Even though Gas Dynamics is applicable to a number of disciplines in Aerospace engineering, in the present article, a brief survey of only the space related developments is presented. It should be noted that a number of nations have contributed to the development of the launchers and space vehicles. There are active space and launcher programmes in the Asian region, where China, Japan, India and Pakistan all have space programmes. China and Japan both have major launcher portfolios. Work on modern rockets began in China in 1956, and by the end of 1957, through an agreement with the USSR, R-1 and R-2 rocket technology had been transferred to the Chinese. But these were old Russian rockets, and bore more resemblance to the German A4 than to the current Russian launchers. Following the breach with USSR in 1960, the Chinese programme continued, with an indigenous version of the R-2 called Dong Feng, or East Wind. The next launcher developed in China was called Chang Zheng, or Long March. This is ultimately used to launch China’s first satellite in 1970, a year after Apollo 11. China has continued to launch satellites for communications and reconnaissance, using versions of the Long March. Since 1990 this vehicle is available as a commercial launcher. The Long March used a variety of engines, all developed in China, including those using liquid hydrogen and liquid oxygen. Despite the setbacks caused by political upheavals, China has succeeded in establishing and maintaining an indigenous modern rocket technology. In Japan rockets were developed in an exclusively non-military environment. In fact, Japan’s first satellite, Osumi, was launched by a rocket designed and built by a group of university professors. The legacy of this remarkable success is that Japan has two space agencies: The Institute of Space and Aeronautical Science (attached to the Ministry of Culture) and the Nation Space Development Agency (attached to the Ministry of Industry). ISAS was founded in the mid-1980s, and has developed a series of indigenous, Solid-fueled launchers used exclusively for scientific missions. These have ranges from small Earth satellites, to missions to the Moon, Mars and Comets. ISAS launched Japan’s first satellite in February 1970, after the US and France, and before China and Britain. ISAS continued to develop advanced rocket technology including liquid hydrogen and liquid oxygen engines. Also, they are experimenting on electric propulsion and single stage to orbit technology. Another Japanese agency; NASDA (Nippon Aero and Space Development Agency) is more closely modeled on NASA and ESA. NASDA is involved in the development of heavy launchers and the launching of communication and Earth resources satellites. Also, it is a partner in the International Space Station. NASDA began work in 1964, using US prototype technology, to produce the N-series of heavy launchers. It has now developed Japanese rocket technology for the H-series of launchers. Japan was the first nation to launch a satellite, and with its space agencies ranks as a major space-faring nation.

India began space activities in 1972, when its first satellite was launched by the USSR. But only in 1980 India achieved success in the development of a native launcher, named SLV rocket which launched the satellite Rohini. Now there is a substantial launcher capability with the ASLV and PSLV rockets. Also, the current development of GSLV is expected to give a prominent place for India in the world of space activity.

After the Second World War, the United States undertook rocket development based on indigenous technology, and the new ideas coming from the German programme, involving Von Braun. Inter-service rivalry contributed to the difficulties in achieving the first US satellite, which was mirrored by the divisions between different design bureaux in the Soviet Union. The army developed Redstone rocket, basically improving upon the A4, in the same way that the R-series developed in the USSR. The navy had its own programme based on the indigenous Viking.

Two competing projects to launch a satellite were finally developed: one involving Von Braun and the Redstone, and the other the Naval Research Laboratory with the Viking. The Redstone version, approved in 1955, was to use existing technology to launch a small satellite, but only three months later the more sophisticated Vanguard project from the NRL was put in operation. On January 31, 1958 US launched its first satellite which weighed 14 kgs. The first stage was a Redstone burning liquid oxygen and alcohol, and the upper stage was a Jupiter C solid motor. The satellite was both a programmatic and a scientific success: it discovered the Van Allen radiation belts. After this, NASA was set up on October 1, 1958 and began exploring possibilities for a moon landing.

The first manned operational launch took place in December 1968, and the first lunar landing mission was launched on July 16, 1969. The mission took eight days, and the astronauts returned safely, having spent 22 hours on the moon. The Saturn V rocket, which propelled Apollo 11 launcher, was the largest rocket ever built. It needed to be, in order to send its heavy payload to the Moon, in direct flight from the surface of the Earth. It needed powerful high-thrust engines to lift it off the ground, and high exhaust speed to achieve the lunar transfer trajectory. The lower stage was based on the liquid oxygen-kerosene engines, which had emerged, via the Redstone rocket, from the original German A4 engine that used liquid oxygen and alcohol. To achieve sufficient thrust to lift the 3 million-kg rocket off the pad, five F-1 engine — the largest ever built — provided a thrust of 34 MN, using liquid oxygen and kerosene. The exhaust velocity of these engines was 2650 m/s. The important innovation for the second and third stage was the use of liquid hydrogen. It was the first operational use of this fuel and was vital in achieving the necessary velocity to reach the Moon. The second stage had five J-2 engines, burning liquid oxygen and liquid hydrogen, and providing a total thrust of 5.3 MN, with an exhaust velocity of 4210 m/s. The third stage had a single J-2 engine, providing a thrust of 1.05 MN.

The first manned operational launch took place in December 1968, and the first lunar landing mission was launched on July 16, 1969. The mission took eight days, and the astronauts returned safely, having spent 22 hours on the Moon. The Saturn V is a technological milestone in the twentieth century; as a human achievement, Apollo II remains unique in the history of the planet. The main technical advance since the Saturn V has been the development of the space shuttle. The shuttle concept was to bring the main vehicle back to Earth so that it could be re-used. The shuttle is the primary means of launching the components of the International Space Station. The payload capability of 24 tonnes to low Earth orbit is not matched by any of the current expandable launchers, although the Ariane 5 has the capability similar to the shuttle for geosynchronous orbit.