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Space Surveillance: DOD and NASA Need Consolidated Requirements and a Coordinated Plan (Chapter Report, 12/01/97, GAO/NSIAD-98-42).

GAO reviewed the Department of Defense's (DOD) and the National
Aeronautics and Space Administration's (NASA) space surveillance
requirements and DOD's space surveillance capabilities, focusing on: (1)
how well DOD's existing surveillance capabilities support DOD's and
NASA's current and future surveillance requirements; and (2) the extent
to which potential surveillance capabilities and technologies are
coordinated to provide opportunities for improvements.

GAO noted that: (1) DOD's existing space surveillance network is not
capable of providing the information NASA needs to adequately predict
collisions between space objects orbiting the earth and multibillion
dollar space programs like the space station; (2) the existing network
cannot satisfy DOD's emerging space surveillance requirements, which are
currently under review; (3) DOD's plans--to modernize an existing
surveillance network radar system and develop three new ballistic
missile warning systems that could contribute to performing the
surveillance function--do not adequately consider DOD's or NASA's
surveillance requirements; (4) these four systems are separately managed
by the Navy, the Air Force, and the Army; (5) an opportunity exists to
consider these systems' potential capabilities to enhance the
surveillance network to better satisfy requirements and achieve greater
benefits from planned investment in space sensor technology; (6) despite
NASA's dependency on DOD to provide space object information, the 1996
National Space Policy makes no provision for an interagency
mechanism--either organizational or funding--to ensure that DOD's
surveillance capabilities satisfy NASA's requirements; (7) overall,
there is no authoritative direction, formal agreement, or clear plan on
how DOD and NASA could consolidate their space surveillance requirements
for a common capability; (8) a coordinated interagency plan that
considers all existing and planned space surveillance capabilities could
be beneficial in making cost-effective decisions to satisfy a
consolidated set of national security and civil space surveillance
requirements; (9) unless DOD and NASA can agree on such a plan, an
opportunity may be missed to simultaneously: (a) achieve efficiencies;
(b) better ensure the safety of the planned multibillion dollar space
station; and (c) help satisfy national security needs, including the
U.S. forces' future needs for space asset information.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  NSIAD-98-42
     TITLE:  Space Surveillance: DOD and NASA Need Consolidated 
             Requirements and a Coordinated Plan
      DATE:  12/01/97
   SUBJECT:  Space exploration
             Aerospace research
             Satellites
             Military communication
             Data collection
             Interagency relations
             Military intelligence
             Radar equipment
             Warning systems
             Systems compatibility
IDENTIFIER:  Space Shuttle
             NASA International Space Station Alpha Program
             DOD Space Surveillance Network
             SDI Ground-Based Radar
             SDI Theater High Altitude Area Defense System
             THAADS
             Navy Space Surveillance System
             DOD Space-Based Infrared System
             DOD Space-Based Infrared System-Low
             
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Cover
================================================================ COVER


Report to Congressional Requesters

December 1997

SPACE SURVEILLANCE - DOD AND NASA
NEED CONSOLIDATED REQUIREMENTS AND
A COORDINATED PLAN

GAO/NSIAD-98-42

Space Surveillance

(707209)


Abbreviations
=============================================================== ABBREV

  DOD - Department of Defense
  GAO - General Accounting Office
  GBR - Ground-Based Radar
  NASA - National Aeronautics and Space Administration
  SBIRS - Space-Based Infrared System
  THAAD - Theater High-Altitude Air Defense

Letter
=============================================================== LETTER


B-275848

December 1, 1997

The Honorable Dana Rohrabacher
Chairman
The Honorable Robert E.  Cramer, Jr.
Ranking Minority Member
Subcommittee on Space and Aeronautics
Committee on Science
House of Representatives

In response to your request, this report discusses (1) the Department
of Defense's (DOD) and the National Aeronautics and Space
Administration's (NASA) requirements for surveillance of space
objects and (2) DOD's space surveillance capabilities to support
these requirements.  This report contains recommendations to the
Secretary of Defense and the Administrator of NASA. 

We are sending copies of this report to the Secretaries of Defense,
the Air Force, the Navy, and the Army; the Administrator of NASA; the
Directors of the Office of Management and Budget, the Office of
Science and Technology Policy, and the Central Intelligence; and
other interested congressional committees.  Copies will be made
available to others upon request. 

If you or your staff have any questions concerning this report,
please call me at (202) 512-4841.  Major contributors to this report
are listed in appendix IV. 

Louis J.  Rodrigues
Director, Defense Acquisitions Issues


EXECUTIVE SUMMARY
============================================================ Chapter 0


   PURPOSE
---------------------------------------------------------- Chapter 0:1

During the past 40 years, the number of manmade space objects
orbiting the earth--active and inactive satellites and debris
generated from launch vehicle and satellite breakups--has increased
dramatically.  Knowing what objects are in space and their locations
are important because of the (1) implications of foreign satellite
threats to U.S.  national security and (2) hazards that such objects
create for multibillion dollar space programs, especially large ones
such as the International Space Station. 

At the request of the Chairman and Ranking Minority Member,
Subcommittee on Space and Aeronautics, House Committee on Science,
GAO is providing this report on the Department of Defense's (DOD) and
the National Aeronautics and Space Administration's (NASA) space
surveillance requirements and DOD's space surveillance capabilities. 
GAO evaluated (1) how well DOD's existing surveillance capabilities
support DOD's and NASA's current and future surveillance requirements
and (2) the extent to which potential surveillance capabilities and
technologies are coordinated to provide opportunities for
improvements. 


   BACKGROUND
---------------------------------------------------------- Chapter 0:2

According to a National Science and Technology Council report,\1

an estimated 35 million manmade space objects are orbiting the earth. 
Of these objects, only about 8,000 can be routinely observed by DOD's
existing space surveillance sensors.  DOD and the intelligence
community are interested in knowing the type, status, and location of
space objects, particularly foreign satellites, as part of DOD's
space control mission and other national security functions.\2 NASA
is interested in accurate and timely information on the location and
orbits of space objects to predict and prevent collisions with
spacecraft designed for human space flight--the space station and
space shuttles. 

DOD and NASA rely on the U.S.  Space Command's Space Surveillance
Network, which is operated and maintained by the Air Force, Naval,
and Army Space Commands, to provide information on space objects. 
The network, consisting of radar and optical sensors, data processing
capabilities, and supporting communication systems, detects space
objects; tracks them to determine their orbits; and characterizes
them to determine their size, shape, motion, and type.  This
information is transmitted from the sensors to two command centers
for processing and maintained in a catalog, which is used for such
purposes as monitoring foreign satellites and analyzing space debris. 


--------------------
\1 This Council was established by the President in 1993 to
coordinate science, space, and technology policies throughout the
federal government.  The President is the Council Chairman, and
membership includes the Vice President and cabinet-level and other
federal agency officials.  See Interagency Report on Orbital Debris,
November 1995. 

