Tag Archives: Two-Stage Rocket

11 November 1966, 20:46:33.419 UTC, T minus Zero

Gemini XII lifts off from LC-19 at 2:21:04 p.m., EST, 11 November 1966. (NASA)
Gemini XII lifts off from LC-19 at 3:46:33 p.m., EST, 11 November 1966. (NASA)

11 November 1966: Gemini 12 lifted off from Launch Complex 19 at the Cape Canaveral Air Force Station, Florida, at 3:36.33.419 p.m., Eastern Standard Time. Two NASA Astronauts, Captain James A Lovell, Jr., United States Navy, and Major Edwin E. (“Buzz”) Aldrin, Jr., United States Air Force, were the crew. This was the second space flight for Lovell, who had previously flown on Gemini VII, and would later serve as Command Module Pilot on Apollo 8 and Mission Commander on Apollo 13. It was Aldrin’s first space flight. He would later be the Lunar Module Pilot of Apollo 11, and was the second human to set foot of the surface of the Moon.

The Gemini 12 mission was to rendezvous and docking with an Agena Target Vehicle, which had been launched from Launch Complex 14, 1 hour, 38 minutes, 34.731 seconds earlier by an Atlas Standard Launch Vehicle (SLV-3), and placed in a nearly circular orbit with a perigee of 163 nautical miles (187.6 statute miles/301.9 kilometers) and apogee of 156 nautical miles (179.5 statute miles/288.9 kilometers).

Artist’s concept of Gemini spacecraft, 3 January 1962. (NASA-S-65-893)

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a reentry module and an adapter section. It had an overall length of 19 feet (5.791 meters) and a diameter of 10 feet (3.048 meters) at the base of the adapter section. The reentry module was 11 feet (3.353 meters) long with a diameter of 7.5 feet (2.347 meters). The weight of the Gemini varied from ship to ship, but Spacecraft 12 weighed 8,296.47 pounds (3,763.22 kilograms) at liftoff.

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin Marietta’s Middle River, Maryland plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 63 feet (19.202 meters) long with a diameter of 10 feet (3.048 meters). The second stage was 27 feet (8.230 meters) long, with the same diameter. The 1st stage was powered by an Aerojet Engineering Corporation LR-87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by a hypergolic combination of hydrazine and nitrogen tetroxide. Ignition occurred spontaneously as the two components were combined in the combustion chambers. The LR-87-7 produced 430,000 pounds of thrust (1,912.74 kilonewtons).¹ It was not throttled and could not be shut down and restarted. The 2nd stage used an Aerojet LR-91 engine which produced 100,000 pounds of thrust (444.82 kilonewtons).²

The Gemini/Titan II GLV combination had a total height of 109 feet (33.223 meters) and weighed approximately 340,000 pounds (154,220 kilograms) when fueled.³

Astronaut Buzz Aldrin standing in the open hatch of Gemini XII in Earth orbit. (NASA)

Gemini XII was the tenth and last flight of the Gemini program. The purpose of this mission was to test rendezvous and docking with an orbiting Agena Target Docking Vehicle and to test extravehicular activity (“EVA,” or “space walk”) procedures. Both of these were crucial parts of the upcoming Apollo program and previous problems would have to be resolved before the manned space flight projects could move to the next phase.

Buzz Aldrin had made a special study of EVA factors, and his three “space walks,” totaling 5 hours, 30 minutes, were highly successful. The rendezvous and docking was flown manually because of a computer problem, but was successful. In addition to these primary objectives, a number of scientific experiments were performed by the two astronauts.

Gemini XII is tethered to the Agena TDV, in Earth orbit over the southwest United States and northern Mexico. (NASA)
Gemini XII is tethered to the Agena TDV, in Earth orbit over the southwest United States and northern Mexico. (NASA)

Gemini XII reentered Earth’s atmosphere and splashed down in the Atlantic Ocean, just 3.8 nautical miles (4.4 statute miles/7.0 kilometers) from the planned target point. Lovell and Aldrin were hoisted aboard a Sikorsky SH-3A Sea King helicopter and transported to the primary recovery ship, USS Wasp (CVS-18). The total duration of the flight was 3 days, 22 hours, 34 minutes, 31 seconds.

