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

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at risk to themselves, started pressurizing pumps and
saved the 12-story structure from further collapse
were awarded Exceptional Bravery Medals from
NASA. Mariner 6 was moved to another Atlas-
Centaur and launched on schedule. The pictures it
sent back of Mars were less Moon-like than those of
Mariner 4, and the south polar cap was identified as
being composed mostly of carbon dioxide.
Mariner 7
A Mars flyby probe that was reprogrammed in the
light of the Mariner 6 findings. It was instructed to go
farther south than originally planned, take more nearencounter
pictures, and collect more scientific data on
the lighted side of Mars. In all, it returned 126 images
and approached to within 3,430 km of the surface.
Mariner H (8)
An intended Mars flyby probe, which suffered a
launch failure.
Mariner 9
The first spacecraft to orbit another planet. The
Mariner Mars ’71 mission was supposed to involve
two spacecraft: Mariner 8, which was to map 70% of
the Martian surface, and Mariner 9, which was to
study changes in the Martian atmosphere and on the
ground. The failure of Mariner 8 forced Mariner 9 to
combine the mission objectives. On November 13,
1971, the probe arrived at Mars and, after a rocket
burn lasting 15 minutes 23 seconds, entered orbit.
Imaging was delayed by a dust storm, which quickly
grew into one of the largest ever seen on the planet.
Of the surface, nothing could be seen except the lofty
summits of Olympus Mons and the three Tharsis volcanoes.
The storm abated through November and
December, and normal mapping operations began.
The spacecraft gathered data on the atmospheric composition,
density, pressure, and temperature and the
surface composition, temperature, gravity, and topography.
A total of 7,329 images were returned that covered
the entire planet. After depleting its supply of
attitude control gas, the spacecraft was turned off on
October 27, 1972, and left in an orbit which should
not decay for at least 50 years. Mariner 9 provided the
first global map of the surface of Mars, including the
first detailed views of the Martian volcanoes, Valles
Marineris, and the polar caps, and of the satellites
Phobos and Deimos.
Mariner 10
The first probe to send back close-up pictures of Mercury’s
surface. En route, it received a gravity-assist
from Venus and returned images of the Venusian
atmosphere in ultraviolet, revealing a previously
unseen level of detail in the upper cloud deck. On
March 29, 1974, it flew past Mercury at a distance of
704 km, sending back pictures of an intensely
Mariner 9 NASA/JPL