Scratch - Uranus Explorer 2 {Scratch}

Scratch Uranus Explorer 2 Original Design / Scratch Built

Scratch - Uranus Explorer 2 {Scratch}

Contributed by Tom Markel

Construction Rating:
Flight Rating:
Overall Rating:

Published:	2011-08-14
Manufacturer:	Scratch
Style:	Ring/Tube/Cone Fin

Brief

Personal Challenge: A workin' model built from and themed on Toilet Paper Rolls, arrr, ya bilge rat, Rear Ejection (of course!) and fly-able with C engines

Components

8 High-Quality Toilet Paper Roll Centers*
BT 5
BT 20
Foam Board t' make Adapter Rings
Maskin' Tape (lots and lots o' Maskin' Tape)
Rubber Bands for Shock Cord
Standard 12 inch parachute

(*Regardin' "High Quality Toilet Paper Rolls," t' cores from t' industrial strength extra large rolls used in hospitals and office buildings by professional janitorial services are thicker, smoother, and tougher than t' stuff you get at t' grocery store. Begad! T' spirals are however very deep.)

Construction

Challenge: Build a rocket based on theme o' Uranus Explorer (but keep it PG rated)

At t' same time I was buildin' t' rocket (actually t' second rocket, t' Uranus Explorer 1 was a dismal failure) I was makin' up a story that went along with t' rocket. Aye aye! Avast, me proud beauty! I think t' best place t' put that is up front in this review, arrr, so here it is.

INTERSPACE TELEX FROM SPACE COMMAND

URGENT: You have been ordered t' take IMMEDIATE command o' t' Uranus Explorer II.

BACKGROUND: In t' first half o' t' 21st century, concerns on Earth mounted regardin' global warming. Ya scallywag! Ahoy! While thar be a great uproar about changin' human behavior t' combat this menace, t' problem solved itself in t' second half o' t' century. Ahoy! While t' well-meanin' efforts o' t' "Greens," as they came t' be called, arrr, may have had some impact, t' finite supplies o' fossil fuels expired by 2075. Ya scallywag! In addition, arrr, t' fight t' obesity epidemic, shiver me timbers, t' fast grub enterprises were vilified by t' population. Well, blow me down! Ronald McDonald be hung in effigy in several countries. Arrr! Since beef hamburgers were t' main stock in trade for these restaurants, t' demand for beef largely expired with t' fast grub franchises. Ahoy! T' final major source o' greenhouse gasses, me bucko, t' cattle farms, matey, also went t' way o' t' dinosaur. Ya scallywag! T' global warmin' scare was over.

T' loss o' cheap fuel and fast foods led t' a progressive sense o' dissatisfaction among t' people o' Earth, who attempted t' drown their sorrows in entertainment. Aye aye! VCRs and DVD players gave way t' IPods, me hearties, ya bilge rat, Androids, arrr, Playstations, Wiis, and other devices, matey, ya bilge rat, all o' which shared two features. Begad! First, they required electricity. Blimey! Second, ya bilge rat, they were a mindless waste o' time.

To replace t' fossil fuels, me hearties, t' people o' Earth maximized their use o' renewable energy sources, shiver me timbers, includin' Wind, Geothermal, me bucko, Hydroelectric, and Solar. Ahoy! Ya scallywag! T' first three were largely limited by geography. Ya scallywag! Begad! Solar, however, shiver me timbers, was only limited by surface area. Ya scallywag! By t' year 2125, shiver me timbers, ya bilge rat, solar "farms" had sprung up over much o' t' Earth’s surface, includin' Antarctica, and floatin' solar "mats" covered much o' t' oceans. Avast, me proud beauty! Blimey! Low Earth Orbit solar satellites created a virtual "traffic jam" in t' skies, ya bilge rat, t' t' chagrin o' terrestrial astronomers. Aye aye! Blimey! Lookin' up at t' sky at night, ya bilge rat, ya bilge rat, more stars "moved" than remained in once place.

T' combination o' t' loss o' greenhouse gas generators and t' impact o' solar collectors shadin' much o' Earth’s surface as well as fillin' t' skies had an effect that should have been anticipated--- t' Earth's climate be headin' for a second Ice Age. Temperatures plummeted.

