Overview of the Marshall Center's Role in Mercury-Redstone Project
(Source Note: The following information is
reproduced here as published
in an article prepared by the Marshall Center Public Affairs Office
The Mercury-Redstone booster used in the Project Mercury launching
was provided and launched for the Space Task Group by the Marshall
Space Flight Center, National Aeronautics and Space Administration.
The vehicle is based upon the Army's Redstone which was designed
and developed by Marshall scientists and technicians prior to
their transfer to NASA. Extensive modifications were incorporated
to adapt the rocket to this special role, with major emphasis
on increased reliability. The Redstone booster has already achieved
a significant record of reliable flight in a launching history
which extends over the past seven years. Of the last 40 Redstones
launched, only one booster has failed.
Changes in the system for the Mercury mission include the elongation
of the tank section to increase fuel capacity, the design of a
new instrument compartment and adapter section to accommodate
the Mercury spacecraft, changes in engine and the control system
in the interest of simplicity, improved reliability and increased
performance, and the development of a mission abort system to
assure safety of the spacecraft and, on later launchings, its
The Mercury-Redstone is 83 feet in height, including the spacecraft
assembly, compared to the 69 feet of the ordinary Redstone. The
body of the rocket is 70 inches in diameter. The lift-off weight
is 66,000 pounds including, the one-ton Mercury spacecraft.
Modifications to the Redstone booster include the
Special emphasis on reliability has been placed in the Mercury
Redstone program. Most of the reliability effort was centered
on new components - those which are peculiar to the Mercury-Redstone.
This program was conducted by the Marshall Center and the Chrysler
Corporation. Reliability tests were conducted on individual components,
subsystems and systems. Test conditions included excessive vibrations
and extreme temperatures. Engineers of the Chrysler Corporation
designed and operated a special "rock and roll" test
device which subjected the entire instrument compartment of the
Mercury-Redstone rocket to environmental stress. This latter phase
was devoted primarily to checking out the abort system to assure
that it would operate properly on demand and could not be activated
Testing At Marshall
Marshall Center personnel ran structural tests on the new Redstone-Mercury
configuration which assure the structural integrity of the vehicle.
Units of the rocket were submitted to considerably higher stresses
and strains than will be encountered in flight.
In addition to the acceptance firing of the engines, the Marshall
Center is static firing each completed booster of the Mercury
series, prior to their shipment to the launch site. During these
static firings a detailed measuring program gives assurance of
proper performance of the engine. The Center also captive-fired
a complete Mercury-Redstone configuration, including a research
model of the spacecraft.
In a grueling survival test, one of the Mercury-Redstone engines
was repeatedly captive-fired for a total duration of about 15
times the normal burning time of the rocket. In a final test program,
the Mercury spacecraft which was launched today was shipped to
the Marshall Center for extensive compatibility tests with the
booster under controlled, laboratory conditions. These checks
included electrical and mechanical areas, and a long series of
checks to exclude the possibility of radio frequency interference
between the spacecraft and booster systems. This sequence of check-out;
included a simulated countdown, launch and flight, using the same
checkout and firing panels which will be used at Canaveral for
the actual checkout and launch operations.
Aerodynamics And Trajectory
In the basic design of the Mercury-Redstone vehicle, the Marshall
Center conducted special studies, theoretically and by means of
wind tunnel models, on the aerodynamic behavior of the new vehicle.
The Center also prepared the trajectories to be flown in the Mercury-Redstone
series and calculated the safety conditions under which the rocket
could be fired at the Atlantic Missile Range.
Launch And Flight Sequence
The Mercury-Redstone takes off vertically.
During the first few seconds of burning time, the rocket begins
to tilt into a predetermined trajectory. The rocket engine operates
for about 140 seconds. Shortly after cutoff, the Mercury spacecraft
is separated from the booster (combined tank and engine sections
plus the instrument compartment) by the ignition of explosive
bolts which release the connecting clamp ring. This is immediately
followed by the firing of three small propellant rockets on the
base of the spacecraft.
The separation occurs at an altitude of about 35 statute miles.
Both the rocket body and the spacecraft continue on separate ballistic
trajectories. The spacecraft will land at about 220 statute miles,
having reached a maximum altitude of about 130 statute miles.
The rocket body should hit the sea some 20 miles beyond the spacecraft.
Hundreds of industrial fabricators and suppliers are contributing
to the Mercury-Redstone program. The first two of the eight rockets
to be provided for Project Mercury by the Marshall Center were
assembled at the Center. MSFC also fabricated many of the components;
major structural components were manufactured by the Reynolds
Metals Company, Sheffield, Alabama. The final six rockets in the
series are being furnished to Marshall by the Chrysler Corporation
Missile Division, Detroit. Chrysler Corporation also conducted
a major reliability program under contract to MSFC. The Rocketdyne
Division of North American Aviation Corporation, Canoga Park,
California, manufactured the engines for the rockets. Major components
of the control system were produced by the Ford Instrument Company,
Long Island City, New York, and Sperry-Farragut Company, Bristol,
Tennessee, divisions of Sperry-Rand Corporation.
Dr. Wernher von Braun, as director of the Marshall Center, has
overall supervision of the Center's contributions to the Mercury
Dr. J. P. Kuettner is the Center's Mercury-Redstone project
manager and is responsible for coordinating the effects of the
ten Marshall technical divisions in this program. His assistant
is Earl Butler. Dr. Kuettner is also a member of the Mercury-Redstone
Flight Safety Review Board. Butler serves as the coordinator for
the project's Design Panel.
Dr. Kurt H. Debus directs the NASA Launch Operations Directorate,
a part of the Marshall Center, which launched the rocket. Dr.
Debus also is chairman of the Mercury-Redstone Flight Operations
Panel, composed of representatives of the NASA Space Task Group,
McDonnell Aircraft and Marshall.