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| Where am I? NASA Spacelink Home The Library NASA
Projects Earth
Science Atmosphere
CRRES
Press
Kit
Press Kit |
CRRES PRESS KIT
COMBINED RELEASE AND RADIATION EFFECTS SATELLITE (CRRES)
ATLAS I
(ATLAS/CENTAUR-69)
LAUNCH VEHICLE
PRESS KIT
JULY 1990
CONTENTS
GENERAL RELEASE.............................................. 1
CRRES MISSION
Science Background...................................... 2
Objectives.............................................. 3
Program History......................................... 4
Operations.............................................. 4
Ground-based, In-Situ, Aircraft Diagnostics............. 5
ATLAS I (ATLAS/CENTAUR) LAUNCH VEHICLE
General Description..................................... 6
Atlas/Centaur-69 Characteristics........................ 7
KENNEDY SPACE CENTER VEHICLE PROCESSING, OPERATIONS
Atlas/Centaur-69 Processing............................. 8
CRRES Processing........................................ 9
Launch Operations....................................... 9
Range Support...........................................10
Launch Weather..........................................10
FLIGHT EVENTS SEQUENCE.......................................11
CRRES SPACECRAFT, SCIENCE MANAGEMENT TEAM....................12
ATLAS I (ATLAS/CENTAUR-69) LAUNCH MANAGEMENT TEAM............13
DETAILED EXPERIMENTS DESCRIPTION.............................14
RELEASE: 90-94
CRRES LAUNCH SET FOR JULY TO STUDY "EARTHSPACE"
Launch of the Combined Release and Radiation Effects Satellite
(CRRES) is currently targeted for no earlier than July 17, 1990,
at 3:41 p.m. EDT. Scheduled to be placed into a highly
elliptical, geosynchronous transfer orbit of approximately 217 by
22,236 miles, CRRES is to conduct complex scientific research in
what is referred to as "Earthspace" -- the space environment just
above Earth's atmosphere which, far from being empty, includes
the ionosphere and magnetosphere containing a dynamic ocean of
invisible magnetic and electrical fields and particles.
Much as a high school physics student spreads iron filings
around a magnet to "see" its invisible magnetic field, CRRES will
carry 24 canisters of various chemicals into orbit and release
the chemicals over a period of time. When released, the
chemicals will be ionized by the Sun's ultraviolet light creating
large luminous clouds that will elongate along Earth's magnetic
field lines, briefly "painting" these invisible structures.
By observing the motion of the clouds, scientists will be
able to measure electric fields in space and "see" how they
interact with charged particles to form waves and to better
understand how the Earth extracts energy from the solar wind.
The luminous clouds also will be studied from the ground, from
specially equipped aircraft and from CRRES itself. The CRRES
releases will be augmented by chemical releases from 10 sounding
rockets launched from Puerto Rico and the Marshall Islands.
Under a launch services contract between NASA and General
Dynamics, launch of the joint NASA/U.S. Air Force payload is to
take place from Complex 36B, Cape Canaveral Air Force Station,
Fla., aboard an Atlas I (Atlas/Centaur-69) launch vehicle.
NASA's Marshall Space Flight Center, Huntsville, Ala.; the
U.S. Air Force Space Systems Division, Los Angeles; and Ball
Aerospace Systems Group, Boulder, Colo. -- prime comtractor of
CRRES -- are principal spacecraft participants in the upcoming
mission. Atlas I launch services, with technical oversight by
NASA's Lewis Research Center, Cleveland, and Kennedy Space
Center, Fla., will be provided by General Dynamics Space Systems
Division, San Diego, Calif. The Lewis Research Center manages
the NASA-General Dynamics launch services contract and is
responsible for launch vehicle/spacecraft integration activities.
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THE COMBINED RELEASE AND RADIATION EFFECTS SATELLITE
SCIENCE BACKGROUND
The Combined Release and Radiation Effects Satellite
(CRRES), a joint NASA/Air Force project, will attempt to learn
more about the hostile environment often referred to as "the
vacuum of outer space."
Outer space, however, is not empty. It is a dynamic mix of
invisible magnetic and electric fields, energetic particle
radiation and electrically charged plasmas, collections of
negatively charged electrons and positively charged atoms whose
interactions are influenced by long-range electric forces, rather
than by the atomic collisions that govern the behavior of neutral
gases.
Complex interactions involving these fields and particles
extract energy from the solar wind, a continual flow of particles
from the Sun, and deposit much of this energy into the Earth's
upper atmosphere, ionosphere and magnetosphere. The Earth's
neutral atmosphere, extending approximately 40 miles above the
Earth's surface, is a shell of neutral gases that encompasses the
Earth's weather and protects its life. The ionosphere, which
extends from above the atmosphere to approximately 620 miles
above the Earth, is an electrically charged transition zone
between the atmosphere and the magnetosphere.
