4 June 1996: The first Ariane 5 heavy launch vehicle, L501, was launched from the Ensemble de Lancement Ariane 3 (Ariane Launch Area 3) at the Centre Spatial Guyanais (CSG), northwest of Kourou, French Guiana, at 12:33:59 UTC, (9:33:59 a.m., local time).
Everything proceeded normally until T + 00:00:36.7. At that time, the backup Inertial Reference System computer failed. 0.05 seconds later, the primary IRS computer also failed.
Having lost its spatial reference, the guidance system began swiveling the engines to correct a perceived attitude change, which, in fact, had not occurred. This caused the rocket to veer off course.
Once the Ariane 5’s angle of attack reached 20°, at T plus 39 seconds, aerodynamic forces caused a structural failure. The two solid rocket boosters broke away. As the rocket began to break apart, the automatic destruct system was activated. L501 exploded at approximately 4,000 meters (13,123 feet), about 1 kilometer (0.6 miles) from the launch pad. Debris fell, covering an area of approximately 5 × 2.5 kilometers (12.5 square kilometers/4.8 square miles).
2.1 CHAIN OF TECHNICAL EVENTS
. . . The internal SRI software exception was caused during execution of a data conversion from 64-bit floating point to 16-bit signed integer value. The floating point number which was converted had a value greater than what could be represented by a 16-bit signed integer. This resulted in an Operand Error. The data conversion instructions (in Ada code) were not protected from causing an Operand Error, although other conversions of comparable variables in the same place in the code were protected. . .
3.2 CAUSE OF THE FAILURE
The failure of the Ariane 501 was caused by the complete loss of guidance and attitude information 37 seconds after start of the main engine ignition sequence (30 seconds after lift- off). This loss of information was due to specification and design errors in the software of the inertial reference system.
The extensive reviews and tests carried out during the Ariane 5 Development Programme did not include adequate analysis and testing of the inertial reference system or of the complete flight control system, which could have detected the potential failure.
—ARIANE 5, Flight 501 Failure, Report of the Inquiry Board, Paris 19 July 1996
When designing the Ariane 5, the same software used in the the Ariane 4 guidance system was used. But the Ariane 5 accelerates in a way that causes horizontal velocity to increase at a rate 5 times that of the Ariane 4. This excessive value could not be processed and the computers shut down.
23 March 1912: Wernher Magnus Maximilian Freiherr von Braun, rocket engineer, was born at Wyrzysk, Province of Posen, in the German Empire, in what is now Poland. He was the second of three children of Magnus Alexander Maximillian von Braun, head of the Posen provincial government, and Emmy Melitta Cécile von Quistorp.
Wernher von Braun originally wanted to be a musician and composer, having learned to play the cello and piano at an early age. After reading a speculative book on space flight, though, his interests shifted.
In 1929, the 17-year-old von Braun joined Verein für Raumschiffahrt, the German rocketry association. He worked with Hermann Oberth in testing liquid-fueled rockets, based on successful rockets designed by Dr. Robert H. Goddard in the United States.
Von Braun graduated from Technische Hochschule Berlin in 1932, with a degree in mechanical engineering (Diplom-Ingenieur). Two years later, he received a doctorate in physics (Dr. phil.) at Friederich-Wilhelm University of Berlin. He also studied at ETH Zürich.
In Germany before World War II, Dr.-Ing. von Braun worked on the problems of liquid-fueled rockets and developed the Aggregat series of rockets, including the A4, which would become known as the V-2 (Vergeltungswaffe 2) military rocket. The German Army’s Ordnance Department gave von Braun a grant to further study liquid-fueled rockets, which he pursued at an artillery range at Kummersdorf, just south of Berlin
As rocketry work expanded, the tests were eventually moved to the Peenemünde Military Test Site on the island of Usedom on the Baltic coast, where von Braun was technical director under Colonel Dr. Ing. Walter R. Dornberger.
The first successful launch of the A4 took place 3 October 1942. By the end of World War II, Nazi Germany had launched more than 3,200 V-2 rockets against Belgium, England, France and The Netherlands.
