PREPARING FOR SPACE
In the summer of 1961, the United States was pushing hard to strengthen
its position in the exploration of space and the near planets. The
National Aeronautics and Space Administration was planning two projects,
both to be launched by an Atlas booster and a Centaur high-energy second
stage capable of much better performance than that available from
earlier vehicles.
The Mariner program had two goals: Mariner A was ticketed for Venus and
Mariner B was scheduled to go to Mars. Caltech’s Jet Propulsion
Laboratory had management responsibility under NASA for both projects.
These spacecraft were both to be in the 1,000- to 1,250-pound class.
Launch opportunities for the two planets were to be best during the
1962-1964 period and the new second-stage booster known as Centaur was
expected to be ready for these operations.
But trouble was developing for NASA’s planners. By August, 1961, it had
become apparent that the Centaur would not be flying in time to take
advantage of the 1962 third-quarter firing period, when Venus would
approach inferior conjunction with the Earth. JPL studied the problem
and advised NASA that a proposed lightweight, hybrid spacecraft
combining certain design features of Ranger III (a lunar spacecraft) and
Mariner A could be launched to Venus in 1962 aboard a lower-powered
Atlas-Agena B launch vehicle.
[Illustration: _The Mariner II spacecraft was launched by an Atlas
first-stage booster vehicle and an Agena B second stage with restart
capability._]
ATLAS-AGENA ADAPTER
AGENA B
MARINER SPACECRAFT
SHROUD
The proposed spacecraft would be called Mariner R and was to weigh about
460 pounds and carry 25 pounds of scientific instruments (later
increased to 40 pounds). The restart capability of Agena was to be used
in a 98-statute-mile parking orbit. (The orbit was later raised to 115
statute miles and the spacecraft weight was reduced to about 447
pounds.)
Two spacecraft would be launched one after the other from the same pad
within a maximum launch period extending over 56 days from July to
September, 1962. The minimum launch separation between the two
spacecraft would be 21 days.
As a result of the JPL recommendations, NASA cancelled Mariner A in
September, 1961, and assigned JPL to manage a Mariner R Project to fly
two spacecraft (Mariner I and II) to the vicinity of Venus in 1962.
Scientific measurements were to be made in interplanetary space and in
the immediate environs of the planet, which would also be surveyed in an
attempt to determine the characteristics of its atmosphere and surface.
Scientific and engineering data would also be transmitted from the
spacecraft to the Earth while it was in transit and during the encounter
with Venus.
Scientists and engineers were now faced with an arduous task. Within an
11-month period, on a schedule that could tolerate no delays, two
spacecraft had to be designed, developed, assembled, tested, and
launched. In order to meet the schedule, tested flight assemblies and
instruments would have to be in the Pasadena assembly facility by
mid-January, 1962, just four months after the start of the project.
Probably no other major space project of similar scope had ever been
planned on such a demanding schedule.
[Illustration: _Mariner II travelled across 180 million miles of
space within our solar system as it spanned the gap between Earth
and Venus (shown here as the third and second planets, respectively,
from the Sun)._]
With the shipment of equipment to Atlantic Missile Range (AMR) scheduled
for 9½ months after inception of the project, management and design
teams went all-out on a true “crash” effort. Quick decisions had to be
made, a workable design had to be agreed upon very early, and, once
established, the major schedule objectives could not be changed. Certain
design modifications and manufacturing changes in the Atlas-Agena launch
vehicle were also necessary.
Wherever possible, Ranger design technology had to be used in the new
spacecraft and adapted to the requirements of a planetary probe. Other
necessary tasks included trajectory calculation; arrangements for
launch, space flight, and tracking operations; and coordination of AMR
Range support.
Following NASA’s September, 1961 decision to go ahead with the Mariner R
Project, JPL’s Director, Dr. William H. Pickering, called on his
seasoned team of scientists and engineers. Under Robert J. Parks,
Planetary Program Director, Jack N. James was appointed as Project
Manager for Mariner R, assisted by W. A. Collier. Dan Schneiderman was
appointed Spacecraft System Manager, and Dr. Eberhardt Rechtin headed
the space tracking program, with supervision of the Deep Space
Instrumentation Facility (DSIF) operations under Dr. Nicholas Renzetti.
