Earth Observing System: Concerns Over NASA's Basic Research Funding
Strategy (Letter Report, 07/11/96, GAO/NSIAD-96-97).

Pursuant to a congressional request, GAO reviewed the National
Aeronautics and Space Administration's (NASA) plans for funding its
Earth Observing System (EOS) and developing EOS-related basic research,
focusing on: (1) the current number of EOS science investigations; (2)
researchers' views on whether changes to EOS have adversely affected
their ability to carry out their interdisciplinary earth sciences
investigations; and (3) the Earth System Science Pathfinder program and
its potential impact on future EOS investigations.

GAO found that: (1) NASA funds 29 interdisciplinary science
investigations that use data from EOS instruments in more than one earth
science discipline; (2) to expand the EOS research community, NASA plans
to maintain an open data access policy, add investigations, reevaluate
current science investigations, and recruit new investigators; (3) most
EOS interdisciplinary scientists believe that EOS budgetary reductions
have little or no effect on their work; and (4) NASA plans to use
anticipated savings resulting from improved technology to fund more
investigations and request a total of $200 million over the next 4
fiscal years for its Earth System Science Pathfinder program.

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

 REPORTNUM:  NSIAD-96-97
     TITLE:  Earth Observing System: Concerns Over NASA's Basic Research 
             Funding Strategy
      DATE:  07/11/96
   SUBJECT:  Space exploration
             Aerospace research
             Earth sciences research
             Earth resources satellites
             Research and development costs
             Mission budgeting
             Budget cuts
IDENTIFIER:  NASA Earth Observing System
             NASA Earth System Science Pathfinder Program
             U.S. Global Change Research Program
             NASA Clouds and Earth's Radiant Energy System
             U.S. Global Change Fellowship Program
             NASA Earth Observing System Data Information System
             NASA Mission to Planet Earth Program
             
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Cover
================================================================ COVER


Report to the Chairman, Committee on Science, House of
Representatives

July 1996

EARTH OBSERVING SYSTEM - CONCERNS
OVER NASA'S BASIC RESEARCH FUNDING
STRATEGY

GAO/NSIAD-96-97

Earth Observing System

(709154)


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

  ACRIM - Active Cavity Radiometer Irradiance Monitor
  CERES - Clouds and Earth's Radiant Energy System
  CHEM - Chemistry mission
  EOS - Earth Observing System
  NASA - National Aeronautics and Space Administration
  SAGE - Stratospheric Aerosol and Gas Experiment
  SOLSTICE - Solar Stellar Irradiance Comparison Experiment
  TOPEX - U.S.-French Oceanography Satellite Ocean Topography
     Experiment
  UARS - Upper Atmosphere Research Satellite

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


B-271690

July 11, 1996

The Honorable Robert S.  Walker
Chairman, Committee on Science
House of Representatives

Dear Mr.  Chairman: 

The National Aeronautics and Space Administration's (NASA) goal is to
launch the first spacecraft of the Earth Observing System (EOS) in
1998.\1 You requested that we assess NASA's plans for funding this
program and for developing its EOS-related basic research
community.\2 This report (1) discusses NASA's strategy for developing
such a community with specific focus on the number of currently
funded EOS science investigations and (2) summarizes researchers'
views on whether changes to EOS over the last few years have
adversely affected their ability to carry out their interdisciplinary
Earth sciences investigations.  We also address issues related to the
new Earth System Science Pathfinder program and its potential impact
on the funding availability for future EOS investigations.\3


--------------------
\1 Refers to the AM-1 spacecraft.  A pre-EOS-era spacecraft, the
U.S.-Japan Tropical Rainfall Measuring Mission is scheduled to be
launched in 1997. 

\2 We addressed NASA's funding plans in NASA's Earth Observing
System:  Estimated Funding Requirements (GAO/NSIAD-95-175, June 9,
1995). 

\3 Pathfinder is a program of low-cost space missions to do high
priority Earth sciences research that is not being addressed by
current programs, including EOS. 


   BACKGROUND
------------------------------------------------------------ Letter :1

EOS is the centerpiece of NASA's Mission to Planet Earth, whose
overall goal is to understand the total earth system (air, water,
land, life, and their interactions) and the effects of natural and
human-induced changes on the global environment.  EOS has three major
components:  (1) a constellation of satellites designed to collect at
least 15 years of key climate-related data; (2) a data and
information system designed to operate the satellites and process,
archive, and distribute the data; and (3) teams of scientists who
develop algorithms for converting sensor data into useful information
and conduct basic research using the information.  The satellites,
and data and information system, which will absorb most of the
program's funding, provide the researchers with measurements that
will enable them to address established research priorities. 

EOS is designed to make 24 types of long-term measurements of solar
irradiance and the earth's atmosphere, land cover, ice sheets, and
oceans from orbiting spacecraft.\4 By 2002, when the full
constellation will be in orbit, EOS will be generating data from 25
instruments on at least
10 spacecraft.  Over the 20-year EOS data-collection phase, about
80 instruments will be launched on more than 30 satellites.  As
currently planned, the last EOS satellite will cease operations in
2020. 

EOS measurements will support researchers' efforts to address Mission
to Planet Earth's research priorities:  (1) determine the causes and
consequences of changes in atmospheric ozone; (2) improve
seasonal-to-interannual climate prediction; (3) determine the
mechanisms of long-term climate variability; (4) document changes in
land cover, biodiversity, and global productivity; and (5) understand
earth processes that can lead to natural disasters and develop risk
assessment capabilities for vulnerable regions. 

Mission to Planet Earth is NASA's contribution to the governmentwide
U.S.  Global Change Research Program.\5 An important goal of these
interconnected efforts is to improve the predictive capability of
numerical earth system models, especially global climate models that
investigate and predict the general circulation of the atmosphere and
ocean.\6 NASA has identified a potentially large and diverse "user
community" for EOS-related information.  Members of this community
could be, for example, educators, businessmen, and public
policymakers.  The focus of our analysis, however, is the EOS basic
research community, by which we mean NASA's currently funded EOS
interdisciplinary science and instrument investigations. 

In our June 1995 report, we estimated that funding requirements of
the EOS baseline program would total about $33 billion for fiscal
years 1991 to 2022.  This estimate was developed for the program
described in NASA's 1995 EOS reference handbook and included costs
for satellites, launch services, data systems, science, construction
of facilities, and civil service personnel.  However, NASA later
recognized that this program was not affordable in an environment of
declining budgets and began studying ways to cut costs by using
advanced technology and increasing collaboration with other agencies,
international partners, and the commercial sector.  NASA intended to
use these future savings to fund more science under EOS and to reduce
the program's total cost.  Over the past several years, the Congress
has progressively reduced NASA's planned spending on EOS for fiscal
years 1990 to 2000 from $17 billion to $7.25 billion.  In response,
NASA changed EOS in 1991 and 1992 from a complete earth system
measuring program that would have supported a wide array of global
change investigations to a measurement program that will primarily
support investigations of global changes to the earth's climate.  For
example, NASA dropped the measurement of upper atmospheric chemistry
and solid earth processes.  Other changes followed in order to
further adjust EOS to its progressively lower budget profile through
2000.  NASA officials stated the current planned spending for EOS
through 2000 is about $6.8 billion. 

The administration's fiscal year 1997 request for Mission to Planet
Earth is $1.402 billion, of which $846.8 million is for development
of EOS' data and information system, spacecraft, instruments, and
algorithms.  NASA's request includes $47.5 million for EOS
interdisciplinary science.  According to NASA's 5-year plan based on
its fiscal year 1996 budget submission, NASA intends to increase
spending on EOS interdisciplinary science to $73.2 million per year
in fiscal year 2000. 


--------------------
\4 See app.  I for types of measurements; app.  II for satellite
missions, instruments, and measurements; and app.  III for the
instruments' flight schedules. 

\5 Research activities of the U.S.  Global Change Research Program
are (1) observing the global system, (2) managing and archiving
information, (3) understanding global change processes, (4)
predicting global change, (5) evaluating the consequences of global
change, and (6) developing tools for assessing policies and options. 

\6 Global Warming:  Limitations of General Circulation Models and
Costs of Modeling Efforts (GAO/RCED-95-164, July 13, 1995). 


   RESULTS IN BRIEF
------------------------------------------------------------ Letter :2

The number of currently funded EOS investigations is relatively small
in comparison with two pre-EOS-era missions and the potential
research opportunities afforded by EOS.  NASA plans to use some of
the anticipated savings resulting from improved technology and
increased collaboration with others to fund more investigations.  The
viability of this plan is uncertain because the anticipated savings
may not materialize or may be absorbed by budget reductions.  If
NASA's strategy for increasing funding is not successful, there may
be a growing imbalance between the number of investigations NASA
would like to fund and the number it can afford. 

