Science: Hubble Telescope

Washington Post science writer Marc Kaufman was online Monday, July 7 at 11 a.m. ET to discuss the Hubble telescope.

In Monday's Science Page story, Kaufman writes:

By the end of the year, the world's greatest telescope should be able to see deeper into space and further back in time than ever. If all goes as planned, it will be able to detect events closer to the big bang, explore the "cosmic web" of galaxies and intergalactic gas that make up the large-scale structure of the universe, and reveal much more about how and when distant stars and planets were formed.

NASA scientists, engineers and astronauts are finalizing plans to fly the space shuttle this fall on a mission to the Hubble Space Telescope to repair and upgrade the orbiting observatory that revolutionized astronomy. The long-delayed servicing mission will be the last for the Hubble, NASA says, but it will allow the telescope to perform at its highest level ever for the remaining five or six years of its operating life.

Transcript follows.

Continue reading: One Last Trip to Open Hubble's Eyes Even Wider

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Marc Kaufman: Good morning, folks. We'll be talking today about the Hubble repair and upgrade mission, which is scheduled to take place in October. Hubble has been a remarkable success, but after the Columbia disaster in 2003 NASA announced that it would no longer service the orbiting telescope and that it's capabilities would gradually decline and peter out. But public pressure, and intense lobbying from the space science community, led to reversals -- first a plan for a robotic repair mission and then in 2006 a decision by NASA Administrator Mike Griffin to send astronauts. Scientists involved with the telescope say that a successful mission will make the observatory better than ever, and let's hope they're right.

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San Bruno, Ca.: When we made the first repairs because of the out of focus mirror, I seem to remember, a portion of equipment, maybe the size of a refrigerator, had to be removed and was brought back to earth. Do you know if the observations planned for that segment have ever been returned to Hubble? If so did they provide any news making observations?

And why are we setting this up to run its course in five or six years. Could we have added more fuel or whatever it takes to keep it running for 10, 15 years?

Marc Kaufman: I'm not sure of the specifics here, but I do know that two additional instruments are going up to Hubble, and that both will add substantially to its capabilities. The upgrades will enable much better analyzing of how galaxies, solar systems and planets form (through the new Wide Field Camera 3) and more capacity to begin unraveling the mysteries of "dark energy" -- which makes up much of the universe. That will also be done through WFC3. The cosmic Origins Spectrograph, another new instrument, will probe the universe's "cosmic web," the large-scale structure created by the gravity of dark matter which can be traced through galaxies and intergalactic gas.

Regarding the lifespan of the upgraded Hubble, NASA has found that some basic parts -- gyros, batteries, etc -- wear out in the intense conditions of space, and the agency will have no ability to reach the Hubble after the space shuttle program is ended in 2010. I guess a new generation spaceship (the Orion) could some day go to Hubble, but it isn't scheduled for completion until 2015 and it has many other tasks to do.

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Pittsburgh, Pa.: Would it be less costly and less risky just to launch a new telescope?

Marc Kaufman: Definitely not -- new telescopes like Hubble cost many billions of dollars, while the repair/upgrade mission will cost about $900 million. But a successor grand observatory is in the wings -- the James Webb Space Telescope is scheduled to launch around 2013, and it will have capabilities on a par with Hubble. It will do different things, but it also is likely to advance astronomy enormously.

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Springfield, Va.: Were there any plans to repair/refurbish NASA's other large telescopes (Compton, Spitzer) in orbit? How are they holding up?

Marc Kaufman: I believe that only Hubble is going to be repaired. With the space shuttle fleet due to be retired in 2010 and much more work needed on the international space station, NASA couldn't do repairs even if it wanted to. But it may also be those instruments are not considered as essential or as amenable to repair.

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Richmond, Va.: G'Day Marc, It's been stated that with the upgraded instruments, Hubble will be able to see "further back" towards the Big Bang. Can you talk about this a little? What type of instruments and "How Close" to the Big Bang can we get? - Tom

Marc Kaufman: As I understand it, the Wide Field Camera 3 will have unprecedented "panchromatic" capabilities through an instrument that will be able to see across the electromagnetic spectrum from ultraviolet through optical and into near infrared. The near infrared in particular is expected to enable the telescope to "see" several hundred million years back. Current technology has allowed Hubble to see back to nearly 13 billion years, and the new instruments will push that back hundreds of millions of years more. The Big Bang is believed to have taken place around 14 billion years ago.

