If today's Atlantis launch goes according to plan, and the astronauts aboard the shuttle manage to complete all of their assigned objectives, the Hubble Space Telescope will once again become the most efficient observatory currently in our possession. The five spacewalks that were scheduled for the STS-125 mission included repairs of two instruments damaged over the years, as well as the installation of two new ones, in addition to a new thermal shield and a small docking bay.

It's expected, NASA officials say, that the renewed space telescope would be able to withstand the hardships of space until at least 2014, with the new repairs. That should give them enough time to finish the James Webb Space Telescope (JWST), and to launch it in orbit, to replace the aging Hubble. With its new “powers,” the observatory will be able to peer even back in the history of the Universe, and to identify even older stars, galaxies, gas bubbles and black holes, more than it has done until now.

In addition to all these advantages, astronomers' biggest hope is that the telescope will be able to provide them with much-sought-after data on the most mysterious things in the Universe, such as dark matter and dark energy, which, together, make up the overwhelming majority of everything that exists in the Universe. It's estimated that the visible galaxies, gas, and dust in the Cosmos make up only four percent of its total mass, with another 22 percent accounted for by dark matter, and a whopping 74 percent made up of dark energy.

With its soon-to-be expanded wavelength range, Hubble should be able to detect these types of matter and energy at least indirectly, and to infer at least some of their basic properties. In all fairness, it's a lot easier to detect dark matter with an X-ray telescope, but this type of observatory works by attempting to detect the matter directly, whereas an optical/ultraviolet observatory such as Hubble rather infers its effects on light and other galaxies.

Hubble's efforts in this direction will be made easier by a new panoramic camera, the Wide Field Camera 3, as well as by the University of California in Berkley (UCB)-built Cosmic Origins Spectrograph (COS). In addition, the most important piece of hardware on the observatory, the Advanced Camera for Surveys (ACS), will be repaired and hopefully brought back online. It remains to be seen how well the five scheduled spacewalks will fare, and how many of the STS-125 mission objectives will actually be completed.