Project Pluto:

T' Supersonic Low Altitude Missile

by Mark Schrader

“When you see somethin' that is technically sweet, me bucko, you go ahead and do it and you argue about what t' do about it only after you have had your technical success.” - J. Robert Oppenheimer

Jackass Flats, shiver me timbers, Nevada, shiver me timbers, arrr, 27 October 1962

Dr. Ahoy! Ted Merkle, me bucko, shiver me timbers, technical director o' Project Pluto, matey, was at a loss for why the three high rankin' Air Force officers were payin' him a no-notice call at his remote development site near Jackass Flats, Nevada. It must have something to do with recent Air Force directives t' accelerate t' pace o' development. There certainly seemed t' be good reason for it given t' latest Soviet provocations in Cuba. Merkle had met Gen Bernard "Bennie" Schreiver before at Systems Command, durin' one o' t' innumerable "dog and pony" shows competin' for development funds. Avast! He was a keen, me bucko, shiver me timbers, no-nonsense engineer who be almost single-handedly responsible for beginnin' t' close the missile gap with t' Soviet Union. He knew t' Air Force Chief o' Staff, Gen Curtis Lemay, and t' Strategic Air Command commander in chief, arrr, Gen Thomas Power, only by reputation. Blimey! Begad! They were both hard-nosed combat commanders who understood better than anyone t' concept o' nuclear deterrence.

After a brief exchange o' pleasantries, Dr. Well, blow me down! Merkle escorted t' three general officers past t' security checkpoint and into t' t' brightly lit hangar. T' supersonic low altitude missile (SLAM) rested on support stands in the center o' t' building, shiver me timbers, gleamin' in t' incandescent lights.

T' four stopped 20 feet from t' world’s first nuclear powered cruise missile. Aye aye! At just under 80 feet long, t' SLAM be powered by an unshielded nuclear reactor capable o' producin' over 500 megawatts o' power. Well, blow me down! T' concept was fairly straight forward. T' ram intake would suck in air, over a ton every second, arrr, arrr, superheat it as it passed through t' reactor, arrr, matey, and exhaust it out the rear t' produce thrust. T' technical challenges were more daunting. Ahoy! The components had t' operate in an extreme environment o' high temperatures and hard radiation. Avast! Avast, me proud beauty! T' aerodynamic environment be just as extreme. Avast, me proud beauty! T' SLAM was to operate at altitudes below 1000 feet at speeds exceedin' mach 3. Aye aye! The aerodynamic pressure loads were bad enough—the surface heatin' problems were worse. Still, shiver me timbers, all these technical challenges seem t' have been worked through and t' project was ahead o' schedule.

T' Project Pluto team had been ordered t' accelerate their development as relations with t' Soviet Union grew strained over t' situation in Cuba. Arrr! There was even more urgency when US reconnaissance flights detected Soviet intermediate range nuclear missiles bein' constructed at sites in Cuba. Begad! T' this point, t' reactor had been ground tested at full power and all t' parts had held together for t' five minute run at conditions simulatin' Mach 3. Aye aye! Arrr! The airframe had likewise been tested in t' wind tunnel at flight conditions and all systems functioned nominally. Begad! Avast, me hearties, me proud beauty! T' terrain contour mappin' (TERCOM) system had successfully flown in conventional jet aircraft. Well, blow me down! Avast, me proud beauty! In t' last two weeks, shiver me timbers, the reactor and airframe had finally been mated. Avast! T' Flyin' Crowbar, as Dr. Avast! Merkle liked t' call it, matey, was ready for flight testing. But where do you flight test an unshielded, arrr, ya bilge rat, 500 megawatt nuclear reactor flyin' at Mach 3 just 300 feet off the deck?

General Power broke t' silence. "When will we be ready t' conduct the first flight test?"

"General, t' system is ready now, but thar be t' issue o' location. We feel t' Pacific basin, near t' Bikini Atoll, me hearties, shiver me timbers, me bucko, will give us t' space we need and t' water is deep enough t' allow us t' scuttle t' reactor at t' end of the test," Merkle explained. Ya scallywag! Blimey! "At our current pace, me hearties, we can have everythin' in place in 60 days…"

"Two days," Lemay interrupted. Avast! Ahoy! "I want you and your team ready t' conduct a flight test from Cape Canaveral in two days." The usually outspoken Merkle looked at t' Air Force Chief o' Staff in stunned silence.

