Thanks to the inspirational images it has captured, and its surprising longevity, the Hubble Space Telescope (HST) has far-outstripped the early expectations of its space scanning skills. Thanks to repair missions to the Earth-orbiting telescope, and the fact that the spacecraft is serviceable, the facility could last for another decade or more, said Steven Beckwith, head of the Space Telescope Science Institute in Baltimore, Maryland.
The HST has revolutionized our understanding of the universe in almost every area of astronomy, said Beckwith, kicking off a series of interdisciplinary lectures Oct 14 at the World Space Congress. Beckwith was speaking under the banner of the Committee on Space Research (COSPAR).
The school bus-size Hubble, dropped off by a space shuttle crew, has been orbiting since 1990. Costing some $2.2 billion, the space borne telescope has been an "image factory" picturing the surrounding universe in unprecedented detail.
Expansion rate
Of particular note, Beckwith said, Hubble has been used to determine the age of the universe, now believed to be 15 billion years old. Furthermore, Hubble observations of distant supernovae imply that the universe is filled with a dark energy that accelerates its expansion.
"That expansion rate has been speeded up as if there is some stuff in the middle creating a pressure and pushing it apart. We have no idea what this stuff is. Its called Dark Energy because we have no other term for it. We had to make something up. But the effect seems to be quite real," Beckwith said.
Numbers of observations made by HST were never planned for, Beckwith said.
As example, Beckwith added, Hubble made the first detection of an element in an atmosphere of a planet outside the solar system. "It was something that we thought wed have to wait for the Terrestrial Planet Finder (TPF) to even get close to it," he said.
Deep field viewing
Hubbles deep field viewing has already yielded unbelievable results. The telescope was pointed at the blackest place in the sky, opening its shutter for 10 days. That time exposure of a slice of the universe proved staggering.
"Many thought it would be a waste of time. It turned out to be the most profound result from Hubble. You can see in this deep field galaxies going back very much to the beginning of time," Beckwith said.
Through the Hubble deep field astronomers can see back far enough in time that that can actually tell that the Universe looks different, Beckwith said. "You dont have to be a rocket scientist to appreciate the magnitude of this discovery."
Beckwith emphasized that Hubble was not assigned a number of observations that have brought more acclaim to the orbiting eye in space.
About half of the major discoveries that Hubble has made have been made in fields for which it wasnt designed. "That shows you the power of designing high-capability into a general purpose observatory. Because you never quite know in science what will come up," Beckwith said.
Beyond Pluto surprises
Hubbles newly installed Advanced Camera for Surveys (ACS) is being tasked next year to snap a deep field image, Beckwith said.
Beckwith likened deep field looking to buying a Ferrari. "At least once in my life I would have to find out just how fast the car would go. So if you have a space telescope, just once in its life you have to find out just how far the thing can see."
A number of observation campaigns using Hubbles newly installed Advanced Camera for Surveys (ACS) instrument are being scripted, including another deep field image session next year.
The ACS was used in August to resolve a Kuiper Belt Object about half as big as Pluto in size.
If the object had been as big as Pluto it would effectively be a 10th planet in the eyes of the public, Beckwith stated. "It is pretty clear that with more surveys we are going to wind up finding an object thats just as big as Pluto, but farther out."
Such a find would likely mean all those Pluto-as-a-planet supporters are going to be disappointed in the near future.
Hubble is currently to be brought down from its orbital niche in 2010. It is to be replaced by the Next Generation Space Telescope (NGST) at this time.
In the event that NGST is delayed, Beckwith said there is no fear of a "telescope gap" occurring.
"Officially right now, there is no gap," he told SPACE.com. "Hubble right now is to be deorbited in 2010, and thats when NGST will be launched."
"I think many of us would like to see some overlap -- if possible -- because Hubble provides a complimentary observing capability with NGST. But whether or not that will happen depends on many factors outside of our control like the funding factor. Our hope is that Hubble will keep demonstrating its worth and popularity so much that people will feel that its worth supporting in the future," Beckwith concluded.
As the audience left the lecture hall, music filtered through the air. The tune: "Dont Fence Me In".
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