As World War II in Europe came to a close and the collapse of Nazi Germany was imminent, von Braun had to choose between being captured by the Soviet Red Army or by the Allies. He surrendered to the 324th Infantry Regiment, 44th Infantry Division, United States Army in the Bavarian Alps, 2 May 1945.
Under Operation Paperclip, Wernher von Braun and many other scientists, engineers and technicians were brought to the United States to work with the U.S. Army’s ballistic missile program at Fort Bliss, Texas, White Sands Proving Grounds, New Mexico, and the Redstone Arsenal, Huntsville, Alabama.
Sufficient parts and materiel and been transferred from Germany to construct more than one hundred V-2 rockets for testing at White Sands. Over a five year period, there were 67 successful launches, but it is considered that as much knowledge was gained from failures as successes.
In 1950, von Braun and his team were sent to Redstone Arsenal, Huntsville, Alabama, where they worked on more advanced rockets. The first production rocket was the short-range ballistic missile, the SSM-A-14 Redstone, which was later designated PGM-11. This rocket was capable of carrying a 3.8 megaton W39 warhead approximately 200 miles (322 kilometers) The first Redstone was launched at Cape Canaveral Air Force Station, 20 August 1953.
Modified Redstone MRLV rockets were used to launch the first Mercury spacecraft with NASA astronauts Alan Shepherd and Gus Grissom. Von Braun later worked on the U.S. Army’s Jupiter-A intermediate range ballistic missile. A modified Jupiter-C was used to launch Explorer 1, the United States’ first satellite.
Wernher von Braun traveled to Germany in 1947 to marry his cousin, Maria Irmengard Emmy Luise Gisela von Quistorp, and then returned to the United States. He became a naturalized citizen of the United States of America in 1955.
In 1960 von Braun and his team were transferred from the Army Ballistic Missile Agency to NASA’s new Marshall Space Flight Center at Redstone Arsenal. He was now able to pursue his original interest, manned flight into space. Work proceeded on the Saturn rocket series, which were intended to lift heavy payloads into Earth orbit. This resulted in the Saturn A, Saturn B and the Saturn C series, ultimately becoming the Saturn V moon rocket.
With the Apollo Program coming to an end, Dr. von Braun left NASA in 1972. A year later, he was diagnosed with kidney cancer. Wernher von Braun died of pancreatic cancer, 17 June 1977 at the age of 65 years.
9 November 1967: The first flight of a Saturn V took place when the unmanned Apollo 4/Saturn V (AS-501) was launched from Pad 39A at the Kennedy Space Center, Cape Canaveral, Florida. The rocket lifted off at 12:00:01.263 UTC.
AS-501 consisted of the first Saturn V launch vehicle, SA-501, with Apollo Spacecraft 017 (a Block I vehicle with Block II upgrades), and included the Launch Escape Tower, Command Module, Service Module, Lunar Module Adapter, and Lunar Module Test Article LTA-10R).
The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet, 0.15 inches (110.64621 meters) tall, from the tip of the escape tower to the bottom of the F-1 engines. The first and second stages were 33 feet, 1.2 inches (10.089 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,948,350 kilograms).¹ It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.
The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust, each, for a total of 7,610,000 pounds of thrust at Sea Level.² These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.
The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust, and combined, 1,161,250 pounds of thrust.³
The Saturn V third stage was designated S-IVB. It was built by Douglas Aircraft Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant.⁴ The S-IVB would place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.
Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.
¹ The AS-501 total vehicle mass at First Motion was 6,137,868 pounds (2,784,090 kilograms).
² Post-flight analysis gave the total thrust of AS-501’s S-IC stage as 7,728,734.5 pounds of thrust (34,379.1 kilonewtons).
³ Post-flight analysis gave the total thrust of AS-501’s S-II stage as 1,086,396 pounds of thrust (4,832.5 kilonewtons).
⁴ Post-flight analysis gave the total thrust of AS-501’s S-IVB stage as 222,384 pounds of thrust (989.2 kilonewtons) during the first burn; 224,001 pounds (996.4 kilonewtons) during the second burn.