THE NEW LOOK OF VENUS
The historic mission of Mariner II to the near-vicinity of Venus and
beyond has enabled scientists to revise many of their concepts of
interplanetary space and the planet Venus.
The composite picture, taken from the six experiments aboard the
spacecraft and the data from the DSIF radar experiments of 1961 and 1962
revealed the following:
—Interplanetary space between the Earth and Venus, at least as it was
during the four months of Mariner’s mission, had a cosmic dust density
some ten-thousand times lower than the region immediately surrounding
the Earth.
—During this period, the extremely tenuous, widely fluctuating solar
winds streamed continually out from the Sun, at velocities ranging
from 200 to 500 miles per second.
—An astronaut travelling through these regions in the last quarter of
1962 would not have been seriously affected by the cosmic and
high-energy radiation from space and the Sun. He could easily have
survived many times the amount of radiation detected by Mariner’s
instruments.
—111
—The astronomical unit, as determined by radar, the yardstick of our
solar system, stands at 92,956,200, plus or minus 300 miles.
—The mass of Venus in relation to the Earth’s is 0.81485, with an error
probability of 0.015%.
—The rotation rate of Venus is quite slow and is now estimated as equal
to 230 Earth days, plus or minus 40 to 50 days. The rotation might be
retrograde, clockwise with respect to a Sun-facing reference, with the
Sun rising in the west and setting in the east approximately one
Venusian year later. The planet seems to remain nearly star-fixed
rather than permanently oriented with one face to the Sun.
—Venus has no magnetic field discernible at the 21,598-mile approach of
Mariner II and at that altitude there were no regions of trapped
high-energy particles or radiation belts, as there are near the Earth.
—The clouds of Venus are about 15 miles thick, extending from a base 45
miles above the surface to a top altitude of about 60 miles.
—At the resolution of the Mariner II infrared radiometer, there were no
apparent breaks in the cloud cover. Cloud-top temperature readings are
about minus 30 degrees F near the center (along the terminator), and
ranging down to minus 60 degrees to minus 70 degrees F at the limbs,
showing an apparent limb-darkening effect, which would indicate a hot
surface and the absence of a supercharged ionosphere.
—A spot 20 degrees F colder than the surrounding area exists along the
terminator in the southern hemisphere: a high mountain could exist in
this region, but such an hypothesis is purely conjectural. A bright
radar reflection is also found on the Equator in the same general
region. Causes of these phenomena are not established.
—At their base, the clouds are about 200 degrees F and probably are
comprised of condensed hydrocarbons held in oily suspension. Below the
clouds, the atmosphere must be heavily charged with carbon dioxide,
may contain slight traces of oxygen, and probably has a strong
concentration of nitrogen.
—112
—As determined by the microwave radiometer, Venus’ surface temperature
averages approximately 800 degrees F on both light and dark sides of
the planet. Some roughness is indicated and the surface reflectivity
is equivalent to that of dust and sand. No water could be present at
the surface but there is some possibility of small lakes of molten
metal of one type or another.
—Some reddish sunlight, in the filterable infrared spectrum, may find
its way through the 15-mile-thick cloud cover, but the surface is
probably very bleak.
—The heavy, dense atmosphere creates a surface pressure of some twenty
times that found on the Earth, or equal to about 600 inches of
mercury.
The mission was completed and the spacecraft had gone into an endless
orbit around the Sun. But before Mariner II lost its sing-song voice, it
produced 13 million data words of computer space lyrics to accompany the
music of the spheres.
APPENDIX
SUBCONTRACTORS
Thirty-four subcontractors to JPL provided instruments and other
hardware for Mariners I and II.