\2 The space control mission includes four functions:  surveillance
to provide awareness of all activities in space; protection to ensure
U.S.  space system survivability; prevention to preclude an adversary
the use of U.S.  or third-party space systems, capabilities, and
products; and, when directed, negation to deny adversaries the use of
their space systems. 


   RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3

DOD's existing space surveillance network is not capable of providing
the information NASA needs to adequately predict collisions between
space objects orbiting the earth and multibillion dollar space
programs such as the space station.  Moreover, the existing network
cannot satisfy DOD's emerging space surveillance requirements, which
are currently under review. 

DOD's plans to (1) modernize an existing surveillance network radar
system and (2) develop three new ballistic missile warning systems,
which could contribute to performing the surveillance function, do
not adequately consider DOD's or NASA's surveillance requirements. 
These four systems are separately managed by the Navy, the Air Force,
and the Army.  An opportunity exists to consider these systems'
potential capabilities to enhance the surveillance network to better
satisfy requirements and achieve greater benefits from planned
investment in space sensor technology. 

Despite NASA's dependency on DOD to provide space object information,
the 1996 National Space Policy makes no provision for an interagency
mechanism--either organizational or funding--to ensure that DOD's
surveillance capabilities satisfy NASA's requirements.  Overall,
there is no authoritative direction, formal agreement, or clear plan
on how DOD and NASA could consolidate their space surveillance
requirements for a common capability.  A coordinated interagency plan
that considers all existing and planned space surveillance
capabilities could be beneficial in making cost-effective decisions
to satisfy a consolidated set of national security and civil space
surveillance requirements.  Unless DOD and NASA can agree on such a
plan, an opportunity may be missed to simultaneously (1) achieve
efficiencies; (2) better ensure the safety of the planned
multibillion dollar space station; and (3) help satisfy national
security needs, including the U.S.  forces' future needs for space
asset information. 


   PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4


      EXISTING NETWORK CANNOT
      SATISFY EMERGING
      SURVEILLANCE REQUIREMENTS
-------------------------------------------------------- Chapter 0:4.1

The U.S.  Space Command cannot satisfy NASA's space surveillance
requirements with the existing surveillance network.  One
requirement--detecting and tracking space objects as small as
1 centimeter--is linked to the potentially catastrophic effect of a
collision between such an object and the space station.  Another
requirement--locating space objects more accurately--is not currently
possible because the network's sensors and processing capability and
capacity are insufficient, and DOD does not have a program to measure
object location accuracy.  These deficiencies necessitate an upgraded
capability to the surveillance network. 

In August 1997, NASA provided surveillance requirements to the U.S. 
Space Command that are commensurate with NASA's responsibilities to
ensure the safety of human space flight.  According to the NASA
Administrator, these requirements reflect NASA's needs to minimize
risk to human and robotic space flight and assist in recovery from
mishaps of both domestic and foreign spacecraft.  However, DOD and
NASA have not reached agreement regarding how to satisfy these
requirements. 

DOD's existing space surveillance requirements have been repeatedly
studied and will likely become more stringent to address emerging
needs regarding future threats.  DOD is concerned about timely
warning to U.S.  forces when a foreign satellite becomes a threat to
military operations.  With larger numbers of smaller size satellites
(known as microsatellites) expected in the future, DOD believes the
space surveillance mission will become more difficult to execute. 
DOD is currently reviewing its requirements. 

<head2<Potential Surveillance Capabilities Are Not Sufficiently
Coordinated

Four systems, which are managed separately by the military services,
could be upgraded or designed to support surveillance functions. 
These systems are an operational Navy-funded space surveillance
system and an Air Force- and two Army-funded developmental systems
associated with ballistic missile defense.  However, there is a lack
of coordination--both within DOD and between DOD and NASA--to take
advantage of these systems' potential contribution to space
surveillance for serving both national security and civil space
sectors. 

DOD's Space Architect organization has a key role in evaluating
national security space missions and capabilities for achieving
acquisition and operational efficiencies.\3 Although it does not have
a similar responsibility for evaluating civil space needs, NASA could
participate with the DOD Space Architect organization in evaluating
space surveillance needs from a broader perspective. 


--------------------
\3 The purpose of the Space Architect organization is to consolidate
the responsibilities for DOD space missions and system architecture
development into a single organization to achieve acquisition and
future operational efficiencies.  The Architect also performs this
function with the intelligence community to support national security
requirements. 


   RECOMMENDATIONS
---------------------------------------------------------- Chapter 0:5

GAO recommends that the Secretary of Defense and the Administrator of
NASA, in consultation with the Director of Central Intelligence,

  -- establish a consolidated set of governmentwide space
     surveillance requirements for evaluating current capabilities
     and future architectures to support NASA's, DOD's, and other
     federal agencies' space programs and surveillance information
     needs and

  -- develop a coordinated governmentwide space surveillance plan
     that (1) sets forth and evaluates all feasible alternative
     capabilities to support human space flight and emerging national
     security requirements and (2) ensures that any planned funding
     for space surveillance upgrades is directed toward satisfying
     consolidated governmentwide requirements. 


   AGENCY COMMENTS
---------------------------------------------------------- Chapter 0:6

Both DOD and NASA provided written comments on a draft of this
report.  Their comments appear in appendixes II and III,
respectively. 

DOD generally agreed with GAO's recommendations.  While DOD supports
a governmentwide group to consolidate requirements, it emphasized the
need for each organization to first establish individual requirements
and then proceed with consolidating the requirements and sharing the
cost for satisfying them.  It noted that an interagency group will be
required to develop a near-term policy on cost or burden sharing and
a long-term policy for government and commercial organizations that
may request space surveillance support.  Also, DOD agreed with an
interagency approach to evaluate existing capabilities, plan future
architectures, and address funding responsibilities. 

Although NASA did not comment on GAO's recommendations, it stated
that, overall, the draft report was an accurate representation of the
national requirements for space surveillance (particularly DOD's and
NASA's) and DOD's current space surveillance network capabilities. 
NASA emphasized that, in August 1997, the NASA Administrator provided
the U.S.  Space Command with quantified space surveillance
requirements.  It stated that, although most of the near-term
requirements are being met, three are not presently being satisfied: 
detecting and tracking relatively small space objects and more
accurately determining the location of such objects, as discussed in
this report, and notifying NASA of a space object breakup within 1
hour. 

Concerning DOD's and NASA's comments about the need for a process to
address requirements, the agencies have the Aeronautics and
Astronautics Coordinating Board--a senior management review and
advisory body--that could oversee the establishment of space
surveillance requirements and the development of a space surveillance
plan.  The Board exists to facilitate coordination of aeronautics and
space activities of mutual interest to DOD and NASA.  It was
established several years ago, and the memorandum of agreement was
renewed in 1993 by the Deputy Secretary of Defense and the
Administrator of NASA.  The Director, National Reconnaissance Office,
is 1 of 18 members on the Board. 