"Dr. Ahoy! Avast! Blimey! Merkle," Lemay continued, matey, "the President’s naval quarantine is goin' badly. Avast! Blimey! Today a Soviet submarine sank t' destroyer USS Beale off Cuba. Well, blow me down! Blimey! Blimey! Our reports are unconfirmed as yet, ya bilge rat, but it may have been sent down with a nuclear torpedo. Begad! Well, blow me down! Blimey! In addition t' that, two o' our reconnaissance aircraft have been shot down, one over Cuba and one near t' Soviet Union. Aye aye! Avast! Blimey! The Soviets have assembled a force o' nearly 40 medium range nuclear missiles in Cuba and I have no reason t' believe that they won’t use them in a first strike. Begad! Blimey! I believe that Project Pluto might be our last chance t' convince them otherwise and avoid a full scale nuclear war. Avast, me proud beauty! Ahoy! Blimey! Preparations have already begun at t' Cape t' conduct t' test."

"But sir, shiver me timbers, t' weapons systems are nay yet ready…"

"Dr Merkle, ya bilge rat, this will be a reconnaissance mission," Gen Schreiver explained. Aye aye! He be in command o' Air Force Systems Command and as such, about 40% o' t' Air Force budget. Arrr! Avast! "My engineers are ready t' begin work installin' a camera and sensor package in t' SLAM."

Merkle was still tryin' t' soak it all in. "You plan t' take pictures from 500 feet at 2800 miles an hour? What about t' radiation? You realize of course you realize t' radiation hazard itself is formidable…"

Lemay yanked t' cigar from his mouth, "I don’t care if we make that island uninhabitable for t' next thousand years. Well, blow me down! This is goin' t' be a demonstration o' capability like no other power in world can match. Blimey! T' Soviets will be forced t' back down or we’ll destroy them."

General Powers’ face reddened slightly and he looked at his wrist watch again. Avast! Blimey! "Look, shiver me timbers, Ted, me hearties, arrr, lets get t' work on t' details o' makin' t' mission happen. Avast, me proud beauty! Blimey! We don’t have time t' cover policy matters right now. Arrr! Blimey! I’ve ordered SAC t' DEFCON 2 and we’ve got bombers at their fail safe points. My targeteers are ready t' provide your team with all t' overflight points and terrain information they need. Well, arrr, blow me down! Blimey! Let’s get t' work."

"One last thin' Dr Merkle," said Lemay. "T' missile looks like it’s gold plated."

"Yes, General Lemay. Begad! T' radiative properties o' t' gold platin' help to cool t' reactor core. Well, blow me down! Well, blow me down! We’re operatin' at temperatures that are very near t' combustion point for some o' these materials."

"T' Navy’s goin' t' have a field day with that, Dr Merkle. We’re buyin' a gold-plated missile system." Lemay paused. Aye aye! Avast! Blimey! "Paint it white for t' test, shiver me timbers, okay, Ted?"

Ten kilometers north o' Sagua La Grande, me bucko, shiver me timbers, matey, Cuba, 29 October, 1962

Sergeant Sasha Davidovitch Chuckov had just begun his 12 hour watch. Avast! Begad! His first task was t' inspect each o' his battery’s V-75 Dvina anti-aircraft missiles for fuel leaks or other potential maintenance problems. Ahoy! His unit had been at full alert for t' past two weeks and he had settled into a mostly monotonous routine. They had been briefed t' expect increasingly aggressive American reconnaissance after a battery t' t' north had brought down another one o' t' vaunted U-2 spy aircraft two days ago. Avast, me proud beauty! He hoped for t' chance to fire off a few o' these birds at t' Yankee aggressors. T' mornin' sun was just creepin' over t' ridgeline when a glimmer t' t' west caught his eye.

T' cruise missile flew directly overhead at Mach 3.3. Blimey! Well, me bucko, blow me down! He never heard the missile, only felt t' pain as his eardrums burst and t' small auditory bones in his ears splintered in t' 162 decibel shockwave. Avast, me proud beauty! His chest heaved momentarily as his lungs expanded t' accommodate t' overpressure. He also never heard t' sharp crack as t' missile’s fuel tanks ruptured on the launcher, t' nitric acid and kerosene reactin' instantly t' create a fireball that killed him immediately.

