Little Joe
Encyclopedia
Little Joe was an unmanned United States solid-fueled booster rocket
Booster rocket
A booster rocket is either the first stage of a multi-stage launch vehicle, or else a strap-on rocket used to augment the core launch vehicle's takeoff thrust and payload capability. Boosters are generally necessary to launch spacecraft into Earth orbit or beyond...

 used for eight launches from 1959–1960 from Wallops Island
Wallops Island
Wallops Island is a island off the east coast of Virginia, part of the barrier islands that stretch along the eastern seaboard of the United States of America.It is located in Accomack County, Virginia...

, Virginia to test the launch escape system
Launch escape system
A Launch Escape System is a top-mounted rocket connected to the crew module of a crewed spacecraft and used to quickly separate the crew module from the rest of the rocket in case of emergency. Since the escape rockets are above the crew module, an LES typically uses separate nozzles which are...

 and heat shield
Heat shield
A heat shield is designed to shield a substance from absorbing excessive heat from an outside source by either dissipating, reflecting or simply absorbing the heat...

 for Project Mercury
Project Mercury
In January 1960 NASA awarded Western Electric Company a contract for the Mercury tracking network. The value of the contract was over $33 million. Also in January, McDonnell delivered the first production-type Mercury spacecraft, less than a year after award of the formal contract. On February 12,...

 capsules, as well as the name given to the test program using the booster. The first rocket designed solely for manned spacecraft qualifications, Little Joe was also one of the pioneer operational launch vehicles using the rocket cluster principle.

A successor, Little Joe II
Little Joe II
Little Joe II was an American space launch vehicle used for five unmanned tests of the launch escape system and to verify the performance of the command module parachutes for the Apollo spacecraft from 1963–66...

, was used for flight testing of the Apollo launch escape system from 1963–1966.

Background

When NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 needed a booster for the Mercury manned space program, the agency found that the Atlas rockets would cost approximately $2.5 million each and that even the Redstone would cost about $
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

1 million per launch. The managers of the Mercury program recognized that the numerous early test flights would have to be accomplished by a far less expensive booster system. As it turned out, the Little Joe rocket NASA designed cost about $200,000 each.

In January 1958, Max Faget and Paul Purser had worked out in considerable detail on paper how to cluster four of the solid-fuel Sergeant rockets
MGM-29 Sergeant
The MGM-29 Sergeant was an American short-range, solid fuel, surface-to-surface missile developed at the Jet Propulsion Laboratory. Activated by the US Army in 1962 to replace the MGM-5 Corporal it was deployed overseas by 1963, carrying the W52 nuclear warhead or alternatively one of high explosives...

, in standard use at the Wallops Flight Facility
Wallops Flight Facility
Wallops Flight Facility , located on the Eastern Shore of Virginia, is operated by NASA’s Goddard Space Flight Center, primarily as a rocket launch site to support science and exploration missions for NASA and other U.S. government agencies...

 in Virginia, to boost a manned nose cone above the stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...

. Faget's short-lived "High Ride" proposal had suffered from comparisons with "Project Adam" at that time, but in August 1958 William Bland
William Bland
Dr. William Bland was a transported convict, medical practitioner and surgeon, politician, farmer and inventor in colonial New South Wales, Australia.-Early life:...

 and Ronald Kolenkiewicz had returned to their preliminary designs for a cheap cluster of solid rockets to boost full-scale and full-weight model capsules above the atmosphere. As drop tests of boilerplate capsules provided new aerodynamic data on the dynamic stability of the configuration in free-fall, the need for comparable data on the powered phase quickly became apparent. So in October 1958, a NASA team prepared new engineering layouts and estimates for the mechanical design of the booster structure and a suitable launcher.

As the blueprints for this cluster of four rockets began to emerge from their drawing boards, the designers' nickname for their project gradually was adopted. Since their first cross-section drawings showed four holes, they called the project "Little Joe," from the craps
Craps
Craps is a dice game in which players place wagers on the outcome of the roll, or a series of rolls, of a pair of dice. Players may wager money against each other or a bank...

 throw of a double deuce on the dice. Although four smaller circles were added later to represent the addition of Recruit rocket motors, the original name stuck. The appearance on engineering drawings of the four large stabilizing fins protruding from its airframe also helped to perpetuate the name Little Joe had acquired.

