Mercury Little Joe I

Little Joe I was the end result of a spaceflight program requirement to confirm new aerodynamic data on drop tests of boilerplate spacecraft associated with the dynamic stability of space capsule in free-fall. NASA began to see the need for comparable data under actual launch and recovery conditions vs. the limited data acquired from drops tests. To aid in the data acquisition needed for the Mercury program, NASA prepared test project requirements in October of 1958 for the design of low altitude, solid fuel booster and compatible launcher.

Mercury capsule lifted up to Little Joe I. Image Credit: NASA/MSFC archives

The primary objective of this simple booster system was to save money by allowing numerous test flights to qualify various solutions to the myriad of problems associated with the development of manned space flight. Specifically, among these were the potential problems associated with escaping from an explosion at or during launch as well as additional test parameters with how capsules behaved under aerodynamic loads and how they respond under actual reentry conditions. The test vehicle would also be used to qualify the parachute system and to verify recovery methods. It was determined that to acquire this kind of data (and as quickly as possible) the test launch vehicle should be kept functionally simple as possible, use readily available components and use solid fuel motors with no on-board guidance systems.

In December 1958, North American Aviation won the contract to build seven test airframes and one mobile launcher. The Little Joe booster assembly needed to approximate the same performance as the Redstone rocket with a payload capsule attached, while being adaptable enough to perform a variety of other test missions. As a side benefit, Little Joe could be made for about one-fifth the basic cost of the Redstone (about $200,000 each) and have a much lower flight to cost ratio as well as being manufactured and delivered more quickly to facilitate the needed data. 

The Little Joe test vehicles were to consist of clustered, solid-fuel motors that could generate almost 230,000 lbs. of thrust and theoretically lift a test spacecraft of 4,000 lbs. to 100 miles above the surface of the earth. After delivery of the 55 foot tall, 6.5 foot diameter test vehicles, 5 actual launches were conducted from 1959 to 1960 from the Wallops Island, Virginia facility. The first rocket designed solely for manned spacecraft qualifications, the Little Joe was a pioneer!

Little Joe
Little Joe I. Image Credit: NASA/MSFC archives
Testing of the Little Joe airframes began in 1959 and concluded in early 1960. Four of the six available boosters had tested prototype capsules, but two qualification flights were needed, including a launch of a real Mercury capsule. The seventh Little Joes had stayed a North American for static load testing but was refurbished to provide a third boost vehicle. The sixth and final test, known as LJ-5 would qualify the Mercury capsule and move it from research and development into operational mode.

Estes Little Joe I

Little Joe I
Apollo Photo Contest Entry: Lee Adams, 2019

Last but not least, the Little Joe I is the latest addition to the Estes’ Apollo Program Series. Estes developed our own 1:34 scale Little Joe I in 2018 after the LJ-5, the very rocket that qualified the Mercury capsule and moved it from R&D to operational mode.  

A  “must-have” for any scale rocket collection, the Estes Little Joe I features the same injection molded, high-impact plastic Mercury capsule found on the Mercury Redstone. Vetern modelers will recognize the balsa wood and printed index card-stock technique used on the fins from the 1:70th scale Saturn 1B model. Each fin will have to be carefully constructed out of five separate pieces of balsa, sanded to a beveled edge, then wrapped with card-stock. You can expect a solid 20 minutes of building time on each fin before it will be ready for painting. High quality waterslide decals will finish off this slick and impressive model. 

Standing almost 18 in. tall and weighing 3.2 oz, the 1:34 Little Joe I is the smallest rocket in the current Estes’ Apollo scale collection. Light-weight enough to use standated engines and launch gear, the rocket can be launched to 400 feet on a C6-5 engine. A colorful 15 in. parachute is included for “safe reentry.”

Little Joe I
Apollo Photo Contest Entry: Lee Adams, 2019
007255 - Little Joe 1

Little Joe I Rocket Kit

  • ADVANCED SKILL LEVEL:  Put your advanced finishing skills to the test with the Little Joe I, while building up to the more complex Expert and Master level models.  
  • RECOMMENDED ENGINES (sold separately): B6-4C6-5 
  • PROJECTED ALTITUDE: 400 ft. (122 m) on a C6-5
  • ESTIMATED ASSEMBLY TIME: 12 hours (painting and glue drying time not included)
  • LAUNCH SYSTEM: (sold separately): Porta-Pad II Launch Pad and Electron Beam Launch Controller.
  • AGES: For boys and girls ages 10+ with adult supervision for those under 12, and rocketeers of all ages.

Learn More About Other Rockets in the Moon Shot Program