Missile Defense: Review of Results and Limitations of an Early National Missile Defense Flight Test
Published: 2002-02-28T00:00:00

Fast Facts:

Highlights:
section_title: What GAO Found
paragraphs: The Department of Defense (DOD) awarded contracts to three companies in 1990 to develop and test exoatmospheric kill vehicles. One of the contractors--Boeing North American--subcontracted with TRW to develop software for the kill vehicle. In 1998, Boeing became the Lead System Integrator for the National Missile Defense Program, and chose Raytheon as the primary kill vehicle developer. Boeing and TRW reported that the June 1997 flight test achieved its primary objectives, but that some sensor abnormalities were detected. The project office relied on Boeing to oversee the performance of TRW. Boeing and TRW reported that deployed target objects displayed distinguishable features when being observed by an infrared sensor. After considerable debate, the program manager reduced the number of decoys planned for intercept flight tests in response to a recommendation by an independent panel. The Phase One Engineering Team, which was responsible for completing an assessment of TRW's software performance within two months using available data, found that although the software had weaknesses, it was well designed and worked properly, with only some changes needed to increase the robustness of the discrimination function. On the basis of that analysis, team members predicted that the software would perform successfully in a future intercept test if target objects deployed as expected.

section_title: Letter
paragraphs: For a number of years, the Department of Defense has been researching  and developing defenses against ballistic missile attacks on the United  States, its deployed forces, friends, and allies. In 1990, the Department  awarded research and development contracts to three contractors to  develop and test exoatmospheric kill vehicles. The Department planned to  use the best of the three vehicles in a follow-on missile defense program.  One of the contractors, Rockwell International, subcontracted a portion of  its kill vehicle design work to TRW. TRW was tasked with developing  software that could operate on a computer onboard the kill vehicle. The  software was to analyze data collected in flight by the kill vehicle’s sensor  (which collects real-time information about threat objects), enabling the  kill vehicle to distinguish an enemy warhead from accompanying decoys.
The three contractors proceeded with development of the kill vehicle  designs and built and tested key subsystems (such as the sensor) until  1994. In 1994, the Department of Defense eliminated Martin Marietta from  the competition. Both Rockwell—portions of which in December 1996  became Boeing North American—and Hughes—now Raytheon—  continued designing and testing their kill vehicles. In 1997 and 1998, the  National Missile Defense Joint Program Office conducted tests, in space,  of the sensors being developed by the contractors for their competing kill  vehicles.  Boeing's sensor was tested in June 1997 (Integrated Flight Test  1A) and Raytheon's sensor was tested in January 1998 (Integrated Flight  Test 2). Program officials said these tests were not meant to demonstrate  that the sensor met performance requirements, nor were they intended to  be the basis for any contract award decisions. Rather, they were early  research and development tests that the program office considered  experiments to primarily reduce risk in future flight tests. Specifically, the  tests were designed to determine if the sensor could operate in space; to  examine the extent to which the sensor could detect small differences in  infrared emissions; to determine if the sensor was accurately calibrated;  and to collect target signature data for post-mission discrimination  analysis.
After the two sensor tests, the program office planned another 19 flight  tests from 1999 through 2005 in which the kill vehicle would attempt to  intercept a mock warhead. Initially, Boeing’s kill vehicle was scheduled for  testing in Integrated Flight Test 3 and Raytheon’s in Integrated Flight Test  4. However, Boeing became the Lead System Integrator for the National  Missile Defense Program in April 1998 and, before the third flight test was  conducted, selected Raytheon as the primary kill vehicle developer.
Meanwhile, in September 1995, TRW had hired a senior staff engineer,  Dr. Nira Schwartz, to work on various projects, including the company’s  effort to develop the exoatmospheric kill vehicle’s discrimination  software. The engineer helped evaluate some facets of a technology  known as the Extended Kalman Filter Feature Extractor, which TRW  planned to add as an enhancement to its discrimination software. The  engineer reported to TRW in February 1996 that tests revealed that the  Filter could not extract the key characteristics, or features, from various  target objects that an enemy missile might deploy and demanded that the  company inform Rockwell and the Department of Defense. TRW fired the  engineer in March 1996. In April 1996, the engineer filed a lawsuit under  the False Claims Act alleging that TRW falsely reported or hid  information to make the National Missile Defense Joint Program Office  believe that the Extended Kalman Filter Feature Extractor met the  Department’s technical requirements. The engineer has amended the  lawsuit several times, including adding allegations that TRW misled the  Department of Defense about the ability of its discrimination software to  distinguish a warhead from decoys and that TRW's test reports on  Integrated Flight Test 1A falsely represented the discrimination software’s  performance.
The False Claims Act allows a person to bring a lawsuit on behalf of the  U.S. government if he or she has knowledge that a person or company has  made a false or fraudulent claim against the government. If the suit is  successful, the person bringing the lawsuit may share in any money  recovered. The Department of Justice reviews all lawsuits filed under the  act before deciding whether to join them. If it does, it becomes primarily  responsible for prosecuting the case.
To determine whether it should join the engineer's lawsuit against TRW,  Justice asked the Defense Criminal Investigative Service, a unit within the  Department of Defense Inspector General’s office, to examine the  allegations. The engineer cooperated with the Investigative Service for  more than 2 years. During the course of the Department of Defense’s  investigation into the allegations of contractor fraud, two groups  examined the former employee’s specific allegations regarding the  performance of TRW’s basic discrimination software and performed  limited evaluations of the Extended Kalman Filter Feature Extractor. The  first was Nichols Research Corporation, a contractor providing technical  assistance to the Ground Based Interceptor Project Management Office for  its oversight of the exoatmospheric kill vehicle contracts. (This office  within the National Missile Defense Joint Program Office is responsible for  the exoatmospheric kill vehicle contracts.) Because an investigator for the  Defense Criminal Investigative Service was concerned about the ability of  Nichols to provide a truly objective assessment, the National Missile  Defense Joint Program Office asked an existing advisory group, known as  the Phase One Engineering Team, to undertake another review of the  specific allegations of fraud with respect to the software. This group is  comprised of scientists from Federally Funded Research and Development  Centers who were selected for the review team because of their  knowledge of the National Missile Defense system. In addition, both  Nichols and the Phase One Engineering Team assessed the feasibility of  using the Extended Kalman Filter Feature Extractor to extract additional  features from target objects that an enemy missile might deploy.
The Department of Justice and the Defense Criminal Investigative Service  investigated the engineer’s allegations until March 1999. At that time, the  Department of Justice decided not to intervene in the lawsuit. The  engineer has continued to pursue her lawsuit without Justice’s  intervention.
When a Massachusetts Institute of Technology professor, Dr. Theodore  Postol, learned of the engineer’s claims, he conducted his own analysis of  Integrated Flight Test 1A. In May 2000, the professor wrote to the White  House alleging that Boeing North American and TRW misrepresented the  results of the test.
