Early Spacecraft Exploration Viking  “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 Exploration Viking Get down, get dirty. Twin orbiter/lander combos

Early Spacecraft Exploration Viking  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 Exploration Viking  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  Delayed landing…

Early Spacecraft Exploration Viking  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  Delayed landing…  Landing sites selected with Mariner 9 imagery, Viking orbiter cameras were higher resolution

Early Spacecraft Exploration Viking  Landing Site Locations

Early Spacecraft Exploration Viking  With landers on the ground, orbiters continued science mission above and acted as data relays for landers

Early Spacecraft Exploration Viking Sinuous canyon in Nanedi Vallis

Early Spacecraft Exploration Viking

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

Early Spacecraft Exploration Viking

 Notable results from Viking orbiters:  Mapped 97% of the surface; 52,000 total images  Definitively determined the North residual polar cap is water-ice, not frozen carbon dioxide  Stirred up a little “controversy” with one particular image

Early Spacecraft Exploration Viking

 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 Exploration Viking  Notable results from Viking landers:  Atmospheric composition:  CO 2 : 95.32%  N: 2.7%  Ar: 1.6%  O: 0.13  CO: 0.7%  H 2 O (vapor): 0.03%

Early Spacecraft Exploration Viking  Notable results from Viking landers:  Atmospheric composition:  CO 2 : 95.32%  N: 2.7%  Ar: 1.6%  O: 0.13  CO: 0.7%  H 2 O (vapor): 0.03%  1963:  72% N 2  25% CO 2  2% Ar  < 0.5% O 2  Trace amounts of H 2 O

Early Spacecraft Exploration Viking  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 Exploration Global 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 Exploration Global Surveyor

Credit: Malin Space Science Systems –

Modern Exploration Global 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 Exploration Global Surveyor  How 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 Exploration Mars 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 Exploration Mars Pathfinder  Landed in Ares Vallis which was believed to be the site of an ancient flood  Landing site selection made using Viking orbiter imagery  First rover; first to use airbags

Modern Exploration Mars Pathfinder  Landing Site Locations

Modern Exploration Mars Pathfinder  Pathfinder Landing Site

Modern Exploration Mars Pathfinder  Pathfinder Landing Site

Modern Exploration Mars Pathfinder  Notable results from Pathfinder  More than 16,500 images from the lander and 550 images from the rover  More than 15 chemical analyses of rocks and soil and extensive data on winds and other weather factors  Findings 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 Exploration Mars 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?