The Hubble Space Telescope has revolutionized the study of astronomy since its launch in 1990 and has sent a steady stream of striking images of space back to Earth from its orbit. It has:
Precisely measured the age of the universe
Found evidence of dark energy
Took images of distant galaxies in the young universe
Captured the “best ever” image of Mars
Provided proof of black holes
Gave first views of star birth
Showed how stars die
Caught spectacular views of Comet Shoemaker-Levy 9’s collision with Jupiter
Confirmed that quasars are galactic nuclei powered by black holes
Gathered evidence that the expansion of the Universe is accelerating
In January 2004, NASA decided to let nature take its course and not send any more servicing missions to Hubble. The outcry from astronomers and the public was amazing. In November 2006, the space telescope escaped its death sentence when NASA approved a shuttle mission to service and upgrade the instrument. And with the state-of-the-art instruments delivered by Servicing Mission 4 (SM4), the Hubble Space Telescope will be able to look onto the universe with new eyes, surpassing even its previous vision. The mission is scheduled for October 8, 2008. Veteran astronaut Scott D. Altman will command the final space shuttle mission to Hubble.
The first objective is to extend Hubble’s operational life by at least five years. Over a series of five spacewalks, astronauts will replace all six gyroscopes, install new batteries, and exchange a degraded Fine Guidance Sensor with a new one. They will also install replacement thermal insulation on critical component bays of the telescope, and attach a mechanism that will aid in Hubble’s final de-orbiting.
The second objective is to enhance Hubble’s scientific power. Astronauts will install two new instruments, the Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS). WFC3, which sees in visible, infrared and ultraviolet light, will improve Hubble’s sensitivity 10-30 times because of improvements in technology and design that have occurred since the last instruments were installed. COS, Hubble’s new spectrograph, will improve Hubble’s sensitivity at least 10 times. Spectrographs are instruments that break light into its component colors, revealing information about the object emitting the light. COS sees ultraviolet light, which is particularly important because most of the ultraviolet light from space is absorbed by the Earth’s atmosphere, making ground-based telescope observations impossible.
The third objective is to repair Hubble’s out-of-commission instruments, the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS). STIS stopped working in 2004 and ACS failed in 2007. ACS is Hubble’s most prominent camera. Its wide field of view and ability to see in wavelengths from ultraviolet to visible light allows it to conduct broad surveys of the universe, study the nature and distribution of galaxies, and examine some of the universe’s earliest activity. ACS was responsible for the Hubble Ultra Deep Field Image, NASA’s deepest view of the cosmos.
STIS is a spectrograph. It separates light into its component colors, allowing scientists to examine the object’s temperature, chemical composition, density and motion. STIS can see in ultraviolet, visible and near-infrared and has been used to examine black holes, quasars and planets.
If these objectives can be successfully carried out during the servicing mission, then Hubble will be at the apex of its scientific capability, with six working, complementary science instruments. These upgrades will keep Hubble functioning at the pinnacle of astronomy well into the next decade.
Behind the Pictures
The Hubble Space Telescope is noted for providing beautiful and often bizarre color pictures of galaxies, planets, and nebulae. Do the pictures really reflect the colors these objects would have if we visited them in a spacecraft? Why do some of the pictures have an unusual stair-step shape?
Hubble On The Go
Get the newest images and discoveries from Hubble sent directly to your email box or PDA.
Showcase of Hubble’s Smash Hits
This slideshow of Hubble’s greatest images is breathtaking. You can also download wallpaper, images, and murals.
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