Page 291 - NS-2 Textbook

286 NAUTICAL SCIENCES

A close-up picture of the Martian surface furnished by one of the two Viking landers that successfully landed on Mars in July 1978,

atmosphere. Its spectacular results are summarized in lunar surface in the early 1960s, and ended with the suc-
chapter 4 of this unit. Also in 1989 the Galileo spacecraft cessfullanding of Apollo 11 on the Moon's surface in 1969.
was launched as a follow-on to the Voyager mission to Five additional manned lunar landings and explorations
Jupiter conducted in 1979. On its way it passed close by were conducted, the last being Apollo 17 in late 1972.
the asteroids Gaspra and Ida, and it sent back several pic- In Februmy 1986 the Soviet Union lawlched the first
tures of them. Galileo arrived at Jupiter in December 1995 components of a small space station called MIR into
and began a mission to take detailed observations of the an elliptical orbit between 300 and 400 kilometers high.
planet and its moons. It also relayed back telemetry from Though originally intended to last only about seven years
a probe that it released months before that plunged into with an intermittent crew of two cosmonauts, additional
the Jovian atmosphere. More on its discoveries is given modules to enlarge it and extend its life were added,
in chapter 4. and it was more or less continually ma1ll1ed by Russians
In 1990 NASA began its Great Observatories Program and occasional visitors fronl other nations, including the
by launching into orbit the first of an eventual four orbit- United States, from 1989 tmtil it was brought down from
ing space telescopes, each designed to observe a different orbit in 2001.
band of radiations within the electromagnetic spectrum- In 1998 the first components of a new International
visible, gamma rays, X-rays, and infrared. The first and Space Station were launched, with parts to be eventually
probably best known of these, the Hubble Space Telescope, contributed by sixteen nations. Two years later, in No-
was placed in orbit around Earth by a space shuttle mis- vember 2000, the first crew of one American and two
sion in April 1990. Its telescope system proved flawed, Russians arrived at the station, and it has been perma-
and had to be repaired during a subsequent shuttle mis- nently manned since then. Additional components are
sion in 1993. It is still in operation today, and has pro- continually being added, which will bring its total mass
vided many astounding images that have added much to in orbit to about 453 metric tons when complete some-
astronomers' knowledge of the universe and its origins. time in the next several years.
In September 1992 a Mars Observer spacecraft was
launched to do detailed photographic mapping of the
THE FUTURE
Martian surface, but wlfortunately all contact with it was
lost as it approached Mars in August 1993. Two more The next few years should be exciting ones in the field of
exploratory spacecraft were launched to Mars by the space exploration. Many additional missions to the
United States during 1996. TIley arrived in July and Sep- planet Mars are planned over the next decade, perhaps
tember 1997. Several more were launched during the next culminating in a manned mission sometime before the
several years. More about them is presented in chapter 4 year 2020. Several new space telescopes are planned, in-
of this unit. cluding the James Webb, a 6.5-meter infrared observatory
In addition to the foregoing unmanned exploratory to be launched in 2011, and a Space Infrared Interferometric
efforts, in the 1960s the United States made a determined Telescope (SPIRIT), to consist of two moveable telescopes
effort to put an astronaut on the Moon by the end of that mounted on a 120-foot bea1ll, scheduled for 2014. Both
decade. The effort began with several Mariner and Sur- would orbit a million miles above Earth. A follow-on
veyor spacecraft that conducted orbital mapping of the mission to Galileo's exploration of Jupiter and its moons