Early Spacecraft Exploration
1965-1976
Early Spacecraft Exploration
Mariner 3 & 4
 “…these missions are being undertaken because Mars is
of physical and geological interest and offers the best
opportunity in our solar system for shedding light on the
possibility of extraterrestrial life. (They)…, however, are
not designed to provide answers to the question of life on
Mars.”
Mariner 4 Press Kit, October 29, 1964
Early Spacecraft Exploration
Mariner 4
 Launched November 24, 1964; closest approach occurred
on July 14, 1965
 Took 22 pictures w/ a TV camera (Mars TV Camera)
viewing through a reflecting telescope
Early Spacecraft Exploration
Mariner 4
 Other instruments:
 Magnetometer
 Geiger Count
 Cosmic Ray Telescope
 Solar Plasma Probe
 Cosmic Dust Detector
 Occultation Experiment
Early Spacecraft Exploration
Mariner 4
DATA!!
Early Spacecraft Exploration
Mariner 4
Early Spacecraft Exploration
Mariner 4
Early Spacecraft Exploration
Mariner 4
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How would you rate the quality of these images?
What observations can you make?
How would you interpret these observations?
What can you say we know about Mars at this
point? How certain are you?
What questions would you ask about Mars?
How would you attempt to answer these questions?
What are the limitations to this type of mission
(spacecraft/instruments)?
Early Spacecraft Exploration
Mariner 4
 Notable observations from Mariner 4
 Images returned showed a Moon-like, cratered terrain
 Surface atmospheric pressure of 4.1 to 7.0 mb and
daytime temperatures of -100° C (-148° F) were
estimated
 No magnetic field was detected
Early Spacecraft Exploration
Mariner 4
 How did Mariner 4 advance scientific understanding of
Mars?
 Mars looked more like the Moon
 Life far less likely
 IMPORTANT: Mariner 4 only imaged ~1% of the surface of
Mars, mostly in the southern hemisphere
 What technological advance(s) did Mariner 4 carry?
 The Mariner 4 spacecraft
Early Spacecraft Exploration
Mariner 6 & 7
 “Study the surface and atmosphere of Mars to establish
the basis for future experiments in the search for extraterrestrial life and to develop technology for future Mars
missions. The 1969 flights will not determine the presence
of life on Mars but will help establish whether or not the
Martian environment is suitable for life.”
Mariner (6 & 7) Press Kit, July 18, 1969
Early Spacecraft Exploration
Mariner 6 & 7
 Launched February 23 (M6) & March 27, 1969 (M7)
 Close approaches occurred July 31 (M6) & August 5 (M7),
1969
Early Spacecraft Exploration
Mariner 6 & 7
 Two TV cameras – medium & high resolution
 IR radiometer (surface temps, is southern cap CO2 or H2O?)
 UV spectrometer (atmospheric composition)
 IR spectrometer (surface & near-surface composition)
Early Spaceraft Exploration
Mariner 6 & 7
DATA!!
Early Spacecraft Exploration
Mariner 6 & 7
Early Spacecraft Exploration
Mariner 6 & 7
Mariner 7 approach of Mars
Early Spacecraft Exploration
Mariner 6 & 7
Early Spacecraft Exploration
Mariner 6 & 7
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•
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How would you rate the quality of these images?
What observations can you make?
How would you interpret these observations?
What can you say we know about Mars at this
point? How certain are you?
What questions would you ask about Mars?
How would you attempt to answer these questions?
What are the limitations to this type of mission
(spacecraft/instruments)?
Early Spacecraft Exploration
Mariner 6 & 7
 Notable observations from the Mariner 6 & 7 missions
report
 Temps range between -73° C (-100° F) & 15° C (60° F)
 The polar cap was crusted with frozen carbon dioxide…
 Features with a dimension of 900 (ft.) could be identified.
 The so-called Martian canals were not in evidence.
 At a location called Nix Olympica…was a huge crater 300
miles in diameter.
