Military Space Programs: Issues Concerning DOD's SBIRS and STSS Programs
CRS Report for Congress
Military Space Programs: Issues Concerning
DOD’s SBIRS and STSS Programs
Marcia S. Smith
Specialist in Aerospace and Telecommunications Policy
Resources, Science, and Industry Division
The Department of Defense’s (DOD’s) programs to develop new satellites to alert
U.S. military commanders to foreign missile launches, and to support missile defense
objectives, are controversial because of cost growth and schedule slippage. SBIRS-
High, managed by the Air Force, would replace existing Defense Support Program
“early warning” satellites. The Space Tracking and Surveillance System (STSS,
formerly SBIRS-Low), managed by the Missile Defense Agency, would perform missile
tracking and target discrimination for missile defense objectives. The SBIRS-High
program has breached Nunn-McCurdy cost growth limits several times, resulting in
several program restructurings. This is the final edition of this report.
Satellite Early Warning Systems
The United States began developing early warning satellite systems in the 1950s to
alert the National Command Authority to foreign missile launches. The current series is
called the Defense Support Program (DSP). The first DSP satellite was launched in
November 1970; 22 have been launched to date, most recently in February 2004. The
final DSP was delivered to the Air Force in May 2005 for launch later in the year. Each
DSP can operate for up to 10 years.1 Four satellites reportedly are needed for a full
operational capability. Six satellites reportedly were operating in January 2001.2
DSP satellites (built by Northrop Grumman Space Technology, which was formerly
TRW Space and Electronics) use infrared sensors to detect the heat of fuel exhausts
associated with missile launches. Sensors on the satellites also can detect nuclear bursts
associated with the detonation of nuclear weapons. A February 2001 General Accounting
1 Space News, Jan. 7, 2002, p. 14.
2 Space & Missile Defense Report, Jan. 18, 2001, p. 8. More recent data could not be obtained
in the open literature.
Congressional Research Service ˜ The Library of Congress
Office (GAO, now the Government Accountability Office) report3 recounted DOD’s
attempts to build a replacement for DSP over more than two decades. None of the
proposed replacement programs — the Advanced Warning System in the early 1980s, the
Boost Surveillance and Tracking System in the late 1980s, the Follow-On Early Warning
System in the early 1990s, and the Alert, Locate and Report Missiles System in the mid-
1990s — reached fruition “due to immature technology, high cost, and affordability
issues,” according to GAO. Instead, enhancements were made to the DSP series. For
example, DSP was designed to detect launches of strategic long range missiles (such as
Intercontinental Ballistic Missiles). However, the need to detect short range tactical
missiles, such as Scud, was highlighted during the 1990-1991 Persian Gulf War. In 1995,
DOD added the ALERT (Attack and Launch Early Reporting to Theater) system to DSP
satellites to augment their theater missile warning capabilities.
DSP-type satellites are intrinsically part of any effort to develop a missile defense
system because they provide the first warning that a foreign missile has been launched
(during the missile’s “boost” phase), but DSP also serves other objectives. Since the
1980s, there has been interest in developing a system explicitly to support missile defense
— one that can track missiles as they progress along their flight path (the “mid-course”
phase), detect and track warheads once they are deployed from the missile, and cue
weapon systems to attack the missiles or warheads. A concept for a constellation of many
satellites in low Earth orbit, called Brilliant Eyes, was developed during the 1980s under
the auspices of the Strategic Defense Initiative Office (SDIO). Following a 1994 DOD
study on how best to meet the nation’s early warning needs, Brilliant Eyes was transferred
to the Air Force, which was given responsibility to build an integrated Space-Based
InfraRed System (SBIRS) with satellites in several orbits. Brilliant Eyes was renamed the
Space and Missile Tracking System and became the low Earth orbit component of SBIRS.
Later it was renamed SBIRS-Low. The system to replace DSP was named SBIRS-High,
consisting of satellites in geostationary orbit (GEO, where DSP satellites are placed) and
sensors on other DOD satellites in highly elliptical orbits (HEO).4 In 2001, SBIRS-Low
was shifted back to the Ballistic Missile Defense Organization (BMDO), which was
SDIO’s successor and is now the Missile Defense Agency. That action was taken to stress
that SBIRS-Low’s main purpose is to support ballistic missile defense. The satellite
program has since been renamed again, and is now the Space Tracking and Surveillance
3 U.S. General Accounting Office. Defense Acquisitions: Space-Based Infrared System-low at
Risk of Missing Initial Deployment Date. GAO-01-6. Washington, U.S. GAO, Feb. 2001. For
more detail on the history of U.S. early warning satellite systems, see Richelson, Jeffrey.
