Anniversary of Explorer I
On January 31, 1958, the Jet Propulsion Laboratory’s Explorer 1 spacecraft became America’s first Earth-orbiting satellite when it was sent into space. On October 4, 1957, the Soviet Union’s Sputnik was launched. Following that event, the U.S Army Ballistic Missile agency was directed to launch a satellite using its Jupiter C rocket developed under Dr. Wehner von Branun’s directions. Is space history in the making or what?
The designing and building of the satellite, the upper stages of the rocket and a tracking system was assigned to the Jet Propulsion Laboratory. The Army’s Redstone Arsenal in Huntsville AL produced the liquid-filled rocket. In less than three months the task was completed. Following the successful launch of Explorer 1 came the formation of NASA in Oct 1958. JPL was transformed from the producer of ballistic missiles to a preeminent center for robotic exploration of our solar system and beyond.
A cosmic ray detector designed to measure the radiation environment in Earth’s orbit was the primary science instrument. A much lower cosmic ray count than expected was revealed by this experiment once it was in space. Under the direction of Dr. James Van Allen of the University of Iowa, it was theorized that the instrument may have been saturated by very strong radiation, originating from a belt of charged particles trapped in space by Earth’s magnetic field. Another U.S, satellite, launched two months later, confirmed the existence of these radiation belts. They became known as the Van Allen Belts in honor of their discoverer.
In a looping orbit that came as close as 220 miles to Earth and as far as 1,563 miles, Explorer 1 revolved around the Earth. One orbit was made every 114.8 minutes or a total of 12.54 orbits per day. The satellite was 80 inches long and 6.25 inches in diameter. After more than 58,000 orbits, the satellite which weighed 30.8 pounds, made its final transmission on May 23,1958. Explorer 2, a similar satellite, made a launch attempt on March 5,1958, but failed to ignite during the fourth stage of Jupiter-C rocket. Explorer 3 was successfully launched on March 26, 1958 and operated until June of the same year. Explorer 4 was launched on July 1958 and operated until Oct of the same year. And in August 1958, Explorer 5 was launched but failed when the rocket’s booster collided with its second step after separation causing the firing angle of the upper stage to be incorrect.
A new documentary “JPL and the Beginnings of the Space Age” will be shown in several locations as well as on local and national media outlets. The 55 minute film was produced by Blaine Baggett, JPL’s executive manager for communications and education. JPL’s Explorer 1 began a half-century of unprecedented exploration. Today JPL manages for NASA, 19 spacecraft and six instruments. Four spacecraft are exploring Mars and that number will increase by one when Phoenix lander touches down near the Martian North Pole on May 25.
Additional JPL missions and instruments are studying Earth and our oceans, making their way to a rendezvous with a comet, probing deeply into the heart of the asteroid belt; exploring Saturn and it’s moons and rings; and peering into the distant universe to study stars, galaxies and planets beyond our sun.
This entry was posted on Friday, February 15th, 2008 at 9:06 am and is filed under Mission History, The Gear to Get There. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