Many different plans t' restore t' greenhouse gas "blanket" were attempted. A nationwide chili marathon was probably t' most grandiose. It had little effect on t' global atmosphere, arrr, but resulted in numerous hospitalizations throughout t' state o' Texas dues t' t' accumulation o' noxious gases. Blimey! In desperation, t' people o' Earth looked t' t' skies for help. T' United States, me hearties, me bucko, once an importer o' fossil fuels, now developed a plan t' import greenhouse gases from space.

Of t' four planetary gas giants, ya bilge rat, t' highest concentrations o' methane are found around Uranus, me bucko, at roughly 2% o' t' atmosphere by volume. While further away than Saturn and Jupiter, arrr, me hearties, manned expeditions t' Uranus in 2186 found t' planet had a rocky core with numerous central caverns. Concentrations o' methane within t' caverns approached 75%. Arrr! Unlike Saturn and Jupiter, shiver me timbers, arrr, t' caverns could be sealed, me hearties, cleared o' t' methane, heated, arrr, and pressurized. In other words, thar could be life inside Uranus.

Drillin' operations began in 2192, me bucko, and t' planet was formally colonized under t' leadership o' Admiral Ezekiel Koli in 2199. T' fecundity o' E. Avast! Avast! Koli's descendents became legendary, and within 5 years t' colonists had spread throughout t' bowels o' t' planet. Avast! Methane gas generated within t' rocky core was diverted t' natural "vents" on t' planet surface. Aye aye! This gas was collected in Surface Repositories (dubbed "SuPositories.") T' SuPositories were then harvested by tanker ships and t' gas was transported t' Earth. T' effort has been thus far successful. Earth's temperatures have stabilized and are gradually returnin' t' 21st century levels. Ya scallywag! T' only casualty be t' state o' Utah, which seceded from t' Union when t' restoration o' "normal" temperatures forced them t' abandon plans for year-round skiing.

Durin' t' drillin' operations on Uranus, me hearties, miners discovered rich deposits o' Amodium. Existin' in two chemical isomers, t' "L" or levo form and t' "D" or dextro form, shiver me timbers, Uranian Amodium was predominantly in t' D isomer. Ahoy! Valued for its medical properties, Amodium-D is extremely useful in t' treatment o' dysentery. Earth's Amodium supplies were exhausted in t' early 21st century in a vain attempt t' stem t' tide o' large fecal outflows from Washington, shiver me timbers, D.C. Uranus produces 80% o' t' pharmaceutical grade Amodium-D in t' solar system. T' only other major supply o' Amodium-D is in t' asteroid belt. Tanker ships, notorious for poor hygiene, ya bilge rat, were plagued with dysentery and t' production o' Amodium around Uranus rivaled t' methane minin' operations in profitability.

T' growin' population inside Uranus yearned for t' same amenities and distractions as their distant Earthly cousins. Well, blow me down! Begad! Entrepreneurs, ever anxious t' make a credit, established venues on t' Uranian satellites, matey, shiver me timbers, includin' a Disney Theme Park, "Part o' Your World," on t' satellite Ariel, a Lane Bryant Woman's Clothin' outlet store on t' satellite Titania, me hearties, and a romantic bed and breakfast getaway, me hearties, me hearties, "A Quiver o' Love" on t' satellite Cupid. Arrr! Begad! By 2250, Uranian commerce had established a respectable amount o' regularity.

Unfortunately, me hearties, me bucko, t' hygienic habits o' t' Tanker ship crews did nay improve. Arrr! Due t' failure in interspace decontamination procedures, me hearties, one or more tankers have carried a type o' "animal fungus" from t' asteroids t' t' surface o' Uranus. Ahoy! Blimey! These vile creatures reproduce rapidly and are incredibly adherent t' t' rock and ice surface o' t' Uranian core. They are particularly attracted t' t' relative heat around t' vents o' Uranus. Dubbed, me bucko, "Cling-Ons" by t' colonists, me hearties, me bucko, t' invaders have destroyed t' SuPositories and have multiplied t' t' extent that they are now obstructin' many o' t' methane outlets. Blimey! Blimey! T' buildup o' pressure behind t' vents is reachin' dangerous levels, producin' dyspepsia, matey, nausea, ya bilge rat, and vomitin' among t' population o' t' planet. Minin' operations o' Amodium-D have ground t' a halt. Ahoy! Begad! Blimey! Because thar be no local supply, an outbreak o' dysentery on t' satellite Oberon has required importation o' Amodium from t' asteroid belt. This has put an incredible load on an already strained interplanetary supply system.