“America’s Space Sentinels.” Lawrence, Kansas, University Press of Kansas, 1999.
4 Geostationary orbit (GEO) exists 35,800 kilometers above the equator. A satellite in GEO
maintains a fixed position relative to a point on Earth. Three or four properly spaced GEO
satellites can view the entire globe, except for the polar regions. HEO orbits can provide
coverage of the polar regions. A classic HEO orbit (called a Molniya orbit after the Soviet
communications satellite system that first utilized it), has an apogee (the highest point of the
orbit) of approximately 40,000 kilometers, and a perigee (the lowest point) of about 500
kilometers, giving the orbit an elliptical shape. With an inclination of about 63 degrees (the angle
at which it intersects the equator), such an orbit allows a satellite to linger or “dwell” over the
northern hemisphere for several hours per orbit, viewing parts of the globe not observable from
GEO. DOD reportedly uses this type of orbit for classified satellites.
Purpose, Design, and Cost Estimate. SBIRS-High was designed to perform
four missions: missile warning, missile defense, technical intelligence, and battlespace
characterization (observing and reporting on military activities on a battlefield). The plan
was for the system to consist of four operational GEO satellites (plus a ground spare),
sensors on two classified DOD satellites in HEO, a ground-based Mission Control Station
(MCS), and ground-based relay stations. MCS achieved initial operational capability in
January 2002 using the existing DSP satellites.
In 1996, Aviation Week & Space Technology described the technical capabilities of
SBIRS-High (November 18, 1996, p. 23) that were expected at that time. Reportedly it
would have high speed scanning sensors and staring sensors. After the scanning sensor
detected a launch, it would cue the staring sensor to observe the event and provide more
detailed data. DSP satellites, by contrast, reportedly have only scanning sensors. DSP
takes 40-50 seconds to detect a missile launch and determine its course, while SBIRS-
High was being designed to make those determinations and relay warnings to ground
forces in 10-20 seconds. The extent to which these technical design characteristics are
still planned is unclear from the open literature.
A Lockheed Martin-Northrop Grumman team won a $2.16 billion contract to build
SBIRS-High in 1996. In September 2002, DOD increased the contract to $4.18 billion,
which does not include the cost of three of the five GEO satellites. DOD’s Selected
Acquisition Report for the quarter ending September 2005
[http://www.acq.osd.mil/ara/am/sar/2005-SEP-SST.pdf] shows the original cost estimate
for SBIRS-High as $3.68 billion in FY1995 dollars ($4.15 billion in current year dollars,
i.e., adjusted for inflation), compared with a new estimate of $9.01 billion in FY1995
dollars ($10.64 billion in current year dollars).
Issues. The SBIRS-High program is controversial because of cost growth and
schedule slippage caused by technical challenges that have been encountered in
developing the sensors and satellites. In the FY2002 DOD appropriations act, Congress
denied all procurement funding ($94 million had been requested) because it felt more
research and development (R&D) was required. It added $40 million to the $395 million
requested for R&D. The House Appropriations Committee’s report on the FY2002 DOD
appropriations act (H.Rept. 107-298, p. 140) cited findings by GAO that the program was
facing serious hardware and software design problems including sensor jitter, inadequate
infrared sensitivity, and stray sunlight. (The GAO report is classified). Space News
reported on January 7, 2002 (p. 14) that the program’s cost estimate had grown from $1.9
billion to $4.5 billion, and the first launch slipped from 2002 to 2006. Space News
attributed the cost increase to technical problems, including software development; faulty
cost estimates; budget erosion; and schedule slippage.
In December 2001, DOD made the first of several notifications to Congress that
SBIRS-High breached one of the two “Nunn-McCurdy” cost growth limits: a 15%
Program Acquisition Unit Cost (PAUC) cost increase limit, which requires notification
to Congress; or a 25% limit, where DOD must notify Congress and certify that the
program is essential to national security, that no alternatives will provide equal or greater
military capability at less cost, that new cost estimates are reasonable, and that the
program management structure is adequate. The first breach violated the 25% limit, and
DOD issued the required certification on May 2, 2002. The Air Force restructured the
program. DOD decided to pay for the first two GEO satellites (then scheduled for launch
in FY2006 and FY2007) using research, development, test, and evaluation (RDT&E)
funds. The remaining three satellites would be purchased with procurement funds, with
a two-year gap between the first two and the last three.