Finally, DOD stated that delaying space surveillance programs, which
it has funded to meet DOD requirements, to insert NASA's recently
provided requirements would result in increased cost and schedule
risk.  GAO recognizes that some funds may be needed for system
maintenance and modernization and therefore modified its
recommendation to only address system upgrades.  GAO believes that
any funding for such upgrades should be directed toward satisfying
consolidated governmentwide requirements. 


INTRODUCTION
============================================================ Chapter 1

Since the former Soviet Union launched its first Sputnik satellite 40
years ago, the number of manmade space objects orbiting the
earth--active and inactive satellites and debris generated from
launch vehicle and satellite breakups--has increased dramatically. 
In 1995, a National Science and Technology Council report estimated
the number of space objects to be over 35 million.  Although nearly
all of these objects are thought to be smaller than 1 centimeter,
about 110,000 are estimated to be between
1 and 10 centimeters, and about 8,000 are larger than 10 centimeters. 
Only the approximate 8,000 objects are large enough, or reflect radar
energy or light well enough, to be routinely observed by the
Department of Defense's (DOD) existing space surveillance sensors. 
About 80 percent of these 8,000 objects are in low-earth orbits, and
the remainder are in geosynchronous and other orbits.\1

The increasing amount of space debris creates a hazard to certain
spacecraft, especially large ones like the planned multibillion
dollar International Space Station,\2 which will operate in low-earth
orbits.  The National Aeronautics and Space Administration (NASA) is
interested in accurate and timely information on the locations and
orbits of space objects to predict and prevent collisions with
spacecraft designed for human space flight--the space station and
space shuttles.  DOD and intelligence agencies are interested in
knowing the type, status, and location of space objects, particularly
foreign satellites, as part of DOD's space control mission and other
national security functions.  NASA and DOD rely on the U.S.  Space
Command's Space Surveillance Network, which is operated and
maintained by the Air Force, Naval, and Army Space Commands, to
provide information on space objects. 

<head1<SURVEILLANCE NETWORK FUNCTIONS

The surveillance network consists of radar and optical sensors, data
processing capabilities, and supporting communication systems.  It
detects objects in space; tracks them to determine their orbits; and
characterizes them to determine their size, shape, motion, and type. 
The network routinely detects and tracks objects larger than about 30
centimeters (somewhat larger than a basketball).  It can sometimes
detect and track objects as small as 10 centimeters (about the size
of a softball), but not routinely. 

The surveillance network also catalogs the approximately 8,000 space
objects and includes information that describes the orbit, size, and
type of object.  The information is used for such purposes as (1)
warning U.S.  forces of foreign reconnaissance satellites passing
overhead and (2) analyzing the space debris environment and the
potential implications of planned space operations.  All space
sectors--defense, intelligence, civil, and commercial--use the
catalog information. 


--------------------
\1 Low-earth orbits are at altitudes less than 5,500 kilometers.  A
geosynchronous orbit is at an altitude of about 36,000 kilometers. 

\2 In Space Station:  Estimated Total U.S.  Funding Requirements
(GAO/NSIAD-95-163, June 12, 1995), we reported that the space station
would cost about $58 billion from program inception in 1985 through
final assembly in space in June 2002.  This cost estimate consisted
of (1) $11.2 billion spent from 1985 through 1993 for designing and
developing earlier versions; (2) $17.4 billion to be spent from 1994
to 2002 to complete assembly of the current design; and (3) $19.6
billion to be spent to 2002 for station-related requirements, such as
space shuttle launch support.  In addition, $9.4 billion was expected
to be spent to 2002 by international partners, other than Russia. 
Finally, $45.7 billion was estimated to support 10 years of
operations after 2002.  NASA is updating its cost estimates, and we
are reviewing them. 


   SURVEILLANCE NETWORK EVOLUTION
---------------------------------------------------------- Chapter 1:1

Subsequent to the launch of Sputnik in 1957, DOD established a space
tracking mission and a network of radars and telescopes to monitor
orbiting satellites.  During the 1960s, DOD built radars to support
two missions--space tracking and ballistic missile warning.  The
Naval Space Surveillance System (known as the Fence) is a chain of
radar equipment extending from California to Georgia that was
constructed to detect foreign reconnaissance satellites and provide
warning to Navy ships of such satellite overflights.  The system is
still operational, and the Navy plans to modernize it beginning in
2003 to improve its maintainability.  Also, Ballistic Missile Early
Warning System radars were constructed in Alaska, Greenland, and
England to detect and track intercontinental ballistic missiles that
could be launched at North America.  A secondary mission for these
missile warning radars has always been space surveillance.  Finally,
a prototype phased-array radar was built in Florida to support the
space surveillance mission. 

During the 1970s, the Air Force reactivated the Safeguard
antiballistic missile phased-array radar in North Dakota.  This radar
provides space surveillance support as a secondary mission.  Also,
the Air Force began a program to build four phased-array radars
(called PAVE PAWS) to detect and track submarine-launched and
intercontinental ballistic missiles.  The four radars--in Georgia,
Texas, California, and Massachusetts--were completed in the 1980s,
but the Georgia and Texas radar sites were closed in 1995.  The
radars in California and Massachusetts continue to operate and
support space surveillance as a secondary mission. 

During the 1980s, DOD acquired four Ground-based Electro-Optical Deep
Space Surveillance telescopes to detect and track objects in
geosynchronous orbit because existing surveillance network sensors
could not detect objects at such a distance.  These telescopes
provide nearly worldwide coverage but are limited to operating at
night and in clear weather.  Three sites, located in New Mexico,
Hawaii, and Diego Garcia (in the Indian Ocean), are currently
operational.  A fourth site in Korea was closed in 1993 due to poor
tracking conditions. 

The existing space surveillance network includes 31 radar and optical
sensors at 16 worldwide locations, a communications network, and
primary and alternate operations centers for data processing. 
Appendix I discusses the surveillance network's composition and
characteristics. 


   NATIONAL SPACE POLICY
   GUIDELINES
---------------------------------------------------------- Chapter 1:2

The September 1996 National Space Policy includes civil, defense, and
intersector guidelines related to space safety, space threats, and
space debris.  Specifically, the policy (1) requires NASA to ensure
the safety of all space flight missions involving the space station
and space shuttles; (2) requires DOD to maintain and modernize space
surveillance and associated functions to effectively detect, track,
categorize, monitor, and characterize threats to U.S.  and friendly
space systems and contribute to the protection of U.S.  military
activities; and (3) declares that the United States will seek to
minimize the creation of space debris and will take a leadership role
internationally, aimed at debris minimization. 

A distinctive interconnection among these policy guidelines is that,
although the increasing amount of space debris creates a hazard to
human space flight, NASA has no surveillance capabilities to locate
space objects.  Instead, it relies on DOD's capabilities to perform
this function.  Despite this dependency relationship, the policy
makes no provision for an interagency mechanism--either
organizational or funding--to ensure that DOD's space surveillance
capabilities meet NASA's requirements. 


