In the mid-1950s the Cold War was running hot. The U.S. and U.S.S.R. each sought to gain an edge over the other with new technologies and weapons developed during World War II and in the burgeoning Atomic Age. The competition to put a satellite into orbit ― a goal of the International Geophysical Year (IGY), which ran from July 1, 1957 to Dec. 31, 1958 ― was particularly intense. Explorer 1 was the first satellite launched by the United States when it was sent into space on January 31, 1958.
Jet Propulsion Laboratory
Jan. 31, 1958
May 23, 1958
Explorer 1 Overview
Explorer 1 was the first satellite launched by the United States when it was sent into space on January 31,…
The science section of the satellite, designed by University of Iowa physicist James Van Allen, was relatively straightforward.
The main instruments were a cosmic-ray detection package; internal, external and nose-cone temperature sensors; a micrometeorite impact microphone; a ring of micrometeorite erosion gauges; and two transmitters.
Explorer 1 was carried into orbit by a Jupiter-C rocket, launched from Cape Canaveral, Florida, at 10:48 p.m. (EST) on Jan. 31, 1958.
The rocket, developed at the Army Ballistic Missile Agency in Alabama, under the direction of Wernher von Braun, was a modified version of the Redstone ballistic missile, topped by three solid-propellant upper stages
Launch of Jupiter-C/Explorer 1 at Cape Canaveral, Florida on January 31, 1958. After the Russian Sputnik 1 was launched in October 1957, the launching of an American satellite assumed much greater importance. After the Vanguard rocket exploded on the pad in December 1957, the ability to orbit a satellite became a matter of national prestige. On January 31, 1958, slightly more than four weeks after the launch of Sputnik.The ABMA (Army Ballistic Missile Agency) in Redstone Arsenal, Huntsville, Alabama, in cooperation with the Jet Propulsion Laboratory, launched a Jupiter from Cape Canaveral, Florida. The rocket consisted of a modified version of the Redstone rocket’s first stage and two upper stages of clustered Baby Sergeant rockets developed by the Jet Propulsion Laboratory and later designated as Juno boosters for space launches
The decision was made that we would make no public comments about the rocket until [its signal] had actually been picked up in California,” then-Director of the Jet Propulsion Laboratory William Pickering said. “And we sat there for an hour-and-a-half. The time came and went, and there was a period of 8 minutes there [before contact], which is the longest 8 minutes I’ve ever spent in my life.
At a jubilant press conference about 2 hours after the launch, Pickering was joined by James Van Allen (center), head of the University of Iowa physics department who designed the science instruments, and Wernher von Braun (right), who directed development of the rocket at the Army Ballistic Missile Agency
Jet Propulsion Laboratory Director Dr. William Pickering, Dr. James van Allen of the State University of Iowa, and Army Ballistic missionile Agency Technical Director Dr. Wernher von Braun triumphantly display a model of the Explorer I, America’s first satellite, shortly after the satellite’s launch on January 31, 1958. The Jet Propulsion Laboratory packed and tested the payload, a radiation detection experiment designed by Dr. van Allen. Dr. von Braun’s rocket team at Redstone Arsenal in Huntsville, Alabama, developed the Juno I launch vehicle, a modified Jupiter-C.
The successful orbit of Explorer 1, launched on a Jupiter-C rocket, made headlines around the world.
The Soviet Union had already launched two satellites in 1957, and the previous U.S. attempt on a Vanguard rocket exploded only a few seconds after liftoff. At the time, many people called the satellite a “moon” or a “man-made moon” because of its Earth orbit. The Huntsville Times, seen here, was particularly proud of the success of the Jupiter-C, as it was made at the Army Ballistic Missile Agency in Huntsville, Alabama.
In January 1958, a modified Redstone rocket lifted the first American satellite into orbit just 3 months after the the von Braun team received the go-ahead. This modified Redstone rocket was known as a Jupiter-C. Its satellite payload was called Explorer I.
Story of Explorer 1
On October 4, 1957, the Soviet Union surprised the world with the launch of a 23-inch-diameter, 184-pound ball designated Sputnik…
Studying the Van Allen Belts 60 Years After America’s First Spacecraft
Tick, tick, tick. The device — a Geiger counter strapped to a miniature tape recorder — was registering radiation levels a thousand times greater than anyone expected. As the instrument moved higher, more than 900 miles above the surface, the counts ceased. Scientists were baffled. It was early 1958, the United States had just launched its first spacecraft, and a new discipline of physics was about to be born.
This composite image shows a model of the Explorer 1 satellite (left) and a photo of a model of Explorer 1 being held up by (left to right) Jet Propulsion Laboratory Director William Pickering, James Van Allen, and Wernher von Braun at a late-night news conference announcing the launch of Explorer 1, held at the National Academy of Sciences in Washington, D.C.
Videos and Downloads
The Big Picture: Explorer 1
This 1958 “official television report of the United States Army” recounts the “exciting, suspenseful story” of the days leading up to the launch of Explorer 1, the first “scientific Earth satellite.”
The Launch of Explorer 1
Explorer-1 was the first United States earth satellite and was sent aloft as part of the United States program for the International Geophysical Year 1957-1958.
Go! Explorer 1 Poster
Check out the poster for the first satellite.
60 Years PDF
See the Explorer 1 timeline.
Eyes on Explorer 1
Watch the entire mission.
Explorer 1 Bookmark
Create your own bookmark with this download.
Print your own 3D model of Explorer 1.
Download a cutout of Explorer 1.
Explorer 1 Card
View the official Explorer 1 card.
Stories of Missions Past: Early Explorers
On September 29, 2011, NASA announced the short list for five potential new “Explorer class” spacecraft. These missions are by…
The educational resources are divided by topics that span the science, technology, engineering and mathematics of this mission and current and future missions resulting from it. Resources include rocketry lessons, computer science activities, 3-D printing resources and reference materials.