A May 2003 report of the Defense Science Board and Air Force Scientific Advisory
Board [http://www.acq.osd.mil/dsb/reports/space.pdf] criticized early program
management of SBIRS-High, and took a cautious attitude concerning whether the
restructured program would succeed. An October 2003 GAO report (GAO-04-48)
concluded the program remained at “substantial risk of cost and schedule increases.” The
program experienced further setbacks. Delivery of the first SBIRS-High sensor, for
launch on one of the HEO satellites, slipped to August 2004 because of electromagnetic
interference between the sensor and other spacecraft equipment. (The second HEO sensor
was delivered in September 2005.) Launch of the first GEO satellite slipped by two years;
that launch is now expected in 2008. DOD notified Congress of additional Nunn-
McCurdy breaches in June 2004 (of the 15% limit) and March 2005 (15% limit), and in
July 2005 informed Congress than an independent program assessment concluded that the
program exceeded the 25% limit (Inside the Air Force, August 5, 2005). DOD’s Selected
Acquisition Report for the period ending September 2005 indicates that the program
exceeded the 15% Nunn-McCurdy limit during that reporting period. As noted above, the
current cost estimate for the program is $10.64 billion in current year dollars. According
to media accounts (e.g. Aerospace Daily, December 16, 2005, p. 1), DOD sent the
required Nunn-McCurdy certification to Congress on December 12, 2005. While DOD
still plans to buy the first two GEO satellites, it will buy, at most, one more. The funds
that would have been spent for the fourth and fifth GEO satellites reportedly will be used
instead to design an alternative system using state-of-the-art technologies.
FY2006 Budget. DOD requested $756 million. The FY2006 DOD authorization
bill (P.L. 109-163) provides full funding. The FY2006 DOD appropriations act (P.L. 109-
148) cut $50 million due to excessive program growth (the Senate had approved a $100
million cut). The House Appropriations report calls the program “extremely troubled”
(H.Rept. 109-119, p. 181).
Space Tracking and Surveillance System (formerly SBIRS-Low)
Purpose, Design, and Cost Estimates. The Space Tracking and Surveillance
System (STSS, previously SBIRS-Low) is designed to support missile defense.
Management of the program was transferred from the Air Force back to the Ballistic
Missile Defense Organization (BMDO, the successor to SDIO — see earlier discussion
of Brilliant Eyes), to emphasize that missile defense is its primary objective. BMDO is
now the Missile Defense Agency (MDA). For more on missile defense, see CRS Report
RL31111, Missile Defense: The Current Debate, by Steven A. Hildreth.
The missile defense system is envisioned as a “layered” defense that can attack
missiles or warheads in three different phases of flight: boost (launch), mid-course
(enroute to a target, when warheads are deployed from the missile), and terminal (after
reentry). The goal of an operational STSS is to track missiles through all three phases;
discriminate between warheads and decoys; transmit data to other systems that will be
used to cue radars and provide intercept handovers; and provide data for intercept hit/kill
assessments. Tracking missiles during the mid-course phase is more difficult than during
boost, because the missile is no longer firing its engines and hence does not have a strong
infrared (heat) signature, making it necessary to track a cold object against the cold
background of space. Similarly, tracking warheads after they have been deployed, and
discriminating between warheads and decoys, is a technically challenging task.
Cost estimates are problematic because there is no final system architecture and the
schedule is in flux. In its February 2001 report, GAO reported that DOD had estimated
the life-cycle cost for STSS (then SBIRS-Low) through FY2022 at $11.8 billion. The
House Appropriations Committee reported in late 2001 (H.Rept. 107-298, p. 250) that the
program’s life cycle cost had grown from $10 billion to over $23 billion. In March 2005,
GAO reported (GAO-05-243) that DOD’s estimate for the program between 2002 and
Two industry teams were chosen in 1999 for program definition and risk reduction
(PDRR): Spectrum Astro/ Northrop Grumman, and TRW/ Raytheon. DOD was expected
to select one of the teams for the next phase in mid-2002 and the satellites were to have
been launched between 2006 and 2010.5 In the April 2002 restructuring (see below),
DOD merged the teams. Northrop Grumman Space Technology (formerly TRW Space
& Electronics) is the prime contractor, and Spectrum Astro (later acquired by General
Dynamics) is a major subcontractor, for building the satellites.
Issues. This program has gone through several name changes, making it difficult
to track. Congress began expressing concern about it in 1996, when it was known as the6
Space and Missile Tracking System, particularly in terms of program management.
Indications of technical and funding problems publicly emerged in 1999 when DOD
cancelled contracts with TRW and Boeing to build and launch three prototype
demonstration satellites because of significant cost growth.7 In the early 2000s, when its
name was SBIRS-Low, questions arose as to whether it was vital to a missile defense
system. Views vary. Some assert that missile defense cannot be achieved without such
a system, while others argue that there are alternatives, such as ground-based radars.
