Early Spacecraft ExplorationViking

“The scientific goal of the Viking missions is to ‘increase our knowledge of the planet Mars with an emphasis on the search for extra-terrestrial life.’ The scientific questions deal with the atmosphere, the surface, the planetary body, and the question of bio-organic evolution.”

Viking Press Kit, July 1975

Early Spacecraft ExplorationViking

Get down, get dirty.

Twin orbiter/lander combos

Early Spacecraft ExplorationViking

V1 devoted the first month to searching for landing sites for the lander; V1 lander touched down July 20, 1976 in Chryse Planitia

V2 first month devoted to searching for a landing site; V2 touched down September 3, 1976 in Utopia Planitia

Early Spacecraft ExplorationVikingV1 devoted the first month to searching for landing sites for the lander; V1

lander touched down July 20, 1976 in Chryse Planitia

V2 first month devoted to searching for a landing site; V2 touched down September 3, 1976 in Utopia Planitia

Delayed landing…

Early Spacecraft ExplorationVikingV1 devoted the first month to searching for landing sites for the lander; V1 lander touched down July 20,

1976 in Chryse Planitia

V2 first month devoted to searching for a landing site; V2 touched down September 3, 1976 in Utopia Planitia

Delayed landing…

Landing sites selected with Mariner 9 imagery, Viking orbiter cameras were higher resolution

Early Spacecraft ExplorationViking

Landing Site Locations

Early Spacecraft ExplorationViking

With landers on the ground, orbiters continued science mission above and acted as data relays for landers

Early Spacecraft ExplorationViking

Sinuous canyon in Nanedi Vallis

Early Spacecraft ExplorationViking

Early Spacecraft ExplorationViking

Early Spacecraft ExplorationViking

Viking 2 lander touched down with one pad on a boulder; tilted 8°.

Early Spacecraft ExplorationViking

Early Spacecraft ExplorationViking

Notable results from Viking orbiters:Mapped 97% of the surface; 52,000 total imagesDefinitively determined the North residual polar cap is

water-ice, not frozen carbon dioxideStirred up a little “controversy” with one particular image

Early Spacecraft ExplorationViking

Early Spacecraft ExplorationViking

Notable results from Viking landers: Biology experiments provided no clear evidence for the presence of

living organisms in soil near the landing sites Gas Chromatograph/Mass Spectrometer found no evidence of

organic material at either landing site Winds blew more slowly than anticipated (200 MPH); highest

recorded wind gust was 120 km/hr (74 mph) and average velocities were much lower

Weather in the Martian midsummer was repetitious but was variable and more interesting in other seasons

Early Spacecraft ExplorationViking

Notable results from Viking landers: Atmospheric composition: CO2: 95.32%

N: 2.7% Ar: 1.6% O: 0.13 CO: 0.7% H2O (vapor): 0.03%

Early Spacecraft ExplorationViking

Notable results from Viking landers: Atmospheric composition: CO2: 95.32%

N: 2.7% Ar: 1.6% O: 0.13 CO: 0.7% H2O (vapor): 0.03%

1963: 72% N2

25% CO2

2% Ar

< 0.5% O2

Trace amounts of H2O

Early Spacecraft ExplorationViking

How did Viking advance scientific understanding of Mars? Difficult for life to exist on the surface at present, but this does not rule out

past life More evidence for past habitability Weather patterns Though no current life, Mars is a dynamic planet

What technological advance(s) did Viking carry? LANDER!! Higher res. Cameras Weather station Biology experiments Orbiters acted as communications relay, selective landing sites

Early Exploration

How did Viking change and/or reaffirm perceptions of Mars?

History of Mars Exploration

Viking mission operations ended in the early 1980s

Viking missions gave scientists the most complete picture of Mars to date

History of Mars Exploration

Attempts to explore Mars did not start up again until the early 1990s. Why not?

Why was it revived?

History of Mars Exploration

Attempts to explore Mars did not start up again until the early 1990s. Why not?

Why was it revived?

History of Mars Exploration

Attempts to explore Mars did not start up again until the early 1990s.

The first one failed.

The next two gave Mars a face-lift and showed a new way to explore.

Modern ExplorationGlobal Surveyor

Modern ExplorationGlobal Surveyor

Objectives: High resolution imaging of the surface Study the topography and gravity Study the role of water and dust on the

surface and in the atmosphere Study the weather and climate of Mars Study the composition of the surface and

atmosphere Study the existence and evolution of the

Martian magnetic field

Modern ExplorationGlobal Surveyor

Modern ExplorationGlobal Surveyor

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Modern ExplorationGlobal Surveyor

Notable results from Global Surveyor The northern hemisphere is probably just as cratered as the

southern hemisphere, but the craters are mostly buried. High-resolution imagery shows modifications to the surface

have taken place over the past decade. Hundreds of gullies were discovered that were formed from

liquid water (probably), possibly in recent times. The Thermal Emission Spectrometer found that just about all

of the surface of Mars is covered with volcanic rock. Magnetometer data show remnant, alternating magnetic

fields

Modern ExplorationGlobal SurveyorHow did Global Surveyor advance scientific understanding of Mars?

Smoking gun evidence that liquid water was stable on the surface for long periods of time

Mars exhibits a “global dichotomy” in terms of topography Spectral ID of the global surface composition

What technological advance(s) did Global Surveyor carry? Highest-resolution camera, for the time Laser altimeter TES; lithology, mineralogy Magnetometer; remnant magnetic field

Early Exploration

How did Mars Global Surveyor change and/or reaffirm perceptions of Mars?

Modern ExplorationMars Pathfinder

Modern ExplorationMars Pathfinder

The primary mission objectives were to demonstrate the feasibility of low-cost landings on, and exploration of, the Martian surface (Faster, Better, Cheaper)

Scientific objectives included atmospheric entry science long-range and close-up surface imaging the general objective was to characterize the Martian environment

for further exploration

Modern ExplorationMars PathfinderLanded in Ares Vallis which was believed to be the site of an ancient floodLanding site selection made using Viking orbiter imageryFirst rover; first to use airbags

Modern ExplorationMars Pathfinder

Landing Site Locations

Modern ExplorationMars Pathfinder

Pathfinder Landing Site

Modern ExplorationMars Pathfinder

Pathfinder Landing Site

Modern ExplorationMars Pathfinder

Notable results from PathfinderMore than 16,500 images from the lander and 550

images from the roverMore than 15 chemical analyses of rocks and soil and

extensive data on winds and other weather factorsFindings from the investigations carried out by scientific

instruments on both the lander and the rover suggest that Mars was at one time in its past warm and wet, with water existing in its liquid state and a thicker atmosphere

Modern ExplorationMars Pathfinder

How did Pathfinder advance scientific understanding of Mars? Evidence on the ground for a warm, wet past

What technological advance(s) did Pathfinder carry? First rover; can be remotely operated New landing system

Early Exploration

How did Mars Pathfinder change and/or reaffirm perceptions of Mars?