   INCREASING ATTENTION TO SPACE
   SURVEILLANCE
---------------------------------------------------------- Chapter 1:3

The surveillance of space objects is receiving increasing attention
from both a civil and national security perspective.  Part of the
reason for the increased attention is because of (1) the planned
assembly of the space station beginning in 1998 and (2) DOD's
recognition that its aging space surveillance network cannot
adequately deal with future national security threats.  In addition,
DOD believes that the growing commercial space sector will result in
increased requests for surveillance support. 


      DEBRIS CREATES HAZARD TO
      SPACE STATION
-------------------------------------------------------- Chapter 1:3.1

According to the National Research Council,\3 the chance of debris
colliding with a spacecraft relates directly to the size and orbital
lifetime of the spacecraft.  The space station will be the largest
spacecraft ever built, with length and width dimensions somewhat
larger than a football field.  Its total exposed surface area will be
almost 10 times greater than that of a space shuttle--about 11,500
square meters compared with about
1,200 square meters.  Also, the space station's orbital lifetime is
expected to exceed that of a space shuttle.  NASA plans to operate
the space station continuously for at least 10 years.  In contrast,
in recent years, individual space shuttle missions have averaged
about 7 per year and 11 days per mission.  In future years, NASA is
planning about eight shuttle missions per year.  The Council
concludes that the space station will face a significant risk of
being struck by potentially damaging meteoroids or orbital debris. 

The space station is to operate at low-earth altitudes--between 330
to
500 kilometers.  According to the National Science and Technology
Council, debris orbiting at altitudes up to about 900 kilometers lose
energy over time through friction with the atmosphere and fall to
lower altitudes, eventually either disintegrating in the atmosphere
or falling to the earth.  New debris is periodically added, sometimes
unexpectedly.  For example, in June 1996, a Pegasus rocket broke up
at an altitude of about
625 kilometers, creating 668 observable objects.  Also, it is likely
that an unknown number of other objects were created, but they are
not observable because of their small size.  Such debris, as it falls
toward the earth, can be expected to pass through the space station's
operating altitudes. 


--------------------
\3 This Council, part of the National Academy of Sciences, provides
advice to the federal government on scientific and technical matters. 
See Protecting the Space Station from Meteoroids and Orbital Debris,
1997. 


      POTENTIAL FOR INCREASED
      THREATS TO U.S.  FORCES
-------------------------------------------------------- Chapter 1:3.2

From a national security (defense and intelligence) perspective,
space surveillance provides (1) warning to U.S.  forces when a
foreign satellite becomes a threat to military operations and (2)
information to support responsive measures.  According to DOD, as the
importance of space services to U.S.  forces increases and the size
of satellites decreases, the need for timely information about space
objects expands.  DOD has acknowledged that its existing surveillance
network is aging, requires replacement or upgrades in the next 10 to
15 years, and is currently limited in its ability to detect and track
objects smaller than 30 centimeters. 


      RECENT DOD AND NASA
      ACTIVITIES RELATED TO
      SURVEILLANCE
-------------------------------------------------------- Chapter 1:3.3

In January 1996, the Deputy Under Secretary of Defense for Space
directed the DOD Space Architect to begin a study of DOD's space
control mission, including the space surveillance function.  The
purpose was to develop a range of architecture alternatives to
satisfy national security needs to 2010 and beyond.  In May 1997, the
team provided its results to the Joint Space Management Board.\4

Regarding space surveillance, the team concluded that next-generation
ground-based radars and potential space-based systems should be able
to provide reliable near-earth tracking of space objects that are 5
to 10 centimeters in size.\5 The team expected such capabilities to
improve debris awareness and ensure that an emerging class of
microsatellites as small as 10 centimeters could be tracked.  The
Board has yet to provide directions to DOD and intelligence
organizations on how to proceed regarding the space surveillance
function. 

In a separate action, NASA and the Air Force Space Command
established a partnership council in February 1997 to study a variety
of space areas of mutual interest.  One area involves DOD's space
surveillance network.  The impetus to address this subject arose from
recognizing the potentially catastrophic consequences of collisions
between manned spacecraft and orbiting debris.  One of the tasks is
to examine ways to enhance orbital debris data collection and
processing on objects as small as 5 centimeters. 


--------------------
\4 This Board was established by the Secretary of Defense and the
Director of Central Intelligence to ensure that defense and
intelligence needs for space systems and their terrestrial components
are satisfied within available resources, using integrated
architectures to the extent possible. 

\5 DOD uses the term near earth to describe a range of altitudes that
are similar to the National Science and Technology Council's
definition of low earth. 


   OBJECTIVES, SCOPE, AND
   METHODOLOGY
---------------------------------------------------------- Chapter 1:4

The Chairman and Ranking Minority Member of the Subcommittee on Space
and Aeronautics, House Committee on Science, expressed an interest in
how NASA intends to ensure protection of the space station against
space debris for which shielding will not be provided.  As a result,
they asked us to provide this report on NASA's and DOD's requirements
and capabilities for detecting and tracking space objects and the
existing relationships between the two agencies for carrying out
their responsibilities in this area.  We evaluated (1) how well DOD's
existing space surveillance capabilities support DOD's and NASA's
current and future surveillance requirements and (2) the extent to
which potential space surveillance capabilities and technologies are
coordinated to provide opportunities for improvements. 

To accomplish these objectives, we reviewed surveillance network
studies; DOD's and NASA's surveillance requirements documents and
emerging needs; reports, plans, and budgets associated with
surveillance network operations, maintenance, and enhancements; and
program documentation on potential capabilities.  We also reviewed
national space policy and interviewed DOD and NASA representatives
responsible for space surveillance.  We performed this work primarily
at the U.S.  and Air Force Space Commands, Colorado Springs,
Colorado, and NASA's Johnson Space Center, Houston, Texas. 

In addition, we held discussions with and obtained documentation from
representatives of the Office of the Deputy Under Secretary of
Defense for Space; the Joint Staff; the Ballistic Missile Defense
Organization; the Office of the DOD Space Architect; the Departments
of the Air Force, the Navy, and the Army; the Naval Research
Laboratory; and NASA Headquarters; all in Washington, D.C. 

We also acquired information from the Naval Space Command, Dahlgren,
Virginia; the Air Force Space and Missile Systems Center, El Segundo,
California; the Air Force Electronic Systems Center, Hanscom Air
Force Base, Massachusetts; the Air Force's Phillips Laboratory,
Albuquerque, New Mexico; the Army Space and Strategic Defense
Command, Huntsville, Alabama; the National Oceanic and Atmospheric
Administration's Office of Satellite Operations, Suitland, Maryland;
the Massachusetts Institute of Technology's Lincoln Laboratory,
Lexington, Massachusetts; and the University of Colorado's Aerospace
Engineering Sciences, Boulder, Colorado.  We visited the Air Force's
Ground-based Electro-Optical Deep Space Sensor, Socorro, New Mexico;
the Massachusetts Institute of Technology's Lincoln Space
Surveillance Complex, Tyngsboro, Massachusetts; and NASA's Liquid
Mirror Telescope, Cloudcroft, New Mexico. 