To some extent, the answer may depend on the nature of the threat the missile
defense system is expected to defeat (e.g., number of incoming warheads, or
sophistication of countermeasures). Radars have been used for early warning of missile
launches for decades, and already are envisioned as part of the missile defense system. To
provide effective coverage, the radars might have to be based not only in the United
States, but in other countries — radars in England and Greenland are part of the early
warning system on which the United States relies today. The question is whether ground-
based or sea-based radars can substitute for a space-based system, especially now that the
United States is no longer bound by numerical and geographic limitations imposed on
radars that are part of an anti-ballistic missile (ABM) system by the 1972 ABM treaty.
5 The first launch was scheduled for 2006, but Congress directed DOD to accelerate the schedule
to 2002. The Defense Science Board concluded that 2002 was technically feasible, but 2004
would represent a more efficient approach. (Aerospace Daily, Oct. 3, 1996, p. 18; Space News,
Sept. 16-22, 1996, p. 10.) The date then slipped back to 2006 primarily due to funding issues.
6 Authorizers Blast DOD for SMTS Management. Aerospace Daily, Aug. 8, 1996, p. 207.
7 Ferster, Warren. SBIRS Demonstration Projects Terminated. Space News, Feb. 15, 1999, p. 1.
In its November 2001 report on the FY2002 DOD appropriations bill (H.R. 3338, H.Rept.
107-298, p. 250), the House Appropriations Committee cited an internal DOD study that
indicated ground-based radars are a viable, lower cost, and lower risk, alternative.
Technical challenges continued. In its February 2001 report (cited earlier), GAO
found that five of six critical satellite technologies were too immature to ensure they
would be ready when needed. The House Appropriations Committee, in its November
2001 report (cited above), expressed concern that the program’s life cycle cost had grown
from $10 billion to over $23 billion. Consequently, the committee zeroed funding ($385
million was requested) and instead created a Satellite Sensor Technology program ($250
million) and a Ground Sensor Technology program ($75 million) as an alternative.
Conferees approved the $250 million for Satellite Sensor Technology, but allowed the
Secretary of Defense to spend it either on SBIRS-Low or new technology. It was spent
A restructuring plan was submitted to Congress on April 15, 2002. A system
consisting of 20-30 satellites had been envisioned, with the first launch in 2006. The
restructuring plan called for completing two “legacy” demonstration satellites that had
been partially built as part of the 1999 plan, and launching them in 2006 and 2007. New
technologies would be introduced in future satellites, and two new demonstration
satellites would be launched beginning in 2010. In August 2002, DOD awarded Northrop
Grumman Space Technologies an $869 million contract to complete the two legacy
satellites, develop a ground system, and conduct preliminary engineering analysis of the
new demonstration satellites, with options for building eight operational satellites. The
program’s name was changed to Space Tracking and Surveillance System (STSS). MDA
modified the plan in late 2002 after it reduced STSS funding; GAO criticized many of
those changes in a May 2003 report (GAO-03-597).
STSS is proceeding in a series of biennial “blocks.” According to MDA’s FY2006
budget documents, STSS’ Block 2006 is the launch of the two legacy satellites; Block
2008 is an improvement of the ground system; and, in Block 2012, operational satellites
would be integrated into the program. Block 2010, which appeared in FY2005 budget
documents (without descriptive detail), is shown at zero in MDA’s FY2006 documents.
A March 2005 GAO report (GAO-05-243) states that the program content of Block 2010
and beyond is classified (and, thus, funding for Block 2010 could be in the classified
budget). GAO reported that its review of STSS activities in 2004 did not find any
indication that the two legacy satellites would not be able to launch on schedule.
FY2006 Budget. According to DOD’s FY2006 budget documentation, $232
million was requested for STSS in the unclassified budget. No changes were specified
in the DOD authorization bill (P.L. 109-163). In their reports on the FY2006 DOD
appropriations bill (H.R. 2863, H.Rept. 109-119, S.Rept. 109-141), the House and Senate
Appropriations Committees restructured MDA’s budget, moving this program out of the
BMDS Sensors line and creating a new Space Surveillance and Tracking System (SSTS,
instead of STSS) line. The committee reports show the requested funding level as $235.5
million. The final version of the bill (P.L. 109-148) cuts $538,000 from SSTS, the entire
amount requested for Block 12, stating it is a “premature request.” It also adds $5 million
for the airborne infrared surveillance system (AIRS) under this line item.