HBD, Hubble

(Image: NASA, ESA, and STScI)
GREAT 28: Time to take a moment out of your April 24th to say, "Happy Birthday, Hubble!"

That's right, NASA's Hubble Telescope turned 28 today.

Back on April 24, 1990, Hubble launched aboard the space shuttle Discovery. The space telescope was deployed into Earth orbit a day later.

Since then, the telescope has been providing we Earthlings with amazing images of our universe.

Originally spec'ed to last a dozen years, Hubble has done more than double that amount! In fact, it continues to produce stunning images like the one above, of the incredible Lagoon Nebula.

To date, Hubble has logged over 163,000 orbits around our planet and has captured and transmitted over a million photos.

Of course, anyone who follows NASA news knows that Hubble's history came with some drama.  In June of 1990, Ed Weiler, the chief scientist with the Hubble Space Telescope program, had the inenviable task of telling a room full of reporters that NASA's new  $1.5 billion observatory's 94.5-inch primary mirror had been ground to the wrong shape, rendering it unable to bring starlight to a crisp focus. Oops. 

Due to an oversight during fabrication, the concave shape of Hubble's primary mirror was too shallow toward its outer edges by 2 microns, a tiny fraction of the width of a human hair. As a result, starlight was not brought to a focus at the same point, resulting in blurry images. These three images show the same star as viewed from a ground-based telescope, left, and from Hubble's uncorrected mirror, center. The corrected image, after a space shuttle repair mission in 1993, is seen on the right. NASA


However, the setback turned into a tremendous story of ingenuity and perseverance, as engineers precisely mapped the mirror's shape, and discovered it was misshapen due to a rather simple math error. Fortunately, fixes were developed in rather rapid fashion, and on a subsequent shuttle mission, some new hardware was delivered and some space walking astronauts installed it, and the rest is history.

Above, NASA astronaut John Grunsfeld, with the Hubble Space Telescope at his back, holds onto the shuttle’s robotic arm while working on the space telescope's repairs.

A while back, PBS aired "Invisible Universe Revealed," all about the Hubble. You can find it on YouTube.
https://youtu.be/GMhXPqUuqnM