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 success was the A4, more commonly known as the V-2.

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 (German army) 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.Fact|date=September 2007

A2

The A2 was designed in 1934 by von Braun under the program at Kummersdorf headed by Walter Dornberger.Fact|date=September 2007

At a length of 1.6 meters and thrust of 3 kN 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.Fact|date=September 2007

Two A2s were built for a full out test, and were named after a Wilhelm Busch cartoon, Max and Moritz. On December 19 and December 20 1934 they were launched in front of the Army brass on Borkum island in the North Sea. They reached altitudes of 2.2 km and 3.5 km. [Gatland 1989, p. 10.] [ [http://www.aggregat-2.de/geschichte.html Raketenaggregate „A1“ und „A2“] ]

A3

The A3 was first launched on December 4 1937, and was intended to test components for the planned A4.Fact|date=September 2007

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.Fact|date=September 2007

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.Fact|date=September 2007

The A3 was the first Peenemünde design (Huzel 1962, p. 235). In 1936, Army General von Fritsch witnessed a static firing of an A3 at Kummersdorf, and was sufficiently impressed to lend his support to the rocket program (Huzel 1962, p. 233). Since ground was not broken until August, 1936, von Fritsch's viewing must have been in September through December. The A3 also used a pressure-fed propellant system, using the same liquid oxygen and 75% alcohol mixture as the A1 and A2. It generated 3,300 pounds of thrust (14.7 kN) for 45 seconds. It used a three-gyroscope system to deflect tungsten-alloy jet vanes (Huzel 1962, p. 236). Several A3s were launched, reaching a maximum downrange of 7.5 miles (12.1 km) and maximum altitude of 11 miles (18 km). Three A3s were launched from Greifswalder Oie in Autumn 1937. They carried a three-axis gyro control system which actuated exhaust vanes. On the first launch, the parachute opened after five seconds, causing the rocket to crash into the sea. Parachutes were omitted on the second and third launches, but both rockets still went out of control. [ Gatland 1989, p. 11.]

pecifications

:"Length": 6.74 meters (22.1 ft):"Diameter": 0.68 meters (2.2 ft):"Finspan": 0.93 meters (3.1 ft):"Launch mass": 748 kilograms (1650 lb):"Fuel": ethanol and liquid oxygen.:"Liftoff thrust": 14.7 kN (1500 kgf).

A4 (V-2 rocket)

The A4 was a full-sized design with a range of about 175 kilometers (109 mi), a top altitude of 80 kilometers (50 mi) and a payload of about a tonne. Versions of the A4 included the first ballistic missile, the first projectile to reach space, and were actively used in warfare. ["Peenemuende," Walter Dornberger, Moewig, Berlin 1985. ISBN 3-8118-4341-9.]

This increase in capability had come through a complete redesign of the A3 engine by Walter Thiel, known as the A5. It became clearer that von Braun's designs were turning into real weapons, and Dornberger moved the team from the artillery testing grounds at Kummersdorf (near Berlin) to a small town, Peenemünde, on the island of Usedom on Germany's Baltic coast, in order to provide more room for testing and greater secrecy. This version was completely reliable, and by 1941 the team had fired about 70 A5 rockets. The first A4 flew in March 1942, flying about 1.6 kilometers (1 mi) and crashing into the water. The second launch reached an altitude of 11 kilometers (7 mi) before exploding. The third rocket, launched on October 3 1942, followed its trajectory perfectly. It landed 193 kilometers (120 mi) away, and reached a height of 80 kilometers (50 mi).Fact|date=September 2007

Production started in 1943 on the rocket, now known as the "Vergeltungswaffe 2" (Vengeance Weapon 2) or V-2, at the insistence of Goebbels' propaganda ministry. The Allies were already aware of the weapon — at a test site at Blizna in Poland a fired missile had been recovered by Polish resistance agents from the banks of the Western Bug, and vital technical details had been given to British intelligence during Operation Most III.