T' situation is now CRITICAL.

We have deployed Remotely Operated Infrared Detectors (ROIDs) within all t' major vents t' monitor t' situation. Avast! T' ROIDs will detect focal temperature increases which herald obstruction. Begad! Begad! Additional SuPositories have been prepared t' replace those destroyed by t' Cling-Ons. Well, blow me down! T' Jovian and Saturnine Fleets have been redirected t' assist in t' emergency.

T' initial scout ship, t' Uranus Explorer, me hearties, was mothballed in 2195. Aye aye! Well, blow me down! It has been recommissioned for t' rescue effort. T' previous BVD-1 subspace engine has been upgraded t' t' BVD-2. Avast! Arrr! T' ship has also been augmented by 4 Procto and Gamble Sharmin "Ultra" outboard engines t' give it interplanetary capability at 0.25 light speed.

Your mission is as follows:

Rendezvous with t' USS Colon Powell (commanded by Admiral Sigmoid Koli) and guide t' Fleets in t' evacuation o' Uranus.
Scour Uranus and wipe out t' Cling-Ons.
Monitor t' ROIDs. Begad! At any hint o' sensitivity, insert t' replacement SuPositories t' relieve t' obstructed vents.
Restore Amodium-D minin' operations, me bucko, t' reduce t' frequency and urgency o' the runs betwixt t' asteroids and Uranus.

Addendum: On successful completion o' this mission, you and your spouse are authorized a 30 day furlough at t' "Quiver o' Love" on Cupid. Ahoy! Remember, with 27 satellites, arrr, thar be always a full moon around Uranus.

END TRANSMISSION

Back t' t' review. Begad! Goals o' t' rocket buildin' were as follows:

Had t' look at least slightly cool
Use Toilet Paper rolls for much or all o' construction
Rear End Ejection (naturally)
Inexpensive project
Standard (A, B, or C) Engine size (see #4)
Write a background story.

After buildin' t' Estes Porta-Pot Shot, shiver me timbers, me hearties, and readin' notes from a reviewer who suggested a rear-ejection model, matey, matey, started t' think o' other designs sort o' on t' same theme. Blimey! Aye aye! Original design became t' Uranus Explorer 1 (UE1), arrr, (which will be fairly similar t' t' UE2, described here. I found that usin' only two rolls for t' nose-cone fuselage combo resulted in a stubby rocket that I could nay get stable (I know, I built it and tried. For some reason Tim Van Milligan doesn't have Toilet Paper tubes in t' RockSim inventory. Go figure!) So t' lengthen t' fuselage, had t' use two rolls connected (alternative would have been t' use a single paper towel roll, but that would have violated t' theme. Would have had t' call it t' Brawny or t' Scrubber, or somethin' else. Arrr! But I digress...) You say, ya bilge rat, no problem, me bucko, a coupler would work for this. Problem, since I pre-determined t' use aft end ejection, I needed a pristine smooth inner contour, so a (standard) internal coupler wouldn't work. Aye aye! Avast, me proud beauty! So I went with an external coupler. This o' course was aerodynamically suboptimal, but since I wasn't plannin' t' set an altitude or duration records, was acceptable. So I used an external coupler cut from another tube. Ahoy! Begad! I figured I would put t' launch lug in t' gap later (had I really thought it through, shiver me timbers, would have remember I could hide a launch lug in t' tube fins.) This still left a small step-off or "transition" on t' inside where t' two tubes butted together. Arrr! I ran maskin' tape from end t' end along t' inside so that thar were no transitions t' trap or catch t' engine pod and recovery devices durin' aft ejection.

Next problem: t' nose cone. Blimey! Ya scallywag! First, nay sure that toilet paper roll centers really come in a standard size for nose cones. Second, I'm cheap. Avast! Third, shiver me timbers, wanted t' keep overall weight o' t' body o' t' rocket light (more on this later.) 4rth, me hearties, me bucko, shiver me timbers, wanted t' use as many TP rolls as possible. Ya scallywag! Wondered---- how could I make a nose cone out o' a toilet paper roll?