The Mariner space flight operations were directed by Marshall S.
Johnson.
A PROBLEM IN CELESTIAL DYNAMICS
In order to send Mariner close enough to Venus for its instruments to
gather significant data, scientists had to solve aiming and guidance
problems of unprecedented magnitude and complexity.
The 447-pound spacecraft had to be catapulted from a launching platform
moving around the Sun at 66,600 miles per hour, and aimed so precisely
that it would intercept a planet moving 78,300 miles per hour (or 11,700
miles per hour faster than the Earth) at a point in space and time some
180.2 million miles away and 109 days later, with only one chance to
correct the trajectory by a planned midcourse maneuver.
And the interception had to be so accurate that the spacecraft would
pass Venus within 8,000 to 40,000 miles. The chances of impacting the
planet could not exceed 1 in 1,000 because Mariner was not sterilized
and might contaminate Venus. Also, much more data could be gathered on a
near-miss flight path than on impact. Furthermore, at encounter (in the
target area) the spacecraft had to be so positioned that it could
communicate with Earth, see the Sun with its solar panels, and scan
Venus at the proper angles.
Along the way, Mariner had to be able to orient itself so that its solar
panels were facing or “locked onto” the Sun in order to generate its own
power; acquire and maintain antenna orientation to the Earth; correct
its attitude constantly to hold Earth and Sun lock; receive, store, and
execute commands to alter its course for a closer approach to Venus; and
communicate its findings to Earth with only 3 watts of radiated power
and over distances never before spanned.
[Illustration: _Mariner II was launched in a direction opposite to
the orbital travel of the Earth. The Sun’s gravity then pulled it in
toward the planet Venus._]
Early in the program it had been decided that two spacecraft would be
launched toward Venus. Only 56 days were available for both launchings
and the planet would not be close enough again for 19 months—the period
between inferior conjunctions or the planet’s closest approach to the
Earth. On any one of these days, a maximum of 2 hours could be used for
getting the vehicles off the launch pad. In addition, the Mariners would
have to leave the Earth in a direction opposite to that of the Earth’s
direction of orbital revolution around the Sun. This flight path was
necessary so the spacecraft could then fall in toward the Sun and
intercept Venus, catching and passing the Earth along the way, about 65
days and 11.5 million miles out.
This feat of celestial navigation had to be performed while passing
through the hostile environment of interplanetary space, where the probe
might be subjected to solar winds (charged particles) travelling at
velocities up to 500 miles per second; intense bombardment from cosmic
radiation, charged protons, and alpha particles moving perhaps 1.5
million miles per hour; radiated heat that might raise the spacecraft
temperatures to unknown values; and the unknown dangers from cosmic
dust, meteorites, and other miscellaneous space debris.
In flight, each spacecraft would have to perform more than 90,000
measurements per day, reporting back to the Earth on 52 engineering
readings, the changes in interplanetary magnetic fields, the density and
distribution of charged particles and cosmic dust, and the intensity and
velocity of low-energy protons streaming out from the Sun.
At its closest approach to Venus, the spacecraft instruments would be
required to scan the planet during a brief 35-minute encounter, to
gather data that would enable Earth scientists to determine the
temperature and structure of the atmosphere and the surface, and to
process and transmit that data back to the Earth.
THE ORGANIZATION
Flying Mariner to Venus was a team effort made possible through the
combined resources of several United States governmental organizations
and their contractors, science, and industry. The success of the Mariner
Project resulted primarily from the over-all direction and management of
the National Aeronautics and Space Administration and the Jet Propulsion
Laboratory, and the production and launch capabilities of the vehicle
builders and the Air Force. Several organizations bore the major
responsibility: NASA Headquarters, JPL, NASA’s Marshall Space Flight
Center and Launch Operations Center, Astronautics Division of General
Dynamics, and Lockheed Missiles and Space Company.