At the same time NASA wants to fund more EOS investigations, it is
also planning to solicit proposals for new Pathfinder satellites. 
Although these satellites would focus on earth system science, they
are not part of the EOS program.  NASA estimates the life-cycle cost
of each Pathfinder mission would not exceed $120 million over 5
years.\7 In setting the pace of the Pathfinder program, the Congress
needs to assure itself that NASA has adequately demonstrated that the
potential value of Pathfinder investigations will exceed the
potential value of additional EOS investigations that could be
obtained with the same resources. 

NASA's principal investigators for interdisciplinary earth system
science affirmed in a 1992-93 program review that changes to EOS
following the 1992 budgetary reductions would not seriously weaken
their ability to conduct interdisciplinary research.  They reaffirmed
their view in 1995, despite further budgetary reductions and other
changes in the program. 


--------------------
\7 The cost estimate is for the total mission, including satellite
development and launch. 


   NASA'S STRATEGY FOR DEVELOPING
   EOS' BASIC RESEARCH COMMUNITY
------------------------------------------------------------ Letter :3

Like EOS-related space systems and information systems, the
development of the EOS basic research community that will conduct
interdisciplinary global climate change research requires planning. 
The current number of EOS investigations funded by NASA is relatively
small, and NASA recognizes that it needs to increase their number,
broaden the membership of EOS science teams, and take other steps to
develop and sustain an EOS-era research community.  NASA's strategy
for developing the EOS research community is partly based on
increased funding.\8 In 1995, it began efforts to fund additional
investigations and to reevaluate the current investigations.  NASA's
ability to add more investigations is uncertain within its expected
future budgets, especially if it must depend on savings from improved
technology and increased collaboration with others. 


--------------------
\8 Another element of this strategy relates to the effectiveness and
cost-efficiency of the EOS data and information system.  See Earth
Observing System:  Concentration on Near-Term EOSDIS Development May
Jeopardize Long-Term Success (GAO/T-AIMD-95-103, Mar.  16, 1995). 


      CURRENT NUMBER OF EOS
      INVESTIGATIONS IS RELATIVELY
      SMALL
---------------------------------------------------------- Letter :3.1

The EOS program is currently funding 29 interdisciplinary science
investigations that were selected in 1989 and 1990 to use data from
EOS instruments in more than one earth science discipline, such as
geology, oceanography, meteorology, and climatology.  Scientists
associated with these investigations serve as members of the
Investigator Working Group, developing detailed science plans and
assisting NASA in optimizing the scientific return of the EOS
mission.\9 Currently, these 29 investigations are led by 31
interdisciplinary principal investigators (2 of the interdisciplinary
science investigations have coprincipal investigators).  There are
354 coinvestigators associated with the 29 interdisciplinary science
investigations, as well as 20 instrument principal investigators/team
leaders and 197 other instrument team members. 

The number of EOS investigations is relatively small when compared
with (1) the number of currently funded investigations associated
with two pre-EOS missions--the Upper Atmosphere Research Satellite
(UARS) and the U.S.-French Oceanography Satellite Ocean Topography
Experiment (TOPEX/Poseidon)--to their EOS-era counterparts and (2)
the ratio of the number of investigations to the raw data acquisition
rate expected from instruments on EOS spacecraft to the number of
investigations and raw data acquisition rates of UARS and TOPEX. 

The comparison is based on the following EOS spacecraft and
instruments:  AM; PM; Chemistry mission (CHEM); Landsat-7; Radar ALT;
Laser ALT; Stratospheric Aerosol and Gas Experiment (SAGE) III on
space station; and Solar Stellar Irradiance Comparison Experiment
(SOLSTICE), Active Cavity Radiometer Irradiance Monitor (ACRIM), and
Clouds and Earth's Radiant Energy System (CERES) on flights of
opportunity.  The data rates of the EOS spacecraft and UARS/TOPEX are
not strictly comparable because the instruments on the latter
satellites do not directly observe the Earth.  Imaging instruments
are more data intensive than nonimaging instruments.  However, data
rate comparisons can serve as a rough indicator of the magnitude of
potential research opportunities afforded by EOS and two pre-EOS-era
missions.  The National Aeronautics and Space Administration (NASA)
used similar comparisons in its 1993 and 1995 editions of the EOS
reference handbook.  In the 1995 edition, NASA graphically compared
the combined data rates of EOS-era satellites with the combined data
rates of numerous pre-EOS-era (including UARS and TOPEX) and foreign
satellites to demonstrate that the magnitude of potential research
opportunities for EOS is much greater than for other combinations of
Earth-sensing satellites.  In its handbooks, NASA depicted the data
streams flowing from the two groups of satellites to "10,000 users"
in the 1993 edition and a more vaguely defined "user community" in
the 1995 edition.  In place of the broadly defined "users" and user
community, we used the actual number of currently funded EOS, UARS,
and TOPEX investigations to illustrate (1) that the magnitude of
potential EOS basic research opportunities is much greater than those
afforded by UARS and TOPEX (as indicated by their respective data
rates) and (2) that the number of currently funded EOS investigations
is small compared to the number of currently funded UARS and TOPEX
investigations. 

UARS, launched in September 1991, consists of 10 instruments that are
measuring the composition and temperature of the upper atmosphere,
atmospheric winds, and energy from the sun.\10 The UARS science
investigations are led by 22 teams.  NASA broadened the UARS science
investigations in 1994 by selecting 40 additional teams led by
"guest" investigators.  It is also funding correlative measurement
investigations led by 38 teams to develop an independent database to
validate and complement measurements made by UARS' instruments.\11 In
the EOS era, solar energy and atmospheric chemistry measurements will
be made principally by the ACRIM, SAGE, and SOLSTICE instruments and
the CHEM spacecraft.\12 Currently, only 12 instrument and
interdisciplinary science investigations are associated with these
instruments and the CHEM spacecraft.  In contrast, UARS supports
research conducted by
62 instrument and science teams.\13

TOPEX was launched in August 1992 to study the circulation of the
world's oceans.  The primary instrument is an altimeter that measures
the height of the satellite above the ocean, wind speed, and wave
height.  NASA and its French partner, Centre National d'Etudes
Spatiales, selected 38 science investigations.  The 38 TOPEX-related
science teams have about 200 members, and NASA plans to solicit
additional investigations.\14 In the EOS era, the follow-on mission
to TOPEX is Radar-ALT.  An instrument team has not yet been selected,
but only 7 of the 29 interdisciplinary science investigations
currently plan to use Radar-ALT data. 

There is a large difference between the number of (1) currently
funded EOS investigations and the expected volume of data from EOS
and (2) the currently funded UARS and TOPEX investigations and volume
of data of these two pre-EOS missions.\15 The combined number of the
UARS and TOPEX science investigations is a little larger than the
current number of EOS investigations, even though EOS' data rate (our
indicator of the magnitude of potential research opportunities) is
close to 1,000 times greater than the combined data rate of UARS and
TOPEX.  EOS will provide up to 42 million bits of data per second to
49 interdisciplinary science and instrument investigations.\16 The
corresponding ratio for UARS and TOPEX is a total of
48 thousand bits of data per second to 60 investigations.\17


--------------------
\9 NASA is wholly or partly funding 22 of these investigations, and
its international partners are
funding 7. 

\10 The atmosphere is divided into layers based on temperature.  In
the bottom layer, or troposphere, temperatures decrease with height
to about 10 km.  The upper atmosphere consists of the stratosphere
(about 10 km to 45 km), where temperatures are constant and then
slowly rise with height; the mesosphere (about 50 to 80 km), where
temperatures again decrease with height; and the thermosphere (no
well-defined upper limit), where temperatures again increase with
height. 

\11 According to the administration's fiscal year 1996 budget
submission, funding for UARS' operations and data analysis will cease
in fiscal year 1998. 

\12 ACRIM (1998) monitors the variability of total solar irradiance;
SAGE (1998) provides profiles of aerosols, ozone, and trace gases in
the atmosphere; SOLSTICE (2002) measures full disk solar ultraviolet
irradiance; and instruments on the CHEM spacecraft (2002) measure, in
part, tropospheric ozone.  Dates are for the first flight of each
instrument in the EOS era. 

\13 For this comparison, the number of UARS science investigations
includes 22 instrument and theoretical science investigations, and 40
guest science investigations.  It does not include the correlative
measurement investigations because the 38 teams associated with them
were required to develop an independent database and did not have
access to UARS-related data. 

\14 According to the administration's fiscal year 1996 budget
submission, funding for TOPEX' operations and data analysis will
cease in fiscal year 1999. 

\15 In commenting on a draft of this report, NASA provided
information on data rates and data analysis and on its ongoing and
planned efforts to prepare EOS investigators for handling large
amounts of data and providing them with the tools for doing so.  (See
app.  V.)

\16 "Bit," contracted from the term "binary digit," is a unit of
information represented by either a zero or a one.  A byte is a group
of eight adjacent bits operated on as a unit and is equivalent to one
character in a text file, such as the letter "a."

\17 We did not include 40 UARS guest investigations for this
comparison because they were selected after UARS was launched and
thus are not comparable to the current number of EOS
interdisciplinary science and instrument investigations. 