We obtained written comments from DOD and NASA on a draft of this
report.  These comments are reprinted in their entirety in appendixes
II and III, respectively.  Both DOD and NASA also provided technical
and editorial comments, which we have incorporated into the report
where appropriate. 

We performed our work from September 1996 to August 1997 in
accordance with generally accepted government auditing standards. 


EXISTING NETWORK CANNOT SATISFY
EMERGING SURVEILLANCE REQUIREMENTS
============================================================ Chapter 2

NASA has established some stringent space surveillance requirements
to protect the space station and other spacecraft from collisions
with space debris.  DOD's space surveillance requirements are under
review and are likely to become more stringent.  Because DOD's
existing space surveillance network cannot satisfy its and NASA's
emerging requirements, changes in the network may be needed.  NASA
and DOD have held discussions over the years regarding NASA's
surveillance requirements, but there is no authoritative direction,
formal agreement, or clear plan on how the two agencies could
consolidate their requirements for a common capability. 


   NASA'S REQUIREMENTS TO PROTECT
   THE SPACE STATION ARE STRINGENT
---------------------------------------------------------- Chapter 2:1

During the past several years, NASA and DOD periodically discussed
space surveillance requirements for the space station, but many
proposed requirements were left to be determined and not formally
provided as firm requirements to DOD.  In August 1997, however, NASA
provided the U.S.  Space Command with an updated set of requirements
for surveillance support that are more specific, comprehensive, and
complete than previous requirements.  Two of these
requirements--detecting and tracking relatively small space objects
and more accurately determining the location of such objects--cannot
be met by DOD's existing surveillance network.  In commenting on a
draft of this report, NASA stated that a third requirement--notifying
NASA within 1 hour of a space object breakup--also cannot be met. 


      RELATIVELY SMALL-SIZED SPACE
      OBJECT INFORMATION NEEDED
-------------------------------------------------------- Chapter 2:1.1

NASA has designed portions of the space station with shielding to
provide protection against objects smaller than 1 centimeter.  It has
concluded that shielding against larger objects would be too costly. 
The National Science and Technology Council estimated that about
118,000 objects 1 centimeter and larger were orbiting the earth. 
However, DOD's surveillance network cannot routinely detect and track
110,000 (93 percent) of the objects that are estimated to be between
1 and 10 centimeters in size.  The National Research Council report
stated that the risk of the space station colliding with untracked
debris could be lowered if more objects were tracked.  The report
mentioned that debris from about 0.5 to 20 centimeters in diameter
was of most concern to the space station because, within this range,
the debris may be too large to shield against and too small to
(currently) track and avoid. 

Because NASA has no location information about these relatively small
sized objects, it is requiring DOD, in the near term, to routinely
detect, track, and catalog all space objects that are 5 centimeters
and larger and have a perigee of 600 kilometers or less.\1 Beginning
in the 2002-2003 time frame, when the space station is to be
completed, NASA will require DOD to detect, track, and catalog
objects as small as 1 centimeter.  DOD agrees that achieving the
ability to detect and track objects 5 centimeters in size would be an
intermediate step to meeting NASA's needs.  However, DOD stated that
achieving the capability to detect and track objects
1 centimeter in size would be technically challenging. 

The importance of the requirement to detect and track 1 centimeter
space objects is linked to the effect of critical collisions between
such objects and the space station.  NASA estimates a 19-percent
probability of critical collisions with objects larger than 1
centimeter during a 10-year period.  Although not all collisions
would be catastrophic, NASA estimates a 5-percent probability that
such collisions would cause a catastrophic failure, resulting in the
loss of a module or a crew member.  The National Research Council
emphasized that these calculations are far from exact because they
are based on many assumptions such as the future debris environment,
which could be higher or lower than estimated, and the effectiveness
of shielding critical space station components.  Also, the
calculations exclude impacts on noncritical items that could
potentially cause severe damage to the station. 


--------------------
\1 The perigee of an object's orbit is the lowest point of the orbit
relative to the earth. 


      ACCURATE SPACE OBJECT
      LOCATION INFORMATION NEEDED
-------------------------------------------------------- Chapter 2:1.2

NASA plans to maneuver the space station to avoid collisions with
those space objects that can be accurately located by DOD's
surveillance network.  Currently, DOD assesses the proximity of the
8,000 cataloged objects relative to an orbiting space shuttle.  NASA
uses these assessments to determine whether a sufficient threat
exists to require a collision avoidance maneuver.  Although NASA has
made such maneuvers with the space shuttle, the shuttle has not been
maneuvered in some instances because of concern for interference with
the primary mission objective. 

For safety reasons, knowing the accurate location of space objects is
important in deciding when to make collision avoidance maneuvers. 
Also, such knowledge would help avoid making unnecessary maneuvers
that would be disruptive to mission objectives, such as microgravity
experiments performed on the space shuttle or space station. 

To ensure accurate information on objects that are 1 centimeter and
larger, in low-earth orbit, and with perigees 600 kilometers or less,
NASA's requirements specifically call for sensor tracking to an
orbital "semi-major axis" uncertainty of 5 meters or less.\2 The
purpose of this requirement is to better predict possible collisions
and better decide on the need for collision avoidance maneuvers. 
However, DOD cannot meet this requirement because the network's
sensors and processing capability and capacity are insufficient, and
because DOD does not have a program to measure the orbital location
accuracy of the 8,000 cataloged objects. 


--------------------
\2 Because most space objects have elliptical orbits, the longer
radius of the ellipse is known as the semi-major axis. 


   DOD'S REQUIREMENTS ARE UNDER
   REVIEW AND LIKELY TO BECOME
   MORE STRINGENT
---------------------------------------------------------- Chapter 2:2

During the 1980s and early 1990s, the U.S.  and Air Force Space
Commands repeatedly studied different aspects of space surveillance
needs and requirements, but not in a comprehensive manner.  Command
representatives told us that the lack of emphasis on space
surveillance during this period was due to its lower priority
compared with other missions, such as ballistic missile defense. 

In 1994, the U.S.  Space Command assessed its surveillance
requirements, which had last been validated in 1985.  The results
showed that the requirements were loosely stated or inferred, had
little supporting rationale, and did not address future threats. 
This assessment led to another study, completed by the Air Force
Space Command in 1995, that established new space surveillance
requirements.  However, these requirements were never validated by
the Joint Requirements Oversight Council--DOD's authoritative forum
for assessing requirements for defense acquisition programs. 