Beyond the ionosphere lies the magnetosphere, populated with
energetic, charged particles. When this magnetosphere is hit by
a cloud of energetic particles from a solar flare, a so-called
geomagnetic storm can occur that can disrupt power systems and
long-distance communications. Today's increasingly complex
satellites, carrying sophisticated electronics and sensors such
as the Tracking and Data Relay Satellite and other geostationary
spacecraft, are susceptible to damage from solar energetic
particles that can limit the satellite operational lifespan.
Scientists have been studying the magnetosphere for decades,
using a combination of ground-based measurements and satellite
observations. Beginning this summer, the CRRES satellite will
conduct experiments allowing direct observations of the Earth's
magnetic field.
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CRRES OBJECTIVES
CRRES will carry 24 canisters containing various
chemicals. For each experiment, one or two canisters will be
ejected by the spacecraft. Approximately 25 minutes later, after
the canister and spacecraft are far enough apart to prevent
contamination, the canister will release its chemical vapors.
The chemical will be ionized by the Sun's ultraviolet light,
creating luminous clouds initially about 60 miles in diameter.
The clouds will elongate along Earth's magnetic field lines,
briefly "painting" these invisible structures so that they become
visible.
By observing the motion of the clouds, scientists will be
able measure electric fields in outer space, to "see" how these
fields interact with charged particles to form waves and to
better understand how the Earth extracts energy from the solar
wind. These clouds will be studied by instruments on the ground,
in specially equipped aircraft and aboard CRRES itself. The
CRRES releases will be augmented by releases from sounding
rockets to conduct further experiments.
The CRRES program is the latest in a new generation of space
research missions studying earthspace, the space environment just
above Earth's atmosphere, through complementary, active
experiments and passive observations. CRRES is a joint program
of NASA, through its Marshall Space Flight Center, and the
Department of Defense's (DOD) Air Force Space Test and
Transportation Program. NASA's role in the mission is the
release of tracers. The DOD experiments will measure the natural
radiation in space and its effects on microelectronics.
The satellite was built by the Ball Aerospace Systems Group,
Boulder, Colo. The scientific instruments and investigations are
being supplied by scientists from institutions throughout the
United Sates, Europe and South America.
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CRRES PROGRAM HISTORY
In 1984, the CRRES satellite was designed as a dual-mission
spacecraft carrying 48 canisters of chemicals for release. The
spacecraft initially was to be deployed from the Space Shuttle in
a low-Earth-orbit (LEO) of 215 miles altitude. At LEO it would
have performed chemical release experiments for 90 days.
Following the LEO mission, a trans-stage motor would have placed
CRRES in a geosynchronous transfer orbit (GTO), where additional
chemical releases and the primary DOD mission would be carried
out.
The loss of Challenger in January 1986 forced a major
restructuring of the CRRES Program. In June 1987, NASA decided
to launch CRRES directly to GTO on an Atlas-Centaur carrying 24
canisters, complemented by a program of sounding rocket launches
to perform some of the experiments deleted from the original 48-
cannister CRRES mission.
CRRES OPERATIONS
The 24 canisters on the CRRES/GTO mission will perform 14
experiments. Seven of these will be undertaken at altitudes
ranging from 1,200 to 21,000 miles (the original GTO releases).
The remainder will be undertaken near perigee at altitudes
between 240 and 300 miles.
The mission will be complemented by 10 sounding rockets to
perform releases that require precise targeting of location,
local time and altitude. Six rockets are to be launched from
Puerto Rico and four from Kwajalein, Marshall Islands.
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GROUND-BASED, IN SITU AND AIRCRAFT DIAGNOSTICS
The successful execution of the chemical release experiment
demands a wide variety of diagnostics. Principal ground-based
facilities that will monitor and track the releases include the
Arecibo Incoherent Scatter Radar and the Arecibo HF Ionospheric
Heater Facility in Puerto Rico, the Jicamarca (Peru) Radar
Facility, the ALTAIR Radar Facility at Kwajalein and the
Millstone Hill Radar Facility in Massachusetts.
These facilities will be used to diagnose the state of the
ionosphere prior to, during and just after each release. They
also will examine in detail the structure of the artificial
plasma clouds. The radars can measure the state of the
ionosphere and artificial plasma clouds simultaneously over a
wide altitude range.
The DOD scientific instruments will complement the CRRES
chemical-science mission, measuring the effects of the releases
at close range. For releases, the instruments will measure the
state of particles and waves in the magnetosphere and assess
whether a large magnetic storm is imminent. This will help the
scientists determine the best time to conduct a release.
No less important will be an array of ground- and aircraft-
based optical diagnostics, including wide-field cameras, high-
sensitivity television systems, spectrographs and
interferometers. Portable VHF coherent scatter radars will
diagnose regions not accessible to the fixed radars, and radio
receivers on board aircraft will measure disruptions in signals
received from satellites resulting from the ionospheric
disturbances.
(See DETAILED EXPERIMENTS DESCRIPTION section of this press kit.)
