The Aggregat series (German for "Aggregate") was a set of ballistic missile designs developed in 1933–1945 by a research program of Nazi Germany's Army (Heer).

It was designed in 1933 by Wernher von Braun at the German Army research program at Kummersdorf headed by Colonel Dr Walter Dornberger.

The engine, designed by Arthur Rudolph, used a pressure-fed rocket propellant system burning ethanol and liquid oxygen, and produced 2.9 kN (660 lbf) of thrust for 16 seconds.

Although the engine had been successfully test fired, the first flight attempt blew up on the launching pad on 21 December 1933, half a second after ignition.

Development of the A3 can be traced at least to February 1935 when Major Ernst Ritter von Horstig sent General der Artillerie Karl Becker a budget of almost half a million marks for the construction of two new test stands at Kummersdorf.

[6] In March 1936, Generaloberst Werner von Fritsch witnessed a static firing of an A3 engine at Kummersdorf, and was sufficiently impressed to lend his support to the rocket program.

[9] The design was finished in early 1936 and further modifications that made the rocket stable at supersonic velocities were finalized later that year.

The SG-33 was fixed to the rocket, not the stabilized platform, and used three rate gyros to sense roll, pitch and yaw deviations.

The guidance and control system was designed by Fritz Mueller, based on Johannes Maria Boykow's ideas, the technical director of Kreiselgeräte GmbH ("Gyro Instruments Limited").

[2]: 53–57 The A3 engine was a scaled-up version of the A2, but with a mushroom-shaped injector at the top of the combustion chamber, based on a design by Walter Riedel.

[11] As part of Operation Lighthouse the first A3 was launched on 4 December 1937, but suffered problems with premature parachute deployment and engine failure, and crashed close to the takeoff point.

Hellmuth Walter also made models of the A5m which included a hydrogen peroxide motor, with potassium permanganate as a catalyst, and were test launched in March 1939.

The final fin configuration was wider, curved outward to accommodate the expanding exhaust gases, included external air vanes, but no ring antenna.

In the late 1920s, Karl Becker realised that a loophole in the Treaty of Versailles allowed Germany to develop rocket weapons.

The missile testing ground at Blizna was quickly located by the Polish resistance movement, the Home Army (Armia Krajowa), thanks to reports from local farmers.

Armia Krajowa field agents managed to obtain pieces of the fired rockets by arriving on the scene before German patrols.

In early March 1944, British Intelligence Headquarters received a report of an Armia Krajowa agent (code name: "Makary") who had covertly surveyed the Blizna railway line and observed a freight car heavily guarded by SS troops containing "an object which, though covered by a tarpaulin, bore every resemblance to a monstrous torpedo".

Around 20 May 1944, a relatively undamaged V-2 rocket fell on the swampy bank of the Bug River near the village of Sarnaki, and local Poles concealed it before German arrival.

In late 1943 German Labour Front (Deutsche Arbeitsfront/DAF) Director, Otto Lafferenz, proposed the idea of a towable watertight container which could hold an A4 rocket.

[23] In June 1939, Kurt Patt of the Peenemünde Design Office, proposed wings for converting rocket speed and altitude into aerodynamic lift and range.

[24] As the rocket encountered thicker atmosphere on its descent phase, it would execute a pullout and enter a shallow glide, trading speed for distance.

[26] It was calculated that by fitting wings, the A4's range would be extended to 750 km (470 mi), allowing targets in Britain to be attacked from launch sites within Germany.

It would be launched vertically by rocket, taking it to an apogee of 95 km (59 mi); after re-entering the atmosphere it would enter a supersonic glide phase, when its single ramjet would be ignited.

It was hoped that this would provide 15 to 20 minutes of cruise at 2,900 km/h (1,800 mph) and would allow the aircraft to return to its base and make a conventional runway landing assisted by a drag chute.

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.

The design had a diameter of 0.38 m and a length of 5.91 m.[citation needed] The A8 was a proposed "stretched" variant of the A4, to use storable rocket propellants (most likely nitric acid & kerosene).

Work on the A10 was resumed in late 1944 under the Projekt Amerika codename, and the A10's design was amended to incorporate a cluster of 6 A4 combustion chambers feeding into a single expansion nozzle.

The pilot was to be guided on his terminal glide towards the target by radio beacons on U-boats and by automatic weather stations landed in Greenland and Labrador.

In either case, a payload of approximately 300 kg (660 lb) could have been placed in a low Earth orbit, roughly equivalent to the modern-day Electron rocket.

Calculations suggested it could place as much as 10 tonnes payload in low Earth orbit, comparable to the later Saturn I rocket of the Apollo program.