Gemini XII astronauts Major Edwin E. Aldrin, Jr., USAF, and Captain James A. Lovell, Jr., USN, arrive aboard USS Wasp (CVS-18), 15 November 1966. (NASA)

¹ Post-flight analysis gave the total average thrust of GLV-12’s first stage as 458,905 pounds of thrust (2,041.31 kilonewtons)

² Post-flight analysis gave the total average thrust of GLV-12’s second stage as 99,296 pounds of thrust (441.69 kilonewtons)

³ Gemini XII/Titan II GLV (GLV-12) weighed 345,710 pounds (156,811 kilograms) at Stage I ignition.

© 2018, Bryan R. Swopes

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4 November 1962, 06:30 GMT

Dominic Tightrope fireball, 00:00 GMT, 4 November 1962. (Nuclear Weapons Archive)
Dominic Tightrope fireball, 06:30 GMT, 4 November 1962. (Nuclear Weapons Archive)

4 November 1962: A Western Electric M6 Nike Hercules air-defense guided missile was launched from Johnston Island in the North Pacific Ocean. The missile was armed with a  W-31 Mod 1 nuclear warhead, and had been modified to include a command arm/fire capability, and an automatic disarm feature.

At an altitude of 69,000 feet (21,031 meters), 2 miles (3.2 kilometers) south-southwest of the island, the warhead detonated with an explosive yield of 12 kilotons.

This nuclear weapon effects test, Dominic Tightrope, was the final test of the Operation Dominic I test series, and was the last atmospheric nuclear test conducted by the United States.

The Nike Hercules was a long-range, high-altitude surface-to-air guided missile, designed and produced by Western Electric Company and the Douglas Aircraft Company. Douglas manufactured the missile at Charlotte, North Carolina. It was a two-stage missile with a cluster of four Hercules Powder Company M5E1 solid-fuel rocket engines as the boost stage.

The Nike Hercules had an overall length of 41 feet, 1.35 inches (12.531 meters). Its weight was 10,710 pounds (4,858 kilograms). The Hercules could reach an altitude of 100,000 feet (30,480 meters) and had a range of 90 miles (145 kilometers). The missile’s maximum speed was Mach 3.65.

The booster stage was 14 feet, 2.845 inches (4.339 meters) long and had a maximum diameter of 3 feet, 7.25 inches (1.099 meters). There were four stabilizing fins spaced at 90°. The fin span was 11 feet, 5.88 inches (3.502 meters). The leading edges were swept aft 24.23°. The booster stage produced 173,600 pounds of thrust (772.211 kilonewtons) and burned for 3.4 seconds.

Nike Hercules second stage.

The second stage was 26 feet, 10.500 inches (8.192 meters) long with a maximum diameter of 2 feet, 7.50 inches (0.800 meters). It had four triangular wings and four small “linealizer” fins, which were also spaced 90°. The maximum wing span was 7 feet, 4.00 inches (2.235 meters). The missile was powered by a Thiokol Chemical Corporation M30 solid-fuel rocket engine which produced 13,750 pounds of thrust (61.163 kilonewtons) and had a burn time of 29 seconds.

A Nike Hercules air defense missile launch. (U.S. Army)
A Nike Hercules air defense missile launch. (U.S. Army)

The Nike air defense missile system used multiple radars to track incoming target aircraft and the outgoing missile. Computer systems analyzed the data and signals were sent to guide the missile toward the target. This was a complex system and multiple missiles were based together at missile sites around the defended area.

The Hercules could be armed with either a M17 high explosive fragmentation warhead or a 20–40 kiloton W-31 nuclear warhead. Although designed to attack jet aircraft, the Nike Hercules also successfully intercepted guided and ballistic missiles, and had a surface-to-surface capability.

The Western Electric SAM-A-25 Nike B was renamed Nike Hercules in 1956 while still in development. It was redesignated Guided Missile, Air Defense M6 in 1958, and MIM-14 in 1963. (“MIM” is Department of Defense terminology for a mobile, ground-launched interceptor missile.) About 25,000 Nike Hercules missiles were built. Initially deployed in 1958, it remained in service with the U.S. Army until 1984.

The W-31 was a boosted fission implosion warhead designed by the Los Alamos Scientific Laboratory. It weighed 900 pounds (408 kilograms) and had a selectable yield of from 2 to 40 kilotons. About 2,550 warheads were produced and remained in service until 1989.

A battery of U.S. Army Nike Hercules SAM-A-25 surface-to-air guided missiles. (U.S. Army)
A battery of U.S. Army Nike Hercules MIM-14 surface-to-air guided missiles. (U.S. Army)

© 2018, Bryan R. Swopes

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