For questions 1-7, mark Y (for YES) if the statement agrees with the
information given in the passage; N (for NO) if the statement contradicts the
information given in the passage; NG (f0r NOT GIVEN) if the information is
not given in the passage. For questions 8-10, complete the sentences with the
information given in the passage. SURVIVING IN SPACE Motion
sickness troubles more than two thirds of all astronauts upon reaching orbit,
even veteran test pilots who have never been airsick. Though everyone recovers
after a few days in space, body systems continue to change. Deprived(丧失) of
gravity information, a confused brain creates visual illusions. Body fluids
surge to chest and head. The heart enlarges slightly, as do other organs.
Sensing too much fluid, the body begins to discharge it, including calcium,
electrolytes (电解液) and blood plasma (血浆). The production of red blood cells
decreases, rendering astronauts slightly anaemic (贫血的). With the loss of fluid,
legs shrink. Spinal (脊骨的) discs expand, and so does the astronaut—who may gain
five centimeters and suffer backache. Though the process may sound terrible,
astronauts adjust to it, come to enjoy it and seem no worse for wear—at least
for short missions such as space shuttle flights that last a week or
two. During longer flights, however, physiology enters an
unknown realm. As director of Russia’s Institute for Biomedical Problems from
1968 to 1988, Oleg Gazenko watched cosmonauts return from long flights unable to
stand without fainting, needing to be carried from the spacecraft. "We are
creatures of the Earth, "Gazenko told me." These changes are the price of a
ticket to space". Americans, returning from months-long flights
on Mir, the Russian space station, also paid the price, suffering losses in
weight, muscle mass and bone density. NASA geared up to see how—even if—humans
would survive the most demanding of space ventures, a mission to Mars, which
could last up to three years. "We don’t even know if a broken bone will heal in
space," said Daniel Goldin, NASA’s administrator. To get answers in 1997 Goldin
established the National Space Biomedical Research Institute (NSBRI), a panel of
experts from a dozen leading universities and research institute. NSBRI will
Study biomedical problems and by 2010 will present NASA with a "go" or "no go"
recommendation on a Mars mission. Jeffrey Sutton, leader of the
medical systems team at the NSBRI, has treated the head trauma, wounds, kidney
stones and heart rhythm irregularities that one could encounter on the way to
Mars. On the spacecraft he envisions, Mars-bound in the year, say, 2018, there
may lurk harmful bacteria or carbon monoxide. No problem. The deadly substances
will be detected by smart sensors—microprocessors no bigger than a
thumbnail—that wander at will through the spacecraft, communicating their finds
to a computer that warns the crew. To cope with infection,
Sutton plans a factory to make drugs, even new ones, to cope with possible
organisms on Mars. Miniature optical and ultrasound devices will image body and
brain, while a small X-ray machine keeps track of any bone loss. Smart sensors
embedded in clothing will monitor an astronaut’s vital functions. The crew will
be able to craft body parts, Sutton says, precisely tooled to an astronaut’s
personal anatomy and genome stored in computer memory. Re searchers are building
artificial liver, bone and cartilage (软骨) tissue right now.
Lying in wait beyond the Earth’s atmosphere, solar radiation poses
additional problems. The sun flings billions of tons of electrically charged gas
into space, relegating Earth’s volcanic eruptions to mere hiccups. Nevertheless,
NASA officials are confident the accurate monitoring will warn astronauts of
such events, allowing the crew to take refuge in an area where polyethylene(聚乙烯)
shielding will absorb the radiation. A second kind of radiation,
cosmic rays from the Milky Way or other galaxies, is a more serious
threat—possessing too much energy, too much speed for shielding to be effective.
"There’s no way you can avoid them, "says Francis Cxucinotta, manager of NASA’s
Johnson Space Centre." They pass through tissue, striking cells and leaving them
unstable, mutilated or dead. Under standing their biological effects is a
priority." Another major concern is the psychological health of
astronauts. And there’s a new stressor on a three-year Mars Mission-people,
other members of the crew. NASA found that the stresses of isolation and
confinement can be brought on rapidly simply by giving people few tasks. Mir
astronaut Andrew Thomas described how six astronauts were confined in a 12-foot
square room for a week. "If you give them little to do, stress can be achieved
in a couple of days," says Thomas. Will NSBRI meet Daniel
Goldin’s 2010 deadline for a decision on Mars "Yes, we will per haps even
before. We’re very confident," says Laurence Young, the director of NABRI. Mean
while, some of NSBRI’s research may bear fruit on Earth. The institute has made
one discovery that promises to save many people at risk of sudden cardiac death,
usually brought on by a heart rhythm disorder Called ventricular fibrillation.
This kills 225,000 people in the US each year. Richard Cohen,
head of the NSBRI cardiovascular (心血管的) team, explained that zero gravity
may—emphasizing "may"—incite this condition in astronauts. So the team invented
a non invasive diagnostic device that measures extremely tiny changes in heart
rhythm. The team found that the device can be used as part of a standard stress
test to identify patients at risk. Then pace maker-like devices can be implanted
to regulate the rhythm disorder. "This technology has the potential to save
hundreds of thousands of lives," says Cohen. "NASA can be proud."
Such discoveries are no accident, says Michael E. DeBakey, a
cardiovascular surgeon who has saved many hearts himself. "The key word is
research. When I was a medical student and a patient came to the hospital with a
heart attack, things were mostly a matter of chance. Today there’s a better than
95 per cent chance of surviving. Now that all comes from research. The
unfortunate thing is that there are people, even some scientists, who look at
the money that goes to NASA and we could use the money to support our work.
That’s very short-sighted. The more research that’s done ii1 any area of
science, the better off everyone is going to be." ______ says research carried out by NASA is ultimately beneficial for everyone.