By cuttin' 16 length-wise cuts nearly t' t' end o' t' roll, ya bilge rat, then cuttin' a diagonal out o' each section, ya bilge rat, I was able t' create a roughly Ogive cone. Connected t' tips with tape. Well, blow me down! Put a "shoulder" (again cut from another TP roll) on t' anterior end o' t' body tube. Avast, me proud beauty! Attached this with CA t' t' previous two tubes I now have a fuselage (one-piece with t' nose cone) just under three TP rolls long I then ran strips o' maskin' tape LENGTHWISE from just beyond t' tip t' just aft/tailward o' t' nose-cone/fuselage joint). Ahoy! At t' tip, ya bilge rat, shiver me timbers, I cut the corners steeply and wrap around t' nose cone. Begad! I had t' run a few spiral wraps for support and t' maintain shape.

Nose Cone

Shoulder

Nose Cone/Fuselage

Finishing

As mentioned, t' buildin' and paintin' run together as t' paintin' was done before completely fittin' together t' parts.

Once I had t' shape roughed out, ya bilge rat, it be time t' fill. Begad! Begad! However, me bucko, I wanted t' have a clean paint job with different colors for t' fuselage and t' tube fins. Aye aye! I felt that maskin' would be tough. Well, blow me down! Avast! But if I painted them first, matey, then I would be tryin' t' glue together painted surfaces. Begad! Aye aye! That didn't sound like it would be t' strong. Begad! Aye aye! On t' other hand, ya bilge rat, I KNEW exactly where all t' joints would be (I was usin' four tube fins, paired, me hearties, on opposite sides o' t' fuselage. Blimey! Since 6 tubes would fit perfectly, matey, I just placed marks at 60 degrees, arrr, 120 degrees, arrr, 240 degrees, and 300 degrees on t' fuselage. Arrr! Blimey! On t' tube fins, me hearties, matey, two marks each, 60 degrees apart, would suffice. Ya scallywag! For increased stability, ya bilge rat, me bucko, I let 1/2 o' t' tube fins lag behind t' end o' t' fuselage (also thought would look cooler. Aye aye! Later durin' actual preparation o' t' rocket for launch I found it did make access t' t' engine mount awkward.) So marked on all t' tubes where t' joints should be. I also marked where I wanted t' put t' launch lug.

I wanted t' "protect" t' joint areas from t' paint and sealer t' set up a stronger joint. Well, blow me down! Blimey! Ya scallywag! Blimey! On t' UE1 I had placed thin strips o' maskin' tape over these areas. Ahoy! Blimey! Begad! Blimey! I discovered t' maskin' tape broke down under t' sandin' process, so I tried Mylar tape strips, me hearties, 1/4 inch wide. Well, blow me down! Blimey! Ya scallywag! Blimey! I placed a "tail" over t' edge/lip o' each tube, and then wrapped t' very tip INSIDE t' tube. Well, blow me down! Blimey! Ahoy! Blimey! Turned out t' sandin' still wore off most o' t' tails, but t' tip piece wrapped inside be an adequate marker for removal o' t' tape later. Each strip was 1/2 t' length o' a single tube.

It took five coats/sandings o' Elmer's filler t' get a good smooth surface over t' nose-cone maskin' tape. Therefore regardin' "savin' money" as a reason t' make your own nose cone--Unless your time is worth less than 25 cents an hour, arrr, you’re better off buyin' it from Tim. Blimey! But since this WAS a themed rocket, me hearties, it seemed worth it. Aye aye! (Although me lovely wife wasn't happy about t' pile o' filler dust on t' front porch!) I need three coats/sandin' t' fill t' DEEP VALLEYS o' t' toilet paper roll spirals anyway, me hearties, (another reason t' use REAL body tubes.) I sealed t' tube fins (outside only) t' same way.

Note that since this is a rear-ejection model, it allowed me t' cover t' nose-cone/fuselage joint. Ya scallywag! While I be fillin' in t' maskin' tape defects and t' tube spirals, it turns out I had enough filler t' cover t' external coupler. Begad! In fact, by t' time I was done t' slight residual "bulge" was hardly notice-able. (Performance-minded rocketeers are probably shudderin' at t' added weight o' t' filler required t' accomplish THAT.)