In early 1997, the U.S.  Space Command determined that the 1995 Air
Force surveillance requirements contained insufficient detail and
justification and, as a result, initiated another requirements
review.  In June 1997, the Command emphasized that space surveillance
is the foundation for all functions that are performed in space and
thus requested updated surveillance requirements from defense,
intelligence, and civil space sector users, stating that the
requirements must be quantitatively linked to the needs of the
warfighter and the Command's assigned civil support responsibilities. 
The final product is to be a space surveillance requirements annex to
the Command's space control capstone requirements document.  This
document, which is still in draft form, emphasizes the necessity of
(1) timely space surveillance assessments relative to hostile actions
in space, foreign reconnaissance satellite overflights, and
operational capabilities of foreign satellites and (2) accurate
information about space object size and orbital locations.  Upon
completion of this effort, the space surveillance requirements are to
be reviewed and validated by the Joint Requirements Oversight
Council. 

The DOD Space Architect used the U.S.  Space Command's draft capstone
requirements as a basis for performing its space control architecture
study.  The study observed that U.S.  forces expect timely
characterization of space threats; that is, forces expect to be
warned in a timely manner when a foreign satellite is a threat to
their theater of operations.  However, the study concluded that, with
the trends in satellite growth indicating not only more satellites
but also smaller and more compact satellites (known as
microsatellites), the task of distinguishing the attributes and
status of orbiting objects with both ground- and space-based sensors
becomes more difficult. 


   PROCESS FOR ESTABLISHING
   CONSOLIDATED REQUIREMENTS IS
   NOT CLEAR
---------------------------------------------------------- Chapter 2:3

DOD has a well-defined process for establishing its own requirements. 
However, because NASA is not a participant in this process and
depends on DOD to provide space surveillance capabilities, it is not
clear how NASA can ensure satisfaction of its surveillance
requirements.  First, although the 1996 National Space Policy implies
that DOD should provide such surveillance capabilities, and the U.S. 
Space Command acknowledges its civil space sector responsibility in
this area, the policy does not provide directions to ensure that DOD
satisfies NASA's requirements.  Second, although NASA has provided
requirements to the U.S.  Space Command, DOD and NASA have not
reached agreement as to how or when these requirements might be
satisfied.  Third, the DOD Space Architect organization's study of
space surveillance, which included both the defense and intelligence
space sectors, noted that detecting and tracking space debris down to
1 centimeter (NASA's requirement) could be important to the safety of
manned space systems, but that the requirement is not a high priority
for DOD.  Thus, there is no authoritative direction, formal
agreement, or clear plan on how the two agencies could consolidate
their requirements for a common capability. 


   CONCLUSIONS
---------------------------------------------------------- Chapter 2:4

The civil and national security (defense and intelligence) space
sectors have a common interest in space surveillance, and there may
be an increasing interest by the commercial space sector.  Better
information is needed regarding the size, location, and
characterization of space objects than the existing space
surveillance network can provide. 

NASA's space surveillance requirements are commensurate with its
responsibilities to ensure the safety of human space flight, but
these requirements have not been acted upon by DOD.  DOD's space
surveillance requirements continue to be reviewed and will likely
become more stringent. 

Unless DOD and NASA can establish a consolidated set of national
security and civil space surveillance requirements, an opportunity
may be missed to (1) better ensure the safety of the planned
multibillion dollar space station and (2) help satisfy national
security needs, including U.S.  forces' future needs for space asset
information. 


   RECOMMENDATION
---------------------------------------------------------- Chapter 2:5

We recommend that the Secretary of Defense and the Administrator of
NASA, in consultation with the Director of Central Intelligence,
establish a consolidated set of governmentwide space surveillance
requirements for evaluating current capabilities and future
architectures to support NASA's, DOD's, and other federal agencies'
space programs and surveillance information needs. 


POTENTIAL SURVEILLANCE
CAPABILITIES ARE NOT SUFFICIENTLY
COORDINATED
============================================================ Chapter 3

DOD's plans to modernize the existing Naval Space Surveillance System
(known as the Fence) and develop three new ballistic missile warning
systems do not adequately consider NASA's or DOD's emerging space
surveillance requirements.  The Fence modernization effort would not
provide an enhanced capability, but instead would only install modern
components while continuing to satisfy DOD's current requirements. 
The development efforts for three missile warning systems do not
adequately consider DOD's or NASA's emerging space surveillance
requirements.  Also, these four separate efforts are not sufficiently
coordinated.  Greater coordination could result in more informed
decisions regarding the best combination of capabilities to satisfy a
consolidated set of emerging national security and civil space
surveillance requirements. 


   RADAR SYSTEM PLAN DOES NOT
   ADDRESS EMERGING SURVEILLANCE
   REQUIREMENTS
---------------------------------------------------------- Chapter 3:1

Beginning in fiscal year 2003, the Navy tentatively plans to
incrementally replace components of the Fence with modern components
because of the system's age and relatively high maintenance costs. 
However, this effort is not currently funded and will not enhance the
system's present capability to detect and track space objects smaller
than about 30 centimeters.  According to DOD and NASA, the Fence
could be upgraded to detect most near- earth space objects larger
than 1 centimeter by changing its operating radio frequency from the
existing very high frequency band to the super-high frequency band
and by locating it near the equator.  Such an upgrade could aid in
satisfying both NASA's requirement related to small-sized space
objects and DOD's emerging requirement related to microsatellites. 

However, according to Naval Space Command officials, such an upgrade
has not undergone comprehensive study.  In addition, they stated that
a radio frequency change (1) is not needed to satisfy existing DOD
surveillance requirements and (2) would have a significant effect on
the surveillance network's data processing needs.  In commenting on
our draft report, DOD stated that the possibility of obtaining funds
to upgrade the Fence to meet NASA's 1 centimeter requirement is not
high because DOD has no comparable requirement. 


   MISSILE WARNING PLANS DO NOT
   ADDRESS EMERGING SURVEILLANCE
   REQUIREMENTS
---------------------------------------------------------- Chapter 3:2

Historically, DOD acquired various sensors to satisfy missions other
than space surveillance and then capitalized on their inherent
capabilities to satisfy the surveillance mission.  This collateral
mission concept enabled DOD to perform two missions with the same
sensors.  Examples included ballistic missile early warning radars to
detect and track intercontinental ballistic missiles and
submarine-launched ballistic missiles and other radars to track space
launch vehicles.  DOD's Space-Based Infrared System (SBIRS),
Ground-Based Radar (GBR), and Theater High Altitude Air Defense
(THAAD) radar are future ballistic missile warning systems that could
contribute to performing the space surveillance function as a
secondary mission. 


      INFRARED SATELLITE SYSTEM
-------------------------------------------------------- Chapter 3:2.1

DOD plans to develop a low-earth orbit satellite component within the
SBIRS program, referred to as SBIRS-Low, to provide missile tracking
support to both national and theater ballistic missile defense
programs.  In May 1997, the Under Secretary of Defense for
Acquisition and Technology testified before a congressional panel
that SBIRS-Low could also perform much of the space surveillance
function, allowing some existing terrestrial surveillance sensor
sites to be closed and eliminating some surveillance network gaps in
space coverage,\1 such as in the Southern Hemisphere.  Although DOD
believes that the planned SBIRS-Low design would provide an inherent
space surveillance capability, its specific capabilities for this
function have not been determined. 