The professor claimed that his analysis of Integrated Flight Test 1A  showed that the system can be defeated by the simplest of decoys and that  the National Missile Defense Joint Program Office and its contractors  attempted to hide this fact by tampering with the flight test data and  altering their analysis of the sensor’s discrimination capabilities. The  professor also alleged that objects deployed as part of Integrated Flight  Test 1A displayed no distinguishable differences that Boeing’s infrared  sensor could use to identify the mock warhead from decoys and that the  program office hid the sensor’s weaknesses by reducing the number of  decoys planned for future tests. Further, the professor claimed that the  Phase One Engineering Team’s analysis was faulty.
At your request, we reviewed the professor’s allegations. Specifically, as  discussed with your office, we addressed the following questions:  1.	 Did Boeing and TRW disclose the key results and limitations of the  flight test to the National Missile Defense Joint Program Office?  2.	 How did the Ground Based Interceptor Project Management Office  oversee Boeing’s and TRW’s technical performance?  3.	 Did the flight test show whether each object deployed in space by an  attacking missile exhibits distinguishable features?  4.	 Why did the National Missile Defense Joint Program Office reduce the  complexity of later flight tests?  5.	 What were the methodology, findings, and limitations of the evaluation  conducted by the Phase One Engineering Team of TRW’s  discrimination software?
You also asked us to determine whether the Department of Defense  misused the security classification process to stifle public discussion of  possible problems with the National Missile Defense system. We  addressed this question in a separate report, dated June 12, 2001.
subsections: section_title: Disclosure of Key Results and Limitations
paragraphs: Boeing and TRW disclosed the key results and limitations of Integrated  Flight Test 1A in written reports released between August 13, 1997, and  April 1, 1998.  The contractors explained in a report issued 60 days after  the June 1997 test that the test achieved its primary objectives, but that  some sensor abnormalities were noted. For example, while the report  explained that the sensor detected the deployed targets and collected  some usable target signals, the report also stated that some sensor  components did not operate as desired and the sensor often detected  targets where there were none.  In December 1997, the contractors  documented other test anomalies.  According to briefing charts prepared  for a December meeting, the Boeing sensor tested in Integrated Flight Test  1A had a low probability of detection; the sensor’s software was not  always confident that it had correctly identified some target objects; the  software significantly increased the rank of one target object toward the  end of the flight; and in-flight calibration of the sensor was inconsistent.  Additionally, on April 1, 1998, the contractors submitted an addendum to  an earlier report that noted two more problems.  In this addendum, the  contractors disclosed that their claim that TRW’s software successfully  distinguished a mock warhead from decoys during a post-flight analysis  was based on tests of the software using about one-third of the target  signals collected during Integrated Flight Test 1A. The contractors also  noted that TRW reduced the software’s reference data so that it would  correspond to the collected target signals being analyzed.  Project office  and Nichols Research officials said that in late August 1997, the  contractors orally communicated to them all problems and limitations that  were subsequently described in the December 1997 briefing and the April  1998 addendum.  However, neither project officials nor contractors could  provide us with documentation of these communications.
Although the contractors reported the test’s key results and limitations,  they described the results using some terms that were not defined. For  example, one written report characterized the test as a “success” and the  sensor’s performance as “excellent.”  We found that the information in the  contractors’ reports, in total, enabled officials in the Ground Based  Interceptor Project Management Office and Nichols Research to  understand the key results and limitations of the test. However, because  such terms are qualitative and subjective rather than quantitative and  objective, their use increased the likelihood that test results would be  interpreted in different ways and might even be misunderstood. As part of  our ongoing review of missile defense testing, we are examining the need  for improvements in test reporting.
Appendix I provides details on the test and the information disclosed.
section_title: Project Office Reliance on Various Sources for Contractor Oversight
paragraphs: The Ground Based Interceptor Project Management Office relied on an on- site engineer and Nichols Research Corporation to provide insight into  Boeing’s work. The project office also relied on Boeing to oversee the  performance of its subcontractor, TRW. Oversight was limited by the  ongoing competition between Boeing and another contractor competing  for the exoatmospheric kill vehicle contract because the Ground Based  Interceptor Project Management Office and its support contractors had to  be careful not to affect competition by assisting one contractor more than  another. Project officials said that they relied more on “insight” into the  contractors’ work rather than oversight of that work. Nichols gained  program insight by attending technical meetings, assessing test reports,  and sometimes evaluating technologies proposed by Boeing and TRW.
For more information on how the project office exercised oversight over  its contractors’ technical performance, see appendix II.
section_title: Distinguishable Differences in Objects Deployed in Space
paragraphs: Boeing and TRW reported that post-flight testing and analysis of data  collected during Integrated Flight Test 1A showed that deployed target  objects displayed distinguishable features when observed by an infrared  sensor. The contractors reported the test also showed that Boeing’s  exoatmospheric kill vehicle sensor could collect target signals from which  TRW’s software could extract distinguishable features and that the  software could identify the mock warhead from other objects by  comparing the extracted features to the features that it had been told to  expect each object to display. However, there has been no independent  verification of these claims.
We talked with Dr. Mike Munn, who was, during the 1980s, the Chief  Scientist for missile defense programs at Lockheed Missiles and Space  Company. He agreed that a warhead and decoys deployed in the  exoatmosphere likely display distinguishable differences in the infrared  spectrum. However, the differences may not be fully understood or there  may not presently be methods to predict the differences. Dr. Munn added  that the key was in the ability to make both accurate and precise  measurements and also to predict signatures accurately. He emphasized  that robust discrimination depends on the ability to predict signatures and  then to match in-space measurements with those predictions. The Phase  One Engineering Team and Nichols Research Corporation have noted that  TRW's software used prior knowledge of warhead and decoy differences,  to the maximum extent available, to discriminate one object from the  other and cautioned such knowledge may not always be available in the  real world.
section_title: Decoy Reduction in Later Tests
paragraphs: National Missile Defense program officials said that after considerable  debate among themselves and contractors, the program manager reduced  the number of decoys planned for intercept flight tests in response to a  recommendation by an independent panel, known as the Welch Panel.The panel, established to reduce risk in ballistic missile defense flight test  programs, viewed a successful hit-to-kill engagement as a difficult task  that should not be further complicated in early tests by the addition of  decoys. After contemplating the advice of the Welch panel and considering  the opinions of program officials and contractors who disagreed over the  number and complexity of decoys that should be deployed in future tests,  the program manager decided that early tests should include only one  decoy, a large balloon.
See appendix III for more information on the reduction of decoys in later  tests.
section_title: Evaluation of TRW’s Discrimination Software
paragraphs: The Phase One Engineering Team was tasked by the National Missile  Defense Joint Program Office to assess the performance of TRW’s  software and to complete the assessment within 2 months using available  data. The team's methodology included determining if TRW’s software was  based on sound mathematical, engineering, and scientific principles and  testing the software’s critical modules using data from Integrated Flight  Test 1A.
