Clementine and Prospector
T
he 1994 mission to the Moon, Clementine, was named
after an old American mining song – because, after the
lunar part of its programme, the probe was scheduled to go
on to an asteroid, and it has been suggested that in the
future it may be possible to carry out mining operations on
asteroids.
Clementine was funded partly by NASA and partly by
the US Department of Defense. The military authorities
were anxious to test instruments and techniques capable
of locating hostile ballistic missiles, and the only way to
circumvent the strict regulations about this sort of activity
was to go to the Moon. Therefore, the Department could
test its anti-ballistic missile system and do some useful
scientific work as well.
Clementine was launched on 24 January 1994 from
the Vandenburg Air Force Base in California, and began
its Earth programme. It weighed 140 kilograms (300 lb)
and carried an array of advanced sensors. After completing
this part of its mission several manoeuvres were carried
out, and Clementine entered lunar orbit on 21 February- For 2^1 / 2 months it orbited the Moon in a highly
inclined path, which took it from 415 kilometres (260
miles) to 2940 kilometres (1830 miles) from the Moon; a
full research programme was successfully completed.
Clementine surveyed the whole of the Moon. Many
gravity measurements were made, and superb images
obtained; the inclined orbit meant that the polar regions
could be mapped more accurately than ever before.
For example, there were detailed views of the vast
South Pole–Aitken Basin which is 2250 kilometres (1400
miles) in diameter and 12 kilometres (7 miles) deep. There
was also the Mendel-Rydberg Basin, 630 kilometres
(390 miles) across, which is less prominent because it lies
under a thick blanket of debris from the adjacent Mare
Orientale.
It was claimed that Clementine had detected indica-
tions of ice inside some of the polar craters, whose floors
are always in shadow – but ice did not seem at all probable
on a world such as the Moon. Clementine left lunar orbit
on 3 May 1995; it had been hoped to rendezvous with a
small asteroid, Geographos, but a programming error ruled
this out. The next lunar probe, Prospector, was launched
on 3 January 1998, and carried out an extensive mapping
survey. On 31 July 1999 it was deliberately crashed into a
polar crater, in the hope that water might be detected in the
debris, but no signs of water were found and the idea of
lunar ice has been generally abandoned.ATLAS OF THE UNIVERSE
Clementine.The latest
American lunar probe was
paid for by the Department
of Defense. It weighed
140 kg (300 lb), and carried
an array of sensors.Launch of Clementine.
The probe was launched
on 24 January 1994 from
the Vandenburg Air Force
Base, and put into a circular
orbit round the Earth. It
departed for lunar orbit on
21 February, and spent two
months mapping the Moon- particularly the polar areas,
which were less well known
than the rest of the surface.
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