Aggregate series
The Aggregate series was a set of rocket designs developed in 1933–1945 by a research program of Nazi Germany's army. Its greatest sucess was the A4, more commonly known as the V-2.
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Variations
A1
The A1 was the first rocket design in the Aggregate series. It was designed in 1933 by Wernher von Braun in a Wehrmacht research program at Kummersdorf headed by Walter Dornberger. The rocket was 1.4 m long, and had a takeoff weight of 150 kg. The engine, designed by Arthur Rudolph, used alcohol and liquid oxygen, and produced 3 kilonewtons of thrust. The rocket was designed to be stabilized using a heavy rotating wheel in the nose, but there was concern that this might cause problems with the liquid fuels. Although the engine had been successfully test fired, the first flight attempt blew up on the launching pad. Since the design was thought to be unstable, no further attempts were made, and efforts moved to the A2 design.
A2
The A2 was designed in 1934 by von Braun under the program at Kummersdorf headed by Walter Dornberger
At a length of 1.6 meters and thrust of 3 kilonewtons from alcohol and liquid oxygen, it was in outline similar to the A1. However, in contrast to the A1, the A2 had the stabilization gyroscopes in the center of the rocket between the alcohol and oxygen tanks, which made it more stable. The rocket weighed 72 kg empty, with takeoff weight of 107 kg. Initial flight testing was done in September 1934 at Kummersdorf.
Two A2s were built for a full out test, and were given the names Max and Moritz. On December 19 and December 20 1934 they were flown in front of the Army brass at an island in the North Sea named Borkum. They reached altitudes of 2.2 km and 3.5 km.
A3
The A3 was first launched on December 4 1937, and was intended to test components for the planned A4.
Only three more test launches were carried out, all of them failures. The final launch, on December 11 1937, was typical of all the attempts: the engine cut out early, and the rocket was destroyed as it fell to the ground, the parachute failing to deploy. All the failures were due to the unstable design of the rocket's experimental inertial guidance system.
After this last unsuccessful launch, the A3 was abandoned, and a complete redesign was carried out to bring the A5 into being, and to continue subscale testing for the A4.
Specifications
- Length: 6.74 meters.
- Diameter: 0.68 m.
- Finspan: 0.93 m.
- Launch mass: 748 kilograms.
- Fuel: ethanol and liquid oxygen.
- Liftoff thrust: 14.7 kN (1500 kgf).
A4 (V-2 rocket)
- Main article: V-2 rocket
A4b
The A4b was a winged version of the A4. It was developed during 1944 and 1945 in order to double the range of the A4. Test starts were made on December 27 1944, January 13, and January 24 1945 in Peenemuende. The first two attempts were aborted, while the third launch was successful, but the rocket did not achieve the planned range because of a wing failure. The program was cancelled at that point.
A5
The A5 had a length of 5.825 meters, a diameter of 0.78 meters, a takeoff weight of 900 kilograms and a takeoff thrust of 1.5 MN. The engines were alcohol fueled with liquid oxygen as an oxidant. The first launch of the A5 took place in the summer of 1938 at Greifswalder Oie. The first successful guided flights were in October 1939 in order to test the control systems planned for use in the A4. The A5 reached a ceiling of up to 12 kilometers and could be used several times.
A6
The A6 was a war rocket suggested by von Braun at the beginning of the 1940s. The A6 was to be an improved A4, propelled by nitric acid and kerosene and with a longer range than the A4. It was not realized because of the progress of the war. The takeoff thrust would have been about 12,500 kgf (123 kN), the diameter 6.33 m, and the overall length 15.75 m.
A7
The A7 was a winged design that was never fully constructed. It was worked on between 1940 and 1943 at Peenemuende for the Kriegsmarine. The A7 was similar in structure to the A5, but had larger tail unit fins (1.621 m2) in order to obtain greater range in gliding flight. Two unpowered models of the A7 were dropped from airplanes in order to test flight stability; no powered test was ever performed. The finished rocket should have produced a takeoff thrust of 15 kN and a takeoff weight of 1000 kg. The design had a diameter of 0.38 m and a length of 5.91 m.
A8
The A8 was prepared in Peenemünde and never finished because of the progressive war situation. The A8 would have had a takeoff thrust of 340 kN with a takeoff weight of 22,370 kg. The diameter was 0.78 m. The weapon designs were finished in 1944.
A9
The A9 was a further development of the A4 rocket. No prototype was ever developed due to the ending of the war, although a variant, the A4b, was produced before the end of the war. The A9 would have been used as the upper stage for an intercontinental missile or a manned craft. The A10 was to have been used for the lower stage.
Parameters of the planned manned A9-rocket
- Length: 14.18 m
- Maximum diameter: 1.65 m
- Takeoff weight: 16,259 kg
- Payload: 1,000 kg
A10
The A10, which was never actually constructed, was intended serve as first stage for the A9, to help it to reach an intercontinental range. New York City and other targets in the northeastern U.S. were its intended targets. Test Stand VII was built at Peenemünde for use in the A10's development.
The A10 designed to have a diameter of 4.12 meters and to exceed the A4 in its size. It was to be fueled with alcohol and liquid oxygen. The thrust of the engines would have been 235,000 kgf (2300 kN) with a 55 second burn time.
A11
The A11, along with the A10 and A9, had the potential of launching a satellite payload. However, the conclusion of the war halted further efforts to develop or deploy this weapon.
It had a takeoff weight of 500 metric tons, a thrust of 1,200,000 kgf (11.8 meganewtons (MN)) or thrust (vacuum) 1,400,000 kgf (14 MN), a diameter of 8.10 m, a span of 16.50 m and a length of 25.00 m.
A12
The A12 would have been a space transporter, capable of bringing up to 10 metric tons into low Earth orbit. The A12 was never constructed.
It is estimated that the A12 would have had a takeoff weight of 3500 metric tons, a thrust of 10,000,000 kgf (100 MN), a diameter of 11 m, a span of 23 m and a length of 33 m. The A12 was similar in design to the initial designs of the Saturn rockets.
External links
- Encyclopedia Astronautica: A1, A2, A3, A5, A7, A8, A9, A10, A11, A9/A10/A11/A12
- Arthur Rudolph and the rocket that took us to the moon (PDF)
- http://www.aggregat-2.de/neubau.html - a site about the A2 (in German)
- The A4 Rocket (in German)
- Aerospace museum
- University of Oregon
- A8 statistics