The Hubble Space Telescope is a powerful telescope that orbits the earth and can show us better pictures of faraway stars than any other telescope on earth can do. It is named after Edwin Hubble, an astronomer who lived in the 1920s.
The telescope is in orbit about 600 km above the earth. It can view the heavens without looking through the earth’s atmosphere.
The atmosphere bends the light that comes through it. When we look at stars from the ground they are blurred because the atmosphere always moves. That is why the Hubble telescope can show pictures that are much sharper than the ones we get from telescopes on earth.
Hubble can also observe light that does not reach the surface . It can see ultraviolet light, which has a shorter wavelength and infrared light which is longer than the light we can see. UV light shows places in the universe with a lot of energy, like exploding stars. Infrared light gives us information on more quiet events such as the formation of dust clouds around new stars.
In 1990 a space shuttle put the telescope into orbit. About one month later, scientists found out that there was a problem with the telescope’s mirror. The pictures that the camera was sending back to Earth were not very sharp.
In 1993 the space shuttle Endeavour was launched and astronauts on board repaired the telescope, so that Hubble could work as planned. In the past 10 years there have been 3 more flights to the Hubble Space Telescope. Astronauts installed better mirrors and cameras that were ten times more powerful than the original ones.
After the space shuttle Columbia exploded in 2003, NASA announced that it would not send any more astronauts up to repair Hubble. Officials were concerned about the safety of the astronauts. Without a new repair mission the telescope would only work for a few more years.
In 2006 NASA finally decided to send one last spacecraft to repair Hubble. In May 2009 the space shuttle Atlantis lifted off on its last mission to Hubble. Astronauts repaired some new instruments and installed a few others. They also changed some of the batteries.
Even though the telescope will still be working for some years to come, NASA is planning to launch a new, more powerful telescope by the year 2014. The James Webb Space Telescope will be able to see even farther than Hubble and may even be able to witness the birth of new stars and solar systems. It will also be able to see light that Hubble cannot detect.
The new telescope will orbit about 1.5 million km above the earth’s surface, much farther away than Hubble. It will have a sunshade as big as a tennis court to protect its instruments from the heat of the sun.