NASA: FOR SCIENCE
The National Aeronautics and Space Administration was an outgrowth of
the participation of the United States in the International Geophysical
Year program and of the nation’s space effort, revitalized following
Russia’s successful orbiting of Sputnik I in 1957.
[Illustration: _Final NACA meeting, August 21, 1958._]
[Illustration: _Model of X-1 research plane._]
[Illustration: _Headquarters of National Aeronautics and Space
Administration, Washington, D.C._]
[Illustration: _JPL developed first JATO units in 1941._]
[Illustration: _Other Laboratory Projects were the Corporal missile
(left) and Explorer I (right), the first U.S. satellite._]
Under the terms of the law which created NASA, it is a Federal Agency
dedicated to carrying out “activities in space ... devoted to peaceful
purposes for the benefit of all mankind.” NASA is charged to preserve
the role of our nation as a leader in the aeronautical and space
sciences and technology and to utilize effectively the science and
engineering resources of the United States in accomplishing these goals.
Activities associated with military operations in space and the
development of weapons systems are specifically assigned to the Defense
Department.
In November, 1957, before the creation of NASA, President Eisenhower had
established a Scientific Advisory Committee to determine the national
objectives and requirements in space and to establish the basic
framework within which science, industry, and the academic community
could best support these objectives.
The Committee submitted a report to the President in March, 1958,
recommending creation of a civilian agency to conduct the national space
programs. The recommendation, endorsed by the President, was submitted
to the Congress on April 2, 1958. The National Aeronautics and Space Act
of 1958 was passed and became law in July, 1958.
NASA was officially established on October 1, 1958, and Dr. T. Keith
Glennan, President of Case Institute of Technology, was appointed as the
first Administrator. The facilities and personnel of the National
Advisory Committee for Aeronautics (NACA) were transferred to form the
nucleus of the new NASA agency.
NACA had performed important and significant research in aeronautics,
wind tunnel technology, and aerodynamics since 1915, including a series
of experimental rocket research aircraft that culminated in the X-15. It
was natural that it be expanded to include space operations.
Among the NACA Centers transferred to NASA were the Langley Research
Center at Hampton, Virginia; Lewis Research Center, Cleveland, Ohio;
Ames Research Center, Moffett Field, California; Flight Research Center,
Edwards, California; and the rocket launch facility at Wallops Island,
Virginia.
Those personnel of the Naval Research Laboratory who had been working on
Project Vanguard were also transferred to NASA, as was the project.
These personnel are now part of the new Goddard Space Flight Center at
Greenbelt, Maryland.
The October, 1958, transfers also included a number of the space
projects of the Advanced Research Projects Agency of the Defense
Department. In a December, 1958, Executive Order, the President assigned
the former Army facilities of the Jet Propulsion Laboratory at Pasadena,
California, to NASA. At the same time, the group working under Dr.
Wernher von Braun at the Army Ballistic Missile Agency (commanded by
Major General John B. Medaris) was made responsive to NASA requirements.
On July 1, 1960, the George C. Marshall Space Flight Center (MSFC) was
organized at Huntsville under von Braun’s direction. The former
Development Operations Division of ABMA formed the nucleus of the new
Center. The MSFC mission was to procure and to supervise the adaptation
of launch vehicles for NASA space missions, including Atlas, Thor, and
Agena. Marshall is directly responsible for the design and development
of advanced, high-thrust booster vehicles such as the Saturn C-1 and C-5
and the Nova.
An agency to conduct NASA affairs at Cape Canaveral was formed within
MSFC on July 1, 1960. Known then as the Launch Operations Directorate
(LOD), it was directed by Dr. Kurt H. Debus. LOD became independent of
Marshall in March, 1962, when it was redesignated the Launch Operations
Center (LOC), reporting directly to the Office of Manned Space Flight.
This separation resulted largely because the activities at AMR were
becoming more operational in character and less oriented toward research
and development.
LOC handles such functions for NASA as the scheduling of launch dates
and liaison with the Atlantic Missile Range for support activities. The
Center will have the responsibility in the field for assembly, checkout,
and launch of the Saturn and Nova boosters.