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Dulles, Va.: How can Hubble see into the past...how is this possible?

Marc Kaufman: Thanks for this question. The Hubble is described as seeing into the past because the light from galaxies it observes is up to 13 billion lightyears away. In other words, the telescope "sees" back to the time when that light/radiation was created, and it has taken that long for it to travel to an observable distance. Without the Hubble, astronomers could never see these super distant galaxies.

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Alexandria, Va.: A previous questioner asked: "Springfield, Va.: Were there any plans to repair/refurbish NASA's other large telescopes (Compton, Spitzer) in orbit? How are they holding up?"

The Compton Gamma Ray observatory was deorbited in 2000. Both Spitzer and Chandra are in orbits that make them inaccessible to the shuttle. Spitzer's cryogen will run out within a year, however there are currently plans to operate the telescope in a 'warm' mode. Webb will also be in an orbit that is inaccessible to repair missions (by whatever manned vehicle we have at that time).

Marc Kaufman: Thanks for the info.

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Pittsburgh, Pa.: You have not addressed risk. When the shuttle goes to repair the Hubble, it will not have the backup option of going to the ISS. So if the shuttle is damaged during launch, then there may be loss of the shuttle and astronauts.

Marc Kaufman: Risk is definitely an issue with any shuttle mission. NASA officials made the decision that the benefit that could come from servicing the Hubble is worth the risk involved with sending astronauts to it. In addition, the mission shows something that NASA is very eager to demonstrate -- that manned missions and science missions can be (and often are) mutually beneficial.

Incidentally, there will be a backup rescue shuttle ready to launch from the Kennedy Space Center if there is any problem with the shuttle headed to the Hubble.

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San Francisco, Ca.: Will the Hubble enable science to develop a greater understanding of dark matter?

Marc Kaufman: Yes, the Cosmic Origins Spectrograph will observe and measure the "cosmic web" that serves as an infrastructure of sorts to the universe. Its form is to some extent determined by the gravity of dark matter, and so learning about "web" is a way to also learn about dark matter.

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To: Kaufman: Isn't it disingenuous for NASA to continue to play up strophysics in general, and the Hubble in particular, when NASA has now hitched its wagon to the jingo that is manned spaceflight?

Marc Kaufman: A somewhat difficult question to answer. NASA has definitely emphasized the manned effort in recent years, as it prepares to retire the space shuttle and replace it with a new spacecraft around 2015. Space science has taken a budgetary hit as a result, and there are a lot of hard feelings.

Still, NASA does fund a very ambitious space science program and Hubble is the jewel in the crown. Give credit to Mike Griffin, who overturned a decision made by his predecessor to let the Hubble degrade without servicing. I don't think Griffin's decision was disingenuous, although it was indeed made during a time that many other science missions were being delayed or mothballed entirely.

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Taylor, Tex., (but currently in Lanzhou, China): With the planned upgrades installed following a presumably successful mission, what is a realistic timeframe for Hubble's remaining functional and productive life? Is there an ultimate plan to de-orbit the craft in a controlled manner after that functional/productive life has ended?

Marc Kaufman: Hello Lanzhou, and thanks for logging on.

NASA predicts the upgraded Hubble will have five to six years of productive life. They are also planning to put a device onto the observatory that will make it easier for a robotic craft to dock with it in the future and send it back to Earth. So yes, the question of de-orbiting is a real one, and NASA wants to control it as much as possible.

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Franconia, Va.: Is there a planned next-generation telescope to follow Hubble? Will this mission add enough years to the Hubble's life so that we won't be without a telescope in the meantime, or will the Hubble be our last hurrah for a while?

