The Mammoth Book of Space Exploration and Disasters

By the end of the Second World War the United States had a considerable advantage in terms of long-range strategic bombers. The superiority of the B-29 Superfortress was not challenged in combat until the Korean War (1950–3) but by 1945 Germany had developed jet fighters and rocket-powered interceptors that could fly at 590 miles per hour and climb to 40,000 feet in two and a half minutes. The German jets and rocket planes came into the Second World War too late to have any effect on its outcome, although the new aircraft caused consternation among American aeronautical scientists and military planners. As the rivalry between the former Allies increased, the United States naturally concentrated on developing jet and rocket engines.

Neville Duke was a British test pilot who in 1953 set the record for highest speed in level flight of 727.6 m.p.h. In 1954 he described rocket propulsion:

The other branch of jet propulsion is the rocket. Rockets can be of the solid-fuel variety used mainly for assisting take-off; in which the propellant is in the form of a highly compressed powder. This is ignited and burns rapidly producing very hot gases which are discharged under great pressure at very high velocity. Once the charge is ignited, however, there is no control over the rate of combustion or the amount of thrust, and as a means of flight the bi-liquid fuel rocket is to be preferred. In this case, combustion takes place through the chemical reaction as the liquid propellant and an oxidizer mix in the combustion chamber.

As the rocket carries its own oxygen with it, it is independent of the outside atmosphere and theoretically is therefore not limited in speed or altitude. Its main drawback is its present highly extravagant consumption of fuel, which is up to six times the rate of that of a ram-jet and from ten to twenty times as much as the turbo-jet fuel consumption. For instance, the German A.4, or V.2 as it was known in this country, consumed 9 tons of alcohol and liquid oxygen in 7.1 seconds. During that time, however, the V.2 had accelerated to a speed of over 3,500 m.p.h., and a height of 22 miles from which it continued to climb by its own momentum to an altitude of 68 miles before dropping to earth.

The Germans also worked on a number of rocket-propelled fighters of which the Me163B, powered by an H.W.K. 509 Unit, was the first to see operational service in 1944. The Me 163B had sharply swept wooden wings and a high fin but no horizontal tail. The rocket unit burnt a mixture of concentrated hydrogen peroxide, and hydrazene hydrate mixed with alcohol, which were carried in separate tanks and pumped by a turbine to the combustion chamber. It developed a maximum thrust of 3,300 lb at the cost of a fuel consumption of 1,000 lb per minute, which gave a climb to 40,000 ft within 4 minutes, and a range after reaching that height of 22 miles which could be extended by gliding. Poor aerodynamic qualities restricted the top speed to 550 m.p.h. at 40,000 ft, or a Mach number of approximately 0.84.

To get better endurance, the H.W.K. 509C was developed with a separate auxiliary combustion chamber. For cruising, the pilot switched over from the main combustion chamber, which gave a thrust of 3,740 lb, to the auxiliary which provided 660 lb thrust and therefore had a much lower fuel consumption.

Attempts were also made to combine rockets with turbojets. The B.M.W. 003R, which was fitted into an Me 262, consisted of the B.M.W. 003 turbo-jet with a 180 lb rocket unti fared into the rear of the engine casing. Using nitric acid as its propellant, the rocket gave a thrust of 275 lb for 3 minutes. Another project was to fit the Me 262 with an auxiliary H.W.K. rocket unit in the tail.