      NASA'S STRATEGY TO EXPAND
      EOS RESEARCH COMMUNITY
---------------------------------------------------------- Letter :3.2

The National Research Council's Board on Sustainable Development
reviewed the U.S.  Global Change Research Program, Mission to Planet
Earth, and EOS in 1995 and stated that one of the "fundamental
guiding principles" of the U.S.  Global Change Research Program is an
"open and accessible program" that will "encourage broad
participation" by the government, academic, and private sectors.\18
Some NASA officials and EOS investigators are concerned that the
Earth sciences research community perceives EOS' science teams as a
"closed shop," whereby membership on a current team is a precondition
for conducting future EOS-related research. 

To counter this perception, NASA's current strategy to expand the EOS
research community involves (1) an open data access policy and (2)
efforts to broaden and change the current community by adding
investigations, reevaluating the current science investigations, and
recruiting new investigators. 


--------------------
\18 A Review of the U.S.  Global Change Research Program and NASA's
Mission to Planet Earth/Earth Observing System National Academy Press
(Washington, D.C., 1995), p.  8. 


         EOS DATA POLICY
-------------------------------------------------------- Letter :3.2.1

A vital part of the EOS data policy is that EOS data will be
available to everyone:  there will be no period of exclusive access
for funded investigators.  This has not always been NASA's policy. 
On some past Earth

observing missions, funded investigators had exclusive use of the
data for an extended period of time.  For example, the original
investigators associated with the Upper Atmosphere Research Satellite
had exclusive access to the first year's data for up to 2 years.  EOS
data users as a rule will not be charged more than the cost of
distributing data to them.  The data policy contemplates a variety of
potential user groups, not all of whom will be engaged in basic
research.  In 1995, NASA sponsored a conference to better define the
user groups.  The conferees identified 12 potential user groups, of
which only 3 were primarily composed of scientists.  The others
included commercial users, resource planners, and educational groups. 

NASA officials stated that about 10,000 Earth scientists might use
EOS-related data.\19

Even with the large size of this potential research community and the
open-access data policy, the sufficiency of EOS investigations might
appear to be the least of NASA's problems.  Even though 10,000 Earth
scientists may be potential users of EOS data, they still need to be
funded to conduct basic research.  According to NASA officials, as a
general rule, for this type of work, scientists analyze data when
they are paid to do so. 

We sought to confirm this observation by reviewing the authorship of
172 journal articles about 2 pre-EOS-era satellites--UARS and
TOPEX/Poseidon.  Our review showed that publicly funded investigators
wrote all but 10 of the articles.  We reviewed the authorship of UARS
and TOPEX articles published in scientific journals from the
approximate dates of launch through May 1995; these articles were
selected from a database consisting of about 4,500 periodicals.\20
The principal investigators wrote 123 (72 percent) of the 172
articles.  In addition, we identified two other kinds of
investigators probably associated with the principal investigators
and/or government funded--that is, investigators associated with the
principal investigator's institution (most often a university or
government agency) or another government agency.  These "associate"
investigators wrote 39 (23 percent) of the journal articles. 

Not all people who get Earth sciences data use it to do basic
research.  For example, from January through May 1995, NASA's Jet
Propulsion Laboratory sent 55,521 TOPEX-related data files to 28,495
requesters through the Internet.  This figure does not necessarily
represent separate requesters.  The laboratory does not know how
these requesters use TOPEX data, but according to a laboratory
official, data accessed through the Internet is generally not
sufficient for doing basic research.  Investigators want less
processed data for this type of research. 


--------------------
\19 In 1994, a NASA contractor estimated the relevant U.S.  science
community to be between 6,100 and 11,600.  See app.  V for NASA's
comments on the potential total EOS user community. 

\20 For example, see the Journal of Atmospheric Sciences (Oct.  15,
1994) and the Journal of Geophysical Research (Dec.  15, 1994) for
papers on UARS and TOPEX-related science, respectively. 


         ADDING INVESTIGATIONS
-------------------------------------------------------- Letter :3.2.2

NASA originally solicited proposals for EOS interdisciplinary science
and instrument investigations in January 1988.  The solicitation
noted that NASA planned to fund 10 to 20 science investigations, with
other selections possible before the launch of the first EOS
platform, then scheduled for late 1995.  NASA received 458 proposals
in response to its solicitation, including about 250 for
interdisciplinary science investigations.  As previously noted, 29
interdisciplinary science and 20 instrument investigations are being
funded by NASA and its international partners.\21 The lifetime of the
science investigations was to extend for 4 years beyond the launch of
the first satellite, or until 1999.  In other words, NASA intended to
add to this first group of investigations over a 10-year period (1989
to 1999).  However, at a minimum, the lifetime of this first group of
investigations has been extended to 13 years (1989 to 2002, including
4 years beyond AM-1's 1998 launch date). 

NASA's plan to supplement the first group of science investigations
with a second group within 6 years was not too optimistic given its
funding expectations at that time.  NASA's EOS mission planning
(1982-87) took place during a time of expanding resources.  During
the 1980s, NASA's funding increased each year, essentially doubling
from about $5 billion to $10 billion between fiscal years 1981 and
1989.\22

NASA has recognized that more EOS investigations are needed, and last
year it took a first step to add more.  NASA solicited proposals in
September 1995 to address, among other things, specific
interdisciplinary science issues that are not well covered by
existing NASA-funded investigations.\23 It received 134
interdisciplinary science proposals and hopes to add 20 to
25 investigations with grants of about $250,000 to $400,000 per year
for a period of up to 3 years. 

NASA is funding the interdisciplinary science part of the September
1995 solicitation with a $9-million "funding wedge" created, in part,
from reductions in the previously planned funding levels for some
existing EOS investigations.  According to a NASA official, no new
money will be used to fund these investigators.  It remains to be
seen if NASA's ability to generate future savings in the program will
become a major factor in increasing the number of EOS investigations. 

Although potentially useful over the longer term, these grants will
not immediately increase the number of EOS investigations in the near
term because the announcement largely precludes investigators from
analyzing data from the first EOS mission, AM-1, which is now
scheduled for launch in 1998.  Instead, NASA is asking for proposals
on interdisciplinary research that primarily uses existing data sets
from past satellite missions and field experiments.\24


--------------------
\21 See app.  IV for information on the interdisciplinary science
investigations. 

\22 Taking the effects of inflation into account, NASA's funding
increased by about 48 percent during this period.  Both current and
constant dollar amounts are from our report on Space Funding:  NASA
and DOD Activities for Fiscal Years 1981 Through 1989
(GAO/NSIAD-89-102FS, Mar.  23, 1989). 

\23 The solicitation asked for 5 types of proposals:  Landsat
investigations, EOS instrument investigations, interdisciplinary
Earth system science investigations, new investigators'
investigations, and science education grant supplements.  NASA
received 336 proposals in response to the solicitation of which at
least 12 were not considered responsive to the announcement.  NASA
stated in the solicitation that it intended to select from 57 to 74
investigations in the 5 areas of consideration. 

\24 The solicitation described five interdisciplinary research
issues, one of which is the implications of continued global
expansion of urbanization and high-input agriculture for the
environment. 


         REEVALUATING
         INVESTIGATIONS
-------------------------------------------------------- Letter :3.2.3

The nature and membership of the EOS science teams has largely
remained unchanged for 6 years.  According to NASA officials, this
longevity has created a perception among some Earth scientists that
currently funded investigators constitute a "closed shop." NASA
attempted to correct this perception by conducting an internal
program review in 1992 and 1993 and an external peer review in 1995
and 1996.  The review by EOS investigators' peers in the Earth
sciences research community is not yet finished, but it could lead to
the possible deselection and recompetition of some EOS
interdisciplinary science teams.  NASA opted for the peer review,
rather than have all the current investigations reevaluated as part
of a new solicitation for proposals. 

NASA's 1992-93 program review found weaknesses in many
interdisciplinary science teams.  The reviewers generally found that
only 30 percent of 23 investigations could be rated "successful" in
terms of science-related assessment measures.  They also noted that
"most teams need work in documenting their scientific progress,
plans, and the policy relevance of their research to the Earth
Science community, as well as to NASA."

The reviewers specifically noted that

  -- 67 percent (of 24 teams) had poor management plans,

  -- 61 percent (of 23 teams) had a less than satisfactory
     publication record, and

  -- 57 percent (of 23 teams) needed to improve their contacts with
     the EOS instrument teams. 

The review concluded that "for most teams, the biggest factor
hindering their success is their lack of a good management
plan--teams that do not have their own house in order will not
benefit from increased collaborations" with other interdisciplinary
and instrument teams. 

In October 1994, the Science Executive Committee of the EOS
Investigator Working Group endorsed the need for a peer review and
possible turnover of teams, if this would enhance the quality of EOS
investigations.  The Committee, however, rejected the idea that the
existing investigations should be evaluated through a new
competition.  It noted that a new competition could cause a loss of
credibility with EOS supporters and that many interdisciplinary
science teams had committed themselves "far beyond" just their
science tasks. 