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ATLAS I (ATLAS/CENTAUR) LAUNCH VEHICLE
GENERAL DESCRIPTION
The Atlas I is a derivative of the Atlas/Centaur built by
General Dynamics Space Systems Division (GDSSD) for NASA. The
Atlas/Centaur previously was used by NASA as its standard launch
vehicle for intermediate weight payloads. Atlas I is the first
of a new family of launch vehicles that can be used to boost
payloads into low-Earth orbit, geosynchronous-Earth orbit and on
interplanetary trajectories. Eleven-foot and 14-foot diameter
payload fairings are available to accommodate a variety of
spacecraft.
The Centaur upper stage was the nation's first high-energy,
liquid hydrogen/liquid oxygen propelled rocket. Developed and
launched under the direction of NASA's Lewis Research Center,
Cleveland, it became operational in 1966 with the launch of
Surveyor 1, the first U.S. spacecraft to soft-land on the lunar
surface.
Since that time, both the Atlas booster and the Centaur
upper stage have undergone many improvements. At present, the
Atlas I vehicle/14-foot fairing combination can place 13,000
pounds into low-Earth orbit, 4,950 pounds in a synchronous
transfer orbit and 2,400 pounds on Earth escape trajectories.
Since the first use of Atlas in the space program in the early
1960s, thrust of the Atlas engines has been increased about
50,000 pounds.
The Atlas I vehicle, approximately 143-feet high, consists
of an Atlas I booster and a Centaur I upper stage. The Atlas
booster develops 438,922 pounds of thrust at liftoff using two
188,750-pound-thrust booster engines, one 60,500-pound-thrust
sustainer engine and two vernier engines developing 461 pounds of
thrust each. The two RL-10 engines on Centaur produce a total of
33,000 pounds of thrust. Both the Atlas and Centaur are 10 feet
in diameter.
Until early 1974, Centaur was used exclusively in
combination with the Atlas booster. Subsequently, it was used
with a Titan III booster to launch heavier payloads into Earth
orbit and interplanetary trajectories. A new wide-body Centaur
will be used as an upper stage on Titan IV launch vehicles.
The Centaur I has an integrated electronic system that
performs a major role in checking itself and other vehicle
systems before launch and also maintains control of major events
after liftoff. The new Centaur system handles navigation and
guidance tasks, controls, pressurization and venting, propellent
management, telemetry forms and transmission and initiates
vehicle events. Most operational needs can be met by changing
the computer software.
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ATLAS/CENTAUR-69 LAUNCH VEHICLE CHARACTERISTICS
The fueled AC-69 weight, including the 3,735-pound CRRES
spacecraft, is 365,374 pounds. Liftoff height is approximately
143 feet. Launch Complex 36 (Pad B) is used for the launch
operation.
ATLAS BOOSTER CENTAUR STAGE
Fueled Weight: 320,821 lbs. 40,818 lbs.
Height: Approx. 77 feet Approx. 67 feet
with payload fairing
Thrust: 438,922 lbs. 33,000 lbs.
at sea level in vacuum
Propellants: Liquid oxygen Liquid oxygen/
and RP-1 Liquid hydrogen
Propulsion: MA-5 system two Two 16,500 pound
188,750 lb. thrust thrust RL-10
booster engines, one engines, 12 small
60,500 lb. thrust hydrazine thrusters
sustainer engine, two
461 lb. thrust vernier
engines
Velocity: 6,527 mph at booster 22,262 mph
engine cutoff (BECO) at spacecraft
9,326 mph at sustainer separation
engine cutoff (SECO)
Guidance Preprogrammed profile Inertial guidance
through BECO. Switch
to inertial guidance
for sustainer phase
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KENNEDY SPACE CENTER VEHICLE PROCESSING, OPERATIONS
ATLAS/CENTAUR-69 PROCESSING
The Atlas/Centaur-69 vehicle arrived aboard a C-5 Air Force
transport plane from the General Dynamics plant, San Diego, on
April 3. The Atlas stage was erected on Pad 36-B, Cape Canaveral
Air Force Station, on April 4 and the Centaur stage was hoisted
atop the Atlas on April 5. The vehicle was powered up to begin
prelaunch testing on April 16.
On May 30, during a routine wet dress rehearsal test, a
high-pressure helium line failed at the beginning of the test
causing minor damage to the interstage adapter and delaying the
target launch date until July 9. A second test was conducted on
June 19, but due to a ground software problem, the test was
halted at the T-31 second mark. The decision was made to conduct
another retest, delaying the target launch date until July 17.
The retest was accomplished on June 26.
On June 14, a simulated flight test was conducted. This
check operated the vehicle's electrical and mechanical systems,
verifying that they will perform as designed during the ascent to
orbit. This was followed by a full countdown demonstration
exercise, including the filling of the vehicle with its full
complement of liquid hydrogen, liquid oxygen and RP-1
propellants. All countdown events were performed as they are on
launch day up to first stage ignition.
A new payload fairing 14 feet in diameter, four feet wider
than previous fairings, underwent final assembly in the Payload
Hazardous Servicing Facility (PHSF) in the KSC Industrial Area.