The subcontractors were:
Aeroflex Corporation Jet vane actuators
Long Island City, New York
American Electronics, Inc. Transformer-rectifiers for flight
Fullerton, California telecommunications
Ampex Corporation Tape recorders for ground telemetry
Instrumentation Division and data handling equipment
Redwood City, California
Applied Development Corporation Decommutators and teletype encoders
Monterey Park, California for ground telemetry equipment
Astrodata, Inc. Time code translators, time code
Anaheim, California generators, and spacecraft signal
simulators for ground telemetry
equipment
Barnes Engineering Company Infrared radiometers
Stamford, Connecticut Planet simulator
Bell Aerospace Corporation Accelerometers and associated
Bell Aerosystems Division electronic modules
Cleveland, Ohio
Computer Control Company, Inc. Data conditioning systems
Framingham, Massachusetts
Conax Corporation Midcourse propulsion explosive
Buffalo, New York valves
Squibs
Consolidated Electrodynamics Corp. Oscillographs for data reduction
Pasadena, California
Consolidated Systems Corporation Scientific instruments
Monrovia, California Operational support equipment
Dynamics Instrumentation Company Isolation amplifiers for telemetry
Monterey Park, California Operational support equipment
Electric Storage Battery Company Spacecraft batteries
Missile Battery Division
Raleigh, North Carolina
Electro-Optical Systems, Inc. Spacecraft power conversion
Pasadena, California equipment
Fargo Rubber Corporation Midcourse propulsion fuel tank
Los Angeles, California bladders
Glentronics, Inc. Power supplies for data
Glendora, California conditioning system
Groen Associates Actuators for solar panels
Sun Valley, California
Houston Fearless Corporation Pin pullers
Torrance, California
Kearfott Division Gyroscopes
General Precision, Inc.
Los Angeles, California
Marshall Laboratories Magnetometers and associated
Torrance, California operational support equipment
Matrix Research and Development Power supplies for particle flux
Corporation detectors
Nashua, New Hampshire
Menasco Manufacturing Company Midcourse propulsion fuel tanks and
Burbank, California nitrogen tanks
Midwestern Instruments Oscillographs for data reduction
Tulsa, Oklahoma
Mincom Division Tape recorders for ground telemetry
Minnesota Mining & Manufacturing and data handling equipment
Los Angeles, California
Motorola, Inc. Spacecraft command subsystems,
Military Electronics Division transponders, and associated
Scottsdale, Arizona operational support equipment
Nortronics Attitude control gyro electronic,
Division of Northrop Corporation autopilot electronic, and antenna
Palos Verdes Estates, California servo electronic modules,
long-range Earth sensors and Sun
sensors
Ransom Research Verification and ground command
Division of Wyle Laboratories modulation equipment
San Pedro, California
Rantec Corporation Transponder circulators and monitors
Calabasas, California
Ryan Aeronautical Company Solar panel structures
Aerospace Division
San Diego, California
Spectrolab Solar cells and their installation
Division of Textron Electronics, and electrical connection on
Inc. solar panels
North Hollywood, California
State University of Iowa Calibrated Geiger counters
Iowa City, Iowa
Sterer Engineering & Manufacturing Valves and regulators for midcourse
Company propulsion and attitude control
North Hollywood, California systems
Texas Instruments, Inc. Spacecraft data encoders and
Apparatus Division associated operational support
Dallas, Texas equipment, ground telemetry
demodulators
Trans-Sonic, Inc. Transducers
Burlington, Massachusetts
In addition to these subcontractors, over 1,000 other industrial firms
contributed to the Mariner Project.
FOOTNOTES
[1]Throughout this book “Mariner” refers to the successful Mariner II
Venus mission. Mariner I was launched earlier but was destroyed when
the launch vehicle flew off course.
[2]For scientific reasons, distances from Venus are calculated from the
center of the planet. Hereafter in this chapter, these distances
will be reckoned from the surface.
