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Estes Cosmic Interceptor

By Steve Lindeman

Estes - Cosmic Interceptor {Kit} (001351) [2013-]

Manny Trotta just finished a beautiful build of this kit and it is only because of a question he asked me from my last build (the Estes - Scorpion) that I am posting this one as I continue to experiment with different paper coatings. I first learned about paper coating balsa from a tip in a magazine that the N.A.R. sent me when I first joined. The first two or three dozen rockets that I built after that I covered using regular printer paper because I had an almost unlimited access to used printer paper at a job I worked before retirement (so I stock piled a bunch of it figuring I could use it for future builds).

On my last build (Estes - Scorpion) I tried a different paper (brown packing paper that came with my order) with mixed results. Pro: It was easy to apply Con: but to thin and fibery and required more sanding to get a good finish which resulted in much of the paper being sanded off (won't be using it again).

This build I opted for a sheet of 22x28" poster board that I bought at Michael's Art & Crafts store for less than a buck. I must say at this point this is the best material I've worked with so far. It is thicker than regular paper but yet thin enough to cut easily with an E-xacto knife and has a surface that will be a breeze to paint. May very well be my goto paper in the future. Following are some pics of the build so far.

Cosmic Interceptor MM.1 Cosmic Interceptor MM.2

MM & Scoop Fin Assembly

(I used a magic marker to blacken the fins)

 After Coating

Balsa parts before and after paper coating

 Baffle bottom

Baffle assembly. Bottom has aluminium duct tape added to help prevent burn through of wood.

(another of my experiments carried over from another build that worked)

Top closeup

Top of baffle showing steel wool insert that I added to help trap hot gas particles

(another of my many experiments with baffles) 

Assembly of wing pieces Assembly of wing pieces.2

Starting wing assemblies

Wings glued on

Wings glued on

Shot from tail

Shot from tail

(rudders are not glued on yet and have not done any painting or priming)


Manny Trotta (February 9, 2016)

Steve, that baffle looks very well designed and I am thinking you definitely will not be damaging any chutes with that in place. It looks like a steel wire scouring pad in there not the finer steel wool correct? Also the pastor board coating looks outstanding. Can't wait to see how the painted finish looks! Thanks for providing the rundown on the paper coating process.

Steve Lindeman (February 12, 2016)

Manny, Thanks for the compliments and your welcome. You are also correct about the steel wire scouring pad. I cut off about 1.5 oz. worth and then ball it backup and tack it in place with wood glue (you can see some glue that spilled through one of the holes). I've used this trick on one other rocket (Tinkerbell) and so far no marks on the chute after 4 flights so I'm feeling pretty confident about the design. Painting may take awhile as it's only going to be in the teens this week and shows no sign of warming any time soon. This was slated as my winter build so no hurry but I am getting very eager to start my birthday build (the Estes - Mega Der Red Max). Will be trying another paper coating for it and will most likely paint both when weather warms and I can get out to the garage.

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Additional build photos (2016-03-01 13:19:54)

Small bottom fins added 

Small bottom fins added

Scoop & top fin added

Scoop and top fin glued on

 The black insert in the scoop and tail ring on MM are not glued on yet as I'm doing all the priming and main coat before they are glued on. Due to expected difficulties of painting between the small fins on the bottom, they also will be painted before glueing them on, but will be glued on before final clear coats are applied.  

Bottom aft end of rocket

Bottom aft end of rocket

Started snowing again. 2" of snow on the ground this morning when I got up and weatherman is calling another 4-6'' through the day so don't look like I'm going out to the garage to paint any time soon. I am soooo tired of snow. 


Manny Trotta (March 27, 2016)

When you do get around to securing the black insert you may want to consider applying the glue to the under side of the scoop, the top of the insert,  as opposed to the body tube side. My first idea, since the insert is attached after painting, was to scratch away small spots on the body to act as anchor points for the glue. This didn't work that well and created some eye sore spots around the insert-body tube joints. Additinally, the insert still seemed a little flimsey, being spot gluded, and I had concerns about it holding up during flight. I went back and allpied glue to the inside of the scoop and that really stabalized the insert. By attaching the insert that way I did not have to add glue to the more visible portion allowing for a cleaner look. The only thing to watch for if you do the scoop side gluing is that the insert could end up being pulled away from the body tube and not sit flush with it. Just make sure its a good fit before you set it and glue it in there.