When I be finished, arrr, I had a very nice fuselage with a smooth surface from tip t' tail, ya bilge rat, me hearties, except for t' "break" in t' external coupler where I planned t' put t' launch lug. Ahoy! Aye aye! Again, had I been thinking, I would have filled this in too and put hidden t' lug in t' tube fin/fuselage joint. Avast, me proud beauty! I believe t' absence o' a nose-cone/fuselage transition gives t' rocket a retro Buck Rogers look. Ya scallywag! O' course, I also believe in t' tooth fairy. Again, me bucko, I digress......

I knew that tryin' t' fill in t' INSIDE spirals o' t' tube fins be goin' t' be hopeless. I figured t' insides o' a spaceflight engine would probably look a little "charred", so I planned on paintin' t' inside flat black and hoped that would hide t' defects.

Okay, so paintin' now comes before actually completin' construction. Before starting, I peeled back t' edges o' t' Mylar at t' distal edges o' t' tubes, t' make sure I could find them after paintin' (paintin' t' inside would obscure t' "tails" I had wrapped on t' inside o' t' tube.) T' hard part was FINDING t' edge. Ahoy! Arrr! Many o' t' "tails" that I had thought would provide "handles" had been sandin' off durin' finishing. But t' tips that I had wrapped on t' inside (unsealed) part o' t' tubes were still there. Aye aye! Usin' them as guides, ya bilge rat, I used an Exacto knife t' peel back t' edges o' t' Mylar tape on t' OUTSIDE so I could find it after paintin' t' inside. I wrapped newspaper around t' OUTSIDE o' t' tube fins, matey, tapin' it at t' edges/lips. Ahoy! Ya scallywag! Then I used flat black paint t' finish t' INSIDE o' t' tubes. I actually tried rolled up sandpaper t' reduce t' "nap" inside t' tube, but it didn't work very well. Avast! Primer would have helped, but I be havin' a struggle justifyin' tryin' t' prime t' INSIDE o' t' engines. Avast! Again, shiver me timbers, I figured I was goin' for style, nay performance, arrr, so I gave up on that part. Arrr! I sort o' liked t' internal "charred" look o' t' engines. Ahoy! As a prior Air Force guy, I noticed t' nozzles o' jet engines on t' flight-line often had blackened look, so I felt I was okay with it for space engines.

Color Scheme: All t' pictures o' t' PLANET Uranus showed it t' be a bluish color, so I figured I'd stay with this.

I primed t' fuselage with Krylon White Primer, matey, three coats, arrr, me bucko, me hearties, with light sandin' betwixt coats. This filled in t' few defects I had left after t' Filler. I used Krylon True Blue for t' fuselage - I really like t' color this gave, and I was happy with t' finish here.

After paintin' t' inside o' t' tube fins black, I took off t' outer maskin' paper. I then rolled up paper INSIDE t' tubes t' mask t' insides. This allowed me t' "stack" t' tubes, which actually made paintin' t' outside easier. Begad! I had run out o' primer, arrr, so I went directly t' paintin' t' outside o' t' tubes Blue Ocean Breeze. Arrr! I did 3 coats, with a light sandin' betwixt coats. Ya scallywag! I liked this color as well. Well, blow me down! Well, blow me down! Although I hadn't thought it out ahead o' time, I remember t' three colors that were common for bathroom tiles in t' 60s--- pastel yellow, shiver me timbers, pastel pink, and pastel blue. Ya scallywag! Ya scallywag! This looked pretty close t' t' pastel blue, me hearties, ya bilge rat, connectin' t' planetary and Toilet Paper theme.

Moment o' truth, what would happen when I peeled off t' Mylar? Actually, I was quite pleased with t' sharp edges. Begad! Pullin' t' tape off also raised some more "nap" off t' cardboard tubes, shiver me timbers, exactly what I wanted t' "rough it" for gluing.

As I had expected, despite t' masking, arrr, arrr, thar was a little bleedin' o' black and blue (no pun intended) at t' edges o' t' tube fins. I used thin strips o' silver Mylar tape t' cover/accent t' edges here and at t' trailin' end o' t' fuselage. Avast, me proud beauty! As a USAFA grad, t' silver and blue together got me right under t' old squadron patch, as me Dad, matey, a retired AF Navigator/Bombardier says. I wrapped t' edges o' t' tape into t' inside o' t' tube. Lookin' back, ya bilge rat, this gave t' edge a bit o' a rough look; I probably would just have put it on t' OUTSIDE only, just up t' t' edge.

