Washington, May 21 (DPA) Five straight days of intense and dangerous repair work have sharpened the vision of the Hubble Space Telescope and prepared it to once again collect groundbreaking insights into the origins of the universe.
The world's most famous telescope has been orbiting Earth since 1990 sending back some of the most spectacular images of galaxies. It helped scientists to place the age of the universe at 13.7 billion years, learn that black holes are at the centre of most galaxies, monitor planetary formation and discover that the universe is expanding at an ever-faster pace.
But despite its storied past, Hubble looked set for the junk heap until the space shuttle Atlantis' repair mission this week. New instruments were installed and existing ones repaired to extend its life until at least 2014, and possibly beyond.
NASA had originally decided against the maintenance mission because of the risk involved and the pressures to complete International Space Station construction by 2010, when the shuttle is to be retired. But US politicians and world astronomers fought successfully to keep alive the instrument that has expanded knowledge of space.
Spacewalkers were able to complete by Monday all the upgrades that NASA had planned despite struggling several times with tricky bolts and screws that threatened to knock the mission off track.
The spacewalks were full of difficult manoeuvres that required astronauts to crawl inside the telescope or remove dozens of tiny pieces, which could have damaged their spacesuits, the shuttle or the telescope.
'This is a really tremendous adventure that we've been on, a very challenging mission. Hubble isn't just a satellite - it's about humanity's quest for knowledge,' said astronaut John Grunsfeld, who has been on three missions to Hubble.
Grunsfeld was part of the final spacewalk Monday and helped carry out the latest repairs to the telescope.
On Tuesday, Atlantis released Hubble back into its own orbit.
Scientists hope the new instruments and repairs will help them learn about the gases between galaxies and take detailed pictures of extremely distant stars.
The space telescope should begin taking images again in about three weeks. It will first focus on known stars to align the instruments before turning to new data. NASA hopes to publish the first photos by September.
NASA officials Tuesday refused to identify the first observation targets, but said the wish list by astronomers is extensive.
'Today begins the second Hubble revolution,' Hubble scientist Dave Leckrone told reporters Tuesday. He stressed that the telescope's early work had profoundly changed astronomy and would likely contribute even more with its more advanced instruments.
Central to this week's repairs was the addition of a new camera. The Wide Field Planetary Camera 3 will allow astronomers to see deeper into space and to capture images across all three regions of the light spectrum - ultraviolet, visible and near infrared.
It will allow scientists to look 'further back in time than man ever has before, looking at the history of galaxies from infancy to middle age and working out where we come from', Leckrone has said.
Another new instrument, the Cosmic Origins Spectrograph, will break up light into its components and allow astronomers to study the large-scale structure and origins of the universe, including how galaxies, stars and planets formed and how elements developed.
The installation of new gyroscopes to keep the telescope aligned was one of the most difficult tasks. Astronauts Mike Massimino and Michael Good could not get one new set of gyroscopes to fit properly on Hubble and had to install a spare set instead.
Repairs on another spectrograph, the Space Telescope Imaging Spectrograph, also presented headaches when a series of complicated steps were halted by a stubborn stripped screw that caused several hours of delay. Astronaut Massimino ultimately yanked off the piece.
Other equally critical, if less sexy repairs, included the swapping of two 209-kg battery units, the replacement of the computer that controls the Hubble's instruments and formats information to be sent to Earth, the replacement of insulation to shield it from the harsh environment of space and fixing its guidance sensors.
Atlantis is due to land at the Kennedy Space Centre in Florida Friday.
null
|
|
Read More: Mon
Comments:
