16.2 Development Status
519
forces at landing impact of the lunar lander. They were designed to accept a force of
approximately 800 kg. Because of engine failure, Surveyor 2 failed.
Surveyor 3 was launched in April 1967. The specific objectives for this mission
were to select potential landing site for Apollo program and obtain information on
lunar surface radar reflectivity, thermal properties and bearing strength. Besides TV
camera, there was lunar surface sampler on the lunar lander. The specification of TV
camera was the same as that of Surveyor 1. The camera returned 6326 pictures to
the Earth. The sampler was mounted below the television camera, which could be
extended about 1.5 m and dig to 0.5 m depth. The scoop sampler was mounted on
a pantograph arm. The arm could also be moved from an azimuth of –72° to +40°.
The scoop was capable of holding a maximum of 100 cm
3 of granular material. The
surface sampler performed seven bearing tests, four trench tests, and 13 impact tests.
A 175 mm depth was reached during trenching operations. According to above exploration results, scientists implied that the density of lunar soil was identical to sand on
Earth and the bearing strength is 0.7 kg/cm
2 , which was enough to support Apollo
lunar module. Because the landing radar was powered off, the radar reflectivity of
lunar soil was not measured. In Nov. 1969, two astronauts of Apollo 12 visited the
spacecraft and removed about 10 kg of parts from the spacecraft, including the TV
camera and the sampler, for later examination back on Earth to study lunar surface
environment effects in two and half years.
Surveyor 4 was launched in July 1967. There were instruments same as that
of Surveyor 3, with additional lunar soil magnetic sensor inside the sampler for
iron abundance measurement in lunar surface soil. Approximately 2.5 min before
touchdown, the radio signals from the probe ceased during the terminal-descent phase
and the mission failed.
Surveyor 5 was launched in Sept. 1967. The specific objectives for this mission
were to perform a soft landing on the Moon in Mare Tranquillitatis and obtain post
landing television pictures of the lunar surface, determine the relative abundances of
the chemical elements in the lunar soil he mechanical properties of lunar soil, conduct
a vernier engine erosion experiment, obtain touchdown dynamics data, and obtain
thermal and radar reflectivity data. The instrumentation for Surveyor 5 was similar to
that of the previous Surveyors and included the television camera and lunar surface
sampler. A α scattering instrument and a small bar magnet attached to one footpad
were included. The spacecraft returned 20018 pictures. On 13 Sept., the main engine
was fired for 0.55 s to study interference to lunar surface. The image showed that there
was no pit and obvious dust cloud. The α scattering instrument was mounted inside
the sampler with six α sources (
242 Cm) to radiate area in 100 mm diameter. There
were two detection systems in the α scattering instrument. One detection system with
two sensors was applied to investigate α particle energy spectrum scattered by lunar
surface. Another detection system with four sensors was applied to investigate proton
energy spectrum generated by lunar surface reaction. The α scattering instrument
worked continuously for 83 h in first lunar day and high quality data was acquired. It
worked continuously for 22 h in second lunar day. The α scattering results indicated
that the oxygen, silicon and aluminum in soil composition was over 50%.
519
forces at landing impact of the lunar lander. They were designed to accept a force of
approximately 800 kg. Because of engine failure, Surveyor 2 failed.
Surveyor 3 was launched in April 1967. The specific objectives for this mission
were to select potential landing site for Apollo program and obtain information on
lunar surface radar reflectivity, thermal properties and bearing strength. Besides TV
camera, there was lunar surface sampler on the lunar lander. The specification of TV
camera was the same as that of Surveyor 1. The camera returned 6326 pictures to
the Earth. The sampler was mounted below the television camera, which could be
extended about 1.5 m and dig to 0.5 m depth. The scoop sampler was mounted on
a pantograph arm. The arm could also be moved from an azimuth of –72° to +40°.
The scoop was capable of holding a maximum of 100 cm
3 of granular material. The
surface sampler performed seven bearing tests, four trench tests, and 13 impact tests.
A 175 mm depth was reached during trenching operations. According to above exploration results, scientists implied that the density of lunar soil was identical to sand on
Earth and the bearing strength is 0.7 kg/cm
2 , which was enough to support Apollo
lunar module. Because the landing radar was powered off, the radar reflectivity of
lunar soil was not measured. In Nov. 1969, two astronauts of Apollo 12 visited the
spacecraft and removed about 10 kg of parts from the spacecraft, including the TV
camera and the sampler, for later examination back on Earth to study lunar surface
environment effects in two and half years.
Surveyor 4 was launched in July 1967. There were instruments same as that
of Surveyor 3, with additional lunar soil magnetic sensor inside the sampler for
iron abundance measurement in lunar surface soil. Approximately 2.5 min before
touchdown, the radio signals from the probe ceased during the terminal-descent phase
and the mission failed.
Surveyor 5 was launched in Sept. 1967. The specific objectives for this mission
were to perform a soft landing on the Moon in Mare Tranquillitatis and obtain post
landing television pictures of the lunar surface, determine the relative abundances of
the chemical elements in the lunar soil he mechanical properties of lunar soil, conduct
a vernier engine erosion experiment, obtain touchdown dynamics data, and obtain
thermal and radar reflectivity data. The instrumentation for Surveyor 5 was similar to
that of the previous Surveyors and included the television camera and lunar surface
sampler. A α scattering instrument and a small bar magnet attached to one footpad
were included. The spacecraft returned 20018 pictures. On 13 Sept., the main engine
was fired for 0.55 s to study interference to lunar surface. The image showed that there
was no pit and obvious dust cloud. The α scattering instrument was mounted inside
the sampler with six α sources (
242 Cm) to radiate area in 100 mm diameter. There
were two detection systems in the α scattering instrument. One detection system with
two sensors was applied to investigate α particle energy spectrum scattered by lunar
surface. Another detection system with four sensors was applied to investigate proton
energy spectrum generated by lunar surface reaction. The α scattering instrument
worked continuously for 83 h in first lunar day and high quality data was acquired. It
worked continuously for 22 h in second lunar day. The α scattering results indicated
that the oxygen, silicon and aluminum in soil composition was over 50%.