Rockets, those elegant and powerful cylinders, are what guide people and robotic spacecraft into space. They also traditionally serve as propulsion systems for spacecraft post-liftoff so the satellite, Space Shuttle, etc, can reach its destination. Rockets represent some of mankind’s most advanced technological creations. From their relatively humble beginnings in the realm of ancient firecrackers to the larger-than-life Saturn V, rockets may have changed in scale and application but they still rely on the same basic principles of physics.
The modern rocket was a long time coming. The ancient Greeks invented a rocket-like device, while the ancient Chinese actually used rockets for entertainment and, later, for warfare. By the 14th century rockets were known in Asia and Europe. In the 18th century the Indians used rockets against the British. At the beginning of the 19th century rockets are used militarily in Europe for the first time. During World War 1 rockets were mounted on planes for the first time.
Johannes Kepler and Isaac Newton, so crucial to all aspects of modern science and technology, laid the scientific foundations for rocketry and rocket-propelled space travel.
The very first person to promote realistically the possibility of developing a jet engine —powered by explosives and designed to propel a flying machine—was almost certainly Nikolai Kibalchich. Kibalchich is far better known for his role in another explosives-based “achievement”—the bombing-assassination of Tsar Alexander II in 1881, which he helped carry out and for which he was quickly executed. Considered a political extremist, his ideas were largely forgotten until the bolshevik revolution in Russia.
Rockets were also used to take photographs from a height of about 100 m at the end of the 19th century. These were designed by Alfred Nobel and launched in Sweden. The German Alfred Maul designed camera-carrying rockets for military use. Rockets themselves saw limited use of any kind during World War I. During World War 1 rockets were mounted on planes for the first time.
The first person to explore seriously a rocket’s potential for space travel was Konstantin Eduardovich Tsiolkovsky. Though the American Robert Goddard and the German Hermann Oberth are also important in this regard, Tsiolkovskiy has the best claim to be considered the father of space travel. This is due both to the priority of his ideas over those of the other two men and to the importance thereof. Not just a visionary, Tsiolkovskiy grounded his ideas in solid science. He worked out the necessary velocity for putting an object into earth orbit. Later, he pondered the possibilities of atomic and solar-powered drives and a permanent human presence in space.
The main predecessor to the modern space rocket was developed by an American named Robert Goddard. He designed and launched the first liquid fueled rocket in 1926 because he was interested in space travel. Although this first rocket (named Nell) made it a mere 12 meters into the air, Goddard continued making advances in both speed and distance until his death in 1945. Goddard’s many contributions to the theory and design of rockets earned him the title of “father of modern rocketry.” He died relatively young and thoroughly unappreciated for the many important contributions he made to spaceflight. Goddard was awarded 214 patents.
Austro-Hungarian born, German scientist Hermann Oberth developed much of the modern theory for rocket and spaceflight independent of Tsiolkovsky and Goddard. Oberth’s classic book, Die Rakete zu den Planetenräumen (“The Rocket into Interplanetary Space”), explained the mathematical theory of rocketry and applied the theory to rocket design. Oberth’s works also led to the creation of a number of rocket clubs in Germany, as enthusiasts tried to turn Oberth’s ideas into practical devices. Oberth was an important spaceflight popularizer.
One of the most important early spaceflight societies was Verein für Raumschiffahrt (VfR: Society for Spaceship Travel), formed in 1927. Oberth was a founding member. Many members went on later to develop rocket technology during and after World War II. Most prominent was Wernher von Braun, about whom more will be said later. The Society’s activities attracted the attention of the German Army for whom many of them would begin to work.
Another important player at this stage, one who like Tsiolkovskiy envisioned rockets as merely a means to the great end of space travel, was Fridrikh Arturovich Tsander (or Zander). Along with fellow space-fanatic Yuri Kondratyuk he founded a Society for the Study of Interplanetary Travel. Tsiolkovsky was also a member. Tsander spent most of his life working without any state support. Nonetheless, in 1933 he would launch Russia’s first ever liquid-fueled rocket, several years after Robert Goddard had done much the same in the United States.
A Russian competitor to GDL appeared. Based in Moscow, it was known as the “Group for the Study of Reactive Motion,” or GIRD (by its Russian acronym). Founded by Tsander, GIRD quickly attracted several talented individuals, most notably Sergey Korolev, who leapt at the chance to work on rockets. Korolev was to be the “chief architect” of the Soviet space programme. At Mikhail Tukhachevsky recommendation, GDL and GIRD were merged into a new and relatively well-funded entity within the Soviet military—the Reaction Propulsion Institute (RNII), based in Moscow. Tsander had died a few months earlier of typhus while only in his mid-forties.