Fit checks, electrical tests and a mechanical verification to
confirm that the fairing would open and separate from the vehicle
properly during the ascent were conducted atop the vehicle at the
launch pad. It was returned to the PHSF and prepared for
encapsulation with the spacecraft.
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CRRES PROCESSING
The CRRES spacecraft arrived at the PHSF on March 23.
Electrical checks and functional testing of the spacecraft were
completed on April 20. During the first week of May, the canisters,
designed for releasing the chemicals in orbit, were loaded with
their respective elements and were placed aboard the spacecraft.
There are eight small and 16 large canisters which collectively
contain the elements barium, lithium, strontium and calcium.
On May 14, 3 days of spacecraft end-to-end compatability tests
were performed between the CRRES satellite at KSC and the Air Force
Consolidated Satellite Test Center (CSTC) in Sunnyvale, Calif. CSTC
will be the control center for the spacecraft during the mission.
Spacecraft commands, telemetry and data communications were
verified.
The spacecraft was fueled with the hydrazine attitude control
propellant on May 21 and transported to Launch Complex 36 for mating
to the AC-69 vehicle on July 2.
LAUNCH OPERATIONS
Atlas Centaur launch operations will be conducted from the
Complex 36 blockhouse by a launch team from General Dynamics, the
vehicle's manufacturer. RP-1, a highly refined kerosene fuel burned
by the Atlas, will be loaded aboard the stage 3 days prior to
launch. The liquid oxygen used by the Atlas and the Centaur will be
loaded aboard during the countdown, beginning at T-75 minutes. The
loading of liquid hydrogen aboard the Centaur stage at T-43 minutes,
running concurrently with the remainder of the liquid oxygen
loading.
Since this is a NASA mission, the agency is accountable for
mission success and government technical oversight as well as
responsibility for supporting CRRES preflight preparations and
testing. The NASA Lewis Research Center Project Manager is
responsible for the administration and technical oversight of the
Atlas I launch services contract.
A NASA launch manager from the Kennedy Space Center represents
NASA interests during the launch vehicle checkout and preparations
and serves as NASA's liaison with General Dynamics at the launch
site. On launch day, he is located in the Mission Director's Center
to monitor the countdown and the launch team activity and will
provide a NASA final concurrence for launch to the General Dynamics
launch director in the blockhouse.
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RANGE SUPPORT
The Eastern Test Range, an arm of the Air Force Eastern Space
and Missile Center, will provide tracking support for the mission.
Radar and communications will be relayed to NASA's Mission
Director's Center and central telemetry facility on Cape Canaveral
Air Force Station and to the Air Force CSTC control facility at
Sunnyvale.
Tracking stations supporting the mission include the U.S. Air
Force Tel-4 facility located at KSC, the Jonathan Dickinson
Instrumentation Facility Jupiter Inlet in south Florida, the Antigua
station in the Bahamas and the NASA radar at Bermuda. Also, two
Advanced Range Instrumentation Aircraft (ARIA) will support over the
South Atlantic off the coast of Africa to cover the second burn of
the Centaur stage and spacecraft separation.
LAUNCH WEATHER
As with the Space Shuttle, weather observations and forecasting
for the launch of AC-69 will be provided by the U.S. Air Force from
the Cape Canaveral Forecast Facility. The weather criteria for the
launch of expendable vehicles and the Space Shuttle are similar in
many respects, but in some areas they are tailored to the unique
characteristics of the expendable vehicle being launched.
On launch day, a total of nine upper air weather balloon
soundings will be made starting at launch minus 6 hours. A weather
reconnaisance aircraft will be deployed at launch minus 90
minutes. It will evaluate the weather downrange in the flight path
of the vehicle and also assess any weather areas of concern that may
be approaching the Cape.
A detailed weather briefing will be provided to the General
Dynamics launch director and the NASA launch manager prior to
retracting the gantry, again prior to fueling, and then immediately
before launch.
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FLIGHT EVENTS SEQUENCE: ATLAS I, CRRES SPACECRAFT
EVENT TIME AFTER ALTITUDE DOWNRANGE SPEED
LIFTOFF (MILES) (MILES) (MPH)
Liftoff T-0
Atlas Booster 2 min 35 sec 37 54 6,527
Engine Cutoff
Jettison Atlas 2 min 38 sec 38 59 6,590
Booster Engine
Jettison Centaur 3 min 0 sec 50 70 6,967
Insulation Panels
Jettison Nose 3 min 36 sec 67 154 7,746
Fairing
Atlas Sustainer/ 4 min 27 sec 85 258 9,326
Vernier Engines Cutoff
Atlas/Centaur 4 min 29 sec 86 266 9,330
Separation
First Centaur 4 min 40 sec 89 286 9,306
Main Engine Start
Centaur Main 9 min 53 sec 94 1,298 17,953
Engine Cutoff
Second Centaur 24 min 53 sec 212 5,366 17,487
Main Engine Start
Second Centaur 26 min 29 sec 241 5,836 22,535
Main Engine Cutoff
Centaur/Payload 28 min 44 sec 334 6,566 22,262
Separation
(These numbers may vary depending on exact launch date, launch
time and spacecraft weight)
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CRRES SPACECRAFT, SCIENCE MANAGEMENT TEAM
NASA HEADQUARTERS
Dr. Lennard A. Fisk Associate Administrator for Space
Science and Applications
Thomas W. Perry Deputy Director, Space Physics Div.