Marc Kaufman: The upgraded Hubble is scheduled to be working at its peak when its successor, the James Webb Space Telescope, is launched in 2013. The Webb is described as being even more powerful, though it has somewhat different capacities. Astronomers are very excited about the possibility of having both of them orbiting at the same time, which may allow some unprecedented kinds of observations.

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Fairfax County, Va.: I read a few weeks ago that the October launch date is in some question because of the need for massive repairs to the launchpad due to damage sustained from a recent shuttle flight. How are things progressing on this and why would there be such launchpad damage, if it doesn't usually happen? I hate to have something like that hold up repairs to the telescope.

Marc Kaufman: The damage came from the most recent shuttle launch, but NASA says all the needed repairs will be done in time for an early October launch for the Hubble mission.

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Alexandria, Va.: Thanks for the excellent article. For those who may not have followed the evolution of HST's instrument packages over its lifetime, I'd like to clarify one reason why the current mission will allow the telescope to "perform at its highest level ever for the remaining five or six years of its operating life". The COSTAR module, which provided the optics to correct for the primary mirror aberration, will be removed during this mission. All of the current instruments have the aberration correction built into them, so COSTAR is no longer needed. The module is using one of the instrument slots, so removing it will allow for the full complement of instruments.

Marc Kaufman: Thanks for the additional info.

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Detroit, Mich.: How much is this repair mission going to cost and isn't there debate in the space science community that more/better science could be obtained by spending the money on other space science programs?

Marc Kaufman: The estimated cost is $900 million, with $200 million for the shuttle launch and mission and $700 million for the Hubble hardware. I'm sure that some scientists think the money could be better spent elsewhere, but Hubble has been enormously productive and the combination of its new equipment and repairs to the Advanced Camera for Surveys in particular are a good bet to make major discoveries.

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Reston, Va.: Would there be any advantage in placing a functional equivalent of the Hubble on the moon?

Marc Kaufman: NASA is indeed exploring the possibility of placing some instruments and even an observatory on the moon--which could be a terrific platform for instruments looking into the distant past. As far as I know, however, the technical obstacles are substantial and no decisions have been made about the idea.

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Camarillo, Ca. (Los Angeles): Just why are space shuttles being retired? They may be old, but all the bugs have been determined and repaired. It seems there are more politics than science involved here.

Marc Kaufman: Space shuttles are being retired because 1/they are very expensive to operate 2) they cannot leave low-earth orbit 3) the Columbia Accident Investigation Board recommended that they be entirely re-certified by 2010 if they were still in use and 4/NASA, Congress and many in the space community want to move on to missions to the moon and/or Mars.

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Bill, Austin, Tex.: At the end of Hubble's "life", do they plan on removing any of the instruments, mirrors, etc. to bring back to earth or will they just let it re-enter the atmosphere and burn up?

Marc Kaufman: I believe the whole observatory will be "de-orbited" in a controlled return to Earth -- one that will result in its destruction.

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Silver Spring, Md.: Current technology has allowed Hubble to see back to nearly 13 billion years, and the new instruments will push that back hundreds of millions of years more. The Big Bang is believed to have taken place around 14 billion years ago.

Hundreds of millions on the scale of 13,000,000,000 is not significant. It won't even make it to 14,000,000,000. Why bother?

Marc Kaufman: As explained by scientists, the new capability should allow them to see back into the time when stars began to form. While the new capabilities may not be so great in the vastness of time, they may well result in discoveries about an especially interesting and little understood period in the history of the universe.

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Arlington, Va.: Projects like Hubble are the best payoff in terms of knowledge gained for the money in my opinion. The distribution of the imagery with the internet is also bound to be greater than ever before. Programs like google-sky are just incredible.

Do you know why in google-sky and in Microsoft telescope there is a small patch of sky around Orion that seems to be redacted? The actual coordinates are at 5h 53m 43s (azimuth) -6 00 00 degree declination.

Marc Kaufman: I also think that Hubble is a remarkable achievement, and that it has made astronomy much more interesting to many people around the country and the world.

But regarding your question about a small "redacted" patch around Orion, I have no information. It seems to me, however, that the issue might be technical rather than the result of any desire to hide images and information.

Afraid I have to run, but many thanks to all of you for your good questions.

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