 No indications of volcanism were found.
 Mariner 6 & 7 imaged 20% of the surface of Mars, mostly in
the southern hemisphere
Early Spacecraft Exploration
Mariner 6 & 7
 How did Mariner 6 & 7 advance scientific understanding of
Mars?
 Temperature range
 South polar cap composed of CO2; temp reading of -123°C
(-190°F)
 NO CANALS
 What technological advance(s) did Mariner 6 & 7 carry?
 Spacecraft with higher resolution cameras & spectrometers
Let’s take a break…
CRATER BOXES!!!
Early Spacecraft Exploration
Mariner 8 & 9
 “Study the surface and atmosphere of Mars in detail, and
over a period of time, to provide a broad picture of the
history of the planet and natural processes currently
shaping the Martian environment. To accomplish this, one
spacecraft will map 70% of the planet and the other will
repeatedly study selected areas on Mars to observe
changes on the surface and in the atmosphere.”
Mariner (8 & 9) Press Kit, April 30, 1971
Early Spacecraft Exploration
Mariner 8 & 9
 Launched May 8 (M8) & May 30, 1971 (M9)
 Mariner 8 failed 4.5 minutes after launch, Mariner 9
arrived at Mars on November 14, 1971
Early Spacecraft Exploration
Mariner 8 & 9
 Visual Imaging System; narrow-angle and wide-angle TV cameras
 IR radiometer (surface temps)
 UV spectrometer (composition of upper atmosphere)
 IR interferometer spectrometer (provide a picture of the circulation of
the atmosphere & composition of the surface)
Early Spacecraft Exploration
Mariner 8 & 9
 DATA!!
Early Spacecraft Exploration
Mariner 9
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How would you rate the quality of these images?
What observations can you make?
How would you interpret these observations?
What can you say we know about Mars at this
point? How certain are you?
What questions would you ask about Mars?
How would you attempt to answer these questions?
What are the limitations to this type of mission
(spacecraft/instruments)?
Early Spacecraft Exploration
Mariner 9
 Arrived at Mars only to find a global dust storm blanketing
the planet
 Circular features peaking through the dust
Early Spacecraft Exploration
Mariner 9
Early Spacecraft Exploration
Mariner 9
Olympus Mons
Caldera Complex
Early Spacecraft Exploration
Mariner 9
Noctis Labyrinthus at
the eastern edge of the
Tharsis bulge; western
end of Valles Marineris
Early Spacecraft Exploration
Mariner 9
Northern Polar Cap
Early Spacecraft Exploration
Mariner 9
Irregular pits and
depressions near
the south pole
Early Spacecraft Exploration
Mariner 9
 Notable results from Mariner 9
 Global mapping (imaging) of the surface of Mars
 The first detailed views of the Martian volcanoes, Valles
Marineris, the polar caps, and the satellites Phobos and
Deimos
 Provided information on global dust storms, the planet’s
rugged gravity field, and evidence for surface aeolian
(wind) activity.
Early Spacecraft Exploration
Mariner 9
 Olympus Mons
 27 km tall (16.8 miles), 600 km (373 miles) wide
 Shield volcano composed of basalt
 Largest (known) volcano in the solar system
Early Spacecraft Exploration
Mariner 9
 Valles Marineris
 4,000 km long (2,500 miles), 200 km (124 miles) wide, 7 km (4 miles)
deep
 Large crack resulting from uplift of Tharsis bulge
 Named after Mariner 9
Early Spacecraft Exploration
Mariner 9
Tharsis Bulge
Credit: NASA/Goddard Space Flight Center
Early Exploration
Mariner 9
 How did Mariner 9 advance scientific understanding of
Mars?
 Mars is more geologically diverse than had ever been
presumed
 Evidence water once flowed on the surface, not in
artificial canals, but natural river channels
 What technological advance(s) did Mariner 9 carry?
 Spacecraft orbited Mars, first unmanned planetary orbiter in
history