A4-SLBM

Under "Projekt Amerika" Nazi Germany tried to develop the first submarine-launched ballistic missiles (SLBMs) to bomb New York and other American cities and objects. The tests of SLBM-variant of A4 rocket was fulfilled from U-boats submarine towed launch platforms. [staff [http://www.uboataces.com/articles-rocket-uboat.shtml Rocket U-Boat Program] , [http://www.uboataces.com/contact.shtml www.uboataces.com] ]

A4b

In June 1939, Kurt Patt of the Peenemünde Design Office, proposed wings for converting rocket speed and altitude into aerodynamic lift and range. [Neufeld, p. 92] He also proposed the "Flossengeschoss" (fin projectile). Both concepts were utilized by Walter Dornberger when he drafted a memo for presentation to Hitler regarding the "America rocket" on July 31, 1940. [Neufeld, pp. 138 & 283] After the A-9 project was altogether halted in October 1942, Wernher von Braun proposed the winged "A-4 Bastard" on October 10, 1944, [Dornberger, p. 250] and serious A-4b development and then production was started. [Neufeld, pp. 63, 93, 250, 283]

Peenemünde A4b Test LaunchesFact|date=September 2007

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 15 kN. 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.Fact|date=September 2007

A6

The A6 was a war rocket suggested by von Braun at the beginning of the 1940s. The A6 was to be an improved A4b, 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 take off thrust would have been about 123 kN / 12,500 kgf , a wing span of 6.3 m, and the overall length 15.75 m. [Mark Wade [http://www.friends-partners.org/partners/mwade/lvs/a6.htm Family: A4. Country: Gernany. Status: Design study 1943] ]

A7

The A7 was a winged design that was never fully constructed. It was worked on between 1940 and 1943 at Peenemünde 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.Fact|date=September 2007

A8

The A8 was prepared in Peenemünde and never finished because of the progressing 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.Fact|date=September 2007

A9

Infobox Weapon
is_missile=yes
name=Aggregat-9


caption=
origin=
type=ICBM second stageFact|date=September 2007
used_by=
manufacturer=studied by Army Research Center Peenemünde
unit_cost=none mass-manufactured
propellant=
production_date=
service=test only, not deployed
engine=A9
engine_power=
weight=16,259 kg
length=14.18 m
height=
diameter=1.65 m maximum
wingspan=3.2 m
speed=3,400 m/s (in A9/A10)
vehicle_range=500 statute miles
ceiling=
altitude=190 km (in single flight) or 390 km (in A9/A10)
filling=2,200 pound payload [Huzel, p. 237]
guidance=
detonation=
launch_platform=ground launch pad or A-10

Under "Projekt Amerika" (besides of SLBM and long-range Amerika Bomber airplanes) Nazi Germany also tried to develop and probably to use the first intercontinental ballistic missile (ICBM) A9/A10 rocket to bomb New York City and other American cities and targets in the north-eastern United States. Work on two-staged 100-ton 41-meter long A9/A10 "Amerikarakete" was started on summer 1940, then postponed on October 1942 and again resumed on September 1944. Test Stand VII launch pad was built at Peenemünde to test the A9 and A9/A10. To keep range to its target (New York City etc) to a minimum and to increase the bomb payload to a maximum, it was intended to launch the A9/A10 from western Spain or France in its original form. Fact|date=September 2007 The planned range of ICBM A9/A10 rocket was of 4100-5000 km, and a total flight time of 35 minutes. Fact|date=February 2008 The ICBM A9/A10 rocket was intended to be guided primarily by radio and secondary by pilot [ [http://www.astronautix.com/lvs/a9a10.htm A9/A10 ] ] (following the failure in November 1944 of "Elster operation", a Nazi plan to install a radio beacon on top of Empire State Building skyscraper).Fact|date=February 2008

The A9, second (upper) stage of ICBM A9/A10 rocket, was a further development of the A4 rocket (as the prototype for the A9 was the A4b). It was able to execute separate start and flight also.

According to some sources, few test launches of A9 were in January, February and March 1945. It is known the official report to Berlin of von Braun in January 1945 that "the problem of the second stage is solved".Fact|date=February 2008

Reported by some sources ( [http://vmechanm.blogspot.com/2007/05/miraculous-water-strong-older-adults.html] , [http://epizodsspace.testpilot.ru/bibl/pervushin/ast-git/05-2.html] , [http://www.newsvm.com/print/2005/09/30/spase.html] , [http://epizodsspace.testpilot.ru/bibl/jeleznyakov/sekret-kosmos/pril.html] , etc), three suborbital "spaceflights" with pilots (astronauts de-facto due to highest point of altitude of flight trajectory above 80 km) aboard of the A9 (or A9/A10) in 1945 are not confirmed and happened very unlikely:
*January 24 Rudolph Schreder
*February 18 Martin von Duhlen "exploded in about three minutes after the start"
*February 24 Raul Streicher "landed on water in Japan"

