04/30/2013 11:39 am ET | Updated Jun 30, 2013

The Hubble Space Telescope at 23

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When the Hubble Space Telescope was launched in 1990, the original idea was that it would operate for 10 years. That period was later extended to 15 years. Well, on April 24, Hubble celebrated 23 years since launch, and the telescope is going as strong as ever. All you have to do is take a look at the recently released image of the "Horsehead Nebula" (Figure 1), to realize that this iconic telescope continues to amaze us. What is it that turned Hubble into what is arguably one of the most successful scientific experiments in history? It's a combination of forward thinking, a lot of hard work, and a fascinating drama.

Hubble was designed so that it could be serviced by shuttle astronauts. Indeed, astronauts reached Hubble five times (the last servicing mission was in 2009), and on each such visit they installed new instruments, repaired existing ones, and made a variety of other upgrades. This continuous care is what gave the telescope its unprecedented longevity, with each servicing mission essentially breathing a new life into it. Think about it for a moment--there is an entire generation of people in their twenties who have grown up with Hubble images throughout their entire lives!

Another element that has contributed to Hubble's popularity was the drama associated with its initially faulty mirror. Shortly after launch, it was discovered that the telescope's 2.4 meter mirror had been perfectly polished, but to the wrong specifications. For a couple of years Hubble was an embarrassment, and the target of many jokes. Then, however, through the ingenuity of many scientists and engineers, and the outstanding performance of space-walking astronauts, corrective optics were installed, restoring and even surpassing the telescope's intended capabilities. This failure-turned-into-success story will undoubtedly become one of the most memorable Hubble legacies.

Finally, to just get an idea of the evolution in Hubble's performance over the years, simply compare Figure 1, taken in near-infrared light with the new Wide Field Camera 3, to an image of the same Horsehead Nebula taken in 2001 (in visible light), with the older Wide Field Planetary Camera 2 (Figure 2). Amazing, isn't it? Happy birthday Hubble, and many happy returns!


Figure 1. The Horsehead Nebula. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).


Figure 2. The Horsehead Nebula, imaged in 2001 with the Wide Field Planetary Camera 2.