Thursday, January 10, 2008

The New “Times Ninety” Hubble Telescope

Spiral Galaxy M74 – Image Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

The New “Times Ninety” Hubble Telescope

The Hubble has proven to be a delicate but productive instrument. The information and confirmation of astronomical theories this instrument, placed in orbit, out in space, has produced have been invaluable.

Color Images of Quasar 1208+101Split by Gravitational Lenses – Image Credit: J. Bahcall/NASA

The Hubble needs to have another repair mission performed and NASA is planning to upgrade the platform with two new instruments that will make the instrument 90 times more powerful than ever. The repair mission is expected to take place this August, 2008.

Without the repair mission, Hubble would likely die by 2011, when its last functioning gyroscope is expected to fail. With new gyroscopes and batteries installed on the upcoming servicing mission, the Hubble Space Telescope (HST) should last at least until 2013, and possibly into the 2020s.

This excerpted from the New Scientist -

Upgraded Hubble telescope to be 90 times as powerful
David Shiga, Austin / news service / 17:58 08 January 2008

Space shuttle astronauts will attempt an unprecedented in-orbit repair of key Hubble Space Telescope (HST) instruments during the servicing mission scheduled for August 2008. The repairs, along with the addition of two new instruments, will make Hubble 90 times as powerful as it was after its flawed optics were corrected in 1993.
Now, the space agency says it will try something never attempted in the three previous Hubble servicing missions – a finicky electronics repair job in space, where astronauts have the challenge of doing everything while wearing bulky spacesuit gloves.
Two powerful new instruments will be installed on the mission. The Wide Field Camera 3 (WFC3) will allow Hubble to see fainter and more distant galaxies than anything it has seen before, shedding light on the early universe.

This could allow Hubble to see galaxies so far away that we see them as they were just 400 million years after the big bang, says Sandra Faber of the University of California in Santa Cruz, US, a member of the panel that recommended that NASA carry out the final servicing mission.

Jupiter’s red spot as seen from the HST. Image Credit: The Hubble Heritage Team (STScI/AURA/NASA) and Amy Simon (Cornell U.)

To date, the most distant galaxies seen by Hubble appear to be from about 800 million years after the big bang, which occurred 13.7 billion years ago. "The universe evolves extremely rapidly at these early times, so a [time] difference like this makes a huge difference in the structure and size of galaxies [that exist in those eras]," Faber said at a press conference on Tuesday at a meeting of the American Astronomical Society in Austin, Texas, US.

Another new instrument, the Cosmic Origins Spectrograph (COS), can obtain ultraviolet light spectra of very faint, distant objects such as quasars – huge black holes that are glowing as they gobble up surrounding gas. COS can measure much fainter objects than STIS, although STIS can get more detailed spectra of the objects it can see.

With its new instruments, Hubble will be 90 times as powerful as it was supposed to be when first launched – it will be like having 90 of the original Hubble Space Telescopes, astronomers say. The improvement comes from a combination of increased sensitivity and wider fields of view, allowing Hubble to see 900 galaxies where its original instruments would have revealed only 10. HST will be about 60% more powerful than it was right after the third servicing mission, before ACS and STIS failed.
Both repairs involve astronauts unfastening dozens of tiny screws to replace some circuit boards on each of the instruments – all while wearing bulky spacesuit gloves. Such a feat has never been attempted before in space.

The astronauts will also have to cut through metal layers to reach the circuit boards, creating sharp edges that could be hazardous to spacesuits. In the case of ACS, Grunsfeld may not even be able to see the screws he is working with because of the way the instrument is angled inside HST.
NASA science chief Alan Stern said although the mission is still scheduled for August 2008, it could slip because of the launch delays the space shuttle has been experiencing in its missions to assemble the International Space Station. "Our watchword in all of this is safety," he said, adding that if the servicing mission needed to wait until October or even later to make sure the shuttle is safe, then NASA would wait.
Reference Here>>

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