In contrast, NASA struck a different balance between continuity and
change in the pre-EOS-era U.S.-Japan Tropical Rainfall Measuring
Mission.  The goal of the spacecraft's three principal instruments is
to measure rainfall more accurately than before, particularly over
the tropical oceans.\25

The science of a long-term investigatory group was reevaluated after
3 years by holding a new funding competition for this program.  NASA
and Japan's National Space Development Agency first solicited
research proposals in 1990 for a possible launch in 1994.  Both
agencies selected a total of 35 investigators.  The two space
agencies in October 1993 again solicited research proposals for a
launch now scheduled for 1997.  The space agencies selected 27 of the
original investigators and added 12 new investigators to the science
team. 


--------------------
\25 The spacecraft also carries two EOS-funded instruments: 
Lightning Imaging Sensor and the Clouds and the Earth's Radiant
Energy System (CERES).  CERES will measure Earth's radiation budget
and atmospheric radiation from the top of the atmosphere to the
surface.  CERES is scheduled to fly on several EOS-era spacecraft. 
In September 1995, NASA announced that it intends to add two new
members to the mission's science team.  NASA received eight proposals
in response to this solicitation. 


         RECRUITING NEW
         INVESTIGATORS
-------------------------------------------------------- Letter :3.2.4

The long-term growth of the EOS research community depends, in part,
on NASA's ability to recruit graduate students and newly graduated
Earth scientists to use remotely sensed data.  NASA supports
prospective researchers in the Earth sciences through the graduate
student Global Change Fellowship program.  Successful candidates can
be funded for up to 3 years, at $20,000 per year, primarily for
tuition support and living expenses.  NASA supported 112 fellowships
for the 1993-94 academic year.  In September 1995, NASA also
established a new investigator program as part of Mission to Planet
Earth and solicited proposals for 10 to 15 interdisciplinary
investigations from recent Ph.D.  recipients.  The proposed
investigations must be based on data from existing satellite
missions.  NASA received 65 proposals in response to this
solicitation. 


   MOST EOS INTERDISCIPLINARY
   SCIENTISTS SAY THEIR PLANNED
   WORK IS NOT SEVERELY AFFECTED
   BY BUDGETARY TURBULENCE
------------------------------------------------------------ Letter :4

Scientists associated with EOS stated in 1994, following the
program's proposed reduction to $7.25 billion, that

     while some of the multi-year reductions may be accomplished
     without serious effect on the program, it must be stated that
     the achievement of several essential elements (e.g., continuity
     of observations for 15 years) of the program are now at
     significantly greater risk. 

Despite this apprehension, most interdisciplinary science
investigators have experienced or expect little or no effect of
budgetary turbulence on their own research.  In the 1992-93 program
review, NASA's investigators were generally optimistic that they
could withstand EOS' continuing budgetary turbulence.  In 1995,
investigators reaffirmed this optimism. 


      INVESTIGATORS' PERCEPTION OF
      PROGRAM CHANGES IN 1992 AND
      1993
---------------------------------------------------------- Letter :4.1

As part of the 1992-93 program review, NASA asked EOS'
interdisciplinary science principal investigators to evaluate the
effect changes to EOS would have on their work.  The reviewers
classified the 23 responding investigators' remarks as follows: 

  -- no effect (11 investigators, 48 percent);

  -- minor effect (8 investigators, 35 percent); and

  -- major effect (4 investigators, 17 percent). 

The program review followed the cancellation of three major EOS
instruments over several years:  Laser Atmospheric Wind Sounder
(observation of lower atmospheric winds); High-Resolution Imaging
Spectrometer (identification of surface composition); and Synthetic
Aperture Radar (high-resolution global measurements of the Earth's
surface).  Whether scientists planned to use a canceled instrument
was a major part of how they perceived the impact on their work. 

Some investigators also cited changes to their ongoing research
resulting from little or no growth in most of their fiscal year 1994
budgets.  According to a NASA official, only seven investigations
received as much as a 10-percent increase in their 1994 budget above
the amount for fiscal year 1992.  One investigator, citing a flat
budget for 1994, said that as a result, coinvestigators could not
give full attention to EOS-related research and that it was
"difficult for us to contemplate an accelerated or broadened attack
on the global change problems we are addressing." Another
investigator noted that such a budget meant that "some research tasks
have to be trimmed" and would not "allow much flexibility in terms of
new ideas and initiatives."


      INVESTIGATORS' PERCEPTION OF
      PROGRAM CHANGES IN 1995
---------------------------------------------------------- Letter :4.2

In 1995, NASA again asked the interdisciplinary science principal
investigators to assess how changes over the previous 3 years to the
EOS program had affected their future and ongoing research.  The
scientists cited the same mix of concerns as they had
previously--namely, the loss of several instruments and lack of
growth in their funding.  One investigator noted that a 20-percent
budget reduction in 1994 "decimated our attempts to carry out field
studies in collaboration with [international] team members." His
view, however, was unique.  Most investigators reported that the
changes had so far created only relatively minor problems that could
be adequately resolved. 

A NASA official told us that a reason for investigators' optimism is
that NASA officials consciously tried to minimize the impact of
budget reductions on EOS-related science. 


   NEW EARTH SYSTEM SCIENCE
   PATHFINDER PROGRAM: 
   IMPLICATIONS FOR EOS SCIENCE
   FUNDING
------------------------------------------------------------ Letter :5

Starting in 1996, NASA plans to solicit additional Earth science
research through a new Earth System Science Pathfinder program.  This
effort will be based on data sets collected by new satellite
missions.  According to NASA officials, the Pathfinder program is
intended to develop quick turnaround, low-cost space missions for
high priority Earth sciences research not being addressed by current
programs, including EOS, thus providing an opportunity to accommodate
new science priorities and to increase scientific participation in
Mission to Planet Earth. 

The administration is requesting $20 million for Pathfinder in fiscal
year 1997 and plans to request $30 million, $75 million, and $75
million for fiscal years 1998, 1999, and 2000, respectively--a total
of $200 million over the next 4 fiscal years.  After then, NASA plans
to offset Pathfinder's funding requirements with reductions generated
from the introduction of lower cost technology into future Mission to
Planet Earth-related research.  Pathfinder's goal is to launch one
mission every year, starting in 1999.  NASA estimates the life-cycle
cost of each mission would not exceed $120 million and would include
the cost of the launch vehicle, civil service labor, investigator
support, and 2 years of spacecraft operations.\26 However, NASA has
not demonstrated that the potential value of Pathfinder's science
would exceed the potential value of additional EOS-related science,
if savings allocated to Pathfinder were allocated to EOS science. 


--------------------
\26 Each Pathfinder mission would have a principal investigator and a
limited number of guest investigators.  Considering satellite
development and launch costs, only a small portion of each mission's
funding would be available to pay for data analysis. 


   AGENCY COMMENTS AND OUR
   EVALUATION
------------------------------------------------------------ Letter :6

NASA criticized our analysis and conclusions.  NASA stated that our
draft report underestimated the size of the EOS research community
and the abilities of EOS investigators to process the large amount of
data expected from EOS.  We do not agree with NASA' s description of
our report's focus and scope.  Our objective was not to estimate the
size of the EOS research or broader user communities, or to assess
the abilities of current researchers to handle the large amount of
data expected from EOS.  Rather, our objective was to assess NASA's
plans for developing its basic research community, with specific
focus on the number of currently funded EOS investigations.  This
issue is the basis for the majority of NASA's concerns.  To address
NASA's point, we revised our final report to clarify the specific
focus and scope of our work. 

NASA said that our analysis of the number of EOS investigations did
not consider the broader user community.  Although NASA's statement
is correct, it was not the objective of our work to analyze the
broader user community.  We focused on comparing the number of NASA's
currently funded EOS-related investigations with the number of funded
investigations associated with two pre-EOS-era missions.  This
comparison constituted our analytic framework and formed the basis of
our conclusion that the magnitude of potential basic research
opportunities afforded by EOS is much greater than those afforded by
UARS and TOPEX, but the number of currently funded EOS investigations
is relatively small compared to the number of investigations funded
under the two pre-EOS-era missions.  Our conclusion is consistent
with NASA's desire, as expressed in its comments on our draft report,
"to expand the size of the direct EOS community," and its actions
during the course of our review to increase the number of EOS
investigations in a budget-constrained environment. 

NASA's comments also addressed our concern about its ability to
increase the number of EOS investigations based on savings from EOS
and other parts of Mission to Planet Earth.  NASA stated that it has
already made changes to lower EOS' costs and that it will be able to
decrease costs further while improving overall capability and
maintaining data continuity.  We have not evaluated NASA's claims in
this regard. 

