The first artificial satellite flew into space in 1957, changing life on earth forever. Before long, we depended on satellites for weather forecasts and telecommunications. Today, fleets of satellites are flying into space for applications like broadband or Earth imaging.
As our skies get more crowded with satellite constellations, engineers must deal with issues such as orbital debris and satellite trails that interfere with astronomical observations. These problems won’t be solved overnight. But in the meantime, this slideshow celebrates some of the good things satellites have done for humanity by highlighting the most historic orbiting satellite trailblazers that revealed secrets of the solar system.
Sputnik, more officially known as Sputnik 1, was the first artificial satellite to safely make it into Earth orbit. The Soviet Union launched it in secret on Oct. 4, 1957, from the Baikonur Cosmodrome in Kazakhstan, the same location where Russia launches crews to the International Space Station nowadays.
While in space, Sputnik gathered data on the density of the upper layers of Earth’s atmosphere and measured how well radio signals transmit in the ionosphere, a layer in the upper atmosphere that is full of charged particles. Space observers commonly say that the surprise of Sputnik spurred the united states to engage in a space race to send satellites — and eventually, astronauts — into orbit to show the merits of democracy over communism.
The united states made two attempts to send a satellite into space after the Soviet Union’s Sputnik. The first effort failed, but Explorer 1 successfully flew into space on Jan. 31, 1958. ترددات النايل سات
Explorer 1 is best remembered for confirming zones of charged particles trapping radiation in the magnetosphere of Earth, called the Van Allen belts. The belts have remained continued objects of investigation across space missions ever since, to better understand how they fluctuate with space weather — the interaction of the sun’s activity with the Earth’s sphere of influence.
The main mission of NASA’s Explorer 6 satellite, which launched on Aug. 7, 1959, was to study radiation trapped in Earth’s upper atmosphere, and to determine how often micrometeorites penetrate our atmosphere and the area near our planet.
But a valuable side mission saw the satellite take the first image of Earth from space on Aug. 14, 1959, over Mexico. The image, although low-resolution by today’s standards, demonstrated the potential of using space machines to take pictures of our planet. Today we commonly use Earth observation satellites to image the surface and atmosphere in many wavelengths of light to track phenomena such as climate change, agricultural yield or natural disasters.
Echo 1 was the first experiment to try passive communications from orbit. The spacecraft was a balloon made of Mylar polyester film that could reflect microwave signals. The satellite was tested for transcontinental and intercontinental telephone, radio and television signals.
While Echo 1 and its successor Echo 2 worked well, NASA elected to focus on active communications technology. Still, the “sateloons” spurred research into inflatable structures that led to applications like the Bigelow Aerospace module now attached to the International Space Station.
NASA’s TIROS 1 (Television and Infrared Observation Satellite) launched on April 1, 1960 on a test mission to see how well satellites could send TV pictures from space to Earth to observe the weather.
The satellite had two cameras, a wide angle one and a narrow angle one, to take pictures of cloud cover over Earth. Today, most of our weather forecasts come from satellites that constantly gaze at the Earth from geosynchronous orbit, although more small satellites in low Earth orbit are supplementing those observations. TIROS also ushered in satellites devoted to TV broadcasting, starting with Telstar in 1962.
Soviet cosmonaut Yuri Gagarin became the first person to fly in space on April 12, 1961, achieving three orbits before returning to Earth. This milestone is celebrated worldwide as “Yuri’s Night” every year on the anniversary of his flight.
At the time of his flight, Gagarin’s mission was seen in the context of the space race between the united states and the Soviet Union. Decades on, however, the mission represents the day that space opened up to humans — humans that eventually participated from numerous countries around the world. More than 500 people have now flown into space, and this number could expand quickly when private space companies begin sending paying customers aloft.
The Soviet Union’s Luna 10 achieved two major milestones in 1966, becoming the first satellite to orbit anybody but Earth — and also becoming the first satellite to orbit the moon.
The spacecraft measured the moon’s magnetic field, radiation environment, gravity field and other metrics. A gamma ray spectrometer gathered compositional information about the moon’s surface, showing a lot of basalt.
Only two years later, in late 1968, the first satellite (spacecraft) with humans on board orbited the moon — NASA’s Apollo 8. The first human moon landing, Apollo 11, followed on July 20, 1969.
NASA’s Mariner 9 mission was originally supposed to be part of a two-spacecraft set orbiting Mars, but Mariner 8 never made it into space. Mariner 9 succeeded and arrived safely to Mars orbit on Nov. 14, 1971, making it the first spacecraft to orbit another planet. Mariner 9 carried out the mission objectives of both spacecraft, mapping 70% of the Martian surface and studying changes on the surface and in the atmosphere.
Mariner 9’s imaging was delayed by a huge Martian sandstorm that obscured most of the surface, but when the dust died down, it sent the first images of Red Planet volcanoes and the huge Valles Marineris (a canyon) back to Earth. Mariner 9 showed that Mars was a dynamic planet and helped spur further investigations into searching for signs of life, which many Red Planet spacecraft continue to do today.