A Small Step for a Pile of Aluminum
Sputnik was the name of a series of Soviet satellites deployed 1957-1961. The successful launch and orbit of the first Sputnik kicked off the space race between the Soviet Union and the United States, and its success had immense psychological and political impact on the peoples of those two nations. All in all, 10 Sputnik-class satellites were launched during the lifetime of the series. The word "Sputnik" literally means "satellite".
Sputnik 1 (October 4th, 1957)
First man-made satellite orbiting Earth. Sputnik 1 travelled at a height interval of 228 to 947 kilometers, and orbited the planet once every 96 minutes. It was a 83.6 kilogram aluminum sphere with a diameter of 58 centimeters, having four attached antennae of 2.4 to 2.9 meters length. The only instruments it carried were a radio transmitter, a pressure gauge and a thermometer. It signaled its internal temperature and pressure back to the Soviet space program command centre at Baikonur Cosmodrome using its radio, which had an added psychological effect on radio listeners across the globe, whose radios picked up its beeps. The Soviet leadership was well aware of this, and only released very limited information about the satellite to the world, in hopes of feeding the sense of fear and awe the satellite had instilled in the Western world. Its scientific mission was to chart the Earth's ionosphere using its simple instrumentation. Although paranoia and speculation ran rampant, this simple satellite carried no other instruments.
Sputnik 2 (November 3rd, 1957)
This much larger Sputnik, with its weight of 508 kilograms, carried the first living being from Earth into space, the famous "space dog" Laika. It carried a radio transmitter, as well as a number of instruments that allowed the Soviet ground control to check on Laika's health condition. It also carried ten days' worth of dog food, the last day of which contained poison to kill Laika before re-entry (the Soviet researchers had not yet figured out a way to actually land the thing, so Laika's trip to space was with a one-way ticket). Sputnik 2 re-entered the Earth atmosphere on th 14th April 1958, burning in the atmosphere on re-entry.
Sputnik 3 (May 15th, 1958)
An even larger satellite, Sputnik 3 weighed in at 1327 kilograms, and was the first well-instrumented Soviet satellite. Its purpose was to confirm the existence of the Van Allen Belts that had been discovered by the American satellite Explorer I. Its mission accomplished, Sputnik 3 burned upon re-entry on 6th April 1960.
Sputnik 4 (May 15th, 1960)
A so-called Korabl Sputnik, the Sputnik 4 was essentially an unmanned version of the Soviet Union's later Vostok-class spacecraft, intended to test the design before they actually put humans in them (the craft that carried Jurij Gagarin, first human in space, was a Vostok). It released a re-entry capsule while burning on re-entry, which unfortunately botched due to a glitch in the capsule's retro rockets, sending the capsule into outer space where it was lost. Gagarin was probably glad he didn't book this flight. The Sputnik 4 weighed 1477 kilograms, and contained a cabin with a redundant life support system, a dummy of a man, a number of scientific instruments, a television system and a radio, which sent pre-recorded voice communications back to Baikonur Cosmodrome (to test if voice communication between Earth and space was viable).
Sputnik 5 (August 19th, 1960)
Second Vostok test flight, the 4600 kilogram Sputnik 5 carried the two dogs Belka and Strelka into space, as well as a television system with which Baikonur Cosmodrome could check on the animals' condition. The satellite carried out 18 orbits before re-entering the Earth atmosphere the day after its launch. It successfully ejected a landing capsule containing the two dogs, who were picked up by Soviet scientists after the successful landing. Both dogs were unharmed, and entered history as the first Earth organisms to fly in space and actually live to tell the tale. Or, I guess, bark the tale. I don't know how canine folklore travels.
Sputnik 6 (December 1st, 1960)
Third Vostok test flight, the Sputnik 6 also carried a canine crew. The dogs Ptsyolka and Mushka both died as the satellite re-entered the atmosphere after 17 orbits, due to the re-entry angle being off.
Sputnik 7 (February 4th, 1961)
First attempt at an interplanetary space flight, Sputnik 7 was an orbital launch platform intended to send a probe to Venus. It carried a Venera-class space probe, which was supposed to be launched by a Soviet Zond-class rocket towards Venus where it would land and perform some surface analysis. Unfortunately, ignition of the rocket failed, and the whole assembly stayed in Earth orbit. Because of its huge size compared to its American contemporaries (and Soviet predecessors), weighing in at 6483 kilograms, American observers believed it to be a failed manned mission.
Sputnik 8 (February 12th, 1961)
Identical in design and construction to Sputnik 7, with minor adjustments to the Zond rocket. Sputnik 8 successfully launched Venera 1 to Venus.
Sputnik 9 (March 9th, 1961)
A slightly modified and refined successor to the Sputnik 6, Sputnik 9 was another Vostok test flight. It weighed 4700 kilograms, and carried a dummy astronaut and the dog Chernushka. The flight lasted a single orbit, and the re-entry capsule, complete with unharmed dog and dummy, was recovered on the same day.
Sputnik 10 (March 25th, 1961)
The fifth and final Vostok test flight, Sputnik was slightly lighter than Sputnik 9, at 4695 kilograms. It had similar instrumentation to its predecessors, and like Sputnik 9, it carried a dummy and a dog (The dog's name Zvezdochka means "little star"). On the 12th April on the same year, Jurij Gagarin became the first human in space.
Sputnik 11-25 (April 12th, 1961 - January 4th, 1963)
A variety of Vostok, Voskhod, Kosmos and other classes of Soviet spacecraft, neither of these were actually named "Sputnik" by the Soviet Union. They were referred to as Sputniks by American observers, although they technically weren't.
- Lademanns Astronomi Leksikon, ISBN 87-15-07429-3