Sunlight produces a force (Solar
Wind) which moves comet tails (they always face
away from the sun). This solar wind concept is being
investigated by NASA as a practical means of propelling
a spacecraft using an ultra thin sail. Continuous
pressure from sunlight on these delicate large sails
would ultimately accelerate the craft to speeds
about five times higher than possible with conventional
rockets -- without requiring any fuel! If launched
in 2010 a solar propelled probe would overtake Voyager
1, the most distant spacecraft, in 2018 going as
far in eight years as Voyager journeyed in 41 years.
Launched more than 25 years ago, NASA's
Voyager 1 and 2 spacecraft are now over 10 billion
kilometres from the Sun. A 12-inch gold plated copper
disk containing recorded sounds and images representing
life on Earth, is affixed to each Voyager.
This cosmic 'message in a bottle'
was selected by a committee chaired by the late
Carl Sagan. However, Voyager spacecraft will not
approach another star system for at least 40,000
years, so there is no point staying at home waiting
for ET to ring.
More than 400 people have flown in
space. The United States alone has sent more than
100 manned missions aloft. John Young, Story Musgrave,
Jerry Ross, and Franklin Chang-Diaz are the only
American astronauts who have flown in space six
times.
Finally, we couldn't discuss space
without mentioning Adelaide born Andy Thomas (18
December 1951 - ). He studied at the University
of Adelaide where he received a degree in mechanical
engineering, with First Class Honours in 1973, and
a doctorate in 1978.
He began his professional career as
a research scientist with Lockheed in 1977. In 1980,
he became Principal Aerodynamic Scientist and, in
1987, he was named manager of Lockheed’s Flight
Sciences Division.
Dr Thomas was selected by NASA in
March 1992 and first flew in space on the shuttle
Endeavour in May 1996. He next trained at the Gagarin
Cosmonaut Training Centre in Star City, Russia.
In 1998, he served aboard the Russian Space Station
Mir for 130 days. He completed his third space flight
on STS-102 in 2001 and has logged over 163 days
in space. From August 2001 to now, he has served
as the Deputy Chief of the Astronaut Office.
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