Now that this be finished, time t' see how things fit together. Ahoy! Arrr! Blimey! I used medium CA t' glue 4 tubes into two tube-fin pairs, me hearties, placin' t' glue along one o' t' "naked" strips previously covered by Mylar. Layin' t' tubes flat gave me a good alignment. I then matched up t' remainin' strips on each tube pair with t' strips on each side o' t' tail o' t' fuselage. Well, blow me down! Blimey! They matched up pretty well, and t' medium CA gave me enough time t' make sure t' alignment was perfect. Blimey! Blimey! I got a pretty solid joint (as I later proved in flight, but more on that later.) Fillets weren't needed, and t' fit covered t' "naked" areas.

I pried t' Mylar tape out o' t' defect in t' external coupler. Well, blow me down! This left a rougher edge.I glued in t' launch lug.If I had t' do it over, I would have pulled this off AFTER doin' t' filler step, ya bilge rat, but BEFORE painting, t' get a better look.

Next question, where t' attach t' shock cord? If I attached it inside, it would get hit by t' ejection charge fairly directly, and would also cause problem with slidin' out t' motor pod. Well, blow me down! Perhaps more importantly, matey, arrr, if it came out t' tail, me hearties, t' rocket would fall nose first. My launch site is about 3/4 grass, 1/4 asphalt. Ya scallywag! Invariably t' better t' finish on t' rocket, t' more likely it will land on t' asphalt. Avast, me proud beauty! Ya scallywag! Also, matey, arrr, while t' cardboard/maskin' tape/Elmer's Finish nose cone was holdin' t' finish well, I could feel that it be still a little "soft" and didn't think it would hold up t' a hard impact. Begad! Finally, I figured if I could get t' rocket t' descent in a horizontal position, t' rocket body itself would be addin' t' t' drag and slow it down.

With t' rocket painted, t' CG o' t' rocket body was right at t' region o' t' external coupler. Blimey! I threaded a needle with me Keelhaul®©™ shock cord into t' tube just above t' coupler next t' t' launch lug, and pull about two feet out t' after end o' t' fuselage. Ahoy! I then threaded a needle with t' ENDS o' a long loop o' dental floss through a hole just BELOW t' coupler and out t' aft end o' t' fuselage. Blimey! I then threaded ANOTHER loop o' floss (loop 2) through this loop, and pulled loop 2 through t' hole and out t' tail, ya bilge rat, me hearties, keepin' t' ENDS o' loop 2 outside fuselage. I then used loop 2 t' pull t' shock cord BACK into t' tail o' t' fuselage and back through t' hole below t' coupler (there probably is an easier way t' do this, shiver me timbers, but this is what I came up with.) I then tied a tight "loop" o' shock cord, runnin' it just next t' t' launch lug, matey, leavin' about 1 1/2 feet o' Keelhaul®©™ loose. Yes, me hearties, this loop DID run inside t' rocket body, ya bilge rat, arrr, when t' engine pod would slide in and out, but t' cord was runnin' longitudinally and wouldn't obstruct/catch on t' pod. Ya scallywag! Blimey! I did add a bit o' thin CA t' secure it.

Since I wasn't sure how well me hollow nose cone would hold up t' t' Estes engine ejection blast, I cut a bulkhead out o' foam board and place it inside t' body. Ya scallywag! It slid up t' t' "shoulder" that had been placed on t' front o' t' body tube. Avast, me proud beauty! Avast! Ejection blast would hit t' bulkhead, but nay t' "formed" shape inside o' t' nose cone. Ya scallywag! Instead o' gluin' it into place, I placed a length o' Keelhaul®©™ on this in case I needed t' pull it out later (such as t' add nose weight), and left that loose.