Richard J. Howard CRRES Program Manager
Dr. David S. Evans CRRES Program Scientist
MARSHALL SPACE FLIGHT CENTER
Thomas J. Lee Director
Sidney P. Saucier Manager, Space Systems Projects Office
William A. Swords CRRES Project Manager
Dr. David L. Reasoner CRRES Project Scientist
UNITED STATES AIR FORCE
Col. John E. Armstrong Program Director, Space Transportation
And Test Program
Maj. Stanley A. Sneegas Program Manager, Space Test Program
BALL AEROSPACE SYSTEMS GROUP
Ron Brown CRRES Program Manager
Brian Pieper Deputy CRRES Program Manager
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ATLAS I (ATLAS/CENTAUR-69) LAUNCH MANAGEMENT TEAM
NASA HEADQUARTERS
Dr. William B. Lenoir Associate Administrator for Space Flight
Joseph B. Mahon Deputy Associate Administrator for
Space Flight (Flight Systems)
Charles R. Gunn Director, Unmanned Launch Vehicles and
Upper Stages
John P. Castellano Chief, Intermediate and Large Launch
Vehicles
KENNEDY SPACE CENTER
Forrest McCartney Director
John Conway Director, Payload Management and
Operations
James L. Womack Director, Expendable Vehicles
Gale Hager CRRES Launch Site Support Manager
George Looshen Chief, Launch Operations Division
LEWIS RESEARCH CENTER
Lawrence J. Ross Director
V.J. Weyers Director of Space Flight Systems
J.W. Gibb Manager, Launch Vehicle Program Office
R.E. Orzechowski CRRES Mission Manager
E. Procasky Atlas/Centaur-69 Chief Engineer
GENERAL DYNAMICS
B.J. Wier GDSSD Vice President and Atlas Program
Director
B.J. Sherwood GD/CLS Mission Manager for CRRES
S.K. Baker GDSSD-CCAFS Engineering Manager, Atlas
I/II Launch Operations
J.T. Heffron GDSSD Atlas Launch Vehicle Program
Director
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DETAILED EXPERIMENTS DESCRIPTION
NASA EXPERIMENTS
NASA's experiments are divided into four areas:
o Magnetospheric Ion Cloud Injections: This group of
experiments will artificially seed the magnetosphere with plasma
and, working with DOD particle and electromagnetic wave
investigators, use ground-based optical and radar diagnostics to
observe large-scale changes in the cloud. In-situ CRRES
measurements will examine smaller, local phenomena. The CRRES
instruments also will determine the state of the magnetosphere,
providing valuable data to allow the determination of optimal
conditions for releases. (Experiments G-1 through G-7, G-10.)
o Ionospheric Modifications: This group of experiments
introduces disturbances into the ionosphere to study the friction
forces arising from the interaction of high-speed injected plasmas
and the ionosphere. Scientists also will inject neutral atoms at
orbital velocities to understand why unusually efficient ionization
occurs when a fast beam of neutral gas passes through a magnetized
plasma. Scientists will compare the observed behavior of the
injected plasmas with computer models. (Experiments G-8, G-9, G-13,
G-14.)
o Electric Fields and Ion Transport: This group of
experiments will study the low-latitude electric fields and the
movement of ions along magnetic field lines into the ionosphere in
response to these electric fields. (Experiments G-11, G-12.)
o Ionospheric Irregularity Simulators: These experiments will
produce large-scale releases of chemicals to study irregularities in
the ionosphere and the effects of the ionosphere on the propagation
of high-frequency-waves. (Experiments AA-1 through AA-7.)
DETAILED PLAN: NASA CRRES SATELLITE EXPERIMENTS
Experiments G-1 through G-4: Diamagnetic Cavity, Unstable
Velocity Distributions, Plasma Coupling. Principal Investigators:
Robert A. Hoffman, Goddard Space Flight Center, G-1, G-2 and G-3;
Steven B. Mende, Lockheed Palo Alto Research Labs,G-4.
Magnetic and solar storms inject plasma into the
magnetosphere. The reaction of the natural magnetosphere to these
injections is important to understanding energy and particle
transport. Injections of barium ions will simulate natural plasma
injections in a precisely controlled manner. These four injections
will be at different altitudes and magnetic field strengths to
understand how different regions of space react to the artificial
cloud plasmas.
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G-5: Stimulated Electron Precipitation to Produce Auroras.
Principal Investigators: Gerhard Haerendal, Max Planck Institut;
Paul A. Bernhardt, Naval Research Laboratories.
