Rocket of the Week

SpaceX has released a new model rocket with payload fairing. It has transparent fins, is 32 inches in height, and runs on a D or E motor.

It can be ordered here


click to enlarge

Launch of my Semroc Astro-1

Many rocketeers from the golden age of rocketry were brought into the sport through beginners kits. The most famous kit was probably the Estes Alpha but many chose the Centuri Astro-1.
The Astro-1 appeared for the first time in the 1969 Centuri catalog. Centuri designed the Astro-1 to be an excellent beginners kit. One of my favorite aspects of the Astro-1 were the large fins that just screamed “Speed”! The Astro-1 included a new concept known as the “Quick-Change” engine lock that became standard on model rockets. Initially the Plastic Nose Cone was advertised as a “Plastic Payload Cone” and the parachute was a mighty 16 inch diameter. The model was available from Centuri from 1969 until 1983.

Centuri #KB-17 and was introduced with a price of $1.75

The original plans can be found at Jim-Z – Link here

Parts for Centuri Astro 1 #KB-17/#5047

  • 1 PNC     5”   (2 parts on payload version)
  • 1  Elastic Shock Cord               SC-18   1/8″W x 24″L
  • 1  Shock Cord Fastener           SCF-1
  • 1 Chute         16”
  • 1 Body Tube    9.45” L      ST-10
  • 1 Launch Lug     2.25″ L   LL-2
  • 1  Balsa Sheet     BFM-10  3″W x 11″L x 3/32″  – Pattern here
  • 1  Thrust Ring       3/8″L     TR-7
  • 2  Centering Rings    1/4″L   CR-10
  • 1  Engine Tube         3″L     ST-7
  • 1  Engine Lock              EL-1
  • 1  Decal    3″W x 4.5″L   – Pattern here

Kits available:
Semroc Astro-1 (Great kit and true to the original)

You can also print up a lovely downscale of the Astro-1.

Astro-1 downscale by Chris Michielssen available in my Partial Paper Rockets section.

Click here to download this paper model. (you will need a PNC-5 Mosquito nose cone or print one from here)

Centuri Astro 1

Chris's downscale of the Centuri Astro 1


At the last NSL Semroc introduced two new kits. The two kits were the VF-261 and the OSO. The OSO is a Retro-Repo release of the 1967 FSI rocket.
FSI (Flight Systems,Inc) was started sometime around mid to late 1966 by George Roos in Louisville, CO. George Roos had worked on the composite motors of the Minuteman missles in the 1950s. The first FSI catalog was released in 1967. You can view it here. The OSO was one of FSI’s first rockets and continued in production throughout the life of FSI.
FSI marketed the rocket with this blurb:
The OSO rocket is the answer for all model rocketeers who wish to fly large experimental payloads to high altitudes. the large forward section is all payload compartment and is separated from the parachute recovery mechanism. Payload section and rocket are gently recovered by a large parachute as one unit”
In the 1967 catalog it says that
“the OSO kit has been designed to make maximum use of the new FSI F-18-8 high performance rocket engine”
I can’t imagine this light rocket on a F-18-8 unless the payload was substantial.
FSI produced 21 and 27mm motors and later 18mm. The OSO was designed to use the 27mm variety. Take a look at the FSI motor line here.
Sometime between 1971-1974 FSI moved to Raytown, Missouri where Lonnie Reese served as president.
Things became quiet for FSI in 1984 when Lonnie Reese was killed in an auto accident. They continued to produce motors and a few catalogs were released up to 1993. Harold Reese who made the motors for FSI died at this time and family did not continue production. It is rumored that Quest obtained some of the FSI motor machines at this time.
The Semroc OSO release continues Semroc’s great line of quality Retro-Repos. There are a few small changes. The rocket includes an ejection baffle and a kevlar to elastic shock cord. The Semroc version is also 18mm. The build is quite easy. The rocket is a nice addition to my repo collection.
Here she is:


