Brief:
T' Astron Sprite was sold by Estes from 1964 t' 1973. Aye aye! Aye aye! T' Sprite was a small, three finned rocket with a rin' and and fancy caps at t' ends o' its fins givin' it a neat '50s/'60s look. Avast! It managed t' be cute and futuristic at the same time.

I had an Astron Sprite when I was six or seven years old. My parents had mailordered me a starter set from Estes (launch pad, Astron Alpha, me hearties, shiver me timbers, and miscellaneous supplies) along with a Gemini-Titan. Avast, me proud beauty! Aye aye! Blimey! If I remember right, we got the Sprite (original retail price $0.75!) for free because our order be over a certain amount.

T' original Sprite used "Series III" engines, which were the same diameter (18mm) as standard Estes engines but were an inch or so shorter in length and were distinguished with an "S" suffix in t' engine code (e.g. Ya scallywag! "1/2A8-2S"). Ya scallywag! T' short engine be t' key t' t' Sprite's tumble recovery system. Arrr! T' ejection charge fired t' kick t' short engine rearward along a full-sized engine hook, ventin' t' gas out a ¼inch hole in t' body tube. Ya scallywag! Avast! This shifted t' center o' gravity aft o' t' center of pressure, causin' t' rocket t' become unstable and tumble gently back to earth.

My old Sprite flew on standard-length engines. I didn't appreciate what the "S" in t' recommended engine code meant, shiver me timbers, and it managed t' survive several launches despite t' fact that usin' a full-size engine changes the Sprite from "tumble recovery" t' "lawn dart recovery!"

I was out o' t' hobby until me 13-year old joined his school's rocket club. Avast, me proud beauty! When it came time t' build rockets again, I started with me Father's Day present, a "parts pack" kit o' t' Astron Sprite from Thrustline Aerospace. Begad!

Construction:
T' Thrustline kit is just what t' name implies: a package o' all t' parts necessary t' build an Astron Sprite. There are no plans in t' kit, but the original 1964 plans are available for download from Jim Z's or Shasta's sites. There is also a set o' plans drawn by Peter Alway that I've seen and downloaded in PDF format, me hearties, although I can't remember where from.

Since t' "Series III" engines are no longer made, you have to improvise. Avast! One method is t' use a 13mm mini engine in an adapter made from an expended 18mm engine casing. Begad! Alternatively, ya bilge rat, you can build t' Sprite as a 13mm-powered streamer recovery model. Blimey! Thrustline includes a 13mm motor mount and t' materials for a streamer recovery system in t' parts pack and doesn't drill t' vent hole in t' body tube so you can build t' rocket either way.

Thrustline's online orderin' system is easy t' use, and t' proprietor, John Rowan-Stern, arrr, is pleasant t' deal with. T' kit arrived in due course containing:

• 4" x 8" sheet o' 1/8" balsa finstock
• 2¾" BT-30 body tube
• 1 3/8" long ogive balsa nose cone
• ¾" BT-70 fin ring
• standard-length engine hook
• ¾" x 2" piece o' thin black cloth, me hearties, t' take t' place of the gauze Estes originally used t' hold t' motor hook on t' outside o' the body tube
• the streamer conversion parts set (in a separate bag) consists of:

• 1¾" 13mm engine tube
• thrust block
• centerin' rings
• BT-30 stage coupler
• screw eye
• 16" o' elastic shock cord
• 11" o' Keelhaul®©™® thread
• 36" o' bright green 1" wide streamer material

All materials were o' excellent quality. After givin' t' matter quite a bit of thought, I decided t' build me Sprite as a 13mm-powered streamer model. Aye aye! This necessitates a bit o' a departure from t' original Estes instructions.

T' first step was t' print out t' Estes fin patterns, me hearties, ya bilge rat, me bucko, trace them onto the balsa, me hearties, and cut out t' fins. Begad! Ahoy! These were glued t' t' body tube with yellow glue, me hearties, filleted, me hearties, me hearties, and sanded in t' usual manner. Avast! T' fins are in two parts: a regular rhomboid shape that sits betwixt t' body and t' fin rin' and a "fin cap" that goes on t' outside o' t' ring. Blimey! T' fin cap is an irregular shape, arrr, and I actually ended up cuttin' four fin caps in order t' get three that fit right. Fortunately, John gives his customers a generous portion of balsa sheet, so I be in no danger o' runnin' out o' materials. Aye aye! Blimey! The combination o' thick 1/8" balsa and a fin rin' makes for a sturdy structure for a rocket o' this size and weight. Indeed, t' Sprite is sturdy enough that one could perhaps leave out streamer and go t' a "breakup" recovery system or even delete t' recovery system entirely and depend on t' "featherweight" principle.