The team reported that although the software had weaknesses, it was well  designed and worked properly, with only some changes needed to  increase the robustness of the discrimination function. Further, the team  reported that the results of its test of the software using Integrated Flight  Test 1A data produced essentially the same results as those reported by  TRW. Based on its analysis, team members predicted that the software  would perform successfully in a future intercept test if target objects  deployed as expected.
Because the Phase One Engineering Team did not process the raw data  from Integrated Flight Test 1A or develop its own reference data, the team  cannot be said to have definitively proved or disproved TRW’s claim that  its software successfully discriminated the mock warhead from decoys  using data collected from Integrated Flight Test 1A.  A team member told  us its use of Boeing- and TRW-provided data was appropriate because the  former TRW employee had not alleged that the contractors tampered with  the raw test data or used inappropriate reference data.
Appendix IV provides additional details on the Phase One Engineering  Team evaluation.
section_title: Agency Comments and Our Evaluation
paragraphs: In commenting on a draft of this report, the Department of Defense  concurred with our findings.  It also suggested technical changes, which  we incorporated as appropriate.  The Department's comments are  reprinted in appendix VII.
We conducted our review from August 2000 through February 2002 in  accordance with generally accepted government auditing standards.  Appendix VI provides details on our scope and methodology. The National  Missile Defense Joint Program Office’s process for releasing documents  significantly slowed our work. For example, the program office took  approximately 4 months to release key documents such as the Phase One  Engineering Team’s response to the professor’s allegations. We requested  these and other documents on September 14, 2000, and received them on  January 9, 2001.
As arranged with your staff, unless you publicly announce its contents  earlier, we plan no further distribution of this report until 30 days from its  issue date. At that time, we plan to provide copies of this report to the  Chairmen and Ranking Minority Members of the Senate Committee on  Armed Services; the Senate Committee on Appropriations, Subcommittee  on Defense; the House Committee on Armed Services; and the House  Committee on Appropriations, Subcommittee on Defense; and the  Secretary of Defense; and the Director, Missile Defense Agency. We will  make copies available to others upon request.
If you or your staff have any questions concerning this report, please contact Bob Levin, Director, Acquisition and Sourcing Management, on (202) 512-4841; Jack Brock, Managing Director, on (202) 512-4841; or Keith Rhodes, Chief Technologist, on (202) 512-6412. Major contributors to this report are listed in appendix VIII.
section_title: Appendix I: Disclosure of Flight Test’s Key Results and Limitations
paragraphs: Boeing and TRW disclosed the key results and limitations of an early  sensor flight test, known as Integrated Flight Test 1A, to the Ground Based  Interceptor Project Management Office. The contractors included some  key results and limitations in written reports submitted soon after the June  1997 test, but others were not included in written reports until December  1997 or April 1998.  However, according to project office and Nichols  officials, all problems and limitations included in the written reports were  communicated orally to the project management office in late August  1997. The deputy project office manager said his office did not report  these verbal communications to others within the Program Office or the  Department of Defense because the project office was the office within  the Department responsible for the Boeing contract.
One problem that was included in initial reports to program officials was a  malfunctioning cooling mechanism that did not lower the sensor’s  temperature to the desired level. Boeing characterized the mechanism’s  performance as somewhat below expectations but functioning well  enough for the sensor’s operation. We hired experts to determine the  extent to which the problem could affect the sensor’s performance. The  experts found that the cooling problem degraded the sensor’s performance  in a number of ways, but would not likely result in extreme performance  degradation. The experts studied only how increased noise affected the  sensor’s performance regarding comparative strengths of the target signals  and the noise (signal to noise ratio).  The experts did not evaluate  discrimination performance, which is dependent on the measurement  accuracy of the collected infrared signals. The experts’ findings are  discussed in more detail later in this appendix.
subsections: section_title: The Test
paragraphs: Integrated Flight Test 1A, conducted in June 1997, was a test of the Boeing  sensor—a highly sensitive, compact, infrared device, consisting of an array  of silicon detectors, that is normally mounted on the exoatmospheric kill  vehicle. However, in this test, a surrogate launch vehicle carried the sensor  above the earth’s atmosphere to view a cluster of target objects that  included a mock warhead and various decoys. When the sensor detected  the target cluster, its silicon detectors began to make precise  measurements of the infrared radiation emitted by the target objects. Over  the tens of seconds that the target objects were within its field of view, the  sensor continuously converted the infrared radiation into an electrical  current, or signal, proportional to the amount of energy collected by the  detectors. The sensor then digitized the signal (converted the signals into  numerical values), completed a preliminary part of the planned signal  processing, and formatted the signal so that it could be transmitted via a  data link to a recorder on the ground. After the test, Boeing processed the  signals further and formatted them so that TRW could input the signals  into its discrimination software to assess its capability to distinguish the  mock warhead from decoys. In post-flight ground testing, the software  analyzed the processed data and identified the key characteristics, or  features, of each signal. The software then compared the features it  extracted to the expected features of various types of target objects. Based  on this comparison, the software ranked each item according to its  likelihood of being the mock warhead. TRW reported that the highest- ranked object was the mock warhead.
The primary objective of Integrated Flight Test 1A was to reduce risk in  future flight tests.  Specifically, the test was designed to determine if the  sensor could operate in space; to examine the extent to which the sensor  could detect small differences in infrared emissions; to determine if the  sensor was accurately calibrated; and to collect target signature data for  post-mission discrimination analysis. In addition, Boeing established  quantitative requirements for the test. For example, the sensor was  expected to acquire the target objects at a specified distance. According to  a Nichols’ engineer, Boeing established these requirements to ensure that  its exoatmospheric kill vehicle, when fully developed, could destroy a  warhead with the single shot precision (expressed as a probability)  required by the Ground Based Interceptor Project Management Office. The  engineer said that in Integrated Flight Test 1A, Boeing planned to measure  its sensor’s performance against these lower-level requirements so that  Boeing engineers could determine which sensor elements, including the  software, required further refinement. However, the engineer told us that  because of the various sensor problems, of which the contractor and  project office were aware, Boeing determined before the test that it would  not use most of these requirements to judge the sensor’s performance.  (Although Boeing did not judge the performance of its sensor against the  requirements as it originally planned, Boeing did, in some cases, report the  sensor’s performance in terms of these requirements. For a summary of  selected test requirements and the sensor’s performance as reported by  Boeing and TRW in their August 22, 1997, report, see app. V.)
section_title: Reported Key Results and Limitations
paragraphs: Table 1 provides details on the key results and limitations of Integrated  Flight Test 1A that contractors disclosed in various written reports and  briefing charts.
