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Date
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Event
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.
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Aug. 29, 1967
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NASA Hq. cancelled the proposed
Voyager unmanned Mars landing mission because of budget
cutbacks by Congress.
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Sept. 6, 1967
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NASA's Langley Research Center's
(LaRC) Planetary Missions Technology Steering Committee held
a planning meeting to determine a follow-on proposal to
Voyager.
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Oct. 9, 1967
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Office of Space Science and
Applications officials outlined for Administrator James E.
Webb five options for planetary exploration in the
1970s.
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Nov. 1967
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NASA proposed to Congress an
alternative to Voyager: two orbiter-small probe missions to
Mars in 1973 and a more ambitious soft-lander mission in
1975. NASA Hq. assigned the former, called Titan Mars 1973
Orbiter and Lander, to LaRC.
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Jan. 29, 1968
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President Lyndon B. Johnson included
approval of the 1973 orbiter-lander Mars mission in his
budget address to Congress.
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Feb. 9, 1968
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OSSA directed LaRC and the Jet
Propulsion Laboratory (JPL) to conduct baseline mission
studies for the 1973 project. JPL would share in the mission
by managing the development of the orbiter; LaRC would have
overall management authority and responsibility for the
lander.
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Winter-Fall 1968
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General Electric, McDonnell Douglas,
and Martin Marietta conducted mission mode studies for
NASA.
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May 1968
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in response to further budget cuts by
Congress, NASA pared down its plans for the 1973 Mars
missions.
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Aug. 1968
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JPL established a Titan-Mars orbiter
design team.
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Sept. 1968
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Gerald Soffen became project
scientist.
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Sept. 28, 1968
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NASA issued a request for
solicitation for participation in the development of
scientific investigations for the lander.
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Oct. 28 - Nov. 14, 1968
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LaRC, JPL, and NASA Hq. personnel
held a series of meetings at LaRC to define alternative Mars
missions for 1973. The group chose a soft-lander mission
with extended life and a flyby support module and labeled
the proposal Viking.
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Nov. 1968-
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JPL produced a baseline orbiter
conceptual design. Feb. 1969
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Dec. 4, 1968
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NASA Administrator Thomas 0. Paine
approved a more ambitious scheme for an orbiter-lander
Viking. The 1973 mission would be launched by a Titan
IIID-Centaur.
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Dec. 6, 1969
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LaRC established an interim Viking
Project Office, with James S. Martin, Jr., as project
manager.
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Feb. 8, 1969
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Paine signed the project approval
document.
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Feb. 11, 1969
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NASA invited 38 scientists to
participate in the planning for lander experiments.
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Feb. 25, 1969
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NASA announced the members of the
eight Viking science teams.
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Feb. 28, 1969
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NASA issued a request for proposals
(RFP) for the Viking lander. Boeing, McDonnell Douglas, and
Martin Marietta responded.
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Apr. 17, 1969
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JPL established a Viking Orbiter
Office, to be managed by Henry W. Norris.
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May 29, 1969
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NASA chose Martin Marietta Corp. as
the prime contractor for the lander.
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July 15, 1969
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NASA Hq. managers issued an
invitation to scientists to work on one of the orbiter or
lander science teams or propose alternatives of proposals or
additional experiments. NASA received 150 proposals by Oct.
20.
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Aug. 11, 1969
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The Viking team released an updated
project definition document.
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Dec. 31, 1969
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Administrator Paine determined that
the 1973 Viking missions would have to be delayed until 1975
to respond to a budget cut by Congress.
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Oct. 19-20, 1971
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The Viking team held the orbiter
preliminary design review.
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Jan.-July 1973
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JPL held critical design reviews of
the orbiter subsystems.
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Apr. 3, 1973
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The Viking site selection team made
the final decision on landing sites for the two
landers.
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July 9-10, 1973
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NASA conducted the orbiter critical
design review.
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Jan. 1974
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JPL began conducting tests with the
proof-test orbiter.
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Sept. 27, 1974
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Because of budget cuts, JPL could not
continue its testing of a third orbiter. The team
redesignated the proof-test orbiter Viking Orbiter I and put
the third craft in storage. NASA also cancelled the third
lander.
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Jan. 4, 1975
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Martin Marietta delivered the first
lander to the Kennedy Space Center, and verification test
teams began their work.
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Jan. 31, 1975
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JPL completed orbiter qualification
tests.
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Feb. 11, 1975
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JPL delivered the first orbiter
flight hardware to KSC, where verification tests were
begun.
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Mar. 8, 1975
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NASA engineers mated a Viking lander
and orbiter for the first time. They enclosed the pair in
the Centaur launch shroud on the 27th.
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June 1975
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Technicians sterilized the two
landers.
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Aug. 11, 1975
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KSC officials were forced to cancel
the countdown for the first Viking mission because of a
corroded thrust-vector-control valve. After the
postponement, technicians discovered that the orbiter's
batteries had been discharged and had to be replaced. The
entire spacecraft was removed from the stack, and the second
spacecraft was prepared for launch.
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Aug. 20, 1975
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NASA successfully launched Viking
1.
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Sept. 9, 1975
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Viking 2 joined the first Mars-bound
spacecraft after a successful launch.
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Dec. 1975 - June 1976
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Viking teams simulated lander and
orbiter operations in preparation for actual mission
events.
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June 21, 1976
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Viking I was inserted into its
precise orbit of Mars. The first pictures returned by the
orbiter indicated that the landing sites chosen for the
spacecraft would have to be rejected.
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June 27, 1976
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Viking managers decided to postpone
the July 4 landing while they looked for safer sites.
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July 20, 1976
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Viking I landed safely on
Mars.
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Aug. 7, 1976
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Viking 2 began its Martian orbits,
and the site certification team continued its search for a
second landing site.
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Sept. 3, 1976
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Viking 2 touched down on the Martian
surface.
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Nov. 15, 1976
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NASA terminated the Viking primary
mission.
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Dec. 1976
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Spacecraft controllers reactivated
the landers and began an extended mission.
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