The promise and potential of the Soviet rocketry effort was cut short abruptly when Joseph Stalin’s purges reached their climax. His plan was put into effect by the NKVD, the secret police force responsible for political repression. Inevitably, the NKVD denounced Korolev and he was thrown into the Lubyanka. Shortly afterward, following severe torture, he “confessed” and was fortunate not to be shot. Instead, he found himself in a cattle truck being taken to the Kolyma death camp in Siberia. At the intervention of some of the country's top aviators Korolev was released from Siberia by Lavrenty Beria.
Development was accelerated during the late 1930s and particularly during the war years. The most notable achievements in rocket propulsion of this era were the German liquid-propellant V-2 rocket and the Me-163 rocket powered airplane. The V2 was developed by German scientist Wernher von Braun. Similar developments were under way in other countries but did not see service during the war. A myriad of rocket weapons also were produced.
Many scientists were aware that the V-2 might be capable of reaching outer space. Knowing that the rocket could carry about 1 ton (1 metric ton) of explosives, German rocket expert Willy Ley suggested that the explosives be substituted by a pilot. Together with a protective suit, a pilot might weigh only 136 kg. The difference would be made up by extra fuel. If something even as simple as that could be done, Ley said, the rocket might be able to reach the fringes of outer space.
During World War II, Germany devised two schemes to bomb the United States. Both involved rockets. The first was the so-called Amerika Bomber. This would have required a piloted, winged V-2 rocket called the A-9 boosted by a huge rocket called the A-10. An even more daring scheme was being developed by the research team of Eugen Sänger and Irene Bredt. Their idea was to construct an Earth-orbiting, single-stage rocket plane capable of taking off from Germany, delivering a bomb while over the United States, and returning to its takeoff point. Like the Amerika Bomber, the Silbervogel (Silver Bird) would skip across the upper layers of the atmosphere.
By the end of World War II, the most advanced rocket technology on Earth was neither American nor Soviet, but the German V-2 program based in Peenemünde on the Baltic coast. As Nazi Germany collapsed, the incoming Soviet and U.S. militaries raced to capture what they could: rockets, plans, and personnel. The Americans fared better, netting most of the hardware and—the greatest prize—the German mastermind behind it all, and the eventual architect of the U.S. space program, Wernher von Braun. The Americans and Russians began to improve upon the V2. The Americans created the Redstone rocket and the Soviets the R series.
After the war propulsion development was still largely determined by military applications. Liquid-propellant engines were refined for use in supersonic research aircraft, ICBMs, and high-altitude research rockets. Similarly, developments in solid propellant motors were in the areas of military tactical rocket applications and high-altitude research. Bombardment rockets, aircraft interceptors, antitank weapons, and air-launched rockets for air and surface targets were among the primary tactical applications.
The rockets used to transport a spacecraft beyond Earth’s atmosphere, either into orbit around Earth or to some other destination in outer space, are called launch vehicles. Practical launch vehicles have been used to send manned spacecraft, unmanned space probes, and satellites into space since the 1950s. They include the Soyuz and Proton launchers of Russia, the Ariane series of Europe, and the space shuttle and Atlas, Delta, and Titan families of vehicles of the United States.
Korolev dreamed of space, not of the intercontinental ballistic missiles his bosses demanded. As early as 1953, he had begun to make suggestions in this direction to the authorities. At the time neither he nor anyone else possessed a rocket nearly powerful enough to achieve escape velocity. Nor was there political support for such an adventure: the Soviet leadership was interested in rockets solely as weapons. The first of these obstacles began to recede in the mid–1950s with development of the R-7. The primary innovations involved joining together multiple rocket clusters in two stages. Korolev proposed to the government to use it to send up an artificial satellite.
The actual launch took place at the Baikonur facility. By all accounts, it was both spectacular and textbook perfect. Some among those watching at first became alarmed to see the rocket tilt shortly after take-off, expecting it instead to head straight up. This, however, was merely a necessary trajectory adjustment in order to achieve orbit—a sign of success, not of failure. Within minutes the little satellite was sweeping around the globe, beeping loud and clear for all to hear. It was a pivotal moment for Russian rocketry, and indeed for the whole world.