Although the contractors disclosed the key results and limitations of the  flight test in written reports and in discussions, the written reports  described the results using some terms that were not defined. For  example, in their August 22, 1997, report, Boeing and TRW described  Integrated Flight Test 1A as a “success” and the performance of the Boeing  sensor as “excellent.”  We asked the contractors to explain their use of  these terms. We asked Boeing, for example, why it characterized its  sensor’s performance as “excellent” when the sensor’s silicon detector  array did not cool to the desired temperature, the sensor’s power supply  created excess noise, and the sensor detected numerous false targets.  Boeing said that even though the silicon detector array operated at  temperatures 20 to 30 percent higher than desired, the sensor produced  useful data. Officials said they knew of no other sensor that would be  capable of producing any useful data under those conditions. Boeing  officials went on to say that the sensor continuously produced usable, and,  much of the time, excellent data in “real-time” during flight. In addition,  officials said the sensor component responsible for suppressing  background noise in the silicon detector array performed perfectly in  space and the silicon detectors collected data in more than one wave  band. Boeing concluded that the sensor’s performance allowed the test to  meet all mission objectives.
Based on our review of the reports and discussions with officials in the  Ground Based Interceptor Project Management Office and Nichols  Research, we found that the contractors’ reports, in total, contained  information for those officials to understand the key results and  limitations of the test. However, because terms such as “success” and  “excellent” are qualitative and subjective rather than quantitative and  objective, we believe their use increases the likelihood that test results  would be interpreted in different ways and could even be misunderstood.  As part of our ongoing review of missile defense testing, we are examining  the need for improvements in test reporting.
subsections: section_title: The August 13 Report
paragraphs: This report, sometimes referred to as the 45-day report, was a series of  briefing charts. In it, contractors reported that Integrated Flight Test 1A  achieved its principal objectives of reducing risks for subsequent flight  tests, demonstrating the performance of the exoatmospheric kill vehicle’s  sensor, and collecting target signature data. In addition, the report stated  that TRW’s software successfully distinguished a mock warhead from  accompanying decoys.
section_title: The August 22 Report
paragraphs: The August 22 report, known as the 60-day report, was a lengthy document  that disclosed much more than the August 13 report. As discussed in more  detail below, the report explained that some sensor abnormalities were  observed during the test, that some signals collected from the target  objects were degraded, that the launch vehicle carrying the sensor into  space adversely affected the sensor’s ability to collect target signals, and  that the sensor sometimes detected targets where there were none. These  problems were all noted in the body of the report, but the report summary  stated that review and analysis subsequent to the test confirmed the  “excellent” performance and nominal operation of all sensor subsystems.
subsections: section_title: Some Sensor Abnormalities Were Observed During the Test
paragraphs: Boeing disclosed in the report that sensor abnormalities were observed  during the test and that the sensor experienced a higher than expected  false alarm rate. These abnormalities were (1) a cooling mechanism that  did not bring the sensor’s silicon detectors to the intended operating  temperature, (2) a power supply unit that created excess noise, and  (3) software that did not function as designed because of the slow  turnaround of the surrogate launch vehicle.
In the report’s summary, Boeing characterized the cooling mechanism’s  performance as somewhat below expectations but functioning well  enough for the sensor’s operation. In the body of the report, Boeing said  that the fluctuations in temperature could lead to an apparent decrease in  sensor performance. Additionally, Boeing engineers told us that the  cooling mechanism’s failure to bring the silicon detector array to the  required temperature caused the detectors to be noisy. Because the  discrimination software identifies objects as a warhead or a decoy by  comparing the features of a target’s signal with those it expects a warhead  or decoy to display, a noisy signal may confuse the software. Boeing and  TRW engineers said that they and program office officials were aware that  there was a problem with the sensor’s cooling mechanism before the test  was conducted. However, Boeing believed that the sensor would perform  adequately at higher temperatures. According to contractor documents,  the sensor did not perform as well as expected, and some target signals  were degraded more than anticipated. Boeing disclosed in the report that  sensor abnormalities were observed during the test and that the sensor  experienced a higher than expected false alarm rate. These abnormalities  were (1) a cooling mechanism that did not bring the sensor’s silicon  detectors to the intended operating temperature, (2) a power supply unit  that created excess noise, and (3) software that did not function as  designed because of the slow turnaround of the surrogate launch vehicle.
In the report’s summary, Boeing characterized the cooling mechanism’s  performance as somewhat below expectations but functioning well  enough for the sensor’s operation. In the body of the report, Boeing said  that the fluctuations in temperature could lead to an apparent decrease in  sensor performance. Additionally, Boeing engineers told us that the  cooling mechanism’s failure to bring the silicon detector array to the  required temperature caused the detectors to be noisy. Because the  discrimination software identifies objects as a warhead or a decoy by  comparing the features of a target’s signal with those it expects a warhead  or decoy to display, a noisy signal may confuse the software. Boeing and  TRW engineers said that they and program office officials were aware that  there was a problem with the sensor’s cooling mechanism before the test  was conducted. However, Boeing believed that the sensor would perform  adequately at higher temperatures. According to contractor documents,  the sensor did not perform as well as expected, and some target signals  were degraded more than anticipated.
section_title: Power Supply Creates Noise
paragraphs: The report also referred to a problem with the sensor’s power supply unit  and its effect on target signals. An expert we hired to evaluate the sensor’s  performance at higher than expected temperatures found that the power  supply, rather than the temperature, was the primary cause of excess  noise early in the sensor’s flight. Boeing engineers told us that they were  aware that the power supply was noisy before the test, but, as shown by  the test, it was worse than expected.
section_title: Payload Launch Vehicle Affected Software’s Ability to Remove Background Noise
paragraphs: The report explained that, as expected before the flight, the slow  turnaround of the massive launch vehicle on which the sensor was  mounted in Integrated Flight Test 1A caused the loss of some target  signals. Engineers explained to us that the sensor would eventually be  mounted on the lighter, more agile exoatmospheric kill vehicle, which  would move back and forth to detect objects that did not initially appear in  the sensor’s field of view. The engineers said that Boeing designed  software that takes into account the kill vehicle’s normal motion to  remove the background noise, but the software’s effectiveness depended  on the fast movement of the kill vehicle. Boeing engineers told us that,  because of the slow turnaround of the launch vehicle used in the test, the  target signals detected during the turnaround were particularly noisy and  the software sometimes removed not only the noise but the entire signal as  well.
section_title: Sensor Sometimes Detected False Targets
paragraphs: The report mentioned that the sensor experienced more false alarms than  expected. A false alarm is a detection of a target that is not there.  According to the experts we hired, during Integrated Flight Test 1A, the  Boeing sensor often mistakenly identified noise produced by the power  supply as signals from actual target objects. In a fully automated  discrimination software program, a high false alarm rate could overwhelm  the tracking software. Because the post-flight processing tools were not  fully developed at the time of the August 13 and August 22, 1997, reports,  Boeing did not rely upon a fully automated tracking system when it  processed the Integrated Flight Test 1A data. Instead, a Boeing engineer  manually tracked the target objects. The contractors realized, and  reported to the Ground Based Interceptor Project Management Office, that  numerous false alarms could cause problems in future flight tests, and  they identified software changes to reduce their occurrence.
section_title: December 11 Briefing
paragraphs: On December 11, 1997, Boeing and TRW briefed officials from the Ground  Based Interceptor Project Management Office and one of its support  contractors on various anomalies observed during Integrated Flight Test  1A.  The contractors’ briefing charts explained the effect the anomalies  could have on Integrated Flight Test 3, the first planned intercept test for  the Boeing exoatmospheric kill vehicle, identified potential causes of the  anomalies, and summarized the solutions to mitigate their effect.  While  some of the anomalies included in the December 11 briefing charts were  referred to in the August 13 and August 22 reports, others were being  reported in writing for the first time.