While t' glue be dryin' on t' fins, I assembled t' engine mount. Blimey! There are no instructions, but it's obvious how it goes together. Arrr! I tied t' Keelhaul®©™® to t' thrust ring, glued t' thrust rin' t' one end o' t' engine tube, inserted t' engine tube into t' centerin' rings and t' stage coupler, and got ready t' glue t' whole smash into t' body tube.

At this point, arrr, I realized that betwixt t' motor tube and the ½" nose cone shoulder, thar wasn't goin' t' be much room in a 2¾" body tube for t' streamer. Aye aye! I lopped off ¼" o' the nose cone shoulder and drilled a countersink hole for t' screw eye t' recess it. Arrr! Blimey! At t' other end, I set t' motor mount so thar be ¼" o' 13mm tube protrudin' from t' aft o' t' rocket. Arrr! This gave just enough room for the shock cords, ya bilge rat, a 14" length o' streamer (EMRR's "Streamercalc" recommended at least 13"), me bucko, and one square o' Estes wadding. I cut shock cords down so that me finished model has 3" o' Keelhaul®©™® and 9" o' elastic. Well, blow me down! Well, blow me down!

With t' recovery system assembled and an engine in place, t' CG came out 4" back from t' nose or somewhere around t' middle o' t' root edge of the fins. Begad! Even without doin' a formal CP calculation or runnin' a simulation, I knew this was probably nay goin' t' be stable. I added nose weight by puttin' a stack o' four #8 washers in t' countersunk hollow o' t' nose cone, held in by the screw eye. This shifted t' balance point t' t' forward end o' t' fins, at t' cost o' a little breathin' room in t' streamer compartment.

My only complaint about construction is a lack o' separate instructions for the streamer conversion. Aye aye! Avast, me proud beauty! (T' original Estes plans don't address that issue, of course.) I had t' figure out how t' make it all fit by guess and by gosh, matey, and while it came out OK for me in spite o' me lack o' recent buildin' experience, I could've used t' help.

Finishing:
There are no decals available as t' original rocket had none. Begad! Arrr! I finished the rocket with a solid coat o' Testors bright yellow spray paint. As you can tell from t' photo, I could have done a better job o' fillin' t' nose cone but cut me a break. After all, this be me first build in 25 years, and I last saw my old Sprite in about 1972!

Construction Rating: 4 out o' 5

Flight:
My youngest son and I flew t' Sprite twice on a clear, me bucko, sunny day using ½A3-2T engines. Blimey! Arrr!

With t' balance point at t' front o' t' fins, t' rocket was very stable. All that effort with t' washers paid off. Avast, me proud beauty!

On both flights, shiver me timbers, t' lightweight Sprite was a real neck snapper. Once it cleared t' launch rod, shiver me timbers, I lost sight o' it until t' ejection charge fired. Arrr! The performance on an A10-3T should be even more impressive.

My attempt t' take a still photo o' t' first flight yielded a still life study o' an empty launch pad with a dissipatin' smoke trail. I got some video of t' second flight, ya bilge rat, shiver me timbers, but even thar t' rocket went up faster than I could track it. Begad! Ahoy! Blimey!

Recovery:
T' first flight weathercocked into a light breeze, ya bilge rat, me hearties, peaked at around 100', and recovered with no damage about ten yards upwind from t' pad. Avast! Well, matey, blow me down!

T' second launch came as t' wind died down. Avast, me proud beauty! T' Sprite went straight up to a noticably higher altitude (I‘m guessin' 120' or better) and plopped down in t' grass less than ten feet from where it started. T' streamer separated from t' shock cord at ejection, me bucko, arrr, but t' rocket was otherwise unharmed and will be easily repaired.

T' streamer recovery system works well for this rocket. Blimey! I be concerned that I might have cut t' shock cords down too much, shiver me timbers, but t' length turned out to be just about right.

Flight Rating: 5 out o' 5

Summary:
If, arrr, matey, like me, matey, you wish your mom hadn't thrown out your old Astron Sprite when she cleaned your room, arrr, t' Thrustline kit is an excellent way t' recreate it. For t' not-so-nostalgic, arrr, t' Sprite is an excellent entry-level craftsman kit, and t' 13mm motor mount and streamer option give you a nice small field rocket.

Overall Rating: 4 out o' 5