Oct 192023
 

There are several ways to accomplish the goal of extracting maximum performance from a solid rocket motor via the nozzle. The most common way – a convergent-divergent nozzle – is the standard for a reason: it’s the simplest, lightest most reliable way to do it. But there are alternatives that provide specific advantages. One of them is the “forced deflection nozzle.” Instead of a single circular throat, the nozzle has several; instead of directing the exhaust gas due aft, it forces it “sideways” to smack into the broader, shallower nozzle.

The advantages here:

1: The nozzle is sort of a hemispherical bowl, rather than a long, slim cone or paraboloid.

2: It provides some altitude compensation, similar to an aerospike.

There are also disadvantages, not least of which is that the throat is now under substantially greater thermal and dynamic forces. Few materials known to Man will be able to long withstand the high heat load and erosive forces. But in 1986, Aerojet proposed to develop such a nozzle for a singular purpose: to integrate into future ICBMs. The reasoning was… the bowl-like nozzle fits the bowl-like forward dome of the lower stage. Instead of a long interstage structure being required, the stages fit together neatly. in principle this would allow ballistic missiles to be more compact, shorter by useful distances. This is not very important for space launchers, but for missiles that need to fit into silos, submarines, bomb bays or Shuttle cargo bays, extra space means extra capacity.

 

 

Diagram showing a conventional 3-stage solid rocket ICBM against three concepts making use of the forced deflection nozzle. You could have a much shorter vehicle with equivalent weight and payload, or same-length boosters with 28.4% greater range for the same payload, or 33% greater payload for the same range.

 Posted by at 2:19 pm
Aug 182023
 

Thanks to ebay and my fabulously lean bank account, I have recently procured a number of items of potential interest:

“NASA Earth Orbital Space Station,” a poster-sized lithograph from McDonnell Douglas depicting a space station that tumbles for artificial-G.

“Re-Entry Payload Launch Vehicle,”  A *brief* General Dynamics presentation on a vehicle to launch re-entry vehicles such as MIRV warhead shapes

 

“Proposed Development Program on Rocket-Type Missiles,” a 1948 Convair report on early ballistic/boost glide missile concepts, that would lead to Atlas. Includes some fantastic large format layout diagrams.

 

“Detail Specification for Consolidated Vultee Model 117 Airplane Class VR Transport Flying Boat,” August 1950, all the details on the then-brand new Tradewind.

 

 

“Detail Specification for Class VP Long Range Patrol Seaplane,” Consolidated Vultee 1946, all the details on a proposed flying boat patrol/bomber

32 issues of “Astronautics” magazine from 1957 to 1969, mostly 57-59 and 63 or so.

The lithograph and the reports will be scanned and put forward for consideration for monthly rewards; the magazines will have the interesting bits scanned and made available to the subscribers/patrons.

 Posted by at 6:21 pm
Jun 062023
 

I put one copy of each of my current books on ebay. They’re all in brand-new condition, and will be signed/dated when sold. They also come with bonus 18X24-inch prints… the “SR-71” book has two prints of the SR-71, the “B-47/B-52” book has one B-47 diagram and two B-52 diagrams; “US Supersonic Bomber Projects Vol. 1” has two B-70 Valkyrie diagrams. Take a look…

 

Lockheed SR-71 Blackbird (Origins and Evolution): Signed, with bonus prints

Boeing B-47 Stratojet and B-52 Stratofortress: Signed, with bonus prints

US Supersonic Bomber Projects Volume 1:  Signed, with bonus prints

 

 Posted by at 10:37 pm
May 212023
 

My next book, released for pre-order and to be shipped in a few weeks:

US Supersonic Bomber Projects 2

“The threat posed by the Soviet Union throughout the postwar period coincided with an explosion of innovation and can-do attitude among America’s aircraft manufacturers. Challenging requirements and experimentation resulted in a huge variety of designs for aircraft powered by nuclear reaction, aircraft capable of flying faster than Mach 5, advanced bombers able to land and take-off from the surface of the ocean, VTOL fighters and bombers, and many others. Aerospace engineer Scott Lowther collects some of the most radical and beyond-the-state-of-the-art ‘secret projects’ in this – the second volume of his US projects series.”