The anomalies referenced in the briefing charts included the sensor’s high  false alarm rate, the silicon detector array’s higher-than-expected  temperature, the software’s low confidence factor that it had correctly  identified two target objects correctly, the sensor’s lower than expected  probability of detection, and the software’s elevation in rank of one target  object toward the end of the test.  In addition, the charts showed that an  in-flight attempt to calibrate the sensor was inconsistent.  According to the  charts, actions to prevent similar anomalies from occurring or impacting  Integrated Flight Test 3 had in most cases already been implemented or  were under way.
subsections: section_title: Contractors Report Further on False Alarms
paragraphs: The contractors again recognized that a large number of false alarms  occurred during Integrated Flight Test 1A.  According to the briefing  charts, false alarms occurred during the slow turnarounds of the surrogate  launch vehicle.  Additionally, the contractors hypothesized that some false  alarms resulted from space-ionizing events.  By December 11, engineers  had identified solutions to reduce the number of false alarms in future  tests.
section_title: Briefing Charts Include Observations on Higher Detector Array Temperature
paragraphs: As they had in the August 22, 1997, report, the contractors recognized that  the silicon detector array did not cool properly during Integrated Flight  Test 1A.  The contractors reported that higher silicon detector array  temperatures could cause noisy signals that would adversely impact the  detector array’s ability to estimate the infrared intensity of observed  objects.  Efforts to eliminate the impact of the higher temperatures, should  they occur in future tests, were on-going at the time of the briefing.
section_title: Some Software Confidence Factors Lower Than Expected
paragraphs: Contractors observed that the confidence factor produced by the software  was small for two target objects.  The software equation that makes a  determination as to how confident the software should be to identify a  target object correctly, did not work properly for the large balloon or  multiple-service launch vehicle.  Corrections to the equation had been  made by the time of the briefing.
section_title: Sensor’s Probability of Detection Is Lower Than Expected
paragraphs: The charts state that the Integrated Flight Test 1A sensor had a lower than  anticipated probability of detection and a high false alarm rate.  Because a  part of the tracking, fusion, and discrimination software was designed for  a sensor with a high probability of detection and a low false alarm rate, the  software did not function optimally and needed revision. Changes to  prevent this from happening in future flight tests were under way.
section_title: Software Increases the Rank of One Object Near Test’s End
paragraphs: The briefing charts showed that TRW’s software significantly increased  the rank of one target object just before target objects began to leave the  sensor’s field of view.  Although a later Integrated Flight Test 1A report  stated the mock warhead was consistently ranked as the most likely  target, the charts show that if in Integrated Flight Test 3 the same object’s  rank began to increase, the software could select the object as the  intercept target.  In the briefing charts, the contractors reported that TRW  made a software change in the model that is used to generate reference  data.  When reference data was generated with the software change, the  importance of the mock warhead increased, and it was selected as the  target. Tests of the software change were in progress as of December 11.
section_title: In-Flight Calibration Was Inconsistent
paragraphs: The Boeing sensor measures the infrared emissions of target objects by  converting the collected signals into intensity with the help of calibration  data obtained from the sensor prior to flight.  However, the sensor was not  calibrated at the higher temperature range that was experienced during  Integrated Flight Test 1A.  To remedy the problem, the sensor viewed a  star with known infrared emissions.  The measurement of the star’s  intensity was to have helped fill the gaps in calibration data that was  essential to making accurate measurements of the target object signals.  Boeing disclosed that the corrections based on the star calibration were  inconsistent and did not improve the match of calculated and measured  target signatures.  Boeing subsequently told us that the star calibration  corrections were effective for one of the wavelength bands, but not for  another, and that the inconsistency referred to in the briefing charts was in  how these bands behaved at temperatures above the intended operating  range.  Efforts to find and implement solutions were in progress.
section_title: April 1, 1998, Report
paragraphs: On April 1, 1998, Boeing submitted a revised addendum to replace an  addendum that had accompanied the August 22, 1997, report. This revised  addendum was prepared in response to comments and questions  submitted by officials from the Ground Based Interceptor Project  Management Office, Nichols Research Corporation, and the Defense  Criminal Investigative Service concerning the August 22 report. In this  addendum, the contractors referred in writing to three problems and  limitations that had not been addressed in earlier written test reports or  the December 11 briefing.  Contractors noted that a gap-filling module,  which was designed to replace noisy or missing signals, did not operate as  designed.  They also disclosed that TRW’s analysis of its discrimination  software used target signals collected during a selected portion of the  flight timeline and used a portion of the Integrated Flight Test 1A  reference data that corresponded to this same timeline.
subsections: section_title: Gap-Filling Software Module Did Not Perform As Designed
paragraphs: The April 1 addendum reported that a gap-filling module that was designed  to replace portions of noisy or missing target signals with expected signal  values did not operate as designed.  TRW officials told us that the module’s  replacement values were too conservative and resulted in a poor match  between collected signals and the signals the software expected the target  objects to display.
section_title: Assessment Uses Selected Target Signals
paragraphs: The April 1, 1998, addendum also disclosed that the August 13 and August  22 reports, in which TRW conveyed that its software successfully  distinguished the mock warhead from decoys, were based on tests of the  software using about one-third of the target signals collected during  Integrated Flight Test 1A.  We talked to TRW officials who told us that  Boeing provided several data sets to TRW, including the full data set.  The  officials said that Boeing provided target signals from the entire timeline  to a TRW office that was developing a prototype version of the  exoatmospheric kill vehicle’s tracking, fusion, and discrimination  software, which was not yet operational.  However, TRW representatives  said that the test bed version of the software that TRW was using so that it  could submit its analysis within 60 days of Integrated Flight Test 1A could  not process the full data set.  The officials said that shortly before the  August 22 report was issued, the prototype version of the tracking, fusion,  and discrimination software became functional and engineers were able to  use the software to assess the expanded set of target signals. According to  the officials, this assessment also resulted in the software’s selecting the  mock warhead as the most likely target.  In our review of the August 22  report, we found no analysis of the expanded set of target signals.  The  April 1, 1998, report, did include an analysis of a few additional seconds of  data collected near the end of Integrated Flight Test 1A, but did not  include an analysis of target signals collected at the beginning of the flight.
