You’ve probably seen the photos. Those glittering, neon-pink nebulae and deep-field shots of galaxies that look like spilled glitter on a black velvet rug. They all come from Hubble. But honestly, the Hubble telescope launch date is a bit of a tricky subject because the telescope almost didn't make it to space at all.
If you just want the quick answer: Hubble launched on April 24, 1990.
But that’s not the whole story. Not even close. If you were around in the late 80s, you’d remember that Hubble was basically the "poster child" for government delays and technical nightmares. It was supposed to go up years earlier.
The 1986 Disaster That Changed Everything
Most people don't realize that the Hubble telescope launch date was originally set for October 1986. The telescope was sitting in a clean room, ready to go. Then, in January 1986, the Space Shuttle Challenger exploded.
Everything stopped.
NASA grounded the entire shuttle fleet. For nearly three years, Hubble sat in a high-tech storage locker in California. This wasn't cheap. It cost about $6 million a month just to keep the thing clean and powered up so the mirrors wouldn't degrade.
By the time the shuttle Discovery was finally cleared for the STS-31 mission in 1990, the project was years behind schedule and billions over budget.
April 24, 1990: The Day It Finally Happened
When the big day finally arrived, the atmosphere at Kennedy Space Center was a mix of pure terror and relief.
The crew of mission STS-31 wasn't just any group of pilots. You had Loren Shriver in the commander's seat and Charles Bolden (who later became the head of NASA) as the pilot. Along for the ride were mission specialists Steven Hawley, Bruce McCandless II, and Kathryn Sullivan.
They blasted off at 8:33 AM EDT. It was a smooth ride, but the real work started the next day, April 25, when they had to actually pull the telescope out of the cargo bay and let it go.
Deployment Drama
Funny enough, even the deployment had a "kinda scary" moment. One of the solar arrays got stuck while unfurling. For a minute there, it looked like two of the astronauts—McCandless and Sullivan—were going to have to do an emergency spacewalk to manually crank the thing open. Luckily, a software fix from the ground saved the day, and the array snapped into place.
The "Blurry" Nightmare After Launch
So, the Hubble telescope launch date was a success, right? Well, sort of.
A few weeks later, the first images started coming back. They were... bad. They looked like someone had smeared Vaseline over the lens. It turned out the primary mirror had a "spherical aberration." Basically, the edges of the 2.4-meter mirror were ground too flat by about 2.2 microns.
How small is that? It’s about 1/50th the thickness of a human hair.
"It was a heartbreaking moment for the team. We had spent decades on this, and the world’s most expensive telescope had blurry vision." — General sentiment from NASA engineers in 1990.
It took three years and a legendary repair mission in 1993 (STS-61) to give Hubble "glasses." Astronauts installed COSTAR—a set of corrective mirrors—and the Wide Field and Planetary Camera 2. Suddenly, the universe snapped into focus.
Why the Date Matters Today
Looking back from 2026, it’s wild to think how close we came to Hubble being a total failure.
Because it launched when it did—in the heart of the shuttle era—it was designed to be serviced. If it had launched on a standard rocket with no way to fix it, Hubble would be a piece of very expensive space junk today. Instead, it’s still up there, working alongside the James Webb Space Telescope (JWST).
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Quick Facts: Hubble by the Numbers
- Weight: 24,500 pounds (roughly two African elephants).
- Speed: 17,000 mph.
- Mirror Size: 2.4 meters ($7.9$ feet) across.
- Orbit Height: About 340 miles up.
What You Should Do Next
If you’re a space nerd or just someone who appreciates a good "comeback story," there are a few things you can do to actually see the fruit of that 1990 launch:
- Check the Live Tracker: You can actually see where Hubble is right now. Since it orbits every 95 minutes, it might be passing over your head sooner than you think.
- Browse the Heritage Gallery: NASA keeps a massive archive of every "Picture of the Week." Compare the early 1990 images with the post-1993 ones; the difference is staggering.
- Watch the Launch Footage: There’s something incredibly "90s" and nostalgic about the STS-31 launch videos. You can find the original NASA TV broadcasts archived online.
The Hubble telescope launch date wasn't just a mark on a calendar; it was the start of a 30-plus-year journey that fundamentally changed how we see our place in the stars.
Actionable Insight: If you're interested in amateur astronomy, use Hubble's discoveries as a roadmap. Many of the objects Hubble made famous—like the Orion Nebula or the Andromeda Galaxy—are actually visible through a decent backyard telescope. Start with a 6-inch or 8-inch Dobsonian telescope to see these celestial wonders for yourself.