 Posted by at 12:36 pm
May 132023
 

Stratolaunch Successfully Completes Separation Test of Talon-A Vehicle

Stratolaunch LLC announces it has successfully completed a separation release test of the Talon-A separation test vehicle, TA-0. The flight was the eleventh for the company’s launch platform Roc and the second time the team has conducted flight operations in Vandenberg Space Force Base’s Western Range off California’s central coast.

 

 Posted by at 7:23 pm
Feb 152023
 

I’m selling the blueprints I’ve recently made. I can sign ’em if the buyer wants, front or back…

Saturn Ib Inboard Profile Cyanotype Blueprint

NERVA nuclear rocket engine Cyanotype Blueprint

NERVA nuclear rocket engine artwork Cyanotype Blueprint

Boeing 2707-200 SST Cyanotype Blueprint

Trident II SLBM Cyanotype Blueprint

Northrop B-2A stealth bomber Cyanotype Blueprint

A-4 (V-2) German Rocket Isometric Cutaway Cyanotype Blueprint

A-4 (V-2) German Rocket Isometric Cutaway Cyanotype Blueprint: Smaller

Wasserfall German WWII Surface to air missile Cyanotype Bluepri

 

USS Monitor Ironclad Cyanotype Blueprint

550 Central Park West Cyanotype Blueprint

Lunar Excursion Module (LEM) Cyanotype Blueprint

X-20 Dyna Soar/Titan IIIC Cyanotype Blueprint

Early X-20 Dyna Soar Cyanotype Blueprint

 

 

 

 Posted by at 4:03 pm
Jan 022023
 

The December 2022 rewards are available for APR Patrons and Subscribers. This latest package includes:

Large Format Diagram: AWACS model diagram

Document: “Preliminary Design of a Mars Excursion Module,” 1964 conference paper, Philco

Document: “Astronauts Memorial” 2 diagrams

Document: “Patrol Reconnaissance Airplane Twin Float,”  Convair brochure (via photos), 1944. Two piston engines, two turbojets

Document: “Hard Mobile Launcher,” Martin Marietta PR, two images. One photo, one artists impression

Document: “JVX Space Proposal” apparently a fragment, 1984 Bell maps of manufacturing facilities for what would become the V-22

Document: “Minimum Man In Space,” 1958 NACA memo describing proposals made to Wright Air Development Center for what would become the Mercury program

If you would like to help fund the acquisition and preservation of such things, along with getting high quality scans for yourself, please consider signing on either for the APR Patreon or the APR Monthly Historical Documents Program. Back issues are available for purchase by patrons and subscribers.




 

And because I forgot to post about it at the time, the November 2022 rewards were made available a month ago:

Large Format Diagram: B-50A Superfortress Model Diagram

Document: “Design Study of a One Man Lunar Transportation device,” 1964 North American Aviation conference paper on a rocket “hopper”

Document: “Project EGRESS (Emergency Global Rescue, Escape and Survival System),” 1964 Martin conference paper on ejection capsule for aerospacecraft

Document: “The Hydrogen Fueled Hypersonic Transport,” 1968 Convair conference paper

CAD Diagram: Mach 3 turbojets: Allison 700 B-2 (J89), GE YJ-93-GE-3 (cutaway), P&W J58

If you would like to help fund the acquisition and preservation of such things, along with getting high quality scans for yourself, please consider signing on either for the APR Patreon or the APR Monthly Historical Documents Program. Back issues are available for purchase by patrons and subscribers.