The late Neil Brice proposed in 1970 that injections of
artificial ion clouds in the Van Allen radiation belts would cause
the high-energy charged particles to "unstick" from the magnetic
field and crash into the atmosphere.
This theory will be tested by injecting an artificial lithium
plasma in a region of high-energy, trapped electrons. Observers
with optical instruments and radars will closely monitor the
footprint of the magnetic field line where it enters the atmosphere
in Canada and South America to search for artificial auroras created
by these particles.
G-6: Stimulation of Ion-Cyclotron Waves and Artificial Ion
Precipitation. Principal Investigator: Steven B. Mende, Lockheed
Palo Alto Research Labs.
High-energy protons dominate the pre-midnight sector of the
high-altitude magnetosphere. Some of these "leak out" of stable
trapped orbits and precipitate into the atmosphere to cause a weak
aurora. This experiment will inject an artificial lithium plasma
cloud into this proton region and measure any increased proton
precipitation.
Essentially this experiment has the same objectives as the
previous one, except the particles of interest are protons rather
than electrons. The enhanced precipitation will be detected by
optical instruments at the base of the magnetic field line, as these
protons will produce light in the distinct wavelengths of the
hydrogen atom. The instruments on CRRES will monitor the state of
the magnetosphere and will aid in determining the best time for the
release.
G-7: Ion Tracing and Acceleration. Principal Investigators:
William K. Peterson, Lockheed Palo Alto Research Laboratories.
The release of tracer lithium ions will be tracked by
instruments aboard the NASA Dynamics Explorer 1, CRRES, SCATHA and
the Japanese AKEBONO satellites. The previous two lithium releases
also can be used for this experiment, but this release will be made
when the relative positions of these satellites are especially
favorable for observing the artificial tracer ions.
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G-8: Gravitational Instability, Field Equipotentiality,
Ambipolar Acceleration. Principal Investigator: Gerhard Haerendel,
Max Planck Institut.
Space plasmas often become highly irregular and structured.
Electric and magnetic fields are known to be important to this
process, but less is known about the effects of gravity. For the
light protons in the magnetosphere, it is safe to assume that the
effect of gravity is negligible compared to electric and magnetic
forces. For the heavier ions, such as oxygen and nitrogen, this
assumption is questionable. This release will create a heavy barium
plasma along a magnetic field line, and the distortions due to the
action of gravity will be studied with optical instruments and the
radar at Jicamarca, Peru.
G-9: Velocity Distribution Relaxation and Field
Equipotentiality. Principal Investigators: Morris B. Pongratz, Los
Alamos National Laboratory; Gene M. Wescott, University of Alaska.
The CRRES satellite releases gas at orbital velocity, and the
ion clouds that form are moving very rapidly (8 to 10 kilometers per
second) relative to the natural ionosphere. This state is common in
nature, occurring when beams of electrons enter the auroral zone or
when material is pulled into a star. The beams eventually slow
down, but not through physical collisions between particles, as is
the case with neutral gases. Instead, the physics of beam-plasma
interactions are dominated by the long-range electrical and magnetic
forces that act on the charged particles. The exact mechanisms of
these interactions are not well understood
In this experiment, barium will be released over an extensive
network of ground and aircraft observatories in the Caribbean, while
instruments on CRRES will measure the electric and magnetic fields
resulting from the interactions.
G-10: Stimulating a Magnetospheric Substorm. Principal
Investigator: David J. Simons, Los Alamos National Laboratory.
Sometimes during a magnetospheric substorm a very large number
of charged particles reach the atmosphere together, causing a very
bright aurora.
This experiment will attempt to create a substorm by injecting
an artificial barium plasma at the precise moment which the
magnetosphere is unstable, "pushing the magnetosphere over the
edge." Since barium ions can be seen glowing in sunlight (the
particles normally there cannot), scientists will be able to obtain
a clear visual picture of the magnetic substorm creation and its
behavior.
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G-11, G-12: Mirror Force, Field Equipotentiality, Ambipolar
Acceleration. Principal Investigator: Gene M. Wescott, University
of Alaska.
As the release of barium ions flows along magnetic field lines,
it will be affected by electric fields as well. By tracking the
details of the ions' motion, these electric fields can be
measured. Such electric fields are important in controlling inter-
hemispheric flows of electrons and ions.
The releases over the Caribbean will fill the entire magnetic
field line over the equator and down to the other end in South
America. Observations from ground and aircraft observatories in the
Caribbean and South America will pinpoint the details of the ion
motions.
G-13, G-14: Critical Velocity Ionization. Principal
Investigator: Gene M. Wescott, University of Alaska.
The objective of these releases is to investigate the critical
ionization velocity phenomenon, first proposed by Alfven to explain
mass differentiation in planetary formation -- why the inner planets
are made of heavy material and the outer planets are mostly
hydrogen.
The critical ionization velocity model states that if the
relative velocity of electrically neutral chemical species and a
magnetized plasma is large enough, ionization of the neutral gas
will take place even though the energy available is less than that
required for ionization.
