Mar 092018

Advanced “space guns,” typically lasers, railguns, coilguns, neutral particle beams and the like, have a problem: power. Nuclear reactors and solar panels can provide power for years at a time, but generally their steady-state power output is only a tiny fraction of the instantaneous power needed when the gun goes off. So to run a weapon that needs many gigawatts for a fraction of a second with a powerplant that produces kilowatts, you need an energy storage system that can convert that energy into power on a moments notice. Things like batteries are great in principle, but their weight is vast and their ability to release power at the high levels needed is generally poor.

Often this has resulted in space weapons that use chemical reactions to provide the power needed. This has meant that the total number of shots that can be fired is strictly limited.

In the 1980’s during the SDI heyday, Westinghouse looked at an alternate approach: rotating hoops. Giant wheels made of advanced composite materials would be spun up over time by a low-power system such as a nuclear reactor, and when needed these flywheels would be electromagnetically braked to generate vast amounts of power as the wheels ground to a  halt. The system could be “reloaded” by slowly spinning the wheels up again… assuming the system hadn’t torn itself part.

The weapon shown below is probably largely notional, no masses or dimensions were given. But based on a smaller terrestrial unit (with ten hoops, each 14.5 meters diameter, massing 140,000 kg each, spinning at 1800 RPM to deliver a total of 1 gigawatt for 10 minutes to power anti-missile lasers and such), this can be assumed to be a fairly *vast* construction, far heavier than anything mankind has so far launched into orbit. Obviously such a thing would be impossible to launch as a unit; it would be assembled in space using spools of fibers wound in place. Presumably the weapon itself would be at least somewhat aimable independent of the flywheels… slewing *them* about to aim at a moving target would seem to be an exercise in futility.

This came from the paper “Rotating Hoop, Pulsed-Energy Converter” contained in “Transactions of the Fifth Symposium on Space Nuclear Power Systems.” A PDF of that can be downloaded if you go HERE and click the “PDF” button.

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 Posted by at 4:23 am
Feb 282018

The L-2000 was Lockheed’s entrance into the mid-1960’s FAA contest to design and develop an American supersonic transport. The FAA wanted the US to have an SST substantially better than the Anglo-French Concorde, with up to 250 passengers and a cruise speed of up to Mach 3 (as fast as an SR-71). Interestingly, the Concorde was not expected to be a long0lived design, but rather was simply going to be the *first* SST, a technology demonstrator, a diplomatic endeavor between historic enemies Britain and France, a flying sales brochure for Angle-French industry. And the Tupolev Tu 144 was an attempt to put something, *anything*, into the air first.

In the end, the FAA selected the Boeing 2707 design, ending the L-2000. And after great promise was shown, politics killed the Boeing 2707, ending substantial forward progress in civil aviation. Since then, air flight has gotten cheaper and more efficient, but it has not gotten any faster… and it certainly hasn’t become more comfortable.

This artwork depicts an earlier configuration with a simpler, less elegant shape.

I’ve uploaded the full rez scans to the 2018-02 APR Extras Dropbox folder, available to all current APR Patrons at the $4 level and above. If you are interested in this and a great many other “extras” and monthly aerospace history rewards, please sign up for the APR Patreon. Chances are good that $4/month is far cheaper than your espresso/booze budget!


 Posted by at 11:03 pm
Feb 272018

Rewards have been issued to APR Patreon patrons for February, 2018. This month, the diagram is a 1/40 scale B-52B diagram. Normally the diagrams are sent out at full 300 dpi (with 125 dpi for the $1.25 patrons), but at 300 dpi the diagram is simply Way Too Big at over 40,000 pixels wide. Most image viewing programs will simply go “nope”and refuse to even try to display such images. so this month the image is sent out at 200 dpi (still slightly over 30,000 pixels wide), and 83 dpi for the $1.25 patrons. The 83 dpi version is also included for the higher level patrons for easier viewing.

Also: the documents this month include a United Aircraft paper on advanced future space propulsion systems as seen from 1969, and a January 1953 Douglas Aircraft design study for the DC-8. The CAD diagram this month is the Ganswindt Weltenfahrzeug… a truly terrible design for a spaceship from 1899. Terrible though it may be, it one of the first designs that is clearly in the Project Orion family tree…

If you are interested in helping to preserve (and get copies of) this sort of thing, consider signing up for the APR Patreon.



 Posted by at 3:38 pm
Feb 252018

Almost forgotten these days is the Fairchild XC-120 “Packplane,” the single example of which flew from 1950 to 1952. It was a cargo plane with a difference… the cargo was carried not in the fuselage, but in a replaceable “pod” carried below the flat-bottomed fuselage. It would permit the carriage and easy swapping of specialty pods… surgical units, housing, that sort of thing. An interesting notion, but not interesting enough to merit production.

Like a lot of aircraft, not a whole lot of good diagrams of the XC-120. I found a kinda horrible copy in a report, split into several pieces, and stitched it back together.

I’ve uploaded the full-rez version to the APR Patreon Extras Feb 2018 folder, available to all APR patrons at the $4 level and higher.

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 Posted by at 10:50 pm
Feb 192018

The NERVA nuclear rocket, studied throughout the sixties into the early 1970’s, would have been a great way to propel spacecraft. But a nuclear rocket is not the same sort of reactor as is generally designed for use in space to generate electrical power. A NERVA can produce *gigawatts* of thermal energy, energy which is carried away with the high mass flow rate of the hydrogen propellant. Power reactors, on the other hand, are generally designed for several orders of magnitude lower thermal power… a few thermal megawatts, perhaps, to produce a few hundred kilowatts of electricity.

