March 17, 2008: Vanguard 1 celebrates fifty years in space

William Atkins
Monday, 17 March 2008 19:55

Science - Energy

Vanguard 1, the fourth artificial satellite launched into space, is the oldest human-made object still orbiting about the Earth. Congratulations--Vanguard 1--on your pioneering efforts in space exploration!   

The earth-science satellite Vanguard 1 was launched by the Department of Defense/U.S. Navy, with assistance from the U.S. Naval Research Laboratory, to study the effects of a space environment on a satellite and its systems while in orbit about the Earth.

The 3.2-pound (1.47-kilogram) satellite was launched at 12:15:41 UTC, on March 17, 1958, while onboard a three-stage Vanguard launch vehicle.

It was launched from Launch Pad LC 18A at Cape Canaveral, Florida as part of the scientific program Project Vanguard for the International Geophysical Year (1957-1958)

The spherical-shaped Vanguard 1 (NSSDC ID: 1958-002B, also called Vanguard TV4), at 5.9 inches (fifteen centimeters) in diameter, was called by Soviet premier Nikita Khrushchev, upon its launch: “the grapefruit satellite.” (NSSDC stands for National Space Science Data Center.)

Vanguard 1 orbits about the Earth with an apogee of 2,466 miles (3,969 kilometers) and a perigee of 406 miles (654 kilometers). Its orbital period is approximately 134.2 minutes.

Vanguard 1’s original mission was designed to last 2,200 days. The probe was composed of a 10-milliwatt, 108-megahertz mercury-battery powered transmitter and a 5-milliwatt, 108.03 megahertz transmitter, which was powered by six square solar cells. Six aerial antennas protruded from its surface. It also carried two thermistors, which measured interior temperature of the probe.

In the early days of U.S. space exploration, the United States was just trying to get its launch vehicles to work. The country was inexperienced in space exploration. However, Vanguard 1 proved the fledgling space explorer could be a master in space travel. Please read more about the accomplishments of Vanguard 1.