Explorer 1, the First US Satellite

January 31^st, 1958.  56 years ago, and the United States had finally succeeded in launching its own satellite, the Explorer 1.  According to this Yahoo! Travel post, the launch of Explorer 1 was linked to the International Geophysical Year (IGY).  The big deal about that, as explained in this wiki entry, is the IGY marked the beginning of scientific interchange between the western and eastern countries.  Sputnik 1, the very first man-made satellite to orbit the Earth, was also launched by the Soviet Union (USSR) for IGY in late 1957.  The US hurried with a response and, 4 months after Sputnik 1’s debut, launched Explorer 1 into a slightly eccentric Medium Earth Orbit.  The “Space Race” between the USSR and the US was on.

Explorer 1 was the satellite to first detect the Van Allen radiation belts.  It’s not surprising, since it had a few instruments on board to specifically detect radiation, micro-meteoroid impacts, and cosmic rays.  Explorer 1 wasn’t shaped like the satellites we work with today.  It looked like a very large rifle bullet with dimensions of about six feet in length, and six inches in diameter.  High tech for the time, the US used solid state transistors on the satellite—a whopping 29 of them (for those not raised in a nerdery, Intel’s most current Core i7 processor contains 1.16 billion transistors).

The operational life of Explorer 1 wasn’t very long.  It took only four months after the Explorer 1’s launch for the satellite’s batteries to die.  It remained in orbit, though, until 1970, when it finally reentered the Earth’s atmosphere.  Just look at the Yahoo post to see a diagram of Explorer 1.  Even better, just click on this link to see the Explorer 1 launch video.  It’s hard to believe such dramatic music was needed for news!

Even now, we’re still learning more about those Van Allen radiation belts in spite of the 56 years of time since Explorer 1’s launch.  Explorer 1 was the start of the United States Explorer satellite program.  That space phenomena data-collecting satellite program is still active today.  IRIS (Interface Region Imaging Spectrograph), a satellite built to observe the chromosphere of the Sun, was launched in June 2013.  About 90 satellites have been fabricated and deployed under the Explorer program’s auspices.