Barium, calcium and strontium will be released in these
experiments. These materials have a range of critical ionization
velocities, allowing study of the effect over a wide range of this
parameter.
DETAILED PLAN: NASA CRRES SOUNDING ROCKET EXPERIMENTS
In addition to the releases from the CRRES spacecraft, the
CRRES program includes chemical-release experiments from several
sounding rockets. Two sounding-rocket campaigns are planned, one
from Kwajalein in the Marshall Islands in July and August 1990 and
the other from Puerto Rico in June and July 1991:
AA-1: F-Region Irregularity Evolution. Principal
Investigators: Herbert C. Carlson, Air Force Geophysics Laboratory;
Frank T. Djuth, The Aerospace Corporation.
The reflection of high-frequency (HF) radio waves by a smooth,
conducting ionosphere allows reception of AM radio, long-range HF
communications and over-the-horizon surveillance radar. When
stressed, the ionosphere "fractures" along the direction of the
magnetic field and acts like a picket fence to scatter radio
waves.
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This experiment and a companion, AA-7, will stimulate this
plasma fracturing process with large barium releases in the F and E
regions of the lower ionosphere over the Arecibo, Puerto Rico, radar
site. The radar will diagnose the details of the structuring while
airborne instruments monitor fading and disruption of satellite
radio signals. Comparing these observations to theoretical
predictions will provide an acid test of present understanding of
principles of plasma physics with far-reaching implications.
AA-2: HF Ionospheric Modification of Barium Plasma. Principal
Investigators: Frank T. Djuth, The Aerospace Corporation; Lewis M.
Duncan, Clemson University.
The Arecibo High-Frequency Radio Ionospheric Heater can beam
powerful radio waves into the ionosphere. These radio waves, with
millions of watts of effective power, can "push the ionosphere
around" and create significant perturbations and structures.
In this experiment, a heavy barium plasma will replace the
natural light ionosphere plasma (normally hydrogen and oxygen) in
the beam of the radio wave heater. The heater beam will be turned
on the heavy plasma and scientists can see its response to the
perturbations and compare the results to heater experiments with the
natural ionosphere.
AA-3: HF-Induced Ionospheric Striations and Differential Ion
Expansion. Principal Investigators: Edward P Szczuzcewicz, Science
Applications International Corporation; Lewis M. Duncan, Clemson
University.
This experiment has two sets of objectives. The first is to
release a small tracer amount of barium into an ionospheric region
that has been heated and disturbed by the Arecibo transmitter,
making the heater-induced perturbations visible. This experiment
complements the previous barium plasma heating experiment and
enlarges the area under study.
The second objective is a study of multi-ion expansion
processes. Since ions are electrically charged, they interact
through long-range electrical forces, not just by physical
collisions. Many natural processes, such as the population of the
magnetosphere with upward flowing ions from the ionosphere and the
expansion of the atmospheres of stars, involve ions of more than one
type or mass. The presence of one type of ion can have a strong
influence on another.
Canisters of lithium (a light ion, mass = 7) and barium (a
heavy ion, mass = 137) will be released. As the expanding ion
clouds sweep past the rocket, on-board instruments will study the
details of the clouds and their complex interactions.
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AA-4: Ionospheric Focused Heating. Principal Investigator:
Paul A. Bernhardt, Naval Research Laboratory.
The ionosphere bends radio waves just like a lens or prism
bends light. A chemical release will create a spherical lens in the
ionosphere focusing waves from a high-power ground transmitter into
a powerful beam travelling upward. The power density input level is
expected to be 10 to 100 times the level it would be without
focusing.
The Arecibo radar and instruments will study how the ionosphere
is changed by this focused radio beam. This will be important to
the understand of how the ionosphere responds to natural energy
inputs from magnetic storms and solar flares.
AA-5, AA-6: Equatorial Instability Seeding. Principal
Investigator: Michael M. Mendillo, Boston University.
The ionosphere near the Equator, where the magnetic field is
horizontal, suffers from natural perturbations known as Spread-F.
The normally smooth ionosphere breaks up and radio wave signals are
distorted.
These experiments will release sulfur hexafluoride, which will
start a "bubble" at the bottom of the ionosphere and trigger
artificial Spread-F. This will allow study of the growth and decay
of this effect with a controlled experiment. In these experiments,
one rocket will deploy the ionospheric depletion chemical, and a
second will carry instruments to diagnose the release effects.
AA-7: E-Region Image Formation. Principal Investigator:
Herbert C. Carlson, Air Force Geophysics Laboratory.
The ionosphere is divided into layers, designated D, E and F
(from lowest to highest). The layers are connected by magnetic
field lines, which allow particles to travel between regions.
A large barium release in the F-region will be placed so the
connected E-region is directly over the Arecibo radar. The
artificial cloud in the F-region will create an image in the E-
region that can be mapped by the radar, allowing scientists to study
the strength and speed of inter-region ionospheric coupling.
