The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

cratered, Moon-like surface and detecting a trace
atmosphere of mostly helium. After the first flyby,
Mariner 10 entered a solar orbit and went on to two
further encounters with the innermost planet. On
September 21, 1974, the second flyby, at an altitude of
47,000 km, afforded another opportunity to photo-
The Mariner Series
Mars Express 259
graph the sunlit side of the planet and the south polar
region. The third and final Mercury encounter on
March 16, 1975, at an altitude of 327 km, yielded 300
photographs and magnetic field measurements.
Mariner 10 was turned off on March 24, 1975, when
its supply of attitude-control gas was depleted.
Launch site: Cape Canaveral
Mariner Date
Launch
Vehicle Mass (kg) Notes
1 Jul. 22, 1962 Atlas-Agena B 200 Failed
2 Aug. 27, 1962 Atlas-Agena B 201 Venus flyby, Dec. 14, 1962
3 Nov. 5, 1964 Atlas-Agena D 260 Failed
4 Nov. 28, 1964 Atlas-Agena D 260 Mars flyby, Jul. 14, 1965
5 Jun. 14, 1967 Atlas-Agena D 244 Mars flyby, Oct. 19, 1967
6 Feb. 24, 1969 Atlas IIIC 412 Mars flyby, Jul. 31, 1969
7 Mar. 27, 1969 Atlas IIIC 412 Mars flyby, Aug. 5, 1969
H (8) May 9, 1971 Atlas IIIC 996 Failed
9 May 30, 1971 Atlas IIIC 974 Mars orbit, Nov. 13, 1971
10 Nov. 3, 1973 Atlas IIID 526 Venus flyby, 3 Mercury flybys
Mars Exploration Rovers
Twin NASA missions to Mars carrying two identical
rovers, each with a mass of about 130 kg, that will be
landed by an airbag system similar to that used by Mars
Pathfinder. The launches are scheduled for May-June
2003, and the landings for January 2004, at two widely
separated sites on Mars that were selected because they
appear to have been associated with liquid water in the
past and may therefore have been favorable to life.
Although the rovers will not search for organic remains
directly, they will seek to determine the history of climate
and water at their sites, which has a direct bearing on the
issue of possible Martian biology.
Immediately after landing, the rovers will begin
reconnaissance of their landing sites by taking 360° visible
color and infrared image panoramas. Then they will
drive off to begin their exploration. Using images and
spectra taken daily from the rovers, mission scientists
on Earth will command the vehicles toward rock and
soil targets of particular interest and then evaluate their
compositions and textures at microscopic scales. Initial
targets will be close to the landing sites, but later targets
are expected to be much farther afield. The rovers will
be able to travel up to 100 m per Martian day (24 hours
37 minutes)—as far as the Sojourner rover did in its
entire lifetime.
Each rover will carry the Athena scientific package
(originally designed for a rover mission in 2001 but canceled
in the wake of two mission failures in 1998),
developed at Cornell University, which consists of a
panoramic camera (Pancam), a rock abrasion tool (RAT)
to expose fresh surfaces of rock, a miniature thermal
infrared spectrometer (MiniTES), a microscopic camera,
a Mossbauer spectrometer, and an alpha-proton-X-ray
spectrometer (APXS). The rovers are each expected to
function for at least 90 days.
Mars Express
An ESA (European Space Agency) mission scheduled for
launch in May or June 2003 by a Soyuz-Fregat rocket and
arrival at Mars in late December of the same year. It will
be the first spacecraft to use radar to penetrate the surface
of Mars and map the distribution of possible underground
water deposits, and it will release the Beagle 2 lander.
Mars Express will carry a remote observation payload
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