EXPLORATIONS -March 13, 2002: Space Digest
By Paul Thompson
This is Steve Ember.
And this is Bob Doughty with the VOA Special English program EXPLORATIONS. Today, we tell about
spacecraft that left Earth thirty years ago. We report about the successful repair of the Hubble Space Telescope
by the crew of the space shuttle Colombia. And we tell about the first scientific information sent to Earth by the
Mars Odyssey spacecraft.
Late last month, the Mars Odyssey spacecraft turned its many scientific instruments toward the planet Mars for
the first time. Almost immediately it began sending home useful scientific information.
Steve Saunders is the Odyssey project scientist at the Jet Propulsion Laboratory in
Pasadena, California. He says the first information sent by the spacecraft as it orbits
Mars has made him and other scientists extremely happy. He says the information
will be added to what has been learned from the Mars Global Surveyor and other
spacecraft. Most importantly, Mister Saunders says, the Mars Odyssey spacecraft
may permit researchers to see water on the surface of Mars rather than just guess
where it might be.
The first information received on Earth included
photographs taken by the Mars Odyssey’s thermal
emissions imaging system. This system shows the
temperature of the Martian surface. Researchers say the photographs sent to Earth
show the temperature differences extremely clearly during the Martian day and
The camera system on the Mars Odyssey is studying the minerals on the surface of Mars. The new photographs
already show thirty times more detail than any other camera or image -recording device sent to Mars.
Another device on the Mars Odyssey spacecraft is the gamma ray spectrometer. Researchers say it shows huge
amounts of hydrogen in the south polar area of Mars. The researchers say the large amounts of hydrogen are most
likely the result of water ice.
The gamma ray spectrometer explored an area almost six-hundred-fifty kilometers across. NASA’s researchers
will continue making maps of the area for another month. They say this will give them the needed information to
confirm the presence of water on Mars.
NASA officials say one device on the Odyssey spacecraft failed in August, Two-Thousand -One. It is called the
Martian Radiation Environment experiment. It measures the daily amount of radiation that would be experienced
by astronauts as they travel from Earth to Mars.
The device did find that the area between Earth and Mars has more than two times the amount of radiation
experienced by the crewmembers of the International Space Station. Investigators are studying the radiation
device to find why the instrument stopped communicating and why it turned off last August.
The Mars Odyssey spacecraft was launched April Seventh of Two -Thousand -One. It began to orbit Mars on
October Twenty-Fourth, Two-Thousand-One. Its main task is to map the surface of Mars. It also is examining the
mineral and chemical elements on Mars, and searching for water.
After Odyssey completes its science tasks, it will support other flights in the Mars Exploration program. It will
provide the communications between the Mars surface and Earth during future explorations. These tasks will
include the next flights in NASA’s Mars program, the Mars Exploration Rovers, to be launched in Two Thousand-
The crew of the American Space Shuttle Colombia has just completed a ten -day flight to repair and rebuild the
Hubble Space Telescope. The shuttle returned Tuesday to the Kennedy Space Center in the southern state of
NASA officials say the seven-person crew of Colombia has made the Hubble into a
much more valuable space science instrument. It can now do ten times more work
than it could before.
NASA scientists say the most valuable piece of
equipment added to the Hubble is a device called the
Advanced Camera for Surveys. It increases by ten
times Hubble’s ability to discover objects in the
The astronauts also gave Hubble several other pieces of equipment that permit it to
do better work. This equipment includes wing -like structures called solar arrays that change sunlight into
electricity. The new solar arrays are forty-five percent smaller than the older ones, but they can produce twenty-
five percent more power.
Colombia’s astronauts also replaced the Hubble’s power control device. The new Power Control Unit controls
the electricity made by the solar arrays. It provides electricity to the Hubble’s electrical storage batteries. It also
supplies electricity to any device that needs power.
NASA officials say it was extremely difficult to replace the Power Control Unit. The work also placed the
telescope in danger because Hubble had to be without power for the first time since its launch in Nineteen-
The astronauts had a limited amount of time to complete the replacement work and turn on Hubble’s power. If
the work was not completed in time, the extreme cold temperatures of space would severely damage the space
Astronauts John Grunsfeld and Rick Linnehan worked outside the space shuttle to replace the Power Control
Unit on Hubble. They were able to complete the work to replace the power unit in less than four hours.
Scientists at the Johnson Space Center in Houston, Texas were watching the two astronauts on television. They
cheered when the new power unit was placed in the telescope and Hubble’s power returned.
The crew of the Colombia also placed a new cooling device in Hubble to replace an older one that had failed. The
cooling device is needed to work with the Near Inferred Camera and Multi-Object Spectrometer, called
NICMOS. NICMOS must be kept at extremely cold temperatures so it can photograph infrared light.
NASA officials hope the new cooling device will permit NICMOS to do useful work again for at least a few
The space shuttle Colombia flew about six-hundred kilometers above the Earth to reach the orbit of the Hubble
Space Telescope. The astronauts then had move the space shuttle near the Hubble and capture the two-thousand
kilogram telescope. The capture had to be done as Hubble orbits the Earth at speeds faster than twenty-seventhousand
kilometers an hour.
This is the fourth time NASA has sent a crew of astronauts to repair the Hubble Space Telescope. NASA officials
say this repair work was the most difficult and perhaps the most dangerous ever attempted.
NASA plans one more flight to provide service to the Hubble Space Telescope. That flight should take place in
Two-Thousand-Four. During that flight, an astronaut crew will place the Cosmic Origins Spectrograph in
Hubble. The instrument will be able to see far into space and take pictures of many different kinds of light that
cannot be seen by the human eye. It will be the most powerful and most complex scientific device to measure
light ever sent into space.
NASA plans to use the Hubble Space Telescope until Two-Thousand -Ten. At that time NASA officials will
decide if it will return to Earth or be raised to a high orbit where it cannot fall back to Earth.
NASA officials have heard from an old friend. The Pioneer Ten spacecraft sent a message back to Earth from
more than eleven-thousand-million kilometers in space. The little spacecraft left the gravity of Earth more than
thirty years ago.
On Friday, March First, scientists sent a message to Pioneer Ten. They sent the message from NASA ’s Jet
Propulsion Laboratory’s Deep Space Network communication center in Goldstone, California. Twenty-Two
hours later researchers heard Pioneer’s answer. Pioneer reported that its systems were still working.
Pioneer Ten was the first spacecraft to take close-up pictures of Jupiter. It also was the first human-made object
to leave the solar system when it passed the orbit of the planet Pluto.
Pioneer Ten is traveling toward the group of stars called Taurus. It will pass the nearest star in that constellation
in about two million years.
This Special English program was written by Paul Thompson. It was produced by George Grow. This is Bob
And this is Steve Ember. Join us again next week for another EXPLORATIONS program on the Voice of
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