Another line of development within the U.S. industry led, in the early 1950s, to the Navaho cruise missile. A cruise missile flies like an unpiloted aircraft to its target, rather than following the ballistic trajectory of an IRBM. This program was short-lived, but the rocket engine developed for Navaho, which itself was derived from the V-2 engine, was in turn adapted for use in a number of first-generation ballistic missiles, including Thor, another IRBM, and Atlas and Titan, the first two U.S. ICBMs. A version of Atlas was used to launch John Glenn on the first U.S. orbital flight. The R7 was the first Russian ICBM.
The first American satellite sent around the Earth, Explorer 1 was launched in 1958. Designed by the Jet Propulsion Laboratory in California, Explorer 1 was launched by the Jupiter-C rocket vehicle, a modified version of the earlier Redstone rocket and an assembly that consisted of ballistic missile technology.
Later years saw rockets, specifically the Saturn series of rockets, used for human space exploration. Primarily developed in the 1960s by scientists who had emigrated from Germany to the U.S., the Saturn rockets were first proposed for launching military satellites. They went on to become the main launch vehicles for Project Apollo, NASA’s foray into lunar exploration. The largest rocket built during this time was the Saturn V.
Since the Apollo missions, liquid systems have been employed by most countries for spaceflight applications, though solid boosters have been combined with liquid engines in various first stages of U.S. launch vehicles—those of the Titan 34D, Atlas, Delta, Pegasus and Space Shuttle. The Soviet launch vehicle Energia was used only for two missions. Solid-rocket motors have been used for several systems for transfer from low Earth orbit to geosynchronous orbit. In such systems, the lower performance of solid-propellant motors is accepted in exchange for the operational simplicity that it provides.
Rockets were traditionally disposable items designed to be discarded after a single use. However, the Space Shuttle Columbia, first launched in 1981, was designed with some reusable parts. The U.S. space shuttle is unique in that it combines the functions of launch vehicle and spacecraft. The first partially reusable launch vehicle, it is one of the most complex machines ever developed, with more than 2.5 million parts.
Russia has the most diverse set of launch vehicles of any spacefaring country. Most were developed while under the rule of the Soviet Union, which included both Russia and Ukraine, and both countries continue to produce launch vehicles. Like the United States, the Soviet Union used various ballistic missiles as the basis for several of its space launch vehicles. The most famous of these ballistic missiles was the aforementioned R-7, developed in under the direction of Sergei Korolev. Other Soviet launchers based on ICBM first stages include the Zenit, Proton and Tsyklon (which is built in the Ukraine).
Several European countries, with France playing a leading role, decided that it was essential for Europe to have its own access to space, independent of the United States and the Soviet Union. To develop a new launcher, these countries formed a new space organization, the ESA, which in turn delegated lead responsibility of what was named the Ariane launch vehicle to the French space agency. The French space agency, Centre National d’Études Spatiales (CNES), has managed Ariane development and upgrades with the support of the ESA. Improved versions of Ariane were developed during the 1980s. Vega is another european launch vehicle.
Like the United States and the Soviet Union, China’s first launch vehicles were also based on ballistic missiles. The Chang Zheng 1 (CZ-1, or Long March 1) vehicle, which put China’s first satellite into orbit in 1970, was based on the Dong Feng 3 IRBM. A CZ-2F vehicle was used to launch the first Chinese astronaut into space in 2003. There are also CZ-3 and CZ-4 launchers.
Until 2003, Japan had three separate space agencies, two of which developed their own line of launch vehicles. Japan did not have a previous ballistic missile program. Japan’s Institute of Space and Astronautical Science based its launch vehicles on the use of solid propellants. Its Lambda L-4S vehicle sent the first Japanese satellite, Osumi, into orbit. Each subsequent launcher in the Mu series gave the institute greater lifting power for its scientific satellites. Initially Japan used launch vehicles based on American design. The first Japanese launch vehicle was the H-II.
After a spacecraft has ridden into space on a rocket, it then needs a propulsion system to take it where it needs to go, whether that’s into Earth orbit or onward to a distant planet. Instead of bringing along a rocket with a huge tank of propellant, future missions may use more-sophisticated propulsion systems. Ion propulsion or solar sails are but two technologies that have been proposed by various scientists. At present both of these designs have had prototypes.