Little Joe 1A prototype and 1/17.44 scale model (click on either photo for larger version)
2010 Update
The build of the "Little Joe" model shown on this website was completed in 2006, and plans called for the model to fly at the FAI World Spacemodeling Champinships held at the Baikonur Cosmodrome that September. Unfortunately, the motors required to fly the model were held up at Russian customs by the the US Team's contracted cargo carrier in the weeks leading up to the event, and the model did not fly there. The Little Joe did fly, however, at a World Cup event held in Lleida (Catalonia), Spain, in 2008. Check out this short video featuring that flight and the further adventures of the US Spacemodeling Team in Spain!
Introduction and Project Overview
Over the next few months, this web page will document the construction of a 1/17.44 scale model of the North American Aviation Little Joe booster, as used in the early days of Project Mercury. If all goes well, the model will be flown at the 16th World Spacemodeling Championships, to be held at the Baikonur Cosmodrome in a Russian-administered portion of Kazakhstan.
This is not the first time that I have constructed a Little Joe model, having built an LJ-5B in 1/35 scale utilizing the Estes (formerly Centuri) Mercury capsule in 1999, an LJ-1A in 1/20 scale for NARAM 42 in 2000, and a 1/12 scale LJ-5B for NARAM 43 in 2001.
July 22, 1959 Mercury Beach Abort test with simple boilerplate capsule and production Grand Central escape tower
This particular model will be a replica of the LJ-1A round, flown on November 4, 1959. This particular flight is notable for the fact that it was the only time a true boilerplate capsule was flown atop a Little Joe booster. The boilerplate capsule flown was recycled from the earlier July 22, 1959 Beach Abort Test. I built a 1/24 scale model of this capsule several years ago, and had originally intended for the masters, molds, and jigs created for that project to be reused for this Little Joe project, but ultimately decided that I wanted to build this replica in a larger scale.
You may notice multiple versions of the various parts and components in the photos that follow. In addition to a competition LJ-1A, a boilerplate model will be built to test and refine flight preparation and performance, and a new July 22, 1959 Beach Abort model will be constructed in a static, non-flying version for IPMS competition.
Flight profile
The Little Joe model will boost powered by a cluster of 4 Estes D12 motors, with black powder motors chosen over composites for their wide availability and ease of cluster ignition. As the D12's burn out, a Perfectflite miniTimer will ignite an Estes B6-2 in the aft end of the Mercury boilerplate capsule, simulating the operation of the escape tower. The booster will recover under a 36" nylon parachute, while the capsule and tower will recover under 12" poly 'chutes.
The booster is being designed to accomodate 4 additional A10 motors in addition to the D-12's, and an additional staging operation to simulate tower jettison operation is a possibility.
Why the screwy scale factor?
The unusual 1/17.44 scale factor was chosen in order to take advantage of an existing body tube with an outside diameter of 4.546", available from Jim Fackert of Totally Tubular. Adding a styrene fascia layer, adhesive, and paint to this tube will create a finished airframe with an O.D. in the neighborhood of 4.59". (Download the scale data worksheet.) (As an aside, I understand that Jim spec'd this tubing to allow folks to build their own 1/1 scale Arcas replica.)
A few comments on scale data sources...
Anyone interested in constructing a replica of any of the Little Joe rounds should visit Peter McQuillan's Project Mercury/Little Joe website. Peter has done a great deal of research into the entire LJ series, and his work has been a great help in building my earlier models. Through Peter I learned that much of the NASA documentation related to Project Mercury was located at the Fort Worth branch of the National Archives and Records Administration. My personal research at the Fort Worth Archives led me to create a DVD package on NASA's Little Joe program, which I offer through my video company, rocket.aero.
Each major component of the Little Joe model will be documented on a separate page:
On to part 1: Capsule assembly...
On to part 2: Escape Tower assembly...
On to part 3: Transition Shroud assembly...
On to part 4: Boilerplate assembly...
On to part 6: Airframe assembly...
On to part 7: Paint and Markings...
On to part 8: Motor Mount assembly...
On to part 9: Final Integration...
On to Beach Abort model assembly...
My Workshop...
A recent discussion on the Space Modeler's Yahoo! discussion group has dealt with folks sharing pictures of their workshops. The picture above is what the workspace looks like during the chaos that reigns during a project. I share the workshop with my lovely bride, Sarah, who uses her end of the workbench for scrapbooking, photo albums, and such. Our workshop is located in an upstairs living area of our house, and occupies an area roughly 15' x 15'. The cabinets and work surface were spec'd out specifically to support our hobby madness. There's a separate area out in the garage for paint work and other noxious activities.