Aggregate-2 (A-2)

Germany



History:

After the destruction of the A-1 rocket, and the discovery that the nose-mounted gyroscope would be ineffective, work got under way early in 1934 to redeem the Kummersdorf rocket unit.
The general arrangement of the A-1 was assumed to be sound, apart from the gyroscope position, so it was moved to the centre of gravity of the rocket, between the two propellant tanks, making the pressurised Nitrogen sphere the top unit inside the pressurised outer casing. The 300 kg thrust engine remained of the same type as with the A-1, that is 16,5 inches long and 7 inches in diameter, and located inside the Alcohol/Water tank for imersion cooling.Above this unit was the gyroscope with an enlarged axle through which the Liquid Oxygen passed to the engine. As before, this was spun up to 9000 rpm by an external motor. Then came the LOX tank, and above this, the Nitrogen tank and the pressurisation control valves. Total weight at launch was 150 kg, while total propellant weight was increased slightly to 38,5 kg.
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.
Two A-2's were static tested at Kummersdorf in the Autumn of 1934, and they were named "Max" and "Moritz" after the two characters from the "Katzenjammer" comic strip. plans were made to fly both rockets in December 1934 and the two rockets, the 12m launch tower, equipment and the crew went to Borkum Island, 15km off the mainland near the moith of the river Ems, on the southernmost of the East Frisian Islands.

Description:

Length : 1.6 m (5 ft 3 in)
Body Diameter: 30.5 cm (12 in)
Launch Weight (kg): 107 kg
Propellant weight (kg): 38,5
Thrust: 3 kgN max
Total burn time: 16-17 sec
Guidance gyroscope
Propulsion alcohol & liquid oxygen
Range(km) -
Development Kummersdorf

Launch log:

NDateAltitude
119 Dec 19341980 m
220 Dec 19342250 m

Note: both were perfect flights with complete stability

A-2 rocket


One unusual observation made on both flights was what happened at apogee, when velocity had fallen to zero. At that point they had both kinked over by ninety degrees and it was assumed that the wind had been the cause, but it was the effect of the gyroscope slowing and turning the whole rocket over. They then tumbled out of the sky, and the first impacted on the beach at a ground range of 800m, where it was recovered, after its 45 seconds flight.
The succes of the A-2 cleared the way for Germany's first large research rocket, the A-3.

Ref.: #98, #102(SL20) - update: 14.06.12 Home