In our draft report, we recommended that the NASA Administrator
provide the Congress with an assessment of Pathfinder's potential
impact on NASA's strategy for Earth system science research,
including a determination that the potential value of Pathfinder's
investigations is expected to exceed the potential value of
additional EOS investigations.  NASA generally agreed with this
recommendation, stating that it would provide a strategic assessment
of Pathfinder.  NASA also said it planned to proceed with the
Pathfinder missions on the basis of already having analyzed the
tradeoffs and having had its approach validated by outside review
groups.  The concern that prompted our recommendation in the draft
report was the availability of adequate funding for EOS basic
research given NASA's funding strategy.  That continues to be our
concern and, in view of NASA's position, we are changing our
recommendation to the NASA Administrator to a matter for
congressional consideration.  Our purpose in making this change is to
alert the Congress to the need to address the EOS funding issue
before substantial funding commitments are made to the new Pathfinder
program. 

NASA's comments are in appendix V. 


   MATTER FOR CONGRESSIONAL
   CONSIDERATION
------------------------------------------------------------ Letter :7

In judging the extent to which it should support the proposed Earth
System Science Pathfinder program, the Congress may wish to have NASA
demonstrate that the potential value of Pathfinder investigations
will exceed the potential value of additional EOS investigations that
could be obtained with the same resources. 


   SCOPE AND METHODOLOGY
------------------------------------------------------------ Letter :8

To accomplish our objectives, we obtained documents related to EOS'
science program from and interviewed officials at NASA headquarters
in Washington, D.C.; NASA's Goddard Space Flight Center, Greenbelt,
Maryland; and at the Jet Propulsion Laboratory, Pasadena, California. 
We attended the EOS Investigators Working Group meeting in June 1995
in Santa Fe, New Mexico, and the Payload Panel meeting in November
1995 in Annapolis, Maryland. 

In analyzing the development of the EOS research community, we
reviewed information on pre-EOS Earth science ground- and space-based
research, as well as EOS' interdisciplinary science research.  In
analyzing the authorship of articles related to UARS and
TOPEX/Poseidon, we used "Scisearch," an international,
multidisciplinary index to science literature.  Scisearch indexes
articles from approximately 4,500 scientific and technical journals. 
We used the scientists' progress reports for 1992 to 1993, and 1995
to assess whether changes to EOS have adversely affected EOS'
interdisciplinary research. 

We performed our work between February 1995 and February 1996 in
accordance with generally accepted government auditing standards. 


---------------------------------------------------------- Letter :8.1

As agreed with your office, unless you publicly announce its contents
earlier, we plan no further distribution of the report until 30 days
from its issue date.  At that time, we will send copies to other
appropriate congressional committees; the NASA Administrator; and the
Director, Office of Management and Budget.  We will also make copies
available to other interested parties upon request. 

Please contact me on (202) 512-8412 if you or your staff have any
questions concerning this report.  Major contributors to this report
were Brad Hathaway, Frank Degnan, Thomas Mills, Richard Eiserman, and
Richard Irving. 

Sincerely yours,

David R.  Warren
Director, Defense Management Issues


TWENTY-FOUR EARTH OBSERVING SYSTEM
MEASUREMENT SETS
=========================================================== Appendix I

The National Aeronautics and Space Administration (NASA) considers
the following measurement sets to be critical to preserving the Earth
system science approach of the Earth Observing System (EOS) and
important to making environmental policy decisions.  The information
in appendixes I-IV was derived from NASA sources. 


   ATMOSPHERE MEASUREMENTS
--------------------------------------------------------- Appendix I:1


      CLOUD PROPERTIES
------------------------------------------------------- Appendix I:1.1

The formation, dissipation, and radiative properties of clouds
influence the atmosphere's response to greenhouse forcing (i.e.,
mechanisms that promote the greenhouse effect).  The net effect of
cloud forcing and feedback determines the energy budget of Earth and
its cozy temperature, which supports life. 


      RADIATIVE ENERGY FLUXES
------------------------------------------------------- Appendix I:1.2

Earth's radiation budget drives the biological and physical processes
of the atmosphere, land, and ocean, which in turn affect water
resources, agriculture, and food production. 


      PRECIPITATION
------------------------------------------------------- Appendix I:1.3

There is a net outflow of atmospheric moisture from the tropics to
the higher latitudes.  This redistribution is accomplished through
evaporation and precipitation, which determine the freshwater
resources for agricultural and industrial development. 


      TROPOSPHERIC CHEMISTRY
------------------------------------------------------- Appendix I:1.4

Tropospheric chemistry is linked to the circulation of Earth's water
(the "hydrologic cycle"), the ecosystem, and transformations of
greenhouse gases in the atmosphere, thus determining the oxidizing
capacity of the atmosphere for cleansing pollutants. 


      STRATOSPHERIC CHEMISTRY
------------------------------------------------------- Appendix I:1.5

Stratospheric chemistry measurements involve chemical reactions,
interactions between the sun and the atmosphere, and the sources and
sinks of gases, such as ozone, that are critical to Earth's radiation
balance. 


      AEROSOL PROPERTIES
------------------------------------------------------- Appendix I:1.6

An aerosol is a fine solid or liquid particle suspended in gas, such
as the atmosphere.  Aerosols affect the climate through their
radiative properties by serving as nuclei for the condensation of
clouds.  Aerosols tend to cool Earth's atmosphere, thus offsetting
some of the warming effects of greenhouse gases. 


      ATMOSPHERIC TEMPERATURE
------------------------------------------------------- Appendix I:1.7

Along with atmospheric humidity, atmospheric temperature is used in
short-term weather prediction and long-term climate monitoring. 
Improved measurement accuracy, precision, and spatial and temporal
coverage will enhance weather prediction skills beyond current limits
and reduce weather prediction "busts," or failures. 


      ATMOSPHERIC HUMIDITY
------------------------------------------------------- Appendix I:1.8

See "Atmospheric Temperature."


      LIGHTNING
------------------------------------------------------- Appendix I:1.9

Lightning measurements will include the distribution and variability
of both cloud-to-cloud and cloud-to-ground lightning.  Electrical
discharge contributes to the formation and dissipation of certain
trace gases in the atmosphere. 


   SOLAR RADIATION MEASUREMENTS
--------------------------------------------------------- Appendix I:2


      TOTAL SOLAR IRRADIANCE
------------------------------------------------------- Appendix I:2.1

Sustained changes in the total radiation output from the sun could
contribute to significant climate changes on Earth over time.  Solar
radiation is the main source of energy for biological activities on
Earth. 


      ULTRAVIOLET SPECTRAL
      IRRADIANCE
------------------------------------------------------- Appendix I:2.2

Out of the entire spectrum of radiation that Earth receives from the
sun, the ultraviolet portion is the dominant energy source for the
Earth's atmosphere.  Small changes in the radiation field have an
important effect on atmospheric temperature, chemistry, structure,
and dynamics.  Excess ultraviolet energy on the Earth's surface is
harmful to living organisms. 


   LAND MEASUREMENTS
--------------------------------------------------------- Appendix I:3


      LAND COVER AND LAND USE
      CHANGE
------------------------------------------------------- Appendix I:3.1

Land use includes monitoring crops for efficient irrigation and pest
control, public lands for good stewardship, and urban areas for
development.  Some changes in land use, such as deforestation and
biomass burning, reduce the standing stock of vegetation, release
carbon dioxide into the atmosphere, and reduce the capacity for the
removal of carbon dioxide from the atmosphere. 


      VEGETATION DYNAMICS
------------------------------------------------------- Appendix I:3.2

Terrestrial vegetation absorbs atmospheric carbon dioxide by
photosynthesis to offset its greenhouse warming effect. 


      SURFACE TEMPERATURE
------------------------------------------------------- Appendix I:3.3

Terrestrial surface temperature controls the formation and
distribution of atmospheric water vapor and also contributes to the
determination of cloud amount.  In addition, surface temperatures
control the biological activity and health of agricultural fields,
forests, and other natural ecosystems. 


      FIRE OCCURRENCE
------------------------------------------------------- Appendix I:3.4

Biomass burning releases carbon dioxide into the atmosphere and also
increases concentrations of other harmful gases, such as carbon
monoxide and nitrogen oxides.  Land cover monitoring can be used to
assess potential fire hazards and monitor fire recovery in natural
ecosystems. 


      VOLCANIC EFFECTS
------------------------------------------------------- Appendix I:3.5

The volcanic ejection of aerosols and particulates into the
atmosphere can increase precipitation and ozone destruction and cause
the lowering of global temperatures.  Volcanic activities also
contribute to the formation of continents. 


      SURFACE WETNESS
------------------------------------------------------- Appendix I:3.6

Surface wetness controls the availability of fresh water resources
for agricultural and industrial activities. 


   OCEAN MEASUREMENTS
--------------------------------------------------------- Appendix I:4


      SURFACE TEMPERATURE
------------------------------------------------------- Appendix I:4.1

Sea surface temperature measurements are important to understanding
heat exchange between the ocean and the atmosphere.  Such an
understanding will contribute to the development of accurate general
circulation models, which enhance our understanding of seasonal and
interannual climate variations that contribute to hurricanes, floods,
and other natural hazards. 


