The Hubble Space Telescope has been given a new lease of life. In the course of five arduous spacewalks, two teams of astronauts from the space shuttle Atlantis successfully refurbished the venerable telescope, giving it two new instruments with which to gaze out at the cosmos, besides repairing two faulty ones and replacing some key parts. The operation would improve the telescope’s discovery capabilities by up to 70-fold and extend its life till at least 2014, according to the National Aeronautics and Space Administration (NASA). The Hubble is without question the world’s best known and most popular space-based observatory. Circling at a height of about 300 km, the telescope escapes the effects of the Earth’s atmosphere and is therefore able to capture light that ground-based instruments cannot. It has had a tremendous impact on every area of astronomy, from the evolution of galaxies, the birth and death of stars, the search for extra-solar planets and the nature of the universe itself. However, right from the start, the survival of this 19-year-old telescope has depended on maintenance and upgrades provided by highly-skilled humans who visited it from time to time. Soon after its launch in April 1990, a tiny kink was discovered in the telescope’s precision-ground mirror that distorted the images it took. Astronauts had to instal lenses to correct the distortion during the first servicing mission that was carried out in 1993. Four more servicing missions, including the latest one, followed. But there will be no more of such missions and when the Hubble telescope reaches the end of its life, it will be nudged to a fiery end in the Earth’s atmosphere.
Meanwhile, the European Space Agency (ESA) launched the Herschel and Planck space observatories on May 14. The two space telescopes are currently heading to a point in space some 1.5 million kilometres away where the gravitational pull from the Earth and the Sun cancel each other out. The Herschel observatory will be able to detect even faint traces of infrared light from the colder and dustier parts of the universe which do not emit much visible light. Those signals will help astronomers penetrate the mysteries of galaxy formation and how stars and their planets are created. The Planck observatory will map, with greater sensitivity and resolution than before, the radiation from the Big Bang that produced the universe. The mapping may also provide clues about mysterious forms of matter and energy in the universe, known as ‘dark matter’ and ‘dark energy’. As ever, the quest for a better understanding of the universe and our place in it will go on.