The Air Force plans to initiate SBIRS-Low development in fiscal year
1999, launch the first satellite in fiscal year 2004, and ultimately
procure up to 24 or more satellites to establish an operational
constellation that would provide worldwide coverage.  Although the
SBIRS program office has begun to investigate the feasibility of
space-based space surveillance, it currently does not plan to develop
the SBIRS' surveillance capabilities because the necessary
operational requirements have not been established.  Until these
requirements are established, DOD can only point to the potential
capabilities provided inherently by the ballistic missile warning
design. 


--------------------
\1 This testimony was presented before a joint session of the
Subcommittee on Military Research and Development and Subcommittee on
Military Procurement, House Committee on National Security. 


      MISSILE DEFENSE RADARS
-------------------------------------------------------- Chapter 3:2.2

The Army is developing two new phased-array radar systems--the GBR to
support national missile defense and the THAAD radar to support
theater missile defense.  Army project officials stated that on the
basis of limited analyses, GBR and THAAD radars each may have
inherent space surveillance capabilities that could support NASA's
and DOD's emerging requirements.  They stated that GBR, for example,
could (1) detect and track space objects that are approximately 1
centimeter or less and (2) maintain 1,000 simultaneous tracks of
these objects compared with only several hundred tracks that
phased-array radars in the existing surveillance network can
maintain.  Similarly, the officials stated that the THAAD radars
could track, characterize, and discriminate objects while performing
their autonomous search function.  Finally, the officials stated that
the GBR and THAAD radars could be used during peacetime for space
surveillance while maintaining readiness for combat. 

As with SBIRS-Low, neither GBR nor THAAD is currently required or
specifically designed to perform space surveillance functions.  Army
officials stated that, although the U.S.  Space Command was briefed
about GBR's ability to perform collateral missions, including space
surveillance, the Command had not established operational
requirements for space surveillance applicable to either GBR or
THAAD. 

By fiscal year 1998, the Army plans to have a GBR prototype in
operation.  A national missile defense deployment decision is
expected in fiscal
year 2000, which may include plans for GBR deployment in 2003. 
Regarding THAAD, the Army currently has two test radars and plans to
award an engineering and manufacturing development contract in 1999
for two radars with more capability.  It expects to deploy as many as
12 mobile THAAD radars worldwide. 


   LACK OF A COORDINATED PLAN
---------------------------------------------------------- Chapter 3:3

The Air Force Space Command's 1995 space surveillance study observed
that the surveillance network evolved without a master plan.  The
space surveillance mission did not have as high a priority as other
missions, and DOD capitalized on the inherent capabilities of sensors
that were designed for purposes other than surveillance.  The lack of
such a comprehensive plan creates difficulties in assessing
operational capabilities to satisfy requirements, particularly when
the need arises to evaluate emerging requirements that are
increasingly stringent. 

The DOD Space Architect's May 1997 space control study assessed a mix
of space surveillance capabilities.  The study observed, for example,
that a modest radio frequency enhancement to the existing Naval Space
Surveillance System, costing roughly $200 million, is feasible for
tracking space debris as small as 2 to 5 centimeters.  The study also
observed that the timing is right to evaluate the presumed inherent
space surveillance capabilities of SBIRS-Low to determine if those
capabilities could actually be provided.  Although GBR and THAAD were
not specifically addressed in the study, it indicated that a system
with similar generic capability would be stressed to achieve NASA's 1
centimeter requirement.  Finally, the study suggested that several
technology efforts be continued to provide a hedge against an
uncertain set of future space control threats and priorities. 

A significant point in the Space Architect's study was that NASA's
1 centimeter requirement would be both technically challenging and
expensive.  In its comments on our draft report, DOD stated that the
requirement is not considered feasible within current budget
constraints.  Until the Joint Space Management Board provides
directions regarding the study's results, implementation plans will
not be prepared.  Even then, the plans may not sufficiently address
NASA's needs without agreement between DOD and NASA. 


   CONCLUSIONS
---------------------------------------------------------- Chapter 3:4

NASA relies on DOD for space surveillance support, and both agencies
need improved surveillance capabilities.  However, four DOD systems
that could provide such capabilities--the Naval Space Surveillance
System, SBIRS-Low, GBR, and THAAD--lack sufficient coordination, both
within DOD and between DOD and NASA.  The three missile defense
sensors (SBIRS-Low, GBR, and THAAD) could provide a collateral space
surveillance capability, a concept DOD has successfully used over the
years.  In times of constrained budgets, capitalizing on ways to
satisfy multiple missions with the same resources appears to be
prudent. 

A coordinated plan between DOD and NASA that considers all existing
and planned capabilities could be beneficial in making cost-
effective decisions to satisfy a consolidated set of emerging
national security and civil space surveillance requirements.  Without
a coordinated plan, DOD and NASA would not be taking advantage of
potential efficiencies.  The DOD Space Architect, along with NASA and
the intelligence space sector, could provide a means for developing
such a plan. 


   RECOMMENDATION
---------------------------------------------------------- Chapter 3:5

We recommend that the Secretary of Defense and the Administrator of
NASA, in consultation with the Director of Central Intelligence,
develop a coordinated governmentwide space surveillance plan that (1)
sets forth and evaluates all feasible alternative capabilities to
support human space flight and emerging national security
requirements and (2) ensures that any planned funding for space
surveillance upgrades is directed toward satisfying consolidated
governmentwide requirements. 


SURVEILLANCE NETWORK COMPOSITION
AND CHARACTERISTICS
=========================================================== Appendix I

The space surveillance network presently includes 31 DOD and
privately owned radar and optical sensors at 16 worldwide locations,
a communications network, and primary and alternate operations
centers for data processing.  Most of the sensors are mechanical
tracking, phased-array, and continuous-wave radars, but optical
telescopes are also used. 

The most common radar type is a mechanical tracker with a movable
antenna, whereby energy is transmitted into space and reflected by a
space object back to the same radar antenna.  A phased-array radar
consists of thousands of individual antennas that produce and steer
energy beams to different locations in space.  A continuous-wave
radar system consists of several transmitters and receivers, each
placed in a different physical location across a horizontal plane. 
The Naval Space Surveillance System, consisting of six receivers and
three transmitters located at sites from California to Georgia, is a
continuous-wave system.  Telescopes, such as the Ground-based
Electro-Optical Deep Space System, detect light reflected from space
objects and track the objects using this reflected light. 

