Roughly the size of a basketball and weighing just 21 pounds, the Vanguard satellite struck an almost comical contrast to the rocket built to launch it: a three-stage, 72-foot, 22,000-pound behemoth. Despite its size, the satellite carried beneath its thin metal surface a range of sophisticated instruments developed to precisely measure the temperatures, pressures and lights it would encounter during orbit. The satellite’s diminutive tracking tool, known as Minitrack, was designed to detect meteorites and to follow the craft’s progress. It also gave the project’s overall monitoring system its name.

Once assembled in Washington, DC, the Vanguard 704 system occupied 1,700 square feet of an air-conditioned, humidity-controlled room at the computing center. Painted to match the program’s color pallet — primarily blue, orange and olive — the 704 and its components formed the heart of Minitrack. Once the satellite launched, Minitrack stations positioned around the world — from Fort Stewart, Georgia, to Lima, Peru — would alert the 704 as the craft passed overhead. The 704 would then relay location data to the Vanguard communications center and to the next Minitrack station along the path.

Originally designed for engineering and scientific applications, the 704 was more than up to the task. It employed a high-speed core memory system to execute calculations twice as fast as the initial 700 series release, the 701. Paired with an IBM-built cathode-ray tube (CRT) — a vacuum tube used to display images — the 704 translated the computer’s output into graphs, orbit trajectories, symbols, figures, numbers and words “just as they might appear on a television screen,” wrote IBM Poughkeepsie News in 1957.

By the time of the first satellite launch, another 704 (later upgraded to a 709) had been assembled in a low, windowless building a few thousand feet from the rocket’s launchpad in Central Florida. This system joined the effort to track potential impacts: monitoring the rocket’s aerial location throughout its flight, at the ready with a self-destruct mode in case of a sudden loss of power over an inhabited area. Utilizing data gathered directly from the missile, this second 704 computed speed and position as well as the exact instant when the missile’s final stage should be fired in order to launch the satellite into orbit.

The Soviet Union satellite Sputnik 1, which had been successfully launched in October of 1957, was followed a month later by Sputnik 2, dealing a blow of defeat to the NRL’s goal to launch the first satellite into space. Even worse, the agency’s first attempt to launch failed dramatically. Broadcast across national television, the rocket carrying Vanguard’s TV3 satellite rose 4 feet before dropping back down in a violent explosion.

By the time NRL launched its first satellite, the Explorer I, in January of 1958, the 704 system in Washington, DC, had been replaced by a 705 capable of powering 1,364,000 logical decisions per minute. A few months later, in March of 1958, Vanguard I launched, becoming the first ever solar-powered satellite in orbit. And in 1959, Project Vanguard came to a close after the successful departure of Vanguard III.

In the ensuing decades, the science and technology developed for Project Vanguard would enable the developments behind NASA’s first crewed spaceflights. IBM machines, software and personnel would also go on to support NASA through many more historic feats, from its mission to the moon to its ambitious Space Shuttle program, and in the agency’s contributions to the International Space Station. But the satellite program also left a unique legacy. Vanguard I has made hundreds of thousands of revolutions of Earth, traveled billions of nautical miles, and still soars over the globe every day. It is the oldest satellite in orbit.