WWW.ASTRONOMY.COM 19
Hits
IT’S HARD TO BELIEVE that nearly half the people
alive today have never known a world without the Hubble
Space Telescope. The space shuttle Discovery blasted off
with its precious cargo from Kennedy Space Center
on April 24, 1990, and the next day, the shuttle’s five-
person crew deployed the school-bus-sized observa-
tory in low Earth orbit. In the 30 years since, Hubble
has helped redefine our universe, tackling problems
that had plagued astronomers for decades, as well
as discovering new mysteries no one imagined.
Of course, Hubble’s history has not been with-
out glitches. The most critical appeared within
weeks of its deployment. Early images revealed
that the telescope’s 2.4-meter mirror was f lawed
— its edges were too f lat by 2 micrometers, or
roughly 1⁄50 the width of a human hair — and
could not focus light sharply. For a telescope
whose whole raison d’être was to deliver
crystal-clear views of the cosmos from above
the distorting effects of Earth’s atmosphere,The space shuttle Discovery lifts off from Cape Canaveral, Florida,
on April 24, 1990. One day later, shuttle astronauts would deploy the
Hubble Space Telescope on its 30-year-and-counting mission. NASAStellar winds from a massive star (the image’s brightest star) carved
the intricate contours of the Bubble Nebula (NGC 7635). The bubble has a
bluish tinge, thanks to short-wavelength radiation emanating from ionized
oxygen atoms. NASA/ESA/THE HUBBLE HERITAGE TEAM (STSCI/AURA)