VOICE ONE:
This is Steve Ember.
VOICE TWO:
And this is Bob Doughty with the VOA Special English programEXPLORATIONS. Today we tell about plans to make the Hubble SpaceTelescope a much more powerful scientific instrument.
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VOICE ONE:
Later this month, NASA astronauts plan to replace much of theequipment that makes the Hubble Space Telescope one of the mostvaluable science tools ever invented. The new equipment will helpHubble do ten times more work than it can today.
The Hubble Space Telescope is an eye in space that permits humansto look far into the universe. The Hubble telescope orbitssix-hundred kilometers above the Earth. It works twenty-four hours aday, seven days a week helping scientists understand the secrets ofthe universe. It provides information and images of the universethat cannot be seen from Earth because of clouds or atmosphericconditions.
VOICE TWO:
NASA launched the Hubble Space Telescope in Nineteen-Ninety.Since then, the telescope has made more thanthree-hundred-thirty-thousand scientific observations of distantobjects in space. It has observed more than twenty-five thousanddifferent objects. And it has provided the scientific informationthat helped researchers produce more than two-thousand six-hundredscientific papers.
The Hubble Space Telescope produces enough good scienceinformation to fill about thirty large books each day. It hasprovided information that has helped us understand the structure ofour universe. Scientists say the telescope has expanded ourknowledge of how stars and planet systems form together.
Hubble has provided detailed pictures and images that help us inunderstanding the history of our solar system. It has also helped usunderstand what makes Earth similar to or different from otherplanets.
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VOICE ONE:
NASA’s plans call for the Space Shuttle Colombia to be launchedfrom the Kennedy Space Center in Florida on February twenty-eighth.It will carry seven astronauts on an eleven-day flight to work onthe space telescope.
The Hubble telescope is the first scientific instrument everdesigned to be repaired and rebuilt by astronauts who work in space.The telescope was built so astronauts can take it apart and replaceold or broken equipment with newer technology. More than ninetypercent of its parts can be replaced by space shuttle astronauts.
As new technology is developed, the telescope is provided withmore modern devices. Each instrument that is replaced is much morepowerful than the older one.
VOICE TWO:
In February, Colombia’s astronauts will complete a number oftasks during their flight. They will replace Hubble’s camera withnew, advanced technology that will permit the telescope to do tentimes the amount of work.
The new camera is called the Advanced Camera for Surveys orA-C-S. NASA says the new A-C-S camera will permit researchers tostudy huge galaxies.
The A-C-S is really three different cameras. Each deals withdifferent kinds of light. Each one can see and record light that isfar beyond what the human eye can see.
The A-C-S also carries equipment that can control light thatenters the camera. It does this by placing different pieces of glassin front of the camera’s eye.
NASA says the information provided by Hubble’s new A-C-S camerawill lead to a better understanding of how our universe changed overtime.
VOICE ONE:
The Hubble Space telescope also will receive new equipment thatpermits it to make electric power from sunlight. The old powerequipment has been in use for eight years. Radiation and small spaceobjects have damaged it.
The power equipment looks like large wings. These wings arecalled solar arrays. The new solar arrays are smaller than thosebeing replaced, but can produce thirty percent more power. They canalso operate better in the extreme temperature changes found inspace.
VOICE TWO:
The astronauts also will replace the electric power controldevice on the space telescope. It has been controlling Hubble’spower for the eleven years it has been in space.
To replace the device, all power on Hubble will have to be turnedoff for the first time since it was launched in Nineteen-Ninety. Thenew power control device will permit the space telescope to use allof the increased power provided by the new solar arrays.
VOICE ONE:
Astronauts also will repair an instrument called the NearInfrared Camera and Multi-Object Spectrometer. They will replace thecooling system for the camera. This special camera was put in thespace telescope in Nineteen-Ninety-Seven. It stopped working twoyears later after its cooling device failed.
NASA hopes the new device will be able to provide the extremelycold temperatures needed by this special camera. They also hope toextend the camera’s working life by several years.
VOICE TWO:
The shuttle crew has learned how to replace or repair each of themany systems that are part of the space telescope. Some of theseinclude the spacecraft’s communications system, its computers, andthe instrument that points the telescope at distant objects.
Hubble’s pointing system is extremely powerful. It is a goodexample of the kind of device the astronauts must learn to repair.It finds and then keeps the Hubble telescope pointing at objects sothey can be studied. Imagine pointing a small light at a very smallobject two-hundred kilometers away. Then imagine holding the lightfor hours or days with little or no movement. The pointing device onHubble has a small computer that watches for any movement ormistakes forty times a second. If movement occurs, other instrumentschange speeds to bring the telescope back into the correct position.
VOICE ONE:
When all the work is completed on the space telescope, theastronauts may use the shuttle’s small rockets to place Hubble in ahigher orbit. This has been done two times before.
Very little atmosphere surrounds the Earth six-hundred kilometersin space. Yet enough atmosphere exists to cause the Hubble to slowdown over a long period of time. When this happens, the Earth’sgravity pulls the orbit of the telescope lower. If the spacetelescope were left alone it would continue to fall lower and fastertowards Earth until it burned up in the atmosphere.
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VOICE TWO:
Repairing the Hubble Space Telescope in space is a very difficulttask. The crewmembers of the Space Shuttle Colombia have beentraining for their flight for many months. They have done each taskmany times here on Earth. The new equipment they will place in thetelescope has been tested again and again for many thousands ofhours.
The astronauts will have to use more than one-hundred-fiftyspecial tools and aids to work on the telescope in space. They haveworked with these tools until they are experts in the use of eachone.
VOICE ONE:
The astronauts also prepare for this difficult flight by askingthe question, “What if?” This is the method they use to prepare forsurprises.
It is similar to you asking yourself, “What if it there is aheavy rain tomorrow morning.” Or “What if I turn here instead ofthere.” You would think of an answer for each of these questions anda solution to each problem. By working out the answers to these”what if” questions, the Hubble team tries to be prepared for anyproblem that might develop.
Experts have spent many days providing the astronauts withdifferent “what if” surprise problems. The astronauts then spenthundreds of hours working on the correct solutions.
VOICE TWO:
Hubble has provided many thousands of pictures of distant objectsin the universe. Many of them are thousands of light years away fromEarth.
The Hubble Space Telescope has seen the birth of stars and theirdeaths. You do not need to be a scientist or a researcher to enjoythe beautiful pictures the telescope provides. If you have acomputer that can link with the Internet, you can see hundreds ofthem. Have your computer search for the word Hubble. That isH-U-B-B-L-E. Once again, H-U-B-B-L-E.
Your computer will answer with several web sites that will permityou to see millions of kilometers into our universe.
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VOICE ONE:
This Special English program was written and produced by PaulThompson. It was produced by George Grow. Our studio engineer wasJohn Ellison This is Steve Ember.
VOICE TWO:
And this is Bob Doughty. Join us again next week for anotherEXPLORATIONS program on the Voice of America.