The Hubble Space Telescope was launched into orbit in April 1990 and one month later, astronomers gathered at NASA's Goddard Space Flight Center for the $1.5 billion telescope's first light.

"Some eyebrows went up," said David Leckrone, a senior scientist who worked on Hubble from 1976 until his retirement in 2009, according to The Guardian. "It was supposed to be a picture of a binary star, a pair of stars. But it was just sort of a fuzzy blur."

The Hubble was originally slated for launch in 1983, but the project fell behind schedule. In 1986, as Hubble was about ready for its glory, NASA suffered a tragedy: the Challenger explosion that killed seven crew members. Not only were lives lost, but the Hubble could not be launched without the spaceshuttle.

Seven years later, Hubble was ready. The launch and release went well and those controlling Hubble on the ground felt confident. "Then, some weeks went by and nothing we did made the image much better," Leckrone said, according to The Guardian. "Suddenly the mood became very morose."

During one status meeting at Goddard, the teams that worked on Hubble gave updates - until Chris Burrows, an optics specialist, spoke. "There was an edge of anger in his voice," Leckrone said, according to The Guardian. "He said: 'You've got half a wave of spherical aberration and there is nothing you can do about it." Burrows had silenced the room.

The problem was Hubble's 2.4m mirror. The curvature of the mirror wasn't right, so the images bounced off of it would always be blurry. Nothing anyone did from Earth could fix it.

Aden Meinel, a telescope designer, came up with a solution: set up a series of coin-sized mirrors to cancel out the primary mirror's distortion. And do it in space.

The first service mission to the Hubble flew in 1993. "When the first image came down, it was extraordinarily beautiful," said Leckrone, according to The Guardian. "From that point on, every place we pointed Hubble in the sky, there was something new and remarkable. It's a terrific comeback story."

To hear more about Hubble, "the comeback kid," check out HNGN's exclusive interview with Mike Massimino, a NASA astronaut who flew on two of the Hubble service missions, including the historic final mission.

For more Hubble celebration, check out Brian Stallard's piece "Hail the Hubble" on our sister-site, Nature World News.