This was a rocket that was intended to be the former Soviet Union's first Intercontinental Ballistic Missile (ICBM). But it swiftly metamorphosed into the country's premier launch vehicle, carrying the world's first artificial satellite and subsequently the first human to orbit the earth.
Improved variants of it have continued to be in service, with the current version known as the Soyuz. With well over 1,700 flights to its credit and a formidable safety record, this is easily the most successful launch vehicle around. The Soyuz rocket is still regularly launched. During 2010 for instance, 10 of these rockets flew, carrying satellites into orbit and ferrying astronauts and cargo to the International Space Station.
The Soyuz rocket is usually launched from the famed Baikonur Cosmodrome in Kazakhstan. But in the few months it will lift-off, for the very first time, from Europe's Guiana Space Centre in South America.
After the Second World War, rocketry in the Soviet Union got under way with efforts to reproduce the German V-2 rocket. Thereafter, there was a sustained effort to build better rockets of their own.
However, neither the Soviet government nor its armed forces, which oversaw the rocket programme, were interested in a space programme. What they wanted were powerful rockets that would be militarily useful.
While the U.S. had access to airbases in Europe and elsewhere from which its nuclear-armed bombers could attack the Soviet Union, the latter needed rockets capable of flying thousands of kilometres in order to retaliate against the U.S. mainland.
The first such Soviet ICBM was the R-7 that was the brainchild of the legendary rocket designer Sergey Pavlovich Korolev and his team. It was initially intended to carry a three-tonne nuclear warhead to a distance of 8,500 km.
But, as space historian Asif Azam Siddiqi graphically narrates in his book Challenge to Apollo: The Soviet Union and the Space Race, 1945-1974, the rocket's payload capability was suddenly hiked. Based on a report from Andrei Dmitrievich Sakharov, the eminent Soviet nuclear physicist who later won the Nobel Prize for his efforts to promote peace and human rights, the government insisted, in October 1953, that the R-7 be capable of carrying at least five tonnes, preferably six tonnes.
This was a bombshell for the country's liquid propulsion engineers led by Valentin Petrovich Glushko. The engines for the R-7, running on liquid oxygen and kerosene, were intended to develop thrust ranging from 50 tonnes to 60 tonnes. Substantially higher thrust was needed to meet the new performance requirements for the rocket. But even as it was, the engines were running into trouble with problems of unstable combustion. Hiking their thrust further could be a nightmare.
An ingenious solution was found. Instead of a single large combustion chamber, each engine would have four smaller chambers fed with propellants from a common turbopump. This configuration cut short development time, simplified production and even reduced weight and improved performance.
In addition, each engine incorporated smaller combustion chambers, called verniers, which could be swivelled to steer the rocket.
The end result was an iconic rocket. Its core stage was much broader at the top than lower down. The core was equipped with a RD-108 engine generating 75 tonnes of thrust. It was surrounded by four large, conical strap-ons, each with a RD-107 engine producing 83 tonnes of thrust. A total of 32 combustion chambers fired at lift-off, a number unmatched by any other rocket.
The novel launch structure for this rocket has also become equally identified with Soviet rocketry. The rocket was held in place on the launch pad by four large metal structures, rather like the petals of a flower. Using a system of counterweights, the four petals would swing clear when the rocket took off.
Previous Soviet missiles were tested at Kapustin Yar on the banks of the Volga river in Russia. But launches from that site could be picked up by Western radar stations in Turkey. So the Government sanctioned the creation of a new launch facility for the R-7 near Tyuratam in Kazakhstan, an obscure settlement on the railway line from Moscow to Tashkent. This became the Baikonur Cosmodrome.
After two launch failures in May and July 1957, the R-7 finally successfully flew in August that year.
The Soviet Union now had a powerful rocket at its disposal. But it was the untiring efforts of people like Sergey Korolev that made it possible for the country to use this asset to produce a string of breathtaking firsts in space. Even so, it was only after the U.S. announced its plan to launch an artificial satellite that the Soviet Government backed efforts to beat them at that endeavour.
On October 4, 1957, the space age began with the R-7 launching the Sputnik, a shiny metal weighing only about 80 kg that was equipped with radio transmitters issuing a series of beeps. A month later, another R-7 took the dog Laika into space.
April 12, 1961 was another historic occasion. On that day, an uprated and improved version of the R-7, equipped with an upper stage, allowed Yuri Gagarin, flying in the Vostok space capsule, to become the first human to orbit the earth.
Steadily improved over the years, launch vehicles derived from the R-7 became the workhorse of the Soviet and later the Russian space programmes. The variant operating currently is known as the Soyuz.
Marketing launches abroad
After the breakup of the Soviet Union, Russia began marketing its launchers abroad. In 1996, Starsem, a partnership between European and Russian space organisations, was established to provide commercial launch services using the Soyuz rocket.
In May 2003, the European Space Agency (ESA) decided to operate the rocket from its Guiana Space Centre. “The decision to develop the launch infrastructure to enable Soyuz to be launched from French Guiana is of mutual interest to both Europe and Russia, and benefits from funding from the European Community,” according to the space agency. The Soyuz would, it said, perfectly complement the capabilities of Europe's more powerful Ariane 5 rocket as well as the smaller Vega that is expected to have its maiden flight this year.
Both European and Russian space agencies and companies are involved, and the launch facilities for the Soyuz at French Guiana have been completed.
As has been done traditionally in Russia, the rocket will be integrated horizontally and transported in that fashion to the launch pad. There it will be lifted to the vertical position and held in place by the four petals of the launch structure.
But one important difference from the Russian practice is to have a massive mobile gantry that can roll into place over the rocket and its launch structure. This allows satellites to be put in place after the rocket has been moved to the the pad, as is done with Europe's Ariane 5 rocket. The gantry would, of course, be moved clear before the launch.
The European commercial launch company Arianespace will begin operating the Soyuz launch complex in April, according to a press release it issued last month. At least two launches of the rocket from Guiana and three from Baikonur were planned for 2011. The company says that it has orders for 18 Soyuz launches.
With the Space Shuttle being retired this year, the Soyuz rocket will become the only way to carry astronauts to the International Space Station. Currently, such manned missions are launched from Baikonur. However, the new launch facilities at Guiana have been been designed “so that it can be smoothly adapted for human spaceflight” if needed, according to the European Space Agency.
A rocket that first flew more than half a century back looks like it will be in service for many years to come.
With well over 1,700 flights to its credit and an impressive safety record, the Soyuz rocket is easily the most successful launch vehicle around.