Most of the signals that were excluded from TRW's discrimination analysis  were collected during the early part of the flight, when the sensor’s  temperature was fluctuating. TRW told us that their software was designed  to drop a target object’s track if the tracking portion of the software  received no data updates for a defined period. This design feature was  meant to reduce false tracks that the software might establish if the sensor  detected targets where there were none. In Integrated Flight Test 1A, the  fluctuation of the sensor’s temperature caused the loss of target signals.  TRW engineers said that Boeing recognized that this interruption would  cause TRW’s software to stop tracking all target objects and restart the  discrimination process. Therefore, Boeing focused its efforts on  processing those target signals that were collected after the sensor’s  temperature stabilized and signals were collected continuously.
Some signals collected during the last seconds of the sensor’s flight were  also excluded. The former TRW employee alleged that these latter signals  were excluded because during this time a decoy was selected as the target.  The Phase One Engineering Team cited one explanation for the exclusion  of the signals. The team said that TRW stopped using data when objects  began leaving the sensor’s field of view. Our review did not confirm this  explanation. We reviewed the target intensities derived from the infrared  frames covering that period and found that several seconds of data were  excluded before objects began to leave the field of view. Boeing officials  gave us another explanation. They said that target signals collected during  the last few seconds of the flight were streaking, or blurring, because the  sensor was viewing the target objects as it flew by them. Boeing told us  that streaking would not occur in an intercept flight because the kill  vehicle would have continued to approach the target objects. We could not  confirm that the test of TRW’s discrimination software, as explained in the  August 22, 1997, report, included all target signals that did not streak. We  noted that the April 1, 1998, addendum shows that TRW analyzed several  more seconds of target signals than is shown in the August 22, 1997,  report. It was in these additional seconds that the software began to  increase the rank of one decoy as it assessed which target object was most  likely the mock warhead. However, the April 1, 1998, addendum also  shows that even though the decoy’s rank increased the software continued  to rank the mock warhead as the most likely target.  But, because not all of  the Integrated Flight Test 1A timeline was presented in the April 1  addendum, we could not determine whether any portion of the excluded  timeline might have been useful data and if there were additional seconds  of useful data whether a target object other than the mock warhead might  have been ranked as the most likely target.
section_title: Corresponding Portions of Reference Data Excluded
paragraphs: The April 1 addendum also documented that portions of the reference data  developed for Integrated Flight Test 1A were also excluded from the  discrimination analysis.  Nichols and project office officials told us the  software identifies the various target objects by comparing the target  signals collected from each object at a given point in their flight to the  target signals it expects each object to display at that same point in the  flight.  Therefore, when target signals collected during a portion of the  flight timeline are excluded, reference data developed for the same portion  of the timeline must be excluded.
section_title: Information Provided Verbally to Project Office
paragraphs: Officials in the National Missile Defense Joint Program Office’s Ground  Based Interceptor Project Management Office and Nichols Research told  us that soon after Integrated Flight Test 1A the contractors orally  disclosed all of the problems and limitations cited in the December 11,  1997, briefing and the April 1, 1998, addendum. Contractors made these  disclosures to project office and Nichols Research officials during  meetings that were held to review Integrated Flight Test 1A results  sometime in late August 1997. The project office and contractors could  not, however, provide us with documentation of these disclosures.
The current Ground Based Interceptor Project Management Office deputy  manager said that the problems that contractors discussed with his office  were not specifically communicated to others within the Department of  Defense because his office was the office within the Department  responsible for the Boeing contract. The project office’s assessment was  that these problems did not compromise the reported success of the  mission, were similar in nature to problems normally found in initial  developmental tests, and could be easily corrected.
section_title: Effect of Cooling Failure on Sensor’s Performance
paragraphs: Because we questioned whether Boeing’s sensor could collect any usable  target signals if the silicon detector array was not cooled to the desired  temperature, we hired sensor experts at Utah State University’s Space  Dynamics Laboratory to determine the extent to which the sub-optimal  cooling degraded the sensor’s performance. These experts concluded that  the higher temperature of the silicon detectors degraded the sensor’s  performance in a number of ways, but did not result in extreme  degradation. For example, the experts said the higher temperature  reduced by approximately 7 percent the distance at which the sensor  could detect targets. The experts also said that the rapid temperature  fluctuation at the beginning and at the end of data acquisition contributed  to the number of times that the sensor detected a false target. However,  the experts said the major cause of the false alarms was the power supply  noise that contaminated the electrical signals generated by the sensor in  response to the infrared energy. When the sensor signals were processed  after Integrated Flight Test 1A, the noise appeared as objects, but they  were actually false alarms.
Additionally, the experts said that the precision with which the sensor  could estimate the infrared energy emanating from an object based on the  electrical signal produced by the energy was especially degraded in one of  the sensor’s two infrared wave bands. In their report, the experts said that  the Massachusetts Institute of Technology’s Lincoln Laboratory analyzed  the precision with which the Boeing sensor could measure infrared  radiation and found large errors in measurement accuracy. The Utah State  experts said that their determination that the sensor’s measurement  capability was degraded in one infrared wave band might partially explain  the errors found by Lincoln Laboratory.
Although Boeing’s sensor did not cool to the desired temperature during  Integrated Flight Test 1A, the experts found that an obstruction in gas flow  rather than the sensor’s design was at fault. These experts said the  sensor’s cooling mechanism was properly designed and Boeing’s sensor  design was sound.
section_title: Appendix II: Project Office Reliance on Various Sources for Contractor Oversight
paragraphs: The Ground Based Interceptor Project Management Office used several  sources to monitor the contractors’ technical performance, but oversight  activities were limited by the ongoing exoatmospheric kill vehicle contract  competition between Boeing and Raytheon. Specifically, the project office  relied on an engineer and a System Engineering and Technical Analysis  contractor, Nichols Research Corporation, to provide insight into Boeing’s  work. The project office also relied on Boeing to oversee TRW’s  performance.
The deputy manager of the Ground Based Interceptor Project Management  Office told us that competition between Boeing and Raytheon limited  oversight to some extent. He said that because of the ongoing competition,  the project office monitored the two contractors’ progress but was careful  not to affect the competition by assisting one contractor more than the  other. The project office primarily ensured that the contractors abided by  their contractual requirements. The project office deputy manager told us  that his office relied on “insight” into the contractors’ work rather than  oversight of that work.