However, the fact remains that a nuclear rocket *is* a nuclear reactor. For most missions it would burn for a few minutes, at most perhaps  few hours, out of a mission lasting perhaps years. It is thus a bit of a shame to waste all that potential. So over the decades many studies have been made for using a nuclear rocket as a power generator .

One such study was reported by Aerojet in 1970. The abstract is HERE, the direct PDF download if HERE.

In this study, the NERVA would pump out 1,500 thermal megawatts during the propulsion phase(producing 75,000 pounds of thrust), dropping to 250 to 505 thermal kilowatts during the power generation phase, enough to create 25 kilowatts of electricity. This would be a very low-power, low-temperature use of the reactor, reducing system efficiency… but still, making use of a reactor that was already there, and not noticeably using up the fission fuel in the reactor. The reactor would be run at very lower power levels and hydrogen would flow through a closed loop built into the reactor; the warmed gaseous hydrogen would flow through a turbogenerator to create electricity; the warm hydrogen would then pass through a radiator built on the outer surface of the hydrogen tank itself.

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 Posted by at 3:27 am
Feb 182018

A few decades before the “X-Wing” configuration gained a measure of popularity, Hughes Tool Company made a detailed study of a somewhat similar concept, the “rotor/wing.” This was a three-bladed helicopter rotor attached to a large central lifting surface, either a circular disk or a triangular structure. The rotor was not turned the conventional way with a turbine engine turning a drive shaft, but instead the engine exhaust was ducted through the center and then out to nozzles at the tips of the rotors. Jet thrust would spin the rotors without transmitting torque to the rest of the vehicles; as a consequence only a small tail rotor would be needed, just powerful enough to orient the craft at low airspeeds.

A few configurations were produced, most of which looking much the same. Probably the most well known configuration was shown in US VTOL Projects 01. Shown below is a lesser-known configuration designed for anti-submarine use. Normally the configurations included the turbojet engines within the upper fuselage, close to the hub of the rotor, but this one rather bizarrely put the engines on the tail. No obvious means of ducting the exhaust to the rotor is evident, so presumably a third (or even fourth) engine was tucked into the fuselage somewhere.


 Posted by at 2:21 am
Feb 132018

Now available: two new US Aerospace Projects issues. Cover art was provided by Rob Parthoens,

US VTOL Projects #2

US VTOL Projects #2 is now available (see HERE for the entire series). Issue #2 includes:

  • SOS Interceptor: A US Navy Mach 3 aircraft with jettisonable wings
  • Lockheed GL-224-3: A small battlefield surveillance and ground attack plane
  • Phalanx Dragon MP-18: An unconventional  small civilian transport
  • Lockheed L-161-1: An early concept for a variable geometry roadable helicopter
  • GE Supersonic V/STOL: A supersonic strike fighter with flip-out lift fans
  • Convair ANP-VTOL: A nuclear-powered ground-effect craft of the Navy of unusual configuration
  • Piasecki 16H-3: A compound helicopter for high speed passenger transport
  • Boeing Vertol Model 147: A tilt-wing close support fire support design for the US Army

USVP #2 can be downloaded as a PDF file for only $4:


US Research & Recon Projects #2

US Research & Recon Projects #2 is now available (see HERE for the entire series). Issue #2 includes:

  • Lockheed A-1: The first true design leading to the SR-71
  • Bell MX-2147 Model 105: The high altitude “X-16”
  • Boeing/CRC/AMROC X-34 Reference Configuration: A reusable launcher test vehicle
  • Martin Model 159: A scout/observation float plane
  • NASA-Langley Low-Boom Demonstrator: a recent design to demonstrate quiet SST tech
  • McDonnell-Douglas DC-9 Super 80 Propfan Configuration 1: A fuel efficient transport demo
  • Convair “HAZEL” MC-10: An inflatable Mach 3 plane for the Navy
  • Republic Manned Hypersonic Reconnaissance Vehicle: an early scramjet concept


USRP #2 can be downloaded as a PDF file for only $4:


 Posted by at 12:53 pm
Jan 312018

Recently sold on ebay was an apparently old display model. It came without markings, stand or engine nacelles, which were obviously formerly pinned to the rear fuselage in the usual bizjet position. So just what it is is unknown, but it looks too good to be Just Some Guys kitbash. But what it *is* is a headscratcher. It’s clearly a B-1 bomber forward fuselage grafted to a bizjet fuselage, but for what purpose I can’t guess. It doesn’t make sense to use a supersonic bombers cockpit as the cockpit of a small corporate jet, even as a way to utilize existing manufacturing infrastructure. Might it have been meant as a training plane, to teach future B-1 pilots the fine art of flying a Bone? A flying laboratory for the B-1 cockpit to make sure it was set up right?

Or did someone down at the model shop just get a little likkered up?

It appears t be a B-1A cockpit, dating it to the mid/late 70’s.

 Posted by at 11:21 pm
Jan 302018

A fanciful late 1950’s Martin Company illustration of a space station. This rendering features a large parabolic solar reflector to concentrate sunlight onto a boiler to run a turbogenerator for electricity, a hockey-puck shaped habitation section (you might think it was meant to rotate, but there are windows in the floor *and* a group of astronauts seemingly standing on the side of the thing, somehow not getting flung off), some standard 1950’s gee-whiz rocketships and something at far right that I can only describe as “a thing.” Maybe it’s meant to represent the radiator for the solar generators working fluid, but if so, it seems a terrible design. Maybe it’s the death ray.

 Posted by at 11:04 pm