Following the election of President Kennedy in 1961, James E. Webb
replaced Dr. Glennan as Administrator of NASA. Shortly after, a new
national goal was announced—placing a man on the Moon and returning him
safely to the Earth in this decade. Meanwhile, JPL had been assigned
responsibility for unmanned exploration of the Moon, the planets, and
interplanetary space, and thus was charged with supporting the NASA
manned flight program through these activities.
In less than five years, NASA grew to include eight flight and research
centers and about 21,000 technical and management personnel. Within
NASA, Dr. Abe Silverstein’s Office of Space Flight Programs was
responsible for the Mariner R Project which was directly assigned to Ed
Cortright, Director of Lunar & Planetary Programs, and Fred
Kochendorfer, who is NASA’s Program Chief for Mariner. A subsequent
reorganization placed responsibility under Dr. Homer Newell’s Office of
Space Sciences, and Oran Nicks became Director of Lunar & Planetary
Programs.
JPL: JATO TO MARINER
The Jet Propulsion Laboratory, staffed and operated for NASA by
California Institute of Technology, had long been active in research and
development in the fields of missiles, rockets, and the space-associated
sciences. The first government-sponsored rocket research group in the
United States, JPL had originated on the Caltech campus in 1939, an
outgrowth of the Guggenheim Aeronautical Laboratories, then headed by
celebrated aerodynamicist Dr. Theodore von Karman.
Von Karman and his associates moved their operation to a remote spot at
the foot of the San Gabriel mountains and, working from this base, in
1941 the pioneering group developed the first successful jet-assisted
aircraft takeoff (JATO) units for the Army Air Force. The Laboratory
began a long association with the Army Ordnance Corps in 1944, when the
Private A test rocket was developed. In retrospect, it is now recognized
that the Private A was the first U. S. surface-to-surface,
solid-propellant rocket. Its range was 10 miles!
JPL’s WAC Corporal rocket set a U. S. high-altitude record of 43.5 miles
in 1945. Mounted on a German V-2 as the Bumper-WAC, it achieved an
altitude record of 250 miles in 1947. More important, this event was the
first successful in-flight separation of a two-stage rocket—the
feasibility of space exploration had been proved.
After the end of World War II, JPL research set the stage for
high-energy solid-propellant rockets. For the first time the solid
propellants, which contained both fuel and oxidizers, were cast in
thin-walled cases. Techniques were then developed for bonding the
propellants to the case, and burning radially outward from the central
axis was achieved. Attention was then turned to increasing the energy of
the propellants.
By 1947, the Corporal E, a new liquid-propellant research rocket, was
being fired. JPL was asked to convert it into a tactical weapon in 1949.
The Corporal E then became the first liquid-propellant
surface-to-surface guided missile developed by the United States or the
Western bloc of nations.
Because of the need for higher mobility and increased firing rate, JPL
later designed and developed the solid-propellant Sergeant—the nation’s
first “second-generation” weapon system. This inertially guided missile
was immune to electronic countermeasures by an enemy.
Meanwhile, JPL scientists had pioneered in the development of electronic
telemetering techniques, which permit an accurate monitoring of system
performance while missiles are in flight. By 1944, Dr. William H.
Pickering, a New Zealand born and Caltech-trained physicist who had
worked with Dr. Robert Millikan in cosmic ray research, had been placed
in charge of the telemetering effort at JPL. Pickering became Director
of the Laboratory in 1954.
Following the launching of Sputnik I, the Army-JPL team which had worked
on the Jupiter C missile to test nose cones, was assigned the
responsibility for putting the first United States satellite into orbit
as soon as possible. In just 83 days, a modified Jupiter C launch
vehicle was prepared, an instrumented payload was assembled, a network
of space communications stations was established, and Explorer I was
orbited on January 31, 1958. Explorer was an instrumented assembly
developed by JPL and the State University of Iowa. It discovered the
inner Van Allen radiation belt.
Subsequently, JPL worked with the Army on other projects to explore
space and to orbit satellites. Among these were Pioneer III, which
located the outer Van Allen Belt, and Pioneer IV, the first U. S. space
probe to reach Earth-escape velocity and to perform a lunar fly-by
mission.