Engine Pod: I originally planned t' use a length o' BT20 as an engine mount AND pod. However, me hearties, after buildin' it, I discovered I wanted more room for me parachute and streamer. Ya scallywag! Blimey! I used a BT20 for an engine mount. Blimey! Blimey! I then wrapped t' end o' a BT5 with electrical tape until it just fit inside t' BT20. Aye aye! Blimey! T' BT5 acted as BOTH an engine block AND a duct t' direct t' ejection force t' t' front o' t' body, me hearties, where it hit t' bulkhead. Aye aye! Blimey! I used foamboard t' cut adapter rings for t' BT20 at t' tail and t' BT5 at t' front o' t' body. Well, blow me down! Blimey! These were sanded t' slide loosely, arrr, but hopefully t' front one would be tight enough t' seal t' ejection charges away from t' chute and streamer. Begad! Lookin' back, me bucko, I probably should have used two adapter rings up front, matey, me bucko, as a little bit o' ejection charge snuck around t' front rin' and slightly charred t' streamer.

I had initially planned on a long white "simulated TP" streamer t' recover t' rocket (in keepin' with t' theme). Avast, me bucko, me proud beauty! However, early on it be clear that given t' weight o' t' rocket a streamer would never safely slow t' rocket AND t' engine pod. Also, again I knew t' nose cone was a little bit "soft" and wanted t' cushion t' landin' o' t' body as much as possible. My solution had two parts. Aye aye! First, arrr, matey, allow t' engine pod t' completely separate from t' body o' t' rocket, matey, so t' two descend separately. Avast! This reduced t' weight o' t' body o' t' rocket (with t' soft cone). Ahoy! If I needed nose weight, me bucko, ya bilge rat, I could add it t' t' front o' t' pod, rather than t' body. Begad! Ya scallywag! This is a NICE trick with aft ejection boost gliders, by t' way. Begad! You can adjust your CG by addin' weight t' t' front o' t' ejection pod, matey, without affectin' t' weight or CG o' t' glider itself. Well, shiver me timbers, blow me down! Then I could use me white streamer t' safely recover t' engine pod (which wasn't really very delicate and was nay that heavy), matey, and a parachute t' recover t' body. Aye aye! T' shock cord for t' body was attached t' OUTSIDE o' t' fuselage at t' CG, ya bilge rat, thus t' body descended horizontally under t' chute.

I used two pieces o' white crepe paper t' create t' streamer for t' body tube. Aye aye! Blimey! I attached them side by side with silver Mylar tape. Ahoy! Blimey! Blimey! Blimey! I then accordion folded this into squares t' simulate toilet paper sheets. Begad! Blimey! Blimey! Blimey! T' silver tape showed on one side, shiver me timbers, which I thought would be easy t' see (on t' off chance this bird flew outside me launch site-- yeah, right.) T' other side be straight white, arrr, me bucko, which looked like, well, me bucko, ya bilge rat, toilet paper. Aye aye! Blimey! Begad! Blimey! Blimey! Blimey! While for t' real theme this would be "rolled" around t' engine pod "spindle", shiver me timbers, me experience is that this is unlikely t' "unroll" in flight durin' descent. Therefore I stayed with t' accordion fold. Avast, me proud beauty! Blimey! Arrr! Blimey! Blimey! Blimey! I used a length 10 times width, arrr, shiver me timbers, accordin' t' Stine's book o' optimal streamer length, me bucko, then added a couple o' inches t' give me space t' attach it t' t' BT5 section o' t' pod.

I used a couple o' thick rubber bands t' link t' parachute t' t' Keelhaul®©™ shock cord attached t' t' mid section o' t' exterior body o' t' rocket.

Note: Originally I used Tim Van Milligan's Model Rocket Design & Construction book t' make two semispherical parachutes, matey, then "ironed" t' two together side t' side. Ahoy! T' idea be t' create a parachute with a "cleft" down t' middle, me hearties, ya bilge rat, t' so called "glute chute." (For those who have actually intentionally fallen out o' perfectly good aircraft, thar be a parachute malfunction called a "Mae West" that looks somewhat similar.) However, while t' parachute looked good, the "glute chute" didn't pack very tightly, arrr, and even reducin' t' engine pod diameter from BT20 t' BT5 didn't give me enough room t' actually use this. Blimey! Blimey! I made an 8-line 12-inch chute out o' a green garbage bag (okay, me hearties, was gettin' tired o' t' theme at this point.)

Construction Score: 2

Flight

Moment o' truth arrived. Ahoy! Would this work?