      PHYTOPLANKTON AND DISSOLVED
      ORGANIC MATTER
------------------------------------------------------- Appendix I:4.2

Planktonic marine organisms and dissolved organic matter play a major
role in the carbon cycle, as they incorporate, or "fix," about as
much carbon as land plants.  This contributes to removing carbon
dioxide from the atmosphere and to offsetting the greenhouse effect. 


      SURFACE WIND FIELDS
------------------------------------------------------- Appendix I:4.3

Surface winds over the oceans contribute to ocean circulation and the
interaction between the air and sea, which affect short-term and
long-term climate variations. 


      OCEAN SURFACE TOPOGRAPHY
------------------------------------------------------- Appendix I:4.4

Sea height and ocean circulation are related.  Ocean circulation
transports water, heat, salt, and chemicals around the planet. 
Accurate information about these circulation patterns should
contribute to understanding the oceans' impact on weather, climate,
and marine life, and thus the fisheries industry and other maritime
commerce. 


   CRYOSPHERE MEASUREMENTS
--------------------------------------------------------- Appendix I:5


      ICE SHEET TOPOGRAPHY AND ICE
      VOLUME CHANGE
------------------------------------------------------- Appendix I:5.1

Measurements of the polar ice caps, including ice sheet elevation and
ice volume, will determine the contribution of the ice sheets to
sea-level variation.  These data will also contribute to
understanding the role of the polar ice caps in Earth's freshwater
and energy budgets, as well as climate fluctuations. 


      SEA ICE
------------------------------------------------------- Appendix I:5.2

Measurements of the extent and thickness of sea ice will help
determine atmospheric warming.  Sea ice measurements will also be
useful to operational ice forecasting centers, thus affecting
maritime commerce. 


      SNOW COVER
------------------------------------------------------- Appendix I:5.3

Snow cover, extent, and duration determine fresh water resources,
especially in Alpine regions of the world. 


EOS SATELLITE MISSIONS,
INSTRUMENTS, AND MEASUREMENTS
========================================================== Appendix II



                               Table II.1
                
                    EOS Instruments and Measurements

Instrument          Measurements
------------------  --------------------------------------------------
ACRIM               Active Cavity Radiometer Irradiance Monitor
                    (ACRIM) monitors the variability of total solar
                    irradiance.

AIRS                Atmospheric Infrared Sounder (AIRS) measures
                    atmospheric temperature and humidity.

AMSR                Advanced Microwave Scanning Radiometer (AMSR)
(Japan)             observes atmospheric and oceanic water vapor
                    profiles and determines precipitation, water vapor
                    distribution, cloud water, sea surface
                    temperature, sea ice, and sea surface wind speed.

AMSU                Advanced Microwave Sounding Unit (AMSU) measures
                    atmospheric temperature.

ASTER               Advanced Spaceborne Thermal Emission and
(Japan)             Reflection Radiometer (ASTER) provides high
                    spatial resolution images of the land surface,
                    water, ice, and clouds.

CERES               Clouds and the Earth's Radiant Energy System
                    (CERES) measures Earth's radiation budget and
                    atmospheric radiation.

DFA                 Dual Frequency Altimeter (DFA) maps the topography
(France)            of the sea surface and its impact on ocean
                    circulation.

EOSP                Earth Observing Scanning Polarimeter (EOSP)
                    globally maps radiance and linear polarization of
                    reflected and scattered sunlight to measure
                    atmospheric aerosols.

ETM+                Enhanced Thematic Mapper Plus (ETM+) provides high
                    spatial resolution images of the land surface,
                    water, ice, and clouds.

GLAS                Geoscience Laser Altimeter System (GLAS) measures
                    ice sheet topography, cloud heights, and aerosol
                    vertical structure.

HIRDLS              High-Resolution Dynamics Limb Sounder (HIRDLS)
(UK-US)             observes gases and aerosols in the troposphere,
                    stratosphere, and mesosphere to assess their role
                    in the global climate system.

LATI                Landsat Advanced Technology Instrument (LATI)
                    provides high spatial resolution images of the
                    land surface, water, ice, and clouds beyond
                    Landsat ETM+.

LIS                 Lightning Imaging Sensor (LIS) measures the
                    distribution and variability of lightning.

MHS                 Microwave Humidity Sounder (MHS) provides
                    atmospheric water vapor profiles.

MISR                Multi-Angle Imaging Spectroradiometer (MISR)
                    measures the top-of-the-atmosphere, cloud, and
                    surface angular reflectance.

MLS                 Microwave Limb Sounder (MLS) measures chemistry
                    from the upper troposphere to the lower
                    thermosphere.

MODIS               Moderate-Resolution Imaging Spectroradiometer
                    (MODIS) studies biological and physical processes
                    in the atmosphere, the oceans, and on land.

MOPITT              Measurements of Pollution in the Troposphere
(Canada)            (MOPITT) measures upwelling radiance to produce
                    tropospheric carbon monoxide profiles and total
                    column methane.

MR                  Microwave Radiometer (MR) provides atmospheric
                    water vapor measurements for DFA.

ODUS                Ozone Dynamics Ultraviolet Spectrometer (ODUS)
(Japan)             measures total column ozone.

SAGE III            Stratospheric Aerosol and Gas Experiment III (SAGE
                    III) provides profiles of aerosols, ozone, and
                    trace gases in the mesosphere, stratosphere, and
                    troposphere.

SeaWinds            Provides all-weather measurements of ocean surface
                    wind speed and direction.

SOLSTICE            Solar Stellar Irradiance Comparison Experiment
                    (SOLSTICE) measures full-disk solar ultraviolet
                    irradiance.

TES                 Tropospheric Emission Spectrometer (TES) provides
                    profiles of all infrared active species from
                    Earth's surface to the lower stratosphere.
----------------------------------------------------------------------


                               Table II.2
                
                         EOS Satellite Missions

Satellite           Description
------------------  --------------------------------------------------
Landsat-7           Mission continues Landsat land-imaging satellite
ETM+                series. Future Landsat-type instrument is planned
                    for AM-2 and AM-3.

AM                  Morning equator-crossing mission (AM series) will
ASTER               study clouds, aerosols, and radiation balance; the
CERES               terrestrial ecosystem; land use; soils;
EOSP                terrestrial energy/moisture; tropospheric chemical
LATI                composition; volcanoes; and ocean productivity.
MISR                ASTER and MOPITT will be on AM-1 only. EOSP and
MODIS               LATI will be on AM-2 and AM-3 only.
MOPITT

PM                  Afternoon equator-crossing mission (PM series)
AIRS                will study cloud formation, precipitation, and
AMSR                radiative properties; air-sea fluxes of energy and
AMSU                moisture; sea-ice extent; and ocean primary
CERES               productivity. The PM series will carry prototypes
MHS                 of future operational weather satellite
MODIS               instruments.


CHEM                Chemistry mission (CHEM series) will study
HIRDLS              atmospheric chemical composition; chemistry-
MLS                 climate interactions; and air-sea exchange of
ODUS                chemicals and energy. ODUS will be on CHEM-1 only.
TES                 A later CHEM flight may include
                    SAGE III.

LaserALT            Laser altimeter mission (LaserALT series) will
GLAS                study ice sheet mass balance.

RadarALT            Radar altimeter mission (RadarALT series) will
DFA                 study ocean circulation. RadarALT is a joint
MR                  mission with France.

ISS, Meteor, and    SAGE III instrument carried on International Space
Flight of           Station (ISS) and Russian Meteor satellite will
Opportunity         study distribution of aerosols, ozone profiles,
SAGE III            and greenhouse gases in the lower stratosphere.

TRMM                Tropical Rainfall Measuring Mission (TRMM) will
CERES               study precipitation and Earth radiation budget in
LIS                 the tropics and high latitudes. TRMM is a joint
                    mission with Japan.

ADEOS-II            Japanese Advanced Earth Observing System II
SeaWinds            (ADEOS II) satellite carrying NASA scatterometer
                    instrument will study ocean surface wind vectors.

ACRIM               Mission will monitor the variability of total
ACRIM               solar irradiance and is currently planned to fly
                    on a series of small satellites.

Flight of           Mission will study Earth's radiation budget and
Opportunity         atmospheric radiation.
CERES

Flight of           Mission will study full-disk solar ultraviolet
Opportunity         irradiance.
SOLSTICE
----------------------------------------------------------------------

EOS INSTRUMENT FLIGHT SCHEDULE
THROUGH 2009
========================================================= Appendix III



   (See figure in printed
   edition.)


EOS SCIENCE OBJECTIVES AND
INTERDISCIPLINARY INVESTIGATIONS
========================================================== Appendix IV

EOS science objectives are listed below, along with the
interdisciplinary investigations designed to address them.  These
investigations are intended to cross discipline boundaries, and
therefore, address more than one science objective. 

