If you’ve ever looked at a stunning image of a distant nebula or a far-off galaxy, chances are it came from one incredible machine. The Hubble Space Telescope was launched into space on April 24, 1990, aboard the Space Shuttle Discovery. This single event changed astronomy forever, giving us a crystal-clear view of the universe without the blurring effect of Earth’s atmosphere.
For over three decades, Hubble has been our eye in the sky. It has answered fundamental questions and raised new ones, all while capturing the public’s imagination with its breathtaking photos. Let’s look at the story of this remarkable telescope, from its troubled beginnings to its legendary status.
When Was The Hubble Space Telescope Launched Into Space
As mentioned, the launch date was April 24, 1990. The mission was STS-31, and the shuttle carrying Hubble was the Discovery. The deployment happened the following day, on April 25. Astronauts used the shuttle’s robotic arm to gently release the telescope into its own orbit about 340 miles (547 kilometers) above Earth.
This was the culmination of decades of planning and dreams. The idea for a large space telescope was first seriously proposed in the 1940s, and after years of funding battles and technical hurdles, NASA finally got the green light in the 1970s. The launch in 1990 was a moment of huge celebration for scientists worldwide.
The Troubled Start: A Mirror Flaw
Excitement soon turned to concern. The first images sent back by Hubble were fuzzy and out of focus. Engineers and scientists quickly diagnosed a catastrophic problem: the telescope’s primary mirror had been ground to the wrong shape. A spherical aberration, though tiny at just 1/50th the thickness of a human hair, meant Hubble’s vision was severely blurry.
This was a major embarassment for NASA and a potential disaster for the multi-billion dollar project. However, it also set the stage for one of the most daring repair missions in history.
The First Servicing Mission: Giving Hubble Glasses
Fortunately, Hubble was designed to be serviced by astronauts. Engineers worked tirelessly to design a corrective solution, much like prescribing glasses for the telescope. In December 1993, Space Shuttle Endeavour embarked on the first servicing mission (STS-61).
In a series of complex spacewalks, astronauts:
- Installed COSTAR (Corrective Optics Space Telescope Axial Replacement), a device containing tiny mirrors to correct the light path.
- Replaced the original Wide Field and Planetary Camera with a new model (WFPC2) that had its own built-in correction.
- Performed other critical maintenance, like replacing solar arrays and gyroscopes.
The mission was a complete sucess. When the first corrected images were beamed back, they were stunningly sharp. Hubble could finally see the universe as intended.
Hubble’s Key Instruments and Discoveries
Over its life, Hubble has been upgraded with newer, more powerful instruments. These tools have allowed it to make countless discoveries. Here are some of the most important ones:
Pinpointing the Age of the Universe
One of Hubble’s main goals was to measure the expansion rate of the universe, known as the Hubble Constant. By observing special stars called Cepheid variables in distant galaxies, scientists used Hubble data to calculate the universe’s age much more precisely. We now know the universe is about 13.8 billion years old.
Observing Galaxy Evolution
Hubble’s deep field images are perhaps its most famous contribution. By staring at a seemingly empty patch of sky for days, it revealed thousands of galaxies, some of the youngest ever seen. These images showed us how galaxies formed and changed over billions of years.
Studying Exoplanet Atmospheres
Hubble wasn’t built to find planets, but it has become a vital tool for studying them. It was the first telescope to directly detect an exoplanet’s atmosphere. By analyzing the starlight filtering through a planet’s air, scientists can identify chemicals like sodium, water vapor, and even methane.
Confirming Supermassive Black Holes
Hubble provided conclusive evidence that supermassive black holes lurk at the centers of most galaxies, including our own Milky Way. It measured the speed of stars whirling around these invisible monsters, allowing astronomers to calculate their immense mass.
Servicing Missions: Keeping Hubble Alive
Hubble’s long life is a testament to the Space Shuttle program and astronaut ingenuity. There were five servicing missions in total:
- STS-61 (1993): The crucial first repair to fix the mirror flaw.