The primary purpose of this relatively small and simple booster system was to save money—by allowing numerous test flights to qualify various solutions to the myriad problems associated with the development of manned space flight, especially the problem of escaping from an explosion at or during launch. Capsule aerodynamics under actual reentry conditions was another primary concern. To gain this kind of experience as soon as possible, its designers had to keep the clustered booster simple in concept; it should use solid fuel and existing proven equipment whenever possible, and should be free of any electronic guidance and control systems.

The designers made the Little Joe booster assembly to approximate the same performance that the Army's Redstone booster would have with the capsule payload. But in addition to being flexible enough to perform a variety of missions, Little Joe could be made for about one-fifth the basic cost of the Redstone, would have much lower operating costs, and could be developed and delivered with much less time and effort. And, unlike the larger launch vehicles, Little Joe could be shot from the existing facilities at Wallops Island.

Launch vehicle development

Twelve companies responded during November 1958 to the invitations for bids to construct the airframe of Little Joe. The technical evaluation of these proposals was carried on in much the same manner as for the spacecraft, except that Langley Research Center
Langley Research Center
Langley Research Center is the oldest of NASA's field centers, located in Hampton, Virginia, United States. It directly borders Poquoson, Virginia and Langley Air Force Base...

 itself carried the bulk of the administrative load. The Missile Division of North American Aviation
North American Aviation
North American Aviation was a major US aerospace manufacturer, responsible for a number of historic aircraft, including the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, and the XB-70, as well as Apollo Command and Service...

 won the contract on December 29, 1958; and began work immediately in Downey, California
Downey, California
Downey is a city located in southeast Los Angeles County, California, United States, southeast of downtown Los Angeles. The city is best known as the birthplace of the Apollo space program, and is the city where folk singer Karen Carpenter lived and died...

, on its order for seven booster airframes and one mobile launcher.

The primary mission objectives for Little Joe as seen in late 1958 (in addition to studying the capsule dynamics at progressively higher altitudes) were to test the capsule escape system at maximum dynamic pressure, to qualify the parachute system, and to verify search and retrieval methods. But since each group of specialists at work on the project sought to acquire firm empirical data as soon as possible, more exact priorities had to be established. The first flights were to secure measurements of inflight and impact forces on the capsule; later flights were to measure critical parameters at the progressively higher altitudes of 20,000, 250,000, and 500,000 feet (6, 75, and 150 km). The minimum aims of each Little Joe shot could be supplemented from time to time with studies of noise levels, heat and pressure loads, heat shield separation, and the behavior of animal riders, so long as the measurements could be accomplished with minimum telemetry. Since all the capsules boosted by the Little Joe rockets were expected to be recovered, onboard recording techniques would also contribute to the simplicity of the system.

The first of only two booster systems designed specifically and solely for manned capsule qualifications, Little Joe was also one of the pioneer operational launch vehicles using the rocket cluster principle. Since the four modified Sergeants (called either Castor
Castor (rocket stage)
The Castor family of solid-fuel rocket stages and boosters were built by Thiokol and used on a variety of launch vehicles. They were initially developed as the second stage motor of the Scout rocket...

 or Pollux rockets, depending upon modification) and four supplemental Recruit rockets were arranged to fire in various sequences, the takeoff thrust varied greatly, but maximum design thrust was almost 230,000 pounds
Pound-force
The pound force is a unit of force in some systems of measurement including English engineering units and British gravitational units.- Definitions :...

 (1,020 kilonewtons). Theoretically enough to lift a spacecraft of about 4,000 pounds
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

 (1,800 kg) on a ballistic path over 100 miles (160 km) high, the push of these clustered main engines should simulate the takeoff profile in the environment that the manned Atlas would experience. Furthermore, the additional powerful explosive pull of the tractor-rocket escape system could be demonstrated under the most severe takeoff conditions imaginable. The engineers who mothered Little Joe to maturity knew it was not much to look at, but they hoped that their ungainly rocket would prove the legitimacy of most of the ballistic capsule design concepts, thereby earning its own honor. A successor, Little Joe II
Little Joe II
Little Joe II was an American space launch vehicle used for five unmanned tests of the launch escape system and to verify the performance of the command module parachutes for the Apollo spacecraft from 1963–66...