GENERAL DYNAMICS: THE ATLAS
The launch vehicle for Mariner was an Atlas D booster with an Agena B
second stage. Historically, Atlas can be traced to October, 1954, when
the former Convair Corporation (later acquired by General Dynamics) was
invited to submit proposals for research and development of four missile
systems, including a 5,000-mile intercontinental weapon.
In January, 1946, Convair assigned K. J. Bossart to begin a study of two
proposed types of 5,000-mile missiles: one jet powered at subsonic
speeds, with wings for aerodynamic control; the other a supersonic,
ballistic (wingless and bullet-like), rocket-powered missile capable of
operating outside the Earth’s atmosphere.
[Illustration: _Photo courtesy of General Dynamics/Astro_
_Atlas missiles in assembly facility at General
Dynamics/Astronautics plant._]
This was the beginning of Project MX-774, lineal ancestor of Atlas.
After captive testing at San Diego in 1947, three of the experimental
missiles were test-launched at White Sands Proving Ground in New Mexico.
The first flight failed at 6,200 feet after a premature engine burnout.
In 1947, the Air Force shelved the MX-774 project. However, this brief
program had proved the feasibility of three concepts later used in
Atlas: swiveling engines for directional control; lightweight,
pressurized airframe structures; and separable nose cones.
The Korean War stimulated the ICBM concept and, in 1951, a new MX-1593
contract was awarded to Convair to study ballistic and glide rockets. By
September, 1951, Convair was proposing a ballistic missile that would
incorporate some of the features of the MX-774 design. A plan for an
accelerated program was presented to the Air Force in 1953. After a year
of study, a full go-ahead for the project, now called Atlas, was given
in January, 1955.
The unit handling the Atlas program was set up as Convair Astronautics,
with J. R. Dempsey as president, on March 1, 1957.
The first Atlas test flight, in June of 1957, ended in destruction of
the missile when it went out of control. Following another abortive
attempt, the first fully successful flight of an Atlas missile was made
from Cape Canaveral on December 17, 1957.
The Atlas program was in full swing by 1958, when 14 test missions were
flown. The entire missile was orbited in December, 1958, as Project
Score. It carried the voice of President Eisenhower as a Christmas
message to the world. The Atlas missile system was accepted for field
operations by the Air Force in 1958.
Also in 1958, an Atlas achieved a new distance record, flying more than
9,000 miles down the Atlantic Missile Range, where it landed in the
Indian Ocean, off the South African coast.
Atlas has been modified for use by NASA as a space vehicle booster.
Known as the Atlas D, it has launched lunar probes, communications and
scientific Earth satellites, and manned space vehicles.
LOCKHEED: AGENA B
The Lockheed Agena B second-stage vehicle was mounted on top of the
Atlas booster in the launch of the Mariner spacecraft. The U. S. Air
Force had first asked Lockheed Missiles and Space Division, headed by L.
E. Root, to work on an advanced orbital vehicle for both military and
scientific applications in 1956. On October 29 of that year, Lockheed
was appointed prime weapon system contractor on the new Agena Project,
under the Air Force Ballistic Missile Division. In order to speed the
program, the Thor missile was used as the booster stage for the early
Agena flights. The Atlas was also utilized in later operations.
In August, 1957, the Air Force recommended that the program be
accelerated as much as possible. After Russia orbited Sputnik I in
October of 1957, a further speed-up was ordered.
The first of the Agena-Discoverer series was launched into orbit on
February 28, 1959, with the Thor missile as the booster. The first
restart in orbit occurred on February 18, 1961, when the new Agena B
configuration was used to put Discoverer XXI into orbit. All of the NASA
missions using Agena, beginning with Ranger I in August, 1961, have been
flown with the B model.
Agena holds several orbiting records for U. S. vehicles. The first water
recovery followed the 17 orbits of Discoverer XIII on August 11, 1960.
The first air recovery of a capsule from orbit occurred with Discoverer
XIV on August 18, 1960. In all, a total of 11 capsules were recovered
from orbit, 7 in the air, 4 from the sea.