DEPARTMENT OF DEFENSE EXPERIMENTS
More than 50 DOD scientific instruments will be operating
aboard CRRES, including a microelectronics package, experimental
high-efficiency solar panels and instruments to investigate the
effects of solar flares and cosmic rays on the Earth's magnetosphere
and radiation belts. Instruments to support the perigee
observations include two pulsed plasma probes (a very low frequency
wave analyzer with two electric field antennas), a magnetic field
loop antenna and a quadrupole ion mass spectrometer.
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Some DOD scientific instruments on CRRES will complement the
CRRES chemical science mission, measuring the effects of the
releases at close range. For some of the releases, the instruments
will measure the state of particles and waves in the magnetosphere
and assess if a large magnetic storm is imminent. This will help
scientists determine the best time to conduct a release. The five
main DOD experiments:
o The High Efficiency Solar Panel (HESP): This experiment
will help determine the performance of experimental gallium arsenide
solar panels under the effects of natural radiation and under
ambient and heated conditions.
o Spacerad: Consisting of approximately 30 instruments,
Spacerad will expose microelectronics to space radiation, measuring
the ambient environment (magnetic and electric fields, plasma,
particles, waves, etc.). The two pairs of long wire booms that
extend up to 50 meters from the spacecraft are part of the Spacerad
experiments.
o Solar Flare Isotopes: This experiment will measure cosmic
ray particles and heavy ion composition in the magnetosphere.
o Energetic Particles and Ion Composition: This experiment
will measure the intensity, energy and pitch angles of low-, medium-
and high-energy ambient ions.
o Low Altitude Scientific Studies on Ionospheric
Irregularities (LASSI): This experiment will conduct a set of
observations near the perigee of selected CRRES orbits during
chemical releases. These observations will help scientists study
and compare natural and artificial ionospheric disturbances and the
effects of these disturbances on communications to and from the
satellite.
(Detailed description of USAF experiments is available from USAF
public information representatives)
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CRRES Program Experiments
Release Release
Experiment no. Chemical Location Altitude Period
____________________________________________________________________________________
SATELLITE EXPERIMENTS
Critical Velocity
Critical Velocity G-13 Strontium Am. Samoa 270-360 mi. Sept. 1990
Ionization Barium
G-14 Calcium Am. Samoa 270-360 mi. Sept. 1990
Barium
High-Altitude Magnetospheric
Diagmagnetic Cavity, G-1 Barium N. America 1.3 Re* Jan-Feb 1991
Plasma Coupling G-2 Barium N. America 1.8 Re Jan-Feb 1991
G-3 Barium N. America 3.5 Jan-Feb 1991
G-4 Barium N. America 5.5 Jan-Feb 1991
Stimulated Electron/ G-5 Lithium N. America >6.0 Re Jan-Feb 1991
Aurora Production
Stimulated Ion- G-6 Lithium N.America >6.0 Re Jan-Feb 1991
Cyclotron Waves
and Ion Precip.
Ion Tracing G-7 Lithium N. America >6.0 Re Jan-Feb 1991
and Acceleration
Velocity Distribution G-9 Barium Caribbean June-July 1991
Relaxation
Caribbean Perigee
Grav. Instability G-8 Barium Caribbean 270-480 mi. June-July 1991
Field Equipotentiality
Field Line G-10 Barium Caribbean 270-480 mi June-July 1991
Tracing and G-11 Barium Caribbean 270-480 mi June-July 1991
Equipotentiality G-11A Barium Caribbean 270-480 mi June-July 1991
G-12 Barium Caribbean 270-480 mi June-July 1991
G-12A Barium Caribbean 270-480 mi June-July 1991
*Re=Earth radii
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CRRES PROGRAM EXPERIMENTS
Release Release
Experiment no. Chemical Location Altitude Period
__________________________________________________________________________________
SOUNDING ROCKET EXPERIMENTS
Kwajalein
Equatorial AA-5 SF6* Kwajalein 240 mi Jul.-Aug. 1990
Instability Seeding AA-6A SF6 Kwajalein 150 mi Jul.-Aug. 1990
AA-6B SF6 Kwajalein 150 mi Jul.-Aug. 1990
Puerto Rican Rockets
F-Region AA-1 Barium Puerto Rico 150 mi June-July 1991
Irregularity Evolution
HF Ionospheric AA-2 Barium Puerto Rico 150 mi June-July 1991
Modification of
a Barium Plasma
E-Region AA-7 Barium Puerto Rico 150 mi June-July 1991
Image Formation
HF-Induced Ion AA-3 Barium Puerto Rico 90-240 mi June-July 1991
Striation/Differential Barium Puerto Rico 90-240 mi June-July 1991
Ion Expansion Barium Puerto Rico 90-240 mi June-July 1991
SF6 Puerto Rico 90-240 mi June-July 1991
Ionospeheric AA-4 SF6 Puerto Rico 210-240 mi June-July 1991
Focused Heating
*SF6=Sulfur hexafluoride
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