INDEX
A
ABMA, 17
Agena B, 21, 22, 40
Antennas, 66
Goldstone, description, 70, 71, 73
onboard, description, 30, 31
directional control, 30
Pioneer tracking site, 70, 71
ARPA, 17
Astronomical unit, 111
refinement, 107
Atlantic Missile Range, 2, 10, 43, 83
Atlas-Agena B, 63, 52
Atlas D, 19, 21, 36-39, 89
Attitude control
Atlas D, 38
Earth acquisition, 58
loss of control and reorientation, 56, 60
Attitude control system, 31, 32
B
Battery, 25, 27
Bumper-WAC, 18
C
C-133 aircraft, 43
Centaur, 8
Central Computer and Sequencer, 28
commands, 56, 58
failure at encounter, 62
midcourse maneuver control, 59
Central Computing Facility, 81, 82
Charged particles, 13, 90
Charged particle detector, 35, 88
Computers, data processing, 84
Corporal E, 18
Cosmic dust, 13
density, 110
distribution and mass, 94, 95
measurement, 89
Cosmic dust detector, 35, 68, 87, 89
Cosmic radiation, 13, 96
Cosmic ray flux, 98
D
Data conditioning system, 88
Data processing, 30, 74, 85
CCF, equipment and operation, 82, 83
launch and tracking operations, 83
telemetry data, 84
transmission time, 88
Detectors
charged particle, 35
cosmic dust, 35
solar plasma, 35
DSIF, 73, 74, 75, 82, 83, 84
functions, 68
Goldstone, 1, 64, 67-79, 68, 69, 70, 71, 73, 75, 84, 107, 108,
109
Johannesburg, 64, 67, 68, 73
Mobile, 68, 73, 80
tracking during midcourse maneuver, 56
orientation, 56
Woomera, 67, 68, 71, 73, 75
E
Earth sensor
final orientation commands, 64
September 8, crises and recovery, 60
Echo Project, 69
Echo site functions, 71
Electronics equipment weight, 25
Explorer I, 19
Experiments, 35
Anton special purpose tube, 87
atmospheric investigation, 85
charged particle detector, 88, 96-100
density variation data, 98
radiation hazard findings, 98
cosmic dust detector data, 87-89, 94, 95
high energy radiation, 90
infrared radiometer, 87, 93
ion chamber and Geiger-Mueller tubes, 87
magnetometers, 87, 88
microwave radiometer, 87, 91-93
objectives, 13, 93
processing of data, 85
radiometers, 85, 105, 106
responsible organizations, 88
results, 110-112
solar plasma detector, 87-90
temperature investigation, 85
transmission of data, 88
weight, 25
G
Geiger counter, 98
Geiger-Mueller tubes, 87, 91
George C. Marshall Space Flight Center, 13, 17
Goldstone Tracking Station, 64, 67, 69, 75, 84, 107
Echo site, 68, 69, 71, 73
Pioneer site, 56, 68, 70
Venus site, 69, 70, 108, 109
Guidance, 13
H
High-energy radiation experiments, 90, 91
I
Infrared radiometer experiment
cloud observations, 103, 105, 106
description, 93
dimensions, 93
operating characteristics, 85, 93
Interplanetary magnetic field, 13, 99
Interplanetary space
cosmic dust density, 110
distribution, 95
hazards to spacecraft, 13
Ion chamber, 98
J
Johannesburg tracking station, 67, 68
equipment, 68, 73
functions, 68, 73
JPL, 2, 8, 13, 75, 76, 80, 82, 84
accomplishments, 18, 19
background, 18
DSIF control point, 67, 68
pre-Mariner spacecraft, 23
Jupiter, contrast to Venus, 101
Jupiter C, 19
L
Launch Operations Center, 12, 17
Launching, 56
Atlas performance, 52, 53
Atlas-Agena B, 52
battery, 52
gyroscopes, 53
radio guidance system, 52
time limitations, 12
M
Magnetometer experiment, 35, 88
data, 101, 102
description, 91
function, 91
objectives, 100
onboard location, 91
Mariner I, 43-45
Mariner R, 41
Masers, 70
Materials, thermal shielding, 33
Microwave radiometer experiment
description, 91
function, 91
measurements, 103, 105
operating characteristics, 85, 92-93
Midcourse maneuver, 32, 58-59, 60, 65
Mission achievements, records, 65
Mobile tracking station, 68, 80
location, equipment and function, 73
MX-774 Project, 21
N
NACA, precursor of NASA, 16
NASA, 8, 16, 17
P
Parking orbit, 55
Pioneer III, 19
Pioneer IV, 19
Pioneer project, 69
Pioneer tracking site, 70, 71
Power system, 25
Private A, 18
