Tag Archives: Intercontinental Ballistic Missile

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

11 June 1957

Convair XSM-65A Atlas 4A launch, 11 June 1957. (U.S. Air Force)

11 June 1957, 4:37 p.m., EST, (20:47 UTC): The Convair XSM-65A Atlas, number 4A, lifted off from Launch Complex 14 at the Cape Canaveral Auxiliary Air Force Station in Florida. This was the first launch of a prototype Atlas intercontinental ballistic missile.

At T+26 seconds, the number two engine lost thrust. The rocket began to tumble and at T+50 seconds, the destruct signal was sent by the range safety officer. The Atlas had reached a peak altitude of approximately 9,800 feet (2,987 meters).

Convair Atlas 4A is launched from the Cape Canaveral Auxiliary Air Force Station 11 June 1957. (San Diego Air & Space Museum Archives, Catalog #:14_015602)

Despite the missile’s destruction, the first flight test of the XSM-65A (also known as Atlas A) was actually considered to be a success. The engines had started normally, the launch pad release mechanism functioned as intended, and perhaps most importantly, the lightweight structure of the missile body withstood the forces experienced during the launch.

Following data analysis of the short flight, engineers determined that engine exhaust had circulated back into the engine’s thrust section, causing it to overheat. The propellant ducts were not sufficiently shielded from the heat and began to collapse. This reduced the flow of the liquid oxygen to the engine, effectively throttling it back.

Atlas 4A had been previously tested at Convair’s static test facility in Sycamore Canyon, east of MCAS Miramar, in the Scripps Ranch area of San Diego, California. It is possible that Atlas 4A had suffered internal damage during test firing.

Static test stands for Atlas rockets at Convair’s Sycamore Canyon Test Facility, near San Diego, California. (siloworld.net)

The Atlas A was a prototype for an intercontinental ballistic missile, designed to test the structure, engines and launch system. Unlike the production Atlas, Atlas A used only two engines. The missile was designed an built by the Convair Astronautics Division of General Dynamics at San Diego, California.

Atlas A 4A

Atlas A was 76 feet, 11 inches (23.444 meters) long and 11 feet (3.353 meters) in diameter. At liftoff the missile weighed 180,666 pounds (81,949 kilograms), and at burnout 17,721 pounds (kilograms).

The Atlas is primarily constructed of very thin stainless steel sheet. Rather than using a supporting internal structure, the rocket used “balloon tanks” so that it could be built with minimal weight. The fuel and oxidizer tanks supported the outer skin, but could only do so when pressurized. When the rocket was not fueled, these tanks were pressurized with nitrogen at 5 pounds per square inch (34 kilopascals). If left unpressurized, the rocket would collapse under its own weight.

Atlas A 4A before erection at Launch Complex 14 (Drew Ex Machina)

Atlas 4A was powered by two Rocketdyne XLR-89-1 engines, which produced 271,432 pounds of thrust (1,207 kilonewtons) at takeoff, burning RP-1, a highly refined kerosene, with liquid oxygen. The two engines shared a single turbopump to provide the fuel. Early versions of this engine had a conical exhaust nozzle, while improved models used a bell-shaped nozzle. Production Atlas missiles added a Rocketdyne LR105-NA sustainer engine which continued to accelerate the missile after the LR-89 booster engines were jettisoned. Because of this configuration, the Atlas was known as a “1½-stage rocket.” The LR105 produced 60,473 pounds of thrust (269 kilonewtons) at Sea Level.

Yaw, pitch and roll control of the Atlas after the booster section was jettisoned was provided by two smaller Rocketdyne LR101 vernier thrusters, producing 1,060 pounds of thrust (4.7 kilonewtons) at Sea Level.

Convair XSM-65A Atlas 4A at Launch Complex 14, 11 June 1957. (NASA 19570611-004A-0408)
Atlas A 4A, Launch Complex 14, Cape Canaveral Air Force Station, Florida. (U.S. Air Force)
Three-view diagram of Convair Atlas A. (Drew Ex Machina)
Atlas A MA-1 with two Rocketdyne LR-89-1 engines. (Rocketdyne)

The SM-65A Atlas ICBM became operational 31 October 1959. The rockets were housed in underground “silos,” or hardened above ground shelters located throughout the continental United States. These missiles carried a single W-49 thermonuclear warhead with a yield of 1.44 megatons. The W-49 was designed by the Los Alamos Scientific Laboratory (LASL) and is believed to be a development of the earlier B-28 two-stage radiation-implosion bomb. It incorporated a 10-kiloton W-34 warhead as a gas-boosted fission primary, and had a one-point-safe safety system. The warhead had a diameter of 1 foot, 8 inches (0.508 meters) and length of 4 feet, 6.3 inches (1.379 meters). It weighed 1,665 pounds (755 kilograms).

An unexpected side effect of the Atlas missile programs was the development by the Rocket Chemical Company of its Water-Displacing Formula 40, popularly known by its trade name of WD-40. This universal lubricant was used on the stainless steel surfaces of the Atlas to prevent rust and corrosion.

© 2023, Bryan R. Swopes

7 March 1986

An LGM-118 Peacekeeper intercontinental ballistic missile begins to emerge from an underground silo at Vandenberg Air Force Base on the central coast of California. (U.S. Air Force)
LGM-118 Peacekeeper launch. (U.S. Air Force)
A LGM-118 Peacekeeper intercontinental ballistic missile leaving an underground silo at Vandenberg Air Force Base on the coast of California. (U.S. Air Force 021126-O-9999G-011)
The cold launch system ejects Peacekeeper from its canister with high-pressure steam. (U.S. Air Force photo)
Shock-absorbing tiles, which help the missile exit its canister, fall away as Peacekeeper is launched. (U.S. Air Force photo)
LGM-118 first stage solid-fuel rocket engine firing as shock absorbing tiles continue to fall away. (U.S. Air Force)

7 March 1986: An LGM-118 Peacekeeper intercontinental ballistic missile was launched from Vandenberg Air Force Base, California, with eight unarmed Mark 21 multiple independently targetable re-entry vehicles (MIRVs).

U.S. Air Force maintenance crews use a overhead crane and hoist to remove and install W87-0 warhead/Mk-21 Reentry Vehicles from the nose section of an LGM-118 Peacekeeper missile during training at Vandenberg AFB, California. (U.S. Air Force 000701-F-2828D-003)
LANDSAT 7 image of Kwajelein Atoll in the Marshall Islands, 12:29:01 UTC, 7 July 2014. (NASA)
Mark 21 MIRV warheads arrive at Kwajelein Atoll, 7 March 1986. (Department of Defense)

This photograph shows what it looked like on the receiving end at Kwajelein Atoll, 4,100 miles (6,598 kilometers) away.

Under START II, multiple warhead missiles were deactivated. The last of the LGM-118 Peacekeepers was removed from service by 2005. Some of the boosters have been used for satellite launch vehicles.

© 2018, Bryan R. Swopes