The Water and Energy Cycles objective covers the formation,
dissipation, and radiative properties of clouds, which influence the
atmosphere's response to greenhouse forcing.  In addition, Water and
Energy Cycles include large-scale hydrology and moisture processes,
such as precipitation and evaporation. 

  -- National Center for Atmospheric Research Project to Interface
     Modeling on Global and Regional Scales With EOS Observations. 
     This investigation is intended to use surface and atmospheric
     data sources to improve climate models and their predictions of
     global change.  Components of climate models to be addressed
     include surface-atmosphere interactions, the hydrologic cycle,
     global energy balance, cloud and aerosol radiative fields, and
     atmospheric chemical cycles. 

  -- Climate Processes Over the Oceans.  Climate is strongly
     influenced by the amount and distribution of water vapor, liquid
     water, and ice suspended in the atmosphere.  This atmospheric
     water, and the climate over land areas, is largely controlled by
     processes occurring over the oceans.  This investigation will
     improve modeling of both the atmosphere and its interactions
     with the ocean.  It will address the roles of circulation,
     clouds, radiation, water vapor, and precipitation in climate
     change as well as the role of ocean-atmosphere interactions in
     the energy and water cycles. 

  -- Hydrologic Processes and Climate Interdisciplinary
     Investigation.  The global water and energy cycles link the
     atmosphere, land, and ocean.  In addition, water supports life
     and plays a crucial role in climate regulation.  This
     investigation is to enhance our understanding of the physical
     processes that affect these cycles. 

  -- The Processing, Evaluation, and Impact on Numerical Weather
     Prediction of AIRS, AMSU, and MODIS Data in the Tropics and
     Southern Hemisphere.  This investigation involves the
     development of algorithms and techniques to improve atmospheric
     science, specifically numerical weather prediction models, using
     three EOS instruments. 

  -- Investigation of the Atmosphere-Ocean-Land System Related to
     Climate Processes.  The atmosphere, ocean, and land interact
     with each other through the exchanges of heat energy, momentum,
     and water substance.  These interactions influence climate. 
     This investigation will examine the atmosphere-ocean-land system
     by pursuing seven supporting studies that will involve both
     observations and modeling. 

  -- The Development and Use of a Four-Dimensional
     Atmospheric-Ocean-Land Data Assimilation System for EOS.  This
     investigation will incorporate all available data, from a
     variety of sources, into a single model of the Earth system. 
     This model can then be used to project the Earth system beyond
     the range of actual observations, estimate expected values of
     observations to assess instrument quality, provide products for
     environmental studies, and supplement observations by estimating
     quantities that are difficult or impossible to observe. 

  -- An Interdisciplinary Investigation of Clouds and the Earth's
     Radiant Energy System:  Analysis.  This investigation will
     examine the role of clouds and radiative energy balance in the
     climate system.  Studies include cloud feedback mechanisms that
     can greatly modify the response of the climate system to
     increased greenhouse gases. 

The Oceans objective covers the exchange of energy, water, and
chemicals between the ocean and atmosphere, and between the upper
layers of the ocean and the deep ocean. 

  -- Coupled Atmosphere-Ocean Processes and Primary Production in the
     Southern Oceans.  The southern ocean plays an important role in
     both the carbon cycle and heat exchange between the ocean and
     atmosphere.  This investigation will focus on developing
     predictive models so we can better understand the effects of
     changes in the physical forcing of the ocean
     (e.g., small shifts in the location of westerly wind systems may
     affect ocean processes). 

  -- Biogeochemical Fluxes at the Ocean/Atmosphere Interface.  Solar
     radiation impinging on the oceans creates chemical, physical,
     and biological effects.  One result is the creation of gases,
     such as carbon dioxide, dimethyl-sulfide, and carbon monoxide,
     which are then circulated by wind and water.  This investigation
     will develop models to better understand these gases and the
     influence of oceanic processes upon them. 

  -- Interdisciplinary Studies of the Relationships Between Climate,
     Ocean Circulation, Biological Processes, and Renewable Marine
     Resources.  This investigation will study (1) the ocean's role
     in climate change, particularly in the Australian region; (2)
     the influence of the carbon cycle in Australia's waters on the
     global carbon cycle; and (3) changes in Australian oceanography
     and the implications for marine ecosystems, including commercial
     fisheries. 

  -- The Role of Air-Sea Exchanges and Ocean Circulation in Climate
     Variability.  Exchanges of water, momentum, and heat at the
     interface of the ocean and atmosphere drive the transport and
     change the storage of heat, water, and greenhouse gases, thus
     moderating the world's climate.  This investigation will study
     these exchanges and ocean circulation in order to improve our
     understanding of natural global changes and enable us to discern
     human-induced effects. 

  -- Polar Exchange at the Sea Surface:  the Interaction of Ocean,
     Ice, and Atmosphere.  This is an investigation of energy
     exchanges in Earth's polar regions, both at the
     atmosphere-ice-ocean interface and lower latitudes.  It will
     study the role these processes play in global oceanic and
     atmospheric circulation and help improve our understanding of
     whether polar regions show any sign of climate change. 

  -- Middle and High Latitude Oceanic Variability Study.  This
     investigation will examine the variability of the atmosphere's
     influence on the oceans, the effect on the oceanic response, and
     the resulting effect on biological productivity in the oceans. 
     The study will focus on the mid- to high-latitude regions of the
     oceans.  It will examine changes in the surface fluxes of
     momentum, heat, water, and radiation, as well as the variability
     of ocean circulation and biological activity. 

  -- Earth System Dynamics:  the Determination and Interpretation of
     the Global Angular Momentum Budget Using EOS.  Momentum and mass
     transport among the atmosphere, oceans, and solid Earth produce
     changes in the planet's rotation and gravity field.  Predictions
     of these changes based on the mass and motion of air and water
     can be compared with observations to improve models of the
     interactions of the oceans, atmosphere, and solid Earth.  This
     investigation will examine these interactions as represented by
     the exchange of angular momentum, mass, and energy among these
     components. 

The Chemistry of the Troposphere and Lower Stratosphere objective
includes links to the hydrologic cycle and ecosystems,
transformations of greenhouse gases in the atmosphere, and
interactions inducing climate change. 

  -- Interannual Variability of the Global Carbon, Energy, and
     Hydrologic Cycles.  Analysis of the carbon, energy, and water
     cycles may increase the predictability of climate change.  The
     goals of this investigation are to (1) understand contemporary
     climate variability and trends and (2) contribute to our ability
     to predict the impact of human activities on the climate. 

  -- Changes in Biogeochemical Cycles.  Models of biogeochemical
     cycles can be used to project the interactions of atmospheric
     composition, climate, terrestrial and aquatic ecosystems, ocean
     circulation and sea level, and human-induced effects.  This
     investigation will develop models and databases to describe the
     dynamics of water, carbon, nitrogen, and trace gases over
     seasonal-to-century time scales. 

The Land Surface Hydrology and Ecosystem Processes objective covers
sources and sinks of greenhouse gases, the exchange of moisture and
energy between the land surface and atmosphere, and changes in land
cover.  Investigations in this category could result in improved
estimates of runoff over the land surface and into the oceans. 

  -- Global Water Cycle:  Extension Across the Earth Sciences.  The
     global water cycle stimulates, regulates, and responds to the
     other components of the Earth system on regional and global
     scales.  This investigation is aimed at developing a hierarchy
     of models, using EOS data, that will contribute to our
     understanding of cloud cover and radiative transfer, as well as
     energy and moisture changes at the interface of the atmosphere
     with the oceans, cryosphere, and land surface.  These models
     will contribute to the prediction of changes in water balance
     and climate. 

  -- Long-Term Monitoring of the Amazon Ecosystems Through EOS:  From
     Patterns to Processes.  Natural and human-induced changes in the
     Amazon are expected to disrupt regional vegetation
     distributions, alter the physical and chemical characteristics
     of the continental river system, and change regional
     hydroclimatology, possibly influencing global climate patterns. 
     The aim of this investigation is to understand the circulation
     of water, sediment, and nutrients through the basin. 

  -- Northern Biosphere Observation and Modeling Experiment.  Natural
     and human-induced climate changes in the northern latitudes will
     affect terrestrial ecosystems, and feedbacks from these changing
     systems will influence the climate.  The goal of this study is
     to better understand the relationship between the climate and
     northern ecosystems over a range of spatial scales. 

  -- Hydrology, Hydrochemical Modeling, and Remote Sensing in
     Seasonally Snow-Covered Alpine Drainage Basins.  Seasonally
     snow-covered Alpine regions are important to the hydrologic
     cycle, as they are a major source of water for runoff, ground
     water recharge, and agriculture.  This investigation will
     monitor conditions in Alpine basins and develop models to better
     understand the cycling of water, chemicals, and nutrients in
     these areas. 

