On October 4, 1957, the Soviet Union launched Sputnik 1, a small but groundbreaking satellite that marked the beginning of the space age. Measuring 58 centimeters in diameter and weighing 83 kilograms, Sputnik 1 had a polished spherical body, four antennas arranged in a fan shape, and two radio transmitters. These components allowed it to send radio signals that could be picked up by amateur radio operators around the world. The signals, transmitted on two frequencies, were detectable for 22 days before the satellite's batteries ran out on October 26, 1957. Sputnik 1 was launched using the R-7 rocket, a powerful vehicle designed by Soviet engineer Sergei Korolev. Originally, a more complex satellite called Object D had been planned, but it was too large and heavy to be finalized in time. Korolev then proposed a simpler design: two hemispheres joined together, with a radio transmitter, antennas, and a power supply. This design was completed in just two months, showcasing the rapid pace of Soviet engineering at the time. The satellite’s communication system included two 1-watt radio transmitters that sent data about the temperature and pressure of nitrogen inside the satellite. This information was used to test how pressurization and thermal regulation systems would function in space. The satellite’s body was made of a special aluminum alloy, AMG6T, which was both lightweight and durable in the extreme temperatures of space. The four antennas, arranged at a 35-degree angle, transmitted a 0.4-second pulsed signal on two frequencies, 20.005 and 40.002 MHz. The satellite’s orbit, which had an inclination of 65 degrees, meant it passed over most of the Earth’s inhabited areas during its time in space. Sputnik 1’s launch came as a shock to the United States, triggering what became known as the Sputnik crisis. The event was seen as a major technological achievement by the Soviet Union and raised fears in the U.S. about the possibility of Soviet missiles reaching American soil. The New York Times compared the event to a "technological Pearl Harbor," highlighting the significance of the moment. In response, the U.S. government established NASA and launched its first satellite, Explorer 1, just four months later. Sputnik 1 remained in orbit for about three months before reentering Earth’s atmosphere and burning up on January 4, 1958, marking the start of an intense global competition in space exploration.