The Amazing Hubble Space Telescope

A Look at Astronomy's Workhorse Observatory

Hubble Space Telescope
Hubble Space Telescope as seen by the astronauts after its final servicing mission in 2009. NASA/ESA/STScI

Who hasn't heard of the Hubble Space Telescope? It's one of the most productive observatories ever built and continues to deliver good science to astronomers around the world. From its orbital perch, this telescope helps astronomers discover incredible things about the universe and has been a major gem in the crown of astronomy.

Hubble's Storied History

On April 24, 1990, Hubble Space Telescope thundered into space aboard the space shuttle Discovery.

Named in honor the famous astronomer Edwin P. Hubble, this 24,500-ton observatory was lofted into orbit and began an eventful "career" of studying planets (solar system and around other stars), comets, stars, nebulaegalaxies, and other many other objects. In addition, Hubble has made observations that allow astronomers to pinpoint distances in the universe more accurately than ever before. They have used the observatory to conduct more than a million observations since launch. Many Hubble images are incredibly gorgeous, appearing in everything from TV shows to movies and advertisements. In short. the telescope and its output have become the very public face of astronomy and space exploration. 

Hubble: A Multiwavelength Observatory

The Hubble Space Telescope was designed to view optical light (which we see with our eyes), plus ultraviolet and infrared parts of the electromagnetic spectrum.

Ultraviolet light is emitted by very energetic objects and events, including our Sun. If you've ever gotten a sunburn, it was caused by ultraviolet light. Infrared light is emitted by warm objects (such as clouds of gas and dust, called nebulae, planets, and stars). 

In order to and get the best possible images and data from distant celestial objects, it's best if the telescope is in space, away from the blurring effects of our atmosphere.

This is why Hubble was launched into a 353-mile-high orbit around Earth. It goes around our planet once every 97 minutes and has nearly constant access to most of the sky. It cannot look at the Sun (because it's too bright) or Mercury (because it's too close to the Sun). 

Hubble is equipped with a set of instruments and cameras which provide all the images and data for the astronomers using the telescope. It also has onboard computers, solar panels for power, and batteries for power storage. Its data transmissions arrive at the NASA Goddard Space Flight Center in Greenbelt, Maryland, and are archived at the Space Telescope Science Institute in Baltimore, Maryland. 

What's Hubble's Future?

Hubble was built to be serviced on-orbit and has been visited by astronauts five times. The first servicing mission was the most famous because the astronauts installed specialized optics and instruments to correct the famous problem introduced when the main mirror was ground incorrectly before launch. Since that time, Hubble has performed nearly flawlessly, and should continue to do so for quite some time.  

If everything continues working, Hubble Space Telescope should provide astronomers with high-resolution looks at the universe for perhaps a decade more.

That's a tribute to how well it has been built and maintained throughout the years.

The Next Orbiting Observatory

Hubble does have a successor observatory that's still under construction. It's called the James C. Webb Space Telescope, which is set for launch in the year 2018. That telescope will provide excellent access to the infrared universe — showing astronomers objects from the most distant reaches of the universe as well as clouds of dust, exoplanets, and other objects in our own galaxy. 

At some point, however, Hubble Space Telescope will stop working and its instruments will begin to fail. Unless there is some way to send another servicing mission (and there have been discussions about that), it will reach a point in its orbit where it will begin to encounter more of Earth's atmosphere.

Rather than have it plunge in an uncontrolled way to Earth, NASA will de-orbit the telescope. Parts of it will burn up on re-entry, but the larger pieces will splash down into the ocean. For now, however, Hubble has a productive life ahead of it, possibly as many as 5 or 10 years of service. 

No matter when it "dies", Hubble will leave behind an amazing legacy of observations that helped astronomers extend our view out to the most distant reaches of the cosmos.