At 11:47:14.99 p.m., 31 July 1958, Hawaii Standard Time (09:47:14.99, 1 August 1958, UTC), a United States Army M8 Redstone Medium Range Ballistic Missile (MRBM), CC-50,¹ was launched from Johnston Island, approximately 715 nautical miles (822 miles/1,323 kilometers) southwest of Honolulu, Hawaii, in the North Pacific Ocean.
This was part of a series of nuclear weapons effects tests under Operation Hardtack. This individual test (“shot”) was designated Teak.
The Redstone carried a W-39 thermonuclear warhead. It also carried four detachable instrumentation pods, located between each of its fins. These pods were detached from the Redstone at various altitudes during the ascent.
At 11:50:5.597 p.m., 2 minutes, 50.607 seconds later, the warhead was detonated at a predetermined altitude of 76.311 kilometers (47.418 miles). The detonation had a yield of 3.8 megatons.
Analysis of the test showed that the warhead detonated 11.192 kilometers (6.964 miles) north, and 800 meters (2,625 feet) east of the intended point in space, and about 50 meters (164 feet) lower than planned. This point was almost directly overhead Johnston Island, just 0.967 kilometers (0.601 miles) south of the launch pad.
At 11:27.34.498 p.m., Hawaiian Standard Time, 11 August 1958, a second M8 Redstone, CC-51 was launched from Johnston Island, also carrying a W39 warhead.
This warhead detonated at 11:30:8.607 p.m, 41.690 kilometers (25.905 miles) south of Johnston Island, at an altitude of 42.973 kilometers (26.702 miles). The detonation was 4.025 kilometers (2.501 miles) south and 50 meters (164 feet) west of the intended point in space, and 4.716 kilometers (2.930 miles) higher than planned.
The W39 was also carried in the weapon pod of the Convair B-58A Hustler Mach 2 strategic bomber. A gravity bomb variant, the Mark 39, was carried by the Boeing B-52 Stratofortress.
The Redstone missile was designed by the United States Army Guided Missile Development Division. It was a liquid-fueled guided missile intended as a medium range nuclear-armed tactical missile for theater-wide support. Development began in May 1951. Initially, it was intended to carry a 1,500 pound (680 kilogram) payload 500 nautical miles (926 kilometers) with an accuracy of 500 feet (152 meters). The requirement changed to carry a much heavier warhead a shorter distance.
During its development, testing and deployment, the Redstone had several designations, which has lead to some confusion. The M8 Redstone, originally known as the XSSM-G-14, then XSSM-A-14 Major, and for a short time, Ursa, was later redesignated PGM-11.
The first XSSM-G-14, RS-01, was launched 20 August 1953, from the Cape Canaveral Air Force Station on the east coast of Florida. RS-01 suffered a control system malfunction, and 80 seconds into its flight, the engine failed. Ground control sent a cutoff command signal.
The M8 Redstone Block I missile is 69 feet, 4 inches (21.133 meters) long, with a diameter of 5 feet, 10 inches (1.778 meters). It weighs 16,512 pounds (7,490 kilograms) empty, and 61,346 pounds (27,826 kilograms) at ignition. Fully fueled, the Redstone carries 25,090 pounds (11,381 kilograms) of liquid oxygen and 18,800 pounds (8,528 kilograms) of alcohol.
Redstone CC-50 and CC-51 were powered by Rocketdyne 75-110-A6 engines. The A6 weighed 1,451 pounds (658 kilograms). This engine burned liquid oxygen and alcohol. It produced 98,138 pounds of thrust (414.299 kilonewtons) at Sea Level. Later production Redstones were powered by the A7 variant, which produced 78,000 pounds of thrust (346.961 kilonewtons) at Sea Level.
The Redstone missile was controlled by an inertial guidance system built by teh Ford Instrument Company.
During powered flight, the Redstone accelerated to a maximum of 4.6g. At engine cutoff, the Redstone had reached Mach 4.8. During atmospheric reentry, the missile experienced a maximum decleration of 7.7 g and maximum and speed of Mach 5.5. At impact, aerodynamic drag had slowed it to Mach 2.3. At a range of 175 nautical miles, the total time of flight was 6 minutes, 15.1 seconds.
The first launch of an M8 Block I tactical missile, CC-1002, took place at Cape Canaveral Air Force Station, Florida, 16 May 1958. The launch was carried out by Battery A, 217th Field Artillery Missile Battalion, 40th Field Artillery Missile Group (Redstone). Both the boost and flight phase were normal, and the missile impacted 578 meters (1,896 feet) of the designated point in the Atlantic Missile Range.
Battery A deployed to Europe in June 1958, joining Seventh Army as part of the NATO Shield Force. It was stationed at Des Gouttes Kaserne, Bad Kreuznach, Rhineland-Palatinate, Federal Republic of Germany. The unit consisted of 650 officers and enlisted men. When it arrived in Germany, the 40th FAMG had only one of its basic load of four Redstone missiles.
The Redstone missiles, by then designated PGM-11, were retired from service on 30 October 1964, to be replaced by the MGM-31A Pershing.
There were several variants of the Redstone. Eight modified, man-rated Redstones were produced for NASA’s Project Mercury. More than 800 changes were required, including lengthening the missile to increase fuel capacity for a longer burn time. Astronauts Alan Bartlett Shepard, Jr., and Virgil Ivan Grissom were launched on suborbital flights in 1961. Six of these Redstone MLRBs were launched, and all were successful.
Another variant of the Redstone was the three-stage Jupiter-C. These missiles were 8 feet longer than the standard Redstone, and used two solid propellant upper stages.
A four-stage Juno I variant launched the United States’ first satellite, Explorer 1, 1 February 1958.
¹ The letters “SX” are painted on Redstone CC-50
² The letters “SH” are painted on Redstone CC-51
© 2024, Bryan R. Swopes
…spaced, not space?
Ooooops.
W-39 warhead had a nominal yield of 3.8 MT and was a development of the original Mark-15 thermonuclear device. It was largely gone from the stockpile by mid sixties.