sprint1 click to enlarge

I’ve always loved the clean lines and subtle curves of the Astron Sprint. This is a beautiful rocket and an amazing performer. The Sprint includes several optimizations that increase it’s performance and lower it’s drag. Elliptical fins are the most aerodynamically efficient of the fin designs (more on this here). The Sprint also includes a boat tail that also increases it’s performance . Estes produced the Sprint from 1970-1983 and advertised it as the “highest performance in it’s class”.
I ordered a clone kit from Thrustline Aerospace. The Kit was high quality parts. I downloaded the Sprint instructions from JimZ.
The build was pretty straight forward. Makes sure you have a sharp hobby knife before you attempt to cut the elliptical fins. I painted mine in the style from the 1972 catalog and printed my own decals. I didn’t buy one of these back in the early seventies but wish I had. Jim Flis has an Aston Sprint that he has launched 500 times! Here is a picture of Vernon Estes and Jim  with the Sprint. Vern pushed the button on the 500th launch.

Update: I just finished my second Sprint. It’s a bit larger…


Want your Sprint to perform even better? Take a look at this mod from Larry Renger in 1971

defendermain click to enlarge def1

In 1967 Centuri released a new kit known as the Defender Space Probe. The Defender was Centuri first rocket kit with a 3 engine cluster. Looking at the kit you can immediately see the influence of NASA and the Apollo program. The rocket incorporates many transistions that suggest staging in modern rockets. The rocket also includes a small payload bay. The description in the original Centuri kit says it can carry a payload of up to 3 ounces.
This month Semroc has released the Defender as part of it’s Retro-Repo line of new kits. The new release includes the usual improvements that Semroc is known for like the Kevlar cord and all balsa transistions. The kit is wonderful piece of nostalgia and was a pleasure to build.

defender1-kit The kit defender2-motorm cluster motor

defender3-sanded sanded and sealed

defender4-paint1 painted cluster

One tip that I used that I’ll pass on is paint the clustered engine tubes prior to inserting into the larger tubes. You can sand the areas that will attach to the larger tubes after the paint has dried to create a good seal with the glue.

Engine Approx. Altitude
Three A8-3 400′
Three B6-4 950′
Three C6-5 1600′

defender-flight Defender in Flight – click to enlarge
Return to the Rocketry Blog home page

cherokeedmy Cherokee D

I just finished a fun kit. I have always wanted a Cherokee D. I think I first saw it in an Estes catalog in the early seventies. I loved it’s look but was a little afraid of what a D engine could do to such a small rocket. I had very limited space to launch during my first incarnation as a rocketeer. As a BAR things have changed. I have room to launch at our club launches. I recently went online to Thrustline Aerospace and ordered the Cherokee D cloned kit. Thrustline Aerospace does a great job of keeping this kit just like the original balsa version that was around from 1971-1974. Estes changed the kit to having a plastic nose cone during it’s 1975-1983 production. Thrustline also made a few improvements to the original kit. They include kevlar to attach to the engine mount and then to the elastic cord. The original used the rubber shock cord to the estes body tab connection. The balsa was all of high quality and the fins were laser cut. You can obtain the decals from Excelsior Rocketry.

Here are some details:
Astron Cherokee D 1971-1974 (original with balsa nose)
Cherokee D 1975-1983 (plastic nose cone)

21.6 inches long
1.325 dia
2.75 oz.

Plans are available at JIM Z
Review on EMRR

How about an upscale? The Cherokee M


This weeks rocket of the week is the versitile payloader – The Semroc Goliath. This rocket kit allows you to build this payloader with 3 engine variations. You can choose from a single 18mm, a single 24mm, or (as I did) the 3 engine 18mm cluster. The Goliath is a true Semroc rocket originally released in 1969 as Semroc's sixth kit and at the time of it's release, it was Semroc's largest rocket. The kit draws it's inspiration from the Estes Astron Ranger. I found the build to be an satisfying experience because of the excellent quality of the Semroc parts. Currently I have yet to define my final plans for the use of the large payload bay. It will probably house a Boostercam in the near future. Here is an EMRR review.

Here is my Goliath

Next Page »


Get every new post delivered to your Inbox.

Join 196 other followers