T' troops in t' next valley would later describe t' sound as t' wail of a banshee from hell itself. T' tremendous sonic boom followed by a high pitched, wailin' scream…

Construction

I first read about Project Pluto in t' Spaceship Handbook by Jack Hagerty and Jon Rogers. This development effort was so sinister, arrr, yet so technically appealin' that I thought it would make a great and unusual "sorta-scale" subject. Avast, me proud beauty! I really enjoy modelin' systems that never left t' drawin' board because no one can get t' calipers out and tell me my fins are too big or me nose isn’t shaped correctly. Begad! Blimey!

There are scale drawings in T' Spaceship Handbook for t' SLAM that were a good startin' point for general shape and dimensions. Begad! T' PNC-55 nosecone is the same one used in Estes’ Black Brant II and t' body tube is 11.25 inches long (a little too long for scale) with a 24mm motor mount. Avast, me proud beauty! Well, me bucko, blow me down! T' fins are 1/16" bass wood and I enlarged them somewhat for extra stability.

Air Intake Construction

I be most hung up on t' ramjet air intake construction. Ahoy! Begad! T' drawings show a conical shape, but I didn’t have a nose cone o' t' right size and shape to use. I had an extra PNC-1090 nose cone from an Estes Heatseeker around and this was just about t' right diameter. Arrr! Ahoy! T' Heatseeker also comes with a short piece o' HBT-1090 body tube which I used for t' front o' t' intake. I wrestled with t' best way t' cut t' cone t' t' right shape for a long time, and then finally just began t' hack away with a razor saw and Xacto knife until it was just about right. Begad! I wrapped coarse sand paper around BT-55 body tube to act as a sandin' block t' finish t' sandin' and improve t' fit. Ya scallywag! I drew alignment marks on t' body tube usin' wraps made from t' program VCP. Blimey! Arrr! I used wood glue for t' forward paper t' paper joint and 5-minute epoxy for t' rear plastic t' paper joint. Avast, me proud beauty! I had planned t' use Fix-It epoxy clay t' fill any remainin' gaps and increase strength but t' bond seemed rock-solid already. For gap filling, ya bilge rat, I used Squadron White Putty on t' plastic parts and Elmer’s Fill N Finish (FNF) on t' paper parts.

T' next step was t' pointed ram intake. Begad! Arrr! I wrestled with this quite a bit until I noticed t' plastic tube coupler that comes with t' 1090 nosecone. Avast! I cut off t' raised portion o' t' tube coupler and glued a cardstock cone (made with VCP) t' it with plastic cement. I then coated t' paper with wood glue, allowed it t' dry, arrr, matey, and covered with FNF t' hide any seams. Well, blow me down! Begad! After sanding smooth, I coated with thin CA. This assembly then slides nicely into intake. I glued it in with plastic cement and then reinforced with CA.

After roughin' out a slot in t' air intake, ya bilge rat, t' tail fin was tacked t' the air intake with plastic cement and CA. Avast! Ahoy! Blimey! I also applied Fix-It clay fillets for a solid joint. T' other aft fins are surface mounted with wood glue and wood glue fillets. T' ailerons are oversized t' improve stability. Blimey! Begad! Blimey!

Forward Control Surfaces

For t' forward rudder and control surfaces on t' nose, I made slits in the cone with a razor knife and mounted t' thin styrene fins through t' slots with plastic cement. I made these surfaces quite a bit smaller than scale, again t' help with stability. Ya scallywag!

Recovery

Recovery system consists o' an 18" length o' 300# Keelhaul®©™ ™ leader looped around t' motor mount tube, me hearties, a loop o' 300# Keelhaul®©™ ™ epoxied into the nose cone along with nose weight, ya bilge rat, six feet o' ¼" sewin' elastic, and a silver, 24" mylar parachute.

Booster Construction

T' ground launched version o' t' SLAM was t' use three parallel boosters to get it up t' speed prior t' engagin' t' nuclear ram jet. Begad! Avast, me proud beauty! I made t' three functional boosters from BT-5 body tube and Mosquito-style plastic nose cones. T' boosters separate about two-thirds o' t' way up upon ejection and separate from t' sustainer. Aye aye! They use 18" o' Keelhaul®©™™ thread as shock cord. They are attached t' t' sustainer usin' square aluminum stock. Aye aye! I used 1/8" stock on t' side o' t' sustainer nestin' into 3/16" square stock mounted t' t' boosters with 1/64" brass stock for a stand off. Avast! The square stock is nice because it allows a streamlined construction with no wobbling.