- STS-82 (1997): Installed new spectrographs and an infrared camera.
- STS-103 (1999): An emergency mission to replace failing gyroscopes.
- STS-109 (2002): Installed the Advanced Camera for Surveys (ACS), a workhorse instrument.
- STS-125 (2009): The final shuttle mission, which replaced key instruments and repaired others, leaving Hubble more powerful than ever.
Without these missions, Hubble likely would have stopped working years ago. Each one extended its capabilities and its operational life.
How Hubble Works: A Simple Explanation
It’s not just a big camera in space. Here’s a basic breakdown of how it operates:
- Light Collection: Light from a distant object enters the telescope tube.
- Mirror Reflection: It hits the primary 2.4-meter (7.9-foot) mirror, which reflects it to a smaller secondary mirror.
- Focusing: The secondary mirror reflects the light back through a hole in the primary mirror to where the scientific instruments are located.
- Instrument Analysis: Various instruments (cameras, spectrographs) capture and analyze the light, converting it into digital data.
- Data Transmission: Hubble uses its high-gain antennas to send this data via satellite to scientists on Earth.
It orbits Earth every 95 minutes, traveling at about 17,000 miles per hour. It’s powered by two large solar panels.
Hubble’s Legacy and Future
Even with the newer James Webb Space Telescope now operating, Hubble remains an active and vital observatory. The two telescopes are designed to see different types of light (Hubble sees mostly visible and ultraviolet light, while Webb sees infrared). They often work together to provide a more complete picture of cosmic objects.
Hubble’s legacy is secure. It has:
- Generated over 1.5 million observations.
- Been the source data for more than 20,000 peer-reviewed scientific papers.
- Inspired generations of students and adults to care about space and science.
- Provided a visual record of the cosmos that is unparaleled in history.
NASA currently expects Hubble to remain operational through the late 2020s or beyond. Its eventual re-entry into Earth’s atmosphere is planned to be controlled, ensuring any debris falls safely into an ocean.
Frequently Asked Questions (FAQ)
How long has the Hubble telescope been in space?
As of 2024, Hubble has been in space for over 34 years, since its launch in 1990.
What space shuttle launched Hubble?
The Space Shuttle Discovery launched the Hubble Space Telescope on mission STS-31.
Is the Hubble telescope still working?
Yes, Hubble is still fully operational and continues to make scientific observations. It is expected to keep working for several more years.
Where is the Hubble telescope right now?
You can actually track it! Hubble orbits Earth at an altitude of about 340 miles (547 km). Websites like NASA’s “Spot the Station” can show you when it might be visible from your location as a fast-moving star.
Why was Hubble launched into space?
Earth’s atmosphere distorts and blocks certain wavelengths of light. By placing a telescope in space, astronomers get a much clearer and broader view of the universe across ultraviolet, visible, and near-infrared light.
How much did the Hubble telescope cost?
The initial development cost was about $2.5 billion. Factoring in the servicing missions and decades of operation, the total cost is estimated to be over $10 billion, which is considered a bargain for its monumental scientific output.
Can I see Hubble from Earth?
Yes, you can see Hubble with the naked eye! It appears as a bright, fast-moving star crossing the night sky. You need to know when and where to look, as it’s only visible during dawn or dusk when it’s dark on the ground but the telescope is still lit by the sun.
Conclusion
The launch of the Hubble Space Telescope on April 24, 1990, was just the beginning of an extraordinary journey. From its initial setback to its triumphant repair and decades of groundbreaking discovery, Hubble has fundamentally changed our understanding of the cosmos. It has shown us the beauty and violence of the universe, from the birth of stars to the collisions of galaxies.
It’s more than just a machine; it’s a symbol of human curiosity and our desire to see beyond our own world. The images and data it has provided will continue to fuel scientific inquiry and wonder for generations to come. Every time you see one of its iconic pictures, remember the precise date it all began and the incredible story that followed.