The Hubble Space Telescope will soon get a visit from the STS-125 space shuttle crew. Image Credit: NASANASA's Hubble Space Telescope is the length of a large school bus and weighs as much as two adult elephants. Hubble flies about 360 miles (550 kilometers) above Earth, far above the dusty haze of the planet's atmosphere. With a clear view of the universe, the telescope can take sharp images of the solar system's planets as well as faraway stars and galaxies. It has taken vivid pictures of the birth and death of stars, comet pieces crashing into Jupiter's atmosphere, and the most distant known galaxies in the universe that are billions of light years away.
With equipment bay doors open, a crew member prepares to work inside of the Hubble mock-up in the Neutral Buoyancy Lab near NASA's Johnson Space Center in Houston. Image Credit: NASADuring five spacewalks, the astronauts will install two new instruments on Hubble and try to repair two others. They also will replace the telescope's six batteries and its six gyroscopes, which keep the telescope stable and pointed in the right direction.
--Wide Field Camera 3: This will be Hubble's main new imaging camera that spans wavelengths from near-ultraviolet to the near-infrared. It will study everything from the formation of distant galaxies to the planets in Earth’s own solar system.The astronauts also will attempt to repair two instruments:
--Cosmic Origins Spectrograph: This instrument is designed to split light into its individual wavelengths. This spectrograph is especially sensitive and efficient at detecting ultraviolet signals. It will be useful to study how stars, planets and galaxies formed and evolved, as well as how elements such as carbon and iron, which are necessary for life, first formed.
--Space Telescope Imaging Spectrograph: This instrument, which complements the Cosmic Origins Spectrograph, covers most of the ultraviolet range of light, the entire visible range and some wavelengths of the near-infrared. The imaging spectrograph stopped working in August 2004 because of a power supply failure.In addition, astronauts will replace the telescope's rechargeable batteries. Hubble orbits Earth once every 96 minutes, spending a third of this time in darkness. While in the sun, Hubble is powered by its solar panels. The solar panels also recharge the batteries, which take over during nighttime orbit. The batteries, which went up with Hubble on space shuttle Discovery in 1990, are now starting to lose their capacity.
The Hubble Space Telescope captured this image of a planetary nebula 6,500 light years away from Earth. Image Credit: NASA--Advanced Camera for Surveys: With its wide field of view and sharp images, this camera took some of the most impressive pictures of deep space. It suffered a power supply failure in January 2007.