Hubble Space Telescope
Full Name: Hubble Space Telescope
Phase: Operating
Launch Date: April 24, 1990
Mission Project Home Page: http://hubble.nasa.gov/
Program(s): Cosmic Origins
The Hubble Space Telescope's launch in 1990 sped humanity to one of its greatest advances in that journey. Hubble is a telescope that orbits Earth. Its position above the atmosphere, which distorts and blocks the light that reaches our planet, gives it a view of the universe that typically far surpasses that of ground-based telescopes.
Space Shuttle Flight STS-125 will conduct Servicing Mission 4 (SM4) to deliver new state of the art instruments to the Hubble Space Telescope allowing it to observe the universe with a new set of eyes, surpassing even its previous vision. Four servicing missions have already occurred since Hubble’s launch in 1990 and SM 4 will be the fifth and final.
SM4 has an ambitious program of activities and three main objectives.
- Extend Hubble's operational life by at least five years.
- Enhance Hubble's scientific power.
- Repair Hubble's out-of-commission instruments
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. Astronauts will install two new instruments, the Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS). WFC3, which sees in visible, ultraviolet and infrared light, will improve Hubble's sensitivity 15 times because of improvements in technology and design that have occurred since the last instruments were installed. Astronauts will also repair the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS). STIS stopped working in 2004 and ACS failed in 2007.
Hubble is one of NASA's most successful and long-lasting science missions. It has beamed hundreds of thousands of images back to Earth, shedding light on many of the great mysteries of astronomy. Its gaze has helped determine the age of the universe, the identity of quasars, and the existence of dark energy.
The Hubble Space Telescope's image of the star V838 Monocerotis (V838 Mon) reveals dramatic changes in the illumination of surrounding dusty cloud structures. The effect, called a light echo, has been unveiling never-before-seen dust patterns ever since the star suddenly brightened for several weeks in early 2002. Credit: NASA, ESA and H.E. Bond (STScI)
Hubble's discoveries have transformed the way scientists look at the universe. Its ability to show the universe in unprecedented detail has turned astronomical conjectures into concrete certainties. It has winnowed down the collection of theories about the universe even as it sparked new ones, clarifying the path for future astronomers. Among its many discoveries, Hubble has revealed the age of the universe to be about 13 to 14 billion years, much more accurate than the old range of anywhere from 10 to 20 billion years. Hubble played a key role in the discovery of dark energy, a mysterious force that causes the expansion of the universe to accelerate.
Hubble has shown scientists galaxies in all stages of evolution, including toddler galaxies that were around when the universe was still young, helping them understand how galaxies form. It found protoplanetary disks, clumps of gas and dust around young stars that likely function as birthing grounds for new planets. It discovered that gamma-ray bursts — strange, incredibly powerful explosions of energy — occur in far-distant galaxies when massive stars collapse. And these are only a handful of its many contributions to astronomy.
The sheer amount of astronomy based on Hubble observations has also helped make it one of history's most important observatories. More than 7,000 scientific articles have been published based on Hubble data.
The policies that govern the telescope have contributed to its incredible productivity. The telescope is an instrument for the entire astronomical community — any astronomer in the world can submit a proposal and request time on the telescope. Teams of experts then select the observations to be performed. Once observations are completed, the astronomers have a year to pursue their work before the data is released to the entire scientific community. Because everyone gets to see the information, the observations have given rise to a multitude of findings — many in areas that would not have been predicted by the telescope’s original proposals. Hubble's success with these policies has helped spread them throughout the astronomical community, and they are becoming common with other observatories.