; this sort of vehicle would, with the aid of a simple pop-up stage, be able to toss quite a payload of band-aids at a disaster zone.

Of course, if such a system becomes available, it’ll still need to be kept in a state of readiness. And how best to do that? By constant operations. Going on a century ago, a lot of people were sure that the future of rocketry was bound up in  postal rockets… shooting mail across the miles via rocket. That of course didn’t work out, and it likely wouldn’t work out today; in the era of email, there’s just not enough mail to justify it. But you know what we’re not going to run out of anytime soon? Crazy people. Any rocketplane-based suborbital payload delivery system that can send a meaningful disaster-recovery payload across the planet can also fire quite a number of high-paying adrenaline junkies out into space. Not in a capsule, mind you, but in little more than space suits. Lob ’em up there in a pop-up stage that looks like any conventional upper stage… rockets and tankage to the rear, cylinder-cone payload shroud at the front, with the passengers sitting inside the shroud as if they were in a bus. As the people-pod exits the atmosphere, blow the “top” off the shroud (or have it split and fold aside) so that the passengers are now sitting in a “convertible,” exposed to space. Then let ’em jump… to continue to ascend, hit apogee and then descend, re-enter and come down on chutes. You *know* that there would be a line around the block for spacediving. This would spur innovations in astronaut maneuver systems, as the spacedivers would want simple and reliable maneuver capability so that they could link up like parachutists do, as well as drive innovations in *cheap* space suits. The upper stage would be recoverable and resuable; probably coming down on chutes. But install bigger chutes, and it could come down loaded with bandaids, meds, generators and perhaps even a doctor or two (presumably wearing space suits and yelling “XTREME!” all the way down.)

Back to the original idea: it’s not new. Not by a long shot. In the late 1950’s the US Army studied using the Redstone rocket as a battlefield cargo delivery system, lobbing weapons and ammo at Our Boys; they even examined launching Our Boys with the Redstone and Jupiter missiles. This led to the Douglas ICARUS concept… a modified Single Stage to Orbit launcher meant to fire 1,200 fully-armed Marines across the planet. More on all these ideas HERE. None of these were ever built.

 Posted by at 10:56 am
Oct 132013
 

This Boeing artwork depicts the late-1970’s concept for a receiver station on Earth for the energy transmitted from an orbiting solar power satellite. The SPS would convert sunlight into electricity, and then into a tightly collimated beam of microwaves; this would be captured at ground level by a vast receiver. Since microwaves are fairly easily captured, the receiver would appear as not a whole lot more than a vast elliptical field of chickenwire. Sunlight, wind and rain would pass right through it, thus the underside, as the painting depicts, could be conventional farmland.

Most of the time I’ve seen this painting reproduced it has been black and white; this rendering, scanned from Gatland’s “Space Technology,” is the only one I know of in color. Anyone have the full-rez version?

solar power satellite 2 2013-10-10

 Posted by at 5:58 am
Oct 122013
 

Earlier today, there was a 17-state failure of the EBT (Electronic Bank Transfer… cards that transfer money from taxpayers to the politically correct nonproductive) system which resulted in EBT cards not working at many grocery stores. Sadly, this system failure was not a result of the government shutdown, but just a glitch:

Access restored for food stamp users, Xerox says

This would have been a perfect opportunity to roll out a wholly revised welfare system, such as the Free Food Loaf proposal I made a while back. Perhaps unsurprisingly, it seems that a number of people who are so grindingly poverty stricken that they can only hope to survive by the use of wealth transfer systems like EBT promptly fired up their laptops, netbooks and smartphones to comment about it on Twitter:

‘Riot time!’: Food stamp users in near-panic over EBT card failures

… where you can read some people saying that the proper response to their not being able to buy a bag of potato chips on someone else’s dime is to commit *murder.* In this age of the NSA knowing every thing about every body, those responsible for the EBT system should check out these comments, find who is making the violent threats and cancel their EBT cards and other welfare payments. Not going to happen, of course, but a guy can dream.

———-

IN other news relevant to ideas I’ve had before:

Grand Canyon And Other National Parks Reopen, On States’ Dime

Arizona, Utah, South Dakota and other states -including New York – have decided to open up a number of National Parks using their own money. This, as I’ve suggested, would be a good time for states to use eminent domain to appropriate Federal lands that are being poorly run.

 Posted by at 8:44 pm
Oct 122013
 

The galaxy, it seems, is lousy with planets. Within my lifetime the sum total of known planets has gone from nine  to now about one thousand, an expansion of mankinds understanding of the universe not seen since stars were recognized as actual suns. A newly discovered exoplanet, PSO J318.5-22, is in some ways fairly mundane… a gas giant about six times as massive as Jupiter (large gas giants make up a large fraction of the so-far discovered exoplanets for the simple fact that bigger worlds are easier to detect). It has an interesting feature though… it has no star. Like Bronson Alpha from “When Worlds Collide” PSO J318.5-22 is simply floating through interstellar space without a star to warm it. As a result, it’s really cold.

Lonely Alien Planet Discovered Without a Parent Star

The Pan-STARRS 1 telescope in Maui, Hawaii, detected the faint heat emitted by the planet. This is a fairly impressive feat given that the planet is almost certainly cryogenically cold… and 80 lightyears away.

Also: a useful website, the Extrasolar Planet Encyclopedia. As of this writing, the catalog lists 998 planets.

 Posted by at 12:17 am