The various network sensors' support to the space surveillance
mission are categorized as being dedicated, collateral, or
contributing.  Dedicated sensors support the space surveillance
mission as their primary purpose.  Collateral sensors primarily
support other missions, such as ballistic missile warning or launch
vehicle range support, but also provide space surveillance
capabilities.  Contributing sensors are used under a contract or an
agreement to support the space surveillance mission only when
requested by the U.S.  Space Command. 

All space surveillance data needs are coordinated through the Space
Control Center, located at Cheyenne Mountain Air Station in Colorado,
or the alternate control center, located at the Naval Space Command
in Virginia.  These control centers direct the network sensors to
collect data on a space object's orbital position.  Such data can
provide information about the time that the space object is observed,
its angle (elevation) from the point of observation, its direction
(azimuth) from true north, and its distance (range) from the sensor. 
Information about a space object's physical properties, such as size,
shape, motion, orientation, and surface materials, can also be
obtained. 

About one-third of the network sensors provide data on space objects
only in near-earth altitudes (5,875 kilometers and less), about
one-third only in deep space, and about one-third in both near earth
and deep space. 
Table I.1 lists the network sensors by category, with the sensor
types and detection ranges by locations. 



                               Table I.1
                
                  Space Surveillance Sensor Locations,
                      Types, and Detection Ranges

Sensor location         Sensor type             Sensor detection range
----------------------  ----------------------  ----------------------
Dedicated support to space surveillance mission
----------------------------------------------------------------------
Diego Garcia, Indian    3 telescopes            Deep space
Ocean

Eglin Air Force Base,   1 phased-array radar    Near earth and deep
Florida                                         space

Maui, Hawaii            6 telescopes            4 deep space and 2
                                                near earth and deep
                                                space

Western and southern    1 continuous-wave       Near earth
U.S. locations for the  radar system
Naval Space
Surveillance System

Socorro, New Mexico     3 telescopes            Deep space


Collateral support to space surveillance mission
----------------------------------------------------------------------
Antigua, British West   1 mechanical tracker    Near earth
Indies                  radar

Ascension Island,       2 mechanical tracker    Near earth
South Atlantic Ocean    radars

Beale Air Force Base,   1 phased-array radar    Near earth
California              with
                        2 faces

Cape Cod Air Force      1 phased-array radar    Near earth
Station, Massachusetts  with
                        2 faces

Cavalier Air Force      1 phased-array radar    Near earth
Station, North Dakota

Clear Air Station,      1 mechanical tracker    Near earth
Alaska                  radar

Fylingdales, England    1 phased-array radar    Near earth
                        with
                        3 faces

Oahu, Hawaii            1 mechanical tracker    Near earth
                        radar

Thule, Greenland        1 phased-array radar    Near earth
                        with
                        2 faces


Contributing support to space surveillance mission
----------------------------------------------------------------------
Kwajalein, Marshall     4 mechanical tracker    Near earth and deep
Islands                 radars                  space

Tyngsboro,              3 mechanical tracker    Near earth and deep
Massachusetts           radars                  space
----------------------------------------------------------------------



(See figure in printed edition.)Appendix II
COMMENTS FROM THE DEPARTMENT OF
DEFENSE
=========================================================== Appendix I



(See figure in printed edition.)



(See figure in printed edition.)


The following are GAO's comments on DOD's letter dated October 8,
1997. 

GAO COMMENTS

1.  Unless DOD and NASA reach an agreement on requirements and cost
or burden sharing for space surveillance, NASA may have to decide
what degree of risk would be acceptable to its interests if
surveillance network improvements are not made.  Interagency
agreements have been reached on other programs.  For example, a
memorandum of agreement for the National Polar-Orbiting Operational
Environmental Satellite System was signed by the Secretaries of
Commerce and Defense and the Administrator of NASA in 1995 that
established a joint requirements process.  It also provided
directions for developing acquisition, technology, operations,
funding, and organizational management plans.  Regarding funding, the
agreement established that a cost-sharing approach would be used for
common requirements and that unique requirements would be funded by
the appropriate agency. 

2.  We made adjustments in our report to refer to the surveillance
network, where applicable, rather than just the surveillance sensors. 

3.  We are aware that the DOD Space Architect's 1997 space control
study included a recommendation to separate the space surveillance
function from the missile warning function.  Initially, this could
take place through procedural changes, and subsequently, through
software and hardware modifications associated with planned system
upgrades.  The stated purpose was to reduce costs of surveillance
that are otherwise required for a rigorous missile warning software
certification process. 

4.  We are aware of various joint processes and infrastructure within
DOD that could be used for plan development and coordination with
other government agencies.  However, for space surveillance, NASA has
an important interest.  The Aeronautics and Astronautics Coordinating
Board--a senior management review and advisory body to DOD and NASA
to facilitate coordination of aeronautics and space activities of
mutual interest--may need to address this subject. 




(See figure in printed edition.)Appendix III
COMMENTS FROM THE NATIONAL
AERONAUTICS AND SPACE
ADMINISTRATION
=========================================================== Appendix I



(See figure in printed edition.)



(See figure in printed edition.)


The following are GAO's comments on NASA's letter dated October 10,
1997. 

GAO COMMENTS

1.  In chapter 1, we briefly discussed DOD's closing of certain
sensor sites that support space surveillance--the results of which
apparently have not seriously affected DOD.  To the extent that the
system's margins have been reduced, particularly relative to NASA's
requirements, interagency consolidation of requirements and
coordination of a capabilities plan is further justified. 

2.  We are aware of several memorandums of agreement between NASA and
DOD.  The 1996 agreement for support of the space shuttles and
station is written in general terms, dealing with working
relationships and the exchange of available information.  Although
such an agreement is essential, the process for agreeing on
stringent, quantified space surveillance requirements, the quality of
information to be provided, and how surveillance network improvements
are to be made and who pays for them, still has to be addressed.  As
discussed in our comments to DOD's response on our draft report, the
Aeronautics and Astronautics Coordinating Board--a senior management
review and advisory body to DOD and NASA to facilitate coordination
of aeronautics and space activities of mutual interest--may be the
proper forum for this subject. 

3.  We state in the report that NASA is dependent on DOD for space
surveillance. 


MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix IV

NATIONAL SECURITY AND
INTERNATIONAL AFFAIRS DIVISION,
WASHINGTON, D.C. 

Thomas J.  Brew
Homer H.  Thomson
James A.  Elgas


   DENVER OFFICE
-------------------------------------------------------- Appendix IV:1

Frederick G.  Day
Arthur Gallegos
Maricela Camarena
Arturo Holguin, Jr. 

RELATED GAO PRODUCTS

Space Station:  Estimated Total U.S.  Funding Requirements
(GAO/NSIAD-95-163, June 12, 1995). 

Space Station:  Delays in Dealing With Space Debris May Reduce Safety
and Increase Costs (GAO/IMTEC-92-50, June 2, 1992). 

Space Program:  Space Debris a Potential Threat to Space Station and
Shuttle (GAO/IMTEC-90-18, Apr.  6, 1990). 


*** End of document. ***