Propellants
Atlas D, 38
attitude control system, 32
spacecraft, controlled burning, 32
rocket thrust system, 32
Propulsion system, Mariner
spacecraft, hydrazine propellant, 33
propellant storage, 32, 38
weight, 25
R
Radiation, 98-100
Ranger III, 8
Receivers, 66
Records, Mariner
attitude control system, 65
measurements near Sun, 65
operation near Venus
telemetry measurements, distance, 65
trajectory correction maneuver, 65
transmission, continuous performance, 65
S
Sensors
Earth, for attitude control, 32
Sun, for attitude control, 32
Sergeant missile, 19
Shielding, 33, 34
Solar cells, 27, 28
Solar flares, 98, 99
Solar panels
description, 25
design, 27
output deterioration, 61
release, 11
support, 25
weight, 27
Solar plasma detector, 35, 88, 96, 97
description, 87, 89, 90
function, 87, 89, 90
recordings, 96, 97
Solar plasma flux
correlation with geomagnetic effects, 97
Solar wind
effects on cosmic-ray movements, 96
magnetic fields, 95, 96
low density and energy, 96
measurement, 89
particle concentration near Earth, 96
particle energies, 96
temperature, 96
theories, 95
velocities, 13, 95, 96, 97, 110
Space Flight Operations Center, 60
organization and operation, 75, 80, 81
Space simulator, temperature control, 41
Spacecraft, 31
attitude control system, 31
Central Computer and Sequencer, 28
components and subsystems, 27
configuration, 23
electronic equipment, 25
frame materials, 23, 25
launching, 12
power system, 25
preliminary design, 41
propulsion system, 32
shroud and adapter, 43
system tests, 41
telecommunications subsystem, 30
temperature, 33
test models, 41
testing, 23
trajectory, 11
weight, 25
Sun sensor, 32
T
Telemetry
continuous transmission, 65
data processing, 84
description, 30
loss of monitoring data, 62
phase-shift modulation, 30
transmission cutoff, 64
Telemetry processing station, 82, 83
Telemetry system
data processing, 30
onboard, description, 30
Temperature control
coatings, 34
heating problems, 62
housing structures, 35
materials, 33
problems, 33
solar panels, 35
solar radiation shielding, 35
thermal shielding, 33
Tracking
Antigua, 53
Ascension, 53, 55
DSIF, 52, 66, 67, 68, 69
Earth noise, 66
Grand Bahama Island, 53
Johannesburg, 56
Pretoria, 53, 55
problems, 66
radio noise, 66
San Salvador, 53
solar noise, 66
Twin Falls Victory, 53, 55
Whiskey, 55
Woomera, 56
Trajectory, 11, 63, 64, 83
V
V-2 rocket, 18
Van Allen radiation belt, 19, 97
Venus
atmosphere, 3, 5, 104, 105, 112
atmospheric temperature, 85
atmospheric winds, 5
CO₂ content above clouds, 106
cloud cover, 105, 106
cloud observations, 104, 105
clouds, data, 111
compared with Earth, 5
description, 4
dielectric constant, surface material, 107
encounter, 93, 94
historical data, 2
inferior and superior conjunctions, 4
magnetic field, 98, 100, 111
comparison with geomagnetic, 100, 101
data, 100, 101, 102
strength, 100, 101, 102
mass, 109, 111
orbit, 4
radar experiments, 1961, 106, 107
radar experiments during mission, 107
reflection coefficient, 107
revolution, 4
rotation, 4, 101, 108, 111
surface, 106
brightness temperature, 103, 104
characteristics, theories, 102, 103
“greenhouse” effect, 106
measurements, 103, 104
pressure, 112
reflectivity, 111
roughness, 107, 108
temperature, 106, 111
temperature, 85, 111
topography, 5
water vapor in atmosphere, 106
Venus encounter, 63
W
WAC Corporal, 18
Woomera Tracking Station, 67, 68, 75
equipment, 68, 71, 73
Transcriber’s Notes
—Retained publication information from the printed edition: this eBook
is public-domain in the country of publication.
—In the text versions only, text in italics is delimited by
_underscores_.
—Silently corrected a few typos.
—In the index, entry “propellant storage”, replaced one nonsensical page
number (200) with a plausible conjecture (38).