I'm Mario Ritter.
And I'm Steve Ember with
EXPLORATIONS in VOA Special English. This
week, we tell about some of the biggest space stories of two thousand nine. First, there was the American space agency's discovery
of water on the moon. We also talk to a
NASA expert about the discovery of methane gas on Mars. And we hear about the test flight of NASA's
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biggest space story this year was the discovery of water on the moon. The best evidence was provided by a dramatic
experiment carried out on October ninth.
NASA used its Lunar Crater Observing and Sensing Satellite, or LCROSS,
to look for water deep beneath the lunar surface.
get below the ancient lunar rocks, NASA crashed a rocket into the moon's south
pole. The crash caused soil to be expelled many kilometers above the lunar
surface. LCROSS studied the soil before
it too crashed into the moon. The
experiment pushed the search for water several meters below the lunar
surface—much deeper than had been possible before.
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November, Anthony Colaprete, a leading scientist with the LCROSS
project, spoke about information gathered by the spacecraft. He said about one hundred kilograms of water
had been found in the material ejected by the moon crash. Water has now been confirmed in amounts much
greater than had been thought.
September, NASA scientists had announced the discovery of water molecules
mainly in the moon's extreme northern and southern areas. They noted, however, that they could also be
seeing evidence of another molecule, hydroxyl.
on three separate spacecraft gathered that evidence of lunar water. NASA's Moon Mineralogy Mapper made the most
recent observations. It was one of
eleven scientific devices carried by the Chandrayaan-One
spacecraft of the Indian Space Research Organization.
Mapper is a spectrometer, which measures reflected light wavelengths. The device shows scientists what an object is
made of from great distances. Similar
devices on NASA's Cassini and Epoxi spacecraft also reported water.
those observations were made years ago. NASA scientists had not trusted the
results without clear confirmation.
Moon Mineralogy Mapper could only examine lunar soil to a depth of a few
millimeters. And the amount of water
found in that layer was very small. Now,
LCROSS has shown that large amounts of water could exist on the moon. And it raises even more questions.
water brought to the moon by space rocks and icy bodies called comets? Or could processes deep within the moon
produce water? If that is the case, it
may be possible that the moon could hold enough water for future explorations
or even colonies.
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The presence of water on the moon was not the only major
solar system discovery NASA made this year.
In January, a team of NASA and university scientists announced that they
had found methane gas on Mars. The group
used NASA's Infrared Telescope Facility and the W.M. Keck telescope. Both instruments are in Mauna Kea, Hawaii.
Methane is better known as natural gas.
On Earth, it is mainly produced by processes linked to biology.
raises the exciting possibility that life may have existed in the past on Mars. Or it may still exist deep below the surface.
Michael Meyer is lead scientist for NASA's Mars Exploration Program in
Washington. He spoke to us about the
MICHAEL MEYER: "It really means that the planet is more
active than we thought, and more active--and that can be geologically or maybe
On Earth, biological activity is very
effective in making methane. But Michael
Meyer notes that methane also can come from a purely non-biological process
called serpentinization. He says the
methane discovery presents scientists with a mystery because it is still not
clear how the gas is being produced.
methane is also unusual because it is not evenly spread over the planet. It can become concentrated in small areas and
then disappear. This suggests processes
that both supply and remove methane from the atmosphere in certain places. Currently, the best explanation for the loss
of methane is that it chemically reacts with dust in the atmosphere. The gas may then turn into something else
such as carbon dioxide.
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NASA plans to send the Mars Science
Laboratory to the red planet in the autumn of two thousand eleven. The exploration vehicle will be able to
measure methane even at very low levels in many places on the surface.
Michael Meyer also says NASA is developing
an orbiter with European scientists. It
will be able to measure small amounts of many different gases. The orbiter could finally provide evidence
about how methane on Mars is created and destroyed. Michael Meyer says
planetary scientists often study processes that are very different from ones on
Earth. But he says understanding these differences can help discover how some
complex processes on our own planet really work.
(SOUND: NASA Rocket Launch)
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October twenty-eighth, NASA took an important step into the future. The agency carried out a test flight of its
next-generation launch vehicle for astronauts.
is developing two separate rockets for the Ares program. Phil Sumrall is the Ares Project Office Advanced
Planning Manager. He says this was done
for safety reasons.
The loss of the space shuttle Columbia in February of
two thousand three led to an investigation by the Columbia Accident
Investigation Board. The group
recommended that human life must not be risked simply to send equipment into
space. The result was a design in which
safety was the top concern.
PHIL SUMRALL: "We designed the Ares One to be the
absolute safest possible vehicle that we could conceive."
Space scientists designed Ares One with
a system that would rescue astronauts whether there was a failure of the rocket
in the launch area or during flight. Mister
Sumrall says NASA estimates the new Ares One will be twenty to thirty times
safer than the Space Shuttle.
other Ares launch vehicle is the huge Ares Five rocket. It will be the biggest rocket ever built. The Ares Five will be one hundred sixteen
meters tall and weigh three point seven million kilograms. It will be able to lift nearly forty percent
more than the Saturn Five rocket that sent Apollo astronauts to the moon.
of the Ares technology has been developed from existing vehicles. Versions of the solid fuel rockets that are
used on the Space Shuttle today will serve as the first stage of the Ares One and
booster rockets on the Ares Five. An
engine first developed for the Saturn Five moon rocket has been updated to be
used on Ares.
Existing manufacturing technologies are also being used
in new ways on Ares. The tanks of the
Ares rockets will be made of aluminum lithium.
This is a strong and light metal alloy that has been used on the Space Shuttle. But Ares will use new methods in metal-working
science such as friction stir welding.
This method uses heat and pressure to join pieces of metal
together. Friction stir welding can be
used to make complex curved and domed structures out of aluminum lithium and
similar alloys. And, friction stir
welding uses fewer workers at less cost than other methods.
Scientists developed the
new welding technology at the Marshall Space Flight Center in Montgomery,
Alabama. It will be used when Ares is
built at the Michoud Assembly Facility in New Orleans, Louisiana.
Phil Sumrall says NASA's estimate to keep the Ares
program going forward as planned calls for three billion dollars in additional
spending a year.
says if money is available, Ares Five could be ready for a test flight by two
thousand seventeen. We asked Phil Sumrall how NASA expects to use Ares in its
space exploration plans.
PHIL SUMRALL: "It's not just for going to the moon or
near Earth objects. It's what we'd use
to go to, eventually, to Mars or to the moons of Mars."
NASA named the new rocket system Ares, the Greek name for
Mars. The name suggests the goal for a
future generation of space explorers.
They may be the first humans to set foot on another planet.
Steve Ember with Mario Ritter who also wrote and produced our program. You can find links to the NASA Web site at
voaspecialenglish.com. You can also find
transcripts, MP3s and podcasts of our programs.
Join us again next week for EXPLORATIONS in VOA Special English.