 Posted by at 10:52 am
Nov 182022
 

A mere sixteen years ago I posted artwork of the Martin “EGRESS” ejection capsule meant to fling crew from a stricken spacecraft anywhere up to and including orbit. Those scans came from photocopies of a conference paper. I have at last now scanned the same work, producing slightly better results. The artwork is remarkable for one detail in particular: of the two crewmen, one is clearly Lance Squarejaw, wholly unfazed at his situation. The other is… not unfazed. I’d pay real money to get at the original color painting.

 

The whole thing – diagrams and art scanned at 600 DPI – will be offered up to APR Patrons & Subscribers soon.

 

 Posted by at 4:59 pm
Nov 102022
 

Atlas launch to test inflatable heat shield

 

A United Launch Alliance Atlas 5 is scheduled to lift off from Vandenberg Space Force Base in California at 4:25 a.m. Eastern Nov. 10. The primary payload of the rocket is the Joint Polar Satellite System (JPSS) 2 weather satellite …

A secondary payload on the launch of JPSS-2 is Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID), a NASA technology demonstration. While JPSS-2 will be deployed nearly a half-hour after liftoff, LOFTID will remain attached to the Centaur until 75 minutes after liftoff, following a deorbit burn of the Centaur.

Shortly before deployment, LOFTID will inflate a reentry shield six meters in diameter. That heat shield will slow down the vehicle from orbital velocity to Mach 0.7 as instruments on board collect data on the performance of the shield. LOFTID will then deploy parachutes to slow it down for the rest of its descent, splashing down in the Pacific east of Hawaii to be recovered by a ship.

Inflatable heat shields have been studied since before humans flew into space. Normal heat shields need to withstand insanely high temperatures, requiring materials that are either insanely expensive and complex, or that involve complex, fragile and heavy active cooling systems (such as water cooling through transpiration), or which are ablative. The latter variety is technologically fairly simple, but ablatives tend to be heavy and they are labor intensive to apply and make reusability difficult.

With temperatures reaching several thousand degrees, inflatable materials would seem inappropriate for heat shields. But those high temperatures are not a mandatory feature of re-entry. To a first hand-wave approximation, the maximum temperature is proportional to the mass-per-surface-area of the re-entry vehicle. A one-ton vehicle is going to have to shed all of its orbital velocity, converting all that kinetic energy into thermal, regardless of the size or shape or cross-sectional area. The way that is done is by compressing the air the vehicle slams into; the heating isn’t due to friction, but to the compression of the gas. If you can spread that heating energy out wider… the gas doesn’t heat up as much per unit surface area. Heating can be reduced from the sort of thing that will melt tungsten to the sort of thing that can be survived by advanced polymer fibers. As a bonus, the inflatable shield, being far larger than the solid shield on the vehicle, provides drag all the way down. In principle it would be possible to dispense with parachutes, wings, retro-rockets, and simply drift down using the shield as an inverted parachute. This was the case for the Douglas “PARACONE” concept from the mid-1960s, designed for, among other uses, as an emergency “life boat” for astronauts in space. It would provide for a safe entry, deceleration and touchdown on either land or water.

 Posted by at 5:15 pm
Nov 012022
 

The October 2022 rewards are available for APR Patrons and Subscribers. This latest package includes:

Large format art: A Bell Aerospace painting of the D188A VTOL fighter/bomber

Document: “Standard Aircraft Characteristics – Convair Class VF Seaplane Night Fighter (SKATE)” diagrams and data for seaplane jet fighter

Document: “21St Century Aerospace – The 20th Century Challenge,” General Dynamics presentation, late 80’s about hypersonics/NASP. From photographs.

Document: “Prototype X-14 VTOL Aircraft,” Bell Aerospace presentation, 1971, on the “SeaKat” operational naval VTOL. From photos, but art and diagrams were also scanned for clarity.

CAD Diagram ($5 and up): XB-70 Valkyrie forward fuselage configuration

 

If you would like to help fund the acquisition and preservation of such things, along with getting high quality scans for yourself, please consider signing on either for the APR Patreon or the APR Monthly Historical Documents Program. Back issues are available for purchase by patrons and subscribers.




 Posted by at 12:23 am