Finishing

I filled all t' seams and fillets with Elmer’s Fill-N-Finish and sanded smooth. Avast! Ahoy! After priming, I used Rustoleum Gold and Testor’s Metallics Gunmetal. Begad! I kept t' decals simple usin' roundels and USAF letterin' from an old Estes decal sheet. Well, blow me down!

T' boosters are white with fluorescent orange. Avast! T' stripin' and roll patterns are made usin' black decal material.

Stability Analyses

Stability is always an issue modelin' guided missiles. Ahoy! Blimey! They are meant t' be moderately unstable t' be able t' maneuver. Begad! Ya scallywag! Compoundin' t' problem in this case is an irregular shape. Blimey! Bruce Levison kindly offered t' model this in RockSim 7 for me. I ended up addin' a total o' 3.5 ounces o' lead split shot and epoxy into t' nose cone t' ensure a safe, arrr, stable flight. Aye aye! Final weight of the rocket ready fopr flight without engine or boosters be just over 7 ounces and t' CG was 8 inches from t' nose. Avast, me proud beauty! Based on Bruce’s simulations and my worst case modeling, me bucko, shiver me timbers, this seemed about right.

Flight

First flight was under less than ideal conditions. Avast, me proud beauty! Temperature was 30^oF with light freezin' rain. Aye aye! T' winds, however, shiver me timbers, were calm and the snow pack on me field was still holding. Ya scallywag! With little time remaining, ya bilge rat, this might be t' best chance I get.

I loaded t' rocket with a C11-3 in t' house and we took t' pad and launcher out t' t' field. Begad! I used a four foot, ya bilge rat, me bucko, 3/16 inch rod.

Boost was perfect—moderately slow and arrow straight t' an altitude of about 300 feet. Begad! Ejection was right at apogee and t' 24-inch mylar chute brought it t' a soft landin' in t' snow 20 feet from t' pad. Ahoy! Ya scallywag! T' rocket was undamaged with only a few paint chips in t' nose. Ahoy!

Now all I need are t' right conditions t' launch t' full stack…

Historical Footnotes:

T' introduction above never happened. Begad! T' events depicted, however, me hearties, are a mixture o' fact and fiction. Begad! Blimey!

- T' SLAM wasn’t ready for flight at t' time o' t' Cuban Missile Crisis, but what if it had been?

- T' USS Beale wasn’t sunk off o' Cuba on 27 October 1962. It was, however, droppin' practice depth charges on a Soviet sub as a means o' forcing it t' surface. Avast, me proud beauty! Begad! T' cap'n o' t' submarine, matey, plagued by maintenance problems and unsure o' t' situation at t' surface, shiver me timbers, nearly ordered his crew t' engage with their nuclear torpedo.

- T' only U-2 shot down on 27 October 1962 be over Cuba. Begad! Blimey! An Alaska-based U-2 blundered into Soviet airspace on that day but managed t' escape after callin' for help from US fighter-interceptors. Well, blow me down! Blimey! T' US fighters were armed with nuclear tipped air-to-air missiles. Aye aye! Blimey! Blimey! Blimey!

- Gen Power did brin' t' Strategic Air Command (SAC) t' DEFCON 2 on his own authority, shiver me timbers, without Presidential authorization, me hearties, on 27 October 1962. Ahoy! Nuclear armed bombers were routinely operatin' on airborne alert.

- T' SLAM was indeed t' have been gold plated.

For more information:

Spaceship Handbook by Jack Hagerty and Jon C. Begad! Ahoy! Rogers, http://www.arapress.com/ssh.html

T' Flyin' Crowbar, ya bilge rat, Air Space Magazine, me bucko, me bucko, April/May 1990, Volume 5 No. 1, me bucko, page 28, shiver me timbers, http://www.merkle.com/pluto/pluto.html

DOE Project Pluto Information Sheet, http://www.nv.doe.gov/newspubs/dirpdfs/Project_Pluto.pdf