A10

The A10, which probably was never actually constructed, was intended to serve as first (lower) stage for the A9, to help it to reach an intercontinental range. Test Stand VII at Peenemünde was constructed as able to test A10.Fact|date=September 2007

The A10 was designed to have a diameter of 4.12 meters and to significantly exceed the A9 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.Fact|date=September 2007

Two different concepts for the A10's engine were studied. In one, a single very large combustion chamber and exit nozzle were used; in the other, six standard A4 (V-2) engines were to exhaust into a single combustion chamber and their mixed exhaust was to exit through a single nozzle.Fact|date=September 2007

The A10 was intended to be recoverable for re-use and would have descended into the Atlantic under a large parachute after the upper stage A9 had separated from it.Fact|date=September 2007

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.Fact|date=September 2007 It had a takeoff weight of 500 metric tons, a thrust of 11.8 meganewtons (MN) / 1,200,000 kgf or thrust "(vacuum)" 14 MN / 1,400,000 kgf, a diameter of 8.10 m, a span of 16.50 m and a length of 25.00 m.Fact|date=September 2007

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 also.Fact|date=September 2007

It is estimated that the A12 would have had a takeoff weight of 3,500 metric tons, a thrust of 100 MN / 10,000,000 kgf, 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.Fact|date=September 2007

References

* cite book
last =Dornberger
first = Walter
authorlink =Walter Dornberger
coauthors =Eberhard Rees
title =Peenemünde : die Geschichte der V-Waffen / Walter Dornberger ; mit einem Geleitwort won Eberhard Rees. --
publisher = Bechtle
date =1981
location =Germany
pages =313
url =http://www.amazon.com/Peenemunde-Geschichte-V-Waffen-Walter-Dornberger/dp/3762804044
language = German
doi =
id =
isbn = 3762804044
* cite book
last =Huzel
first = Dieter K.
authorlink =
coauthors =
title =Peenemünde to Canaveral
publisher = Greenwood Press (Reprint)
date =1981(Reprint)
location =
pages =313
url =http://www.amazon.com/Peenemunde-Canaveral-Dieter-K-Huzel/dp/0313229287/ref=sr_1_7/103-1097535-3692624?ie=UTF8&s=books&qid=1187928049&sr=1-7
language = English
doi =
id =
isbn = 0313229287
* cite book
last =Neufeld
first =Michael
authorlink =
coauthors =
title =The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era
publisher =Harvard University Press
date = 1996
location =Cambridge, Massachusetts
pages =
url =http://www.amazon.com/gp/reader/067477650X/ref=sib_dp_pt/103-1097535-3692624#reader-link
doi =
id =
isbn = 067477650X

Further reading

*Encyclopedia Astronautica: [http://www.astronautix.com/lvs/a1.htm A1] , [http://www.astronautix.com/lvs/a2.htm A2] , [http://www.astronautix.com/lvs/a3.htm A3] , [http://www.astronautix.com/lvs/a5.htm A5] , [http://www.astronautix.com/lvs/a7.htm A7] , [http://www.astronautix.com/lvs/a8.htm A8] , [http://www.astronautix.com/craft/a9.htm A9] , [http://www.astronautix.com/engines/a10.htm A10] , [http://www.astronautix.com/lvs/a9a10a11.htm A11] , [http://www.astronautix.com/lvs/a9a11a12.htm A9/A10/A11/A12]
* [http://www.kheichhorn.de/html/body_v2_emw_a4b_.html V2 EMW A4b die bemannte Rakete]
*http://www.aggregat-2.de/neubau.html - a site about the A2 (in German)
* [http://www.bernd-leitenberger.de/text/a4.html The A4 Rocket] (in German)
* [http://www.aeromuseum.org/Articles/Oct04/V2PartTwo.htm Aerospace museum]
* [http://zebu.uoregon.edu/~js/space/lectures/lec04.html University of Oregon]
* [http://www.friends-partners.org/partners/mwade/lvs/a8.htm A8 statistics]

Footnotes