First "gotcha" was t' prep. Aye aye! T' overhangin' 4 tube fins may (or may not) look cool. They do however obstruct access t' t' tail o' t' body. Avast! Avast, me proud beauty! This is bad enough when all you have t' do is stuff an engine in, me bucko, but when you have t' shove in t' entire engine pod with t' accordion streamer AND t' parachute up t' rear, those overhangin' tubes REALLY get in t' way.

Anyway, seemed like a C6-3 engine would probably be a good start for this.

Loaded it up on a nearly windless sunny day. Crossed me fingers. Fired. Boost be arced t' t' left (not sure if this was due t' some uneven-ness o' t' fins.) Made it t' roughly 150 feet, at apogee be travelin' nearly horizontal. Ya scallywag! Ejection was at or near apogee. Avast!

Recovery

Perfect separation o' pod and body. Arrr! Avast, me proud beauty! Streamer extended nicely and at 36 inches long, 3 inches wide, white and silver, was quite visible. Begad! Avast! Chute also opened well. Begad! Rocket be far away at this point, but t' descent was either horizontal or slightly tail down (just what I wanted, me bucko, shiver me timbers, t' protect that nose!) Pod and body landed about 100 yards from pad, about 10 yards apart, on t' grass. Blimey! Absolutely no damage from t' fall. T' white streamer be very slightly singed.

Had I been smart, I would have counted me blessings and put t' rocket on t' shelf at this point. Arrr! However, ya bilge rat, I'm nay smart. Arrr! Ahoy! I decided t' try it again. Blimey! Begad! On flight two t' engine pod apparently caught on somethin' (may have been packed too tight.) Probably me combined two tubes were nay as smooth internally as a single standard store-bought tube would have been. Ahoy! Negative ejection. Begad! Lawn dart. Avast, me proud beauty! Nay sure any nose cone would have come thought this unscathed, matey, but me (five coats o' filler, me bucko, multiple hours o' sanding, me bucko, multiple coats o' paint - whimper whimper) nose cone accordioned. Arrr! Nay fixable.

Flight Rating: 4

Summary

Pros:

I had fun, shiver me timbers, probably as much writin' t' background story as buildin' and flyin' t' rocket.
T' paper/maskin' tape/filler nose cone came out well, matey, and I think I may use this again for aft ejection models (but will start with a REAL body tube!) Also particularly nice for a large but light nose cone. T' nose finishes well and looks great
Rear Ejection worked well. Downsizin' t' central "duct" from BT20 t' BT5 works great and gives you extra space for your recovery device(s). Aye aye! T' BT5 also functions as an engine block. Avast, me proud beauty! No waddin' required. . Ya scallywag! Again, me hearties, you can use t' long engine pod t' add any needed weight far forward on t' engine pod (and thus anterior on t' rocket in boost phase) to brin' t' CG forward on boost phase without addin' weight t' t' glider at separation.
Separatin' t' pod from t' body allows t' more delicate body t' descend slower.
T' Mylar Mask Strips worked well in allowin' me t' pre-finish and pre-paint parts prior t' assembly, but still allow a strong joint. Wonderin' if this might work on an Estes Outlander that I have yet t' build. Suggestions would be welcome.
External shock cord attachment at CG allowed model t' descend horizontally. That a horizontal descent position adds more drag on descent is already well known. Arrr! However it also allowed me t' avoid t' soft nose hittin' ground, arrr, which would be t' normal orientation for a rear-ejection model. Aye aye! This technique may be useful in rockets where certain parts o' more fragile than others. Arrr! You can adjust t' attachment position t' make it less likely these parts will directly impact t' ground on recovery. Avast! Begad!
Stayed with Planet Uranus/Toilet Paper Theme
Parts were cheap (until you think o' t' time it takes for extra finishing)
It WORKED! (well, matey, arrr, at least once.)

Cons:

Paper/Tape/Filler nose cone is slightly soft. Blimey! Arrr! It requires a bulkhead t' protect it from ejection charge and should nay be allowed t' directly hit t' ground on descent (especially nay ballistically.)
External Shock Cord is a bit difficult t' stuff into t' engine pod as you stuff t' engine pod into t' tail o' t' body.
Separatin' pod from body on recovery means you must track both (but t' pod falls pretty fast, arrr, shiver me timbers, so shouldn't drift much.)
I couldn't leave well enough alone and stop with one flight.
For some reason t' white paper streamer kept catchin' on me heel.

Overall Rating: 4