Karoline Fab (March 31, 2016)


I wanted to drop you a quick comment to thank you for posting your build. My brothers, sister-in-law, brother-in-law, dad & I received these for Christmas to build and launch in a competition on Easter. I'd never built a rocket before and following your build helped me figure out some of the things I needed to do. I didn't win the competition, as my younger brother modified his wings to send his rocket higher. My dad thinks his rocket went higher than mine, but didn't set his altimeter correctly, so we don't know just how high his flew. Out of the measured flights, I did have the second highest on the D12-3 engines. I thoroughly enjoyed researching and building my Cosmic Interceptor.

I did wonder about the purpose of the intake to nowhere. It seemed to me that it may have hindered the flight of the rocket, as there was no place to vent the air. Neither my dad, nor my younger brother included that on their rockets. The rest of us did. I'm tempted (now that the competition is over) to use my exacto knife and add vents in the scoop to allow the air to pass through, but I'm not sure how it would change the flight.

Thanks again!

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Painting (2016-05-09 23:01:42)

Well I must admit I almost forgot about this build what with doing 3 projects at the same time. So once the weather broke I started the paint work by priming the entire rocket with Rust-Olium 2X white primer followed by a light sanding. I then removed the two small bottom fin pieces and the wing tips and painted them separately with Rust-Olium White Gloss. I then painted the rest of the rocket Gloss White. After giving everything a day to dry I masked off the raised section of the wing tips and then painted them with Gloss Black. The tail ring was also painted at this time. After allowing all parts another day to dry I then removed the tape from wing tips and glued them on. Wings and BT were then masked and the black trim was added.

Wing tips glued on

Wing tips glued on

Black trim added

Black trim added

Black trim added

Note: MM removed 

Once all paint was dry all tape and paper was removed and rocket was taken back outside to air dry for the rest of the afternoon.

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Final glueing (MM, Tail ring, Intake vanes, Fin tabs) (2016-05-11 19:26:47)

MM was next on the list and was glued in as per instructions. With it glued in the tail ring was set in place and tacked on with super glue. The intake vanes were then put back in place and tacked in with super glue as well. The 2 fin tabs under the wing were also glued on at this time with wood glue. Rocket was again given the afternoon to dry while I turned my attention to the NC.

CI Air Drying

Air drying

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NC Detailing (2016-05-11 19:46:19)

I'm sorry I neglected to take any photos of the next set of steps but I'll tell you what I did. The NC has 5 black panels and 2 black vents shown in the cover photo to which there are no decals provided on the decal sheet. So taking my frog tape, I masked off all of these. I then took an exacto knife and following the indent on each I cut them out. The rest of the NC was then masked off and the exposed areas were then painted gloss black. Once these areas were dry I removed the tape and then masked off the tip of the NC and spray painted it Bright Red. After allowing paint to dry a bit paper was removed and NC left to dry overnight. The following afternoon I again masked off the tip for the black section. After spraying it with gloss black I then gave it the rest of the afternoon to dry. 

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Decals and Clear coating (2016-05-11 20:09:33)

The final step was to add the decals. All decals were trimmed as close as possible and as such were a bit difficult to apply but with the aid of some Windex all were applied to my satisfaction. After giving rocket one more afternoon to dry I clear coated it with two coats of Rust-Oleum Clear coat to seal everything up.

Decals Applied.1

CI - 1351 Top shot 

Decals Applied.2

Another angle 

Decals Applied.3

CI -1351 Bottom shot 

Decals Applied.4

Yet another angle

Just need to finish installing the parachute and this bird is a wrap 

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Flight (2020-04-24 11:56:51)

Sorry I took so long in posting the flight of this kit. Maiden flight was on 05-28-16 on an Estes E9-4. This was a slow lift off the pad and weather cocking badly. End result saw rocket going horizontal. Way under powered as it didn't gain much altitude. Had the new Jolly Logic Chute Release System onboard and set for 400' and it deployed just after ejection charge fired. Forgot to get a recovery photo. Definitely needs a bigger motor. Second flight was on 07-29-17 at NARAM 59 on an Areotech E20-4. This was a near perfect flight. Will definitely be using this motor for future flights.

Maiden flight

Second flight for Cosmic Interceptor

Cosmic Interceptor recovery

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