The project office gained insight by placing an engineer on-site at Boeing  and tasking Nichols Research Corporation to attend technical meetings,  assess test reports, and, in some cases, evaluate Boeing’s and TRW’s  technologies. The on-site engineer was responsible for observing the  performance of Boeing and TRW and relaying any problems back to the  project office. He did not have authority to provide technical direction to  the contractors. According to the Ground Based Interceptor Project  Management Office deputy manager, Nichols essentially “looked over the  shoulder” of Boeing and TRW. We observed evidence of Nichols’ insight in  memorandums that Nichols’ engineers submitted to the project office  suggesting questions that should be asked of the contractors,  memorandums documenting engineer’s comments on various contractor  reports, and trip reports recorded by the engineers after various technical  meetings.
Boeing said its oversight of TRW’s work complied with contract  requirements.  The contract between the Department of Defense and  Boeing required Boeing to declare that “to the best of its knowledge and  belief, the technical data delivered is complete, accurate, and complies  with all requirements of the contract.” With regard to Integrated Flight  Test 1A, Boeing officials said that they complied with this provision by  selecting a qualified subcontractor, TRW, to develop the discrimination  concepts, software, and system design in support of the flight tests, and by  holding weekly team meetings with subcontractor and project office  officials. Boeing officials stated that they were not required to verify the  validity of their subcontractor’s flight test analyses; rather, they were only  required to verify that the analyses seemed reasonable. According to  Boeing officials, both they and the project office shared the belief that  TRW possessed the necessary technical expertise in threat  phenomenology modeling, discrimination, and target tracking, and both  relied on TRW’s expertise.
section_title: Appendix III: Reduced Test Complexity
paragraphs: National Missile Defense Joint Program Office officials said that they  reduced the number of decoys planned for intercept flight tests in  response to a recommendation by an independent panel, known as the  Welch Panel. The panel, established to reduce risk in ballistic missile  defense flight test programs, viewed a successful hit-to-kill engagement as  a difficult task that should not be further complicated in early tests by the  addition of decoys. In contemplating the panel’s advice, the program  manager discussed various target options with other program officials and  the contractors competing to develop and produce the system’s  exoatmospheric kill vehicle. The officials disagreed on the number of  decoys that should be deployed in the first intercept flight tests. Some  recommended using the same target set deployed in Integrated Flight Test  1A and 2, while others wanted to eliminate some decoys. After considering  the differing viewpoints, the program manager decided to deploy only one  decoy—a large balloon—in early intercept tests.
subsections: section_title: Decoys in Early Intercept Tests
paragraphs: As flight tests began in 1997, the National Missile Defense Joint Program  Office was planning two sensor tests—Integrated Flight Test 1A and 2—  and 19 intercept tests. The primary objective of the sensor flight tests was  to reduce risk in future flight tests.  Specifically the tests were designed to  determine if the sensor could operate in space; to examine the extent to  which the sensor could detect small differences in infrared emissions; to  determine if the sensor was accurately calibrated; and to collect target  signature data for post-mission discrimination analysis.
Initially, the next two flight tests were to demonstrate the ability of the  competing kill vehicles to intercept a mock warhead. Integrated Flight  Test 3 was to test the Boeing kill vehicle and Integrated Flight Test 4 was  to test the Raytheon kill vehicle. Table 1 shows the number of target  objects deployed in the two sensor tests, the number of objects originally  planned to be deployed in the first two intercept attempts, and the number  of objects actually deployed in the intercept attempts.
By the time Integrated Flight Tests 3 and 4 were actually conducted,  Boeing had become the National Missile Defense Lead System Integrator  and had selected Raytheon’s exoatmospheric kill vehicle for use in the  National Missile Defense system. Boeing conducted Integrated Flight Test  3 (in October 1999) and Integrated Flight Test 4 (in January 2000) with the  Raytheon kill vehicle. However, both of these flight tests used only the  mock warhead and one large balloon, rather than the nine objects  originally planned. Integrated Flight Test 5 (flown in July 2000) also used  only the mock warhead and one large balloon.
Program officials told us that the National Missile Defense Program  Manager decided to reduce the number of decoys used in Integrated Flight  Tests 3, 4, and 5, based on the findings of an expert panel. This panel,  known as the Welch Panel, reviewed the flight test programs of several  Ballistic Missile Defense Organization programs, including the National  Missile Defense program. The resulting report,which was released shortly  after Integrated Flight Test 2, found that U.S. ballistic missile defense  programs, including the National Missile Defense program, had not yet  demonstrated that they could reliably intercept a ballistic missile warhead  using the technology known as “hit-to-kill.” Numerous failures had  occurred for several of these programs and the Welch Panel concluded  that the National Missile Defense program (as well as other programs  using "hit-to-kill" technology) needed to demonstrate that it could reliably  intercept simple targets before it attempted to demonstrate that it could  hit a target accompanied by decoys. The panel reported again 1 month  after Integrated Flight Test 3 and came to the same conclusion.
The Director of the Ballistic Missile Defense Organization testified at a  congressional hearing that the Welch Panel advocated removing all decoys  from the initial flight tests, but that the Ballistic Missile Defense  Organization opted to include a limited discrimination requirement with  the use of one decoy. Nevertheless, he said that the primary purpose of the  tests was to demonstrate the system’s “hit-to-kill” capability.
section_title: Opinions on Decoys
paragraphs: Program officials said there was disagreement within the Joint Program  Office and among the key contractors as to how many targets to use in the  early intercept flight tests. Raytheon and one high-ranking program official  wanted Integrated Flight Tests 3, 4, and 5 to include target objects  identical to those deployed in the sensor flight tests. Boeing and other  program officials wanted to deploy fewer target objects. After considering  all options, the Joint Program Office decided to deploy a mock warhead  and one decoy—a large balloon.
Raytheon officials told us that they discussed the number of objects to be  deployed in Integrated Flight Tests 3, 4, and 5 with program officials and  recommended using the same target set as deployed in Integrated Flight  Tests 1A and 2. Raytheon believed that this approach would be less risky  because it would not require revisions to be made to the kill vehicle’s  software. Raytheon and program officials told us that Raytheon was  confident that it could successfully identify and intercept the mock  warhead even with this larger target set.
One high-ranking program official said that she objected to reducing the  number of decoys used in Integrated Flight Test 3, because there was a  need to more completely test the system. However, other program officials  lobbied for a smaller target set. One program official said that his position  was based on the Welch Panel’s findings and on the fact that the program  office was not concerned at that time about discrimination capability. He  added that the National Missile Defense program was responding to the  threat of “nations of concern,” which could only develop simple targets,  rather than major nuclear powers, which were more likely to be able to  deploy decoys.
The Boeing/TRW team also wanted to reduce the number of decoys used  in the first intercept tests. In a December 1997 study, the companies  recommended that Integrated Flight Test 3 be conducted with a total of  four objects—the mock warhead, the two small balloons, and the large  balloon. (The multi-service launch system was not counted as one of the  objects.) The study cited concerns about the inclusion of decoys that were  not part of the initially expected threat and about the need to reduce risk.  Boeing said that the risk increased significantly that the exoatmospheric  kill vehicle would not intercept the mock warhead if the target objects did  not deploy from the test missile as expected.