, would later be used for flight testing of the Apollo crew escape system.

Flights

As of January 21, 1960, the Little Joe series of five actual and attempted flights had expended four of the six test boosters North American had made for NASA and five prototype capsules made in the Langley shops. The primary test objectives for these solid-fuel-boosted models were an integral part of the development flight program conducted within NASA by the Space Task Group, with Langley and Wallops support. Now only two Little Joe boosters remained for the qualification flight tests. North American had manufactured seven Little Joe airframes, but one of these had been retained at the plant in Downey, California, for static loading tests. STG ordered the refurbishment of this seventh airframe so as to have three Little Joe boosters for the qualification flight program. The success of Little Joe 1B
Little Joe 1B
The Little Joe 1B was a Launch Escape System test of the Mercury spacecraft, conducted as part of the U.S. Mercury program. The mission also carried a female Rhesus monkey named Miss Sam in the Mercury spacecraft. The mission was launched January 21, 1960, from Wallops Island, Virginia...

 in January 1960 meant that the next flight, the sixth, to be known as Little Joe 5
Little Joe 5
Little Joe 5 was an unmanned Launch Escape System test of the Mercury spacecraft, conducted as part of the U.S. Mercury program. The mission used a production Mercury spacecraft #3. The mission was launched November 8, 1960, from Wallops Island, Virginia. The Little Joe 5 flew to an apogee of 10.1...

, would be the first to fly a real Mercury capsule from the McDonnell production line. In passing from development flight tests with boilerplate models to qualification flight tests with the "real McDonnell" capsule, the Space Task Group moved further away from research into development and toward operations.


Mission numbering

The official Mercury mission numbering designation was a two letter designation which corresponded to the launch vehicle type, followed by a dash then a digit indicating the particular set of flight objectives, and an optional letter used to distinguish further flights to accomplish those objectives. So the official designation for the first Little Joe flight was "LJ-1." Flights did not occur in numeric sequence as the project scheduling was adapted as it progressed. The actual flight order was:

Specifications

  • Little Joe I
    • Thrust: 235,000 lbf (1,044 kN)
    • Length: 15.2 m
    • Diameter: 2.03 m
    • Fin Span: 6.5 m
    • Weight: 28,000 lb (12,700 kg)
    • Fuel: Solid
    • Burn Time: ~40 s

  • Recruit rocket (Thiokol XM19)
    • Thrust: 37,500 lbf (167 kN)
    • Length: 2.7 m
    • Diameter: 0.23 m
    • Weight: 350 lb (159 kg)
    • Fuel: Solid
    • Burn Time: 1.53 s

  • Castor rocket (Thiokol XM33)
    • Thrust: 58,200 lbf (259 kN)
    • Length: 6.04 m
    • Diameter: 0.79 m
    • Weight: 9,753 lb (4,424 kg)
    • Fuel: Solid
    • Burn Time: 37 s

See also

  • Big Joe
  • Little Joe II
    Little Joe II
    Little Joe II was an American space launch vehicle used for five unmanned tests of the launch escape system and to verify the performance of the command module parachutes for the Apollo spacecraft from 1963–66...

  • Boilerplate (spaceflight)

External links


First Mission:
Little Joe 1
Little Joe 1
Little Joe 1 was a failed launch of a Little Joe solid fuel rocket that was designed to test the Mercury spacecraft Launch Escape and Recovery systems. The vehicle was in height, weighed approximately , and was in diameter with a fin span of...

Mercury program
Mercury program
Mercury Program might refer to:*the first successful American manned spaceflight program, Project Mercury*an American post-rock band, The Mercury Program...

Last Mission:
Little Joe 5B
Little Joe 5B
Little Joe 5B was an unmanned Launch Escape System test of the Mercury spacecraft, conducted as part of the U.S. Mercury program. The mission used production Mercury spacecraft # 14A. The mission was launched April 28, 1961, from Wallops Island, Virginia. The Little Joe 5B flew to an apogee of 2.8...

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