  -- Climate, Erosion, and Tectonics in Mountain Systems.  In
     mountain belts, climatic and tectonic processes produce Earth's
     highest rates of weathering and erosion.  Alpine regions are
     important to downstream hydrology, providing both inorganic and
     organic material to lowland areas.  This investigation will
     observe the effects of climate changes on Alpine land processes
     and develop models to improve our understanding of these
     interactions. 

  -- The Hydrologic Cycle and Climatic Processes in Arid and Semiarid
     Lands.  Knowledge of the hydrologic cycle will help scientists
     predict the effects of natural and human-induced climate change. 
     This investigation will study the hydrologic cycle and climatic
     processes in arid and semiarid lands, where agricultural
     productivity is especially sensitive to changes in the cycle. 

  -- Using Multi-Sensor Data to Model Factors Limiting Carbon Balance
     in Global Arid and Semiarid Land.  This investigation will
     address the role of arid and semiarid lands in processes
     affecting the global environment, such as the production and
     consumption of trace gases.  It will also examine the
     vulnerability of these lands to climate change in terms of
     productivity and soil quality, and develop predictive models of
     ecosystem function for dry lands. 

  -- Biosphere-Atmosphere Interactions.  This investigation is to
     improve our understanding of the role of the terrestrial
     biosphere in global change.  It will cover short-term
     interactions between the land and atmosphere, such as
     biophysics, as well as long-term interactions, such as ecology
     and human-induced impacts.  The goal of the investigation is to
     understand and predict the response of the biosphere-atmosphere
     system to global change, specifically to the increase in
     atmospheric carbon dioxide. 

Glaciers and Polar Ice Sheet measurements could contribute to
predictions of sea level and global water balance. 

  -- Use of the Cryospheric System to Monitor Global Change in
     Canada.  The cryosphere is an important component of the global
     climate system, and better understanding of cryospheric
     processes may improve global climate models.  This investigation
     seeks to understand cryospheric variations, develop models that
     will improve our knowledge of the role of the cryosphere in the
     climate system, and use various cryospheric data sets to support
     climate monitoring and model development. 

The Chemistry of the Middle and Upper Stratosphere objective includes
chemical reactions, solar-atmosphere relations, and sources and sinks
of radiatively important gases. 

  -- Observational and Modeling Studies of Radiative, Chemical, and
     Dynamical Interactions on the Earth's Atmosphere.  Understanding
     the circulation, transformations, and sources and sinks of
     gases, such as carbon dioxide, water vapor, ozone, and
     chlorofluorocarbons, is important in dealing with the issues of
     global warming, ozone depletion, and the coupling of atmospheric
     chemistry and climate.  This investigation seeks to improve our
     understanding of the fundamental processes influencing these
     gases in the atmosphere and contribute to the development of a
     predictive capability for global change studies. 

  -- Chemical, Dynamical, and Radiative Interactions Through the
     Middle Atmosphere and Thermosphere.  Carbon dioxide and ozone
     play important radiative roles in the middle atmosphere.  Ozone
     absorbs ultraviolet radiation, heating the middle atmosphere and
     shielding the biosphere from dangerous ultraviolet dosages.  The
     interactions of other gases, as well as temperature and middle
     atmosphere circulation, affect ozone.  This investigation will
     improve our understanding of interactions in the middle
     atmosphere and our ability to predict long-term atmospheric
     trends. 

  -- Investigation of the Chemical and Dynamical Changes in the
     Stratosphere.  Chemical changes in the atmosphere are occurring
     largely as a result of changes in the surface emission of trace
     gases.  This investigation will focus on the response of ozone
     to trace gas changes, isolating natural from human-induced
     changes to determine their effects on ozone and to assess
     radiative and dynamical feedbacks. 

The Solid Earth objective deals with volcanoes and their role in
climate change. 

  -- A Global Assessment of Active Volcanism, Volcanic Hazards, and
     Volcanic Inputs to the Atmosphere from EOS.  The injection of
     material from volcanoes into the atmosphere can affect the local
     or hemispheric climate.  This investigation will improve our
     understanding of the processes behind volcanic eruptions; study
     the injection of sulfur dioxide, water vapor, carbon dioxide,
     and other gases into the atmosphere; and place eruptions into
     the context of the regional tectonic setting of the volcano. 




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

See comment 1. 



(See figure in printed edition.)

See comment 1. 



(See figure in printed edition.)

See comment 1. 



(See figure in printed edition.)

See comment 2. 



(See figure in printed edition.)

See comment 3. 



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)

See comment 1. 

See comment 4. 

See comment 5. 

See comment 1. 

See comment 1. 



(See figure in printed edition.)

See comment 6. 

See comment 7. 

See comment 8. 



(See figure in printed edition.)



(See figure in printed edition.)

See comment 9. 

See comment 10. 

See comment 11. 

See comment 12. 


The following are GAO's comments on NASA's letter dated May 17, 1996. 


   GAO COMMENTS
-------------------------------------------------------- Appendix IV:1

1.  Refer to the "agency comments and our evaluation" section of the
report. 

2.  Our analytic framework was not designed to assess the science
teams' ability to do the tasks they are currently funded to do.  In
its comments, NASA points out that the breadth of scientific interest
in EOS measurements is likely to be greater than the interest in
Upper Atmosphere Research Satellite (UARS) and Ocean Topography
Experiment (TOPEX) measurements.  This view is consistent with our
observation that the scientific opportunities afforded by EOS are
likely to be greater than those afforded by these pre-EOS-era
missions.  The difference in potential research opportunities
afforded by EOS and, for example, UARS and TOPEX is illustrated by
the differences in the number of investigations and data rates of EOS
and these two pre-EOS-era missions.  NASA's strategy is to begin
increasing the number of EOS investigations. 

3.  We met with NASA personnel at various times throughout our
fieldwork and considered their views in preparing our draft report. 
In this section of its comments, NASA notes a number of issues
related to its interpretation that our draft report was intended to
estimate the potential EOS user community and to assess the ability
of current EOS researchers to process the large amounts of data
expected from EOS.  We have made changes in the final report to
clarify our objectives.  As an example of NASA's misinterpretation,
it specifically criticizes our data rate comparison, presents a
comparison of its own, and expresses its confidence that this
difference (EOS CHEM mission investigators must handle 100 times more
data than UARS investigators) is not significant.  Again, we did not
assess the ability of investigators to handle data.  Also, we did not
discuss the "average data rate per investigator," as stated by NASA. 
Further, our use of data rates is consistent with the way NASA used
them in its 1993 and 1995 editions of the EOS Reference
Handbook--namely, to help illustrate the magnitude of science
opportunities afforded by EOS compared to pre-EOS-era Earth observing
missions. 

4.  Our comparisons, coupled with NASA's efforts to begin increasing
the number of EOS investigations, support the need to assess what is
necessary and sufficient EOS basic research.  As NASA stated, this
question merits "further, more detailed, and more comprehensive
analysis." The recommendation to NASA in our draft report was
intended to ensure that this question is at least addressed in the
context of Pathfinder.  In our judgment, the matter for congressional
consideration has the same intention. 

5.  The observation that "scientists analyze data when they are paid
to do so" was made by several senior NASA officials.  Our analysis of
the authorship of UARS and TOPEX journal articles was to verify these
officials' observation. 

6.  Our use of the term "limited" was not referring to the number of
investigations NASA hopes to add.  Rather, it refers to the fact that
newly selected interdisciplinary science investigators will be
largely precluded from analyzing data from the first EOS mission.  We
have clarified the report. 

7.  We did not say the near-term community of researchers is "too
small." We said the number of currently funded EOS science
investigations is small compared with two pre-EOS-era missions and
the potential research opportunities afforded by EOS.  Senior NASA
officials told us that budget constraints slowed their efforts to
increase the number of EOS investigations.  In September 1995, NASA
began its formal efforts to add more investigations because it had
created sufficient "savings" to fund them.  We did not say, as NASA
contends, that it is limiting the "focus" of newly selected
investigations to pre-EOS-era missions.  Rather, we said that the new
investigators would be largely precluded from analyzing data from the
first EOS mission, based on the following language from the September
1995 announcement: 

     Investigations to begin in 1996 cannot depend solely on data
     from EOS instruments because the earliest launch dates are
     planned for 1997 (for [Tropical Rainfall Measuring Mission]) and
     1998 (for EOS-AM-1).  Instead, research plans should be based on
     use of existing data sets .  .  .  or expected data from
     relevant near-term (1996-1997) satellite missions and field
     experiments. 

8.  Our draft report discussed the 1995-96 peer review, noting that
the review could lead to possible deselection and recompetition of
some EOS science teams. 

9.  We incorporated the amount of funds involved in the program into
the report's text. 

10.  We included NASA's current estimate of planned EOS spending
through fiscal year 2000 in the report's text. 

11.  We revised our report to include NASA's comments about lower
program baseline costs and its confidence that it will decrease costs
further. 

12.  We deleted the material NASA is referring to. 

*** End of document. ***