According to Boeing/TRW, as the types and number of target objects  increased, the potential risk that the target objects would be different in  some way from what was expected also increased. Specifically, the  December 1997 study noted that the medium balloons had been in  inventory for some time and had not deployed as expected in other tests,  including Integrated Flight Test 1A. In that test, one medium balloon only  partially inflated and was not positioned within the target cluster as  expected. The study also found that the medium rigid light replicas are the  easiest to misdeploy and the small canisterized light replica moved  differently than expected during Integrated Flight Test 1A.
section_title: Appendix IV: Phase One Engineering Team’s Evaluation of TRW’s Software
paragraphs: In 1998, the National Missile Defense Joint Program Office asked the  Phase One Engineering Team to conduct an assessment, using available  data, of TRW’s discrimination software even though Nichols Research  Corporation had already concluded that it met the requirements  established by Boeing. The program office asked for the second  evaluation because the Defense Criminal Investigative Service lead  investigator was concerned about the ability of Nichols to provide a truly  objective evaluation.
The Phase One Engineering Team developed a methodology to  (1) determine if TRW’s software was consistent with scientific,  mathematical, and engineering principles; (2) determine whether TRW  accurately reported that its software successfully discriminated a mock  warhead from decoys using data collected during Integrated Flight Test  1A; and (3) predict the performance of TRW’s basic discrimination  software against Integrated Flight Test 3 scenarios. The key results of the  team’s evaluation were that the software was well designed; the  contractors accurately reported the results of Integrated Flight Test 1A;  and the software would likely perform successfully in Integrated Flight  Test 3. The primary limitation was that the team used Boeing- and TRW- processed target data and TRW-developed reference data in determining  the accuracy of TRW reports for Integrated Flight Test 1A.
subsections: section_title: Phase One Engineering Team’s Methodology
paragraphs: The team began its work by assuring itself that TRW’s discrimination  software was based on sound scientific, engineering, and mathematical  principles and that those principles had been correctly implemented. It did  this primarily by studying technical documents provided by the  contractors and the program office. Next, the team began to look at the  software’s performance using Integrated Flight Test 1A data. The team  studied TRW’s August 13 and August 22, 1997, test reports to learn more  about discrepancies that the Defense Criminal Investigative Service said it  found in these reports. Team members also received briefings from the  Defense Criminal Investigative Service, Boeing, TRW, and Nichols  Research Corporation.
Team members told us that they did not replicate TRW’s software in total.  Instead, the team emulated critical functions of TRW’s discrimination  software and tested those functions using data collected during Integrated  Flight Test 1A. To test the ability of TRW’s software to extract the features  of each target object’s signal, the team designed a software routine that  mirrored TRW’s feature-extraction design. The team received Integrated  Flight Test 1A target signals that had been processed by Boeing and then  further processed by TRW. These signals represented about one-third of  the collected signals. Team members input the TRW-supplied target  signals into the team’s feature-extraction software routine and extracted  two features from each target signal. The team then compared the  extracted features to TRW’s reports on these same features and concluded  that TRW’s software-extraction process worked as reported by TRW. Next,  the team acquired the results of 200 of the 1,000 simulations that TRW had  run to determine the features that target objects deployed in Integrated  Flight Test 1A would likely display.Using these results, team members  developed reference data that the software could compare to the features  extracted from Integrated Flight Test 1A target signals. Finally, the team  wrote software that ranked the different observed target objects in terms  of the probability that each was the mock warhead. The results produced  by the team’s software were then compared to TRW’s reported results.
The team did not perform any additional analysis to predict the  performance of the Boeing sensor and its software in Integrated Flight  Test 3. Instead, the team used the knowledge that it gained from its  assessment of the software’s performance using Integrated Flight Test 1A  data to estimate the software’s performance in the third flight test.
section_title: The Phase One Engineering Team’s Key Results
paragraphs: In its report published on January 25, 1999, the Phase One Engineering  Team reported that even though it noted some weaknesses, TRW’s  discrimination software was well designed and worked properly, with only  some refinement or redesign needed to increase the robustness of the  discrimination function. In addition, the team reported that its test of the  software using data from Integrated Flight Test 1A produced essentially  the same results as those reported by TRW. The team also predicted that  the Boeing sensor and its software would perform well in Integrated Flight  Test 3 if target objects deployed as expected.
subsections: section_title: Weaknesses in TRW’s Software
paragraphs: The team's assessment identified some software weaknesses.  First, the  team reported that TRW’s use of a software module to replace missing or  noisy target signals was not effective and could actually hurt rather than  help the performance of the discrimination software. Second, the Phase  One Engineering Team pointed out that while TRW proposed extracting  several features from each target-object signal, only a few of the features  could be used.
The Phase One Engineering Team also reported that it found TRW’s  software to be fragile because the software was unlikely to operate  effectively if the reference data—or expected target signals—did not  closely match the signals that the sensor collected from deployed target  objects. The team warned that the software’s performance could degrade  significantly if incorrect reference data were loaded into the software.  Because developing good reference data is dependent upon having the  correct information about target characteristics, sensor-to-target  geometry, and engagement timelines, unexpected targets might challenge  the software. The team suggested that very good knowledge about all of  these parameters might not always be available.
section_title: Accuracy of Contractors’ Integrated Flight Test 1A Reports
paragraphs: The Phase One Engineering Team reported that the results of its  evaluation using Integrated Flight Test 1A data supported TRW’s claim  that in post-flight analysis its software accurately distinguished a mock  warhead from decoys. The report stated that TRW explained why there  were differences in the discrimination analysis included in the August 13,  1997, Integrated Flight Test 1A test report and that included in the August  22, 1997, report. According to the report, one difference was that TRW  mislabeled a chart in the August 22 report. Another difference was that the  August 22 discrimination analysis was based on target signals collected  over a shorter period of time (see app. I for more information regarding  TRW’s explanation of report differences). Team members said that they  found TRW’s explanations reasonable.
section_title: Predicted Success in Integrated Flight Test 3
paragraphs: The Phase One Engineering Team predicted that if the targets deployed in  Integrated Flight Test 3 performed as expected, TRW's discrimination  software would successfully identify the warhead as the target.  The team  observed that the targets proposed for the flight test had been viewed by  Boeing’s sensor in Integrated Flight Test 1A and that target-object features  collected by the sensor would be extremely useful in constructing  reference data for the third flight test. The team concluded that given this  prior knowledge, TRW’s discrimination software would successfully select  the correct target even in the most stressing Integrated Flight Test 3  scenario being considered, if all target objects deployed as expected.  However, the team expressed concern about the software’s capabilities if  objects deployed differently, as had happened in previous flight tests.
section_title: Limitations of the Team’s Evaluation
paragraphs: The Phase One Engineering Team’s conclusion that TRW’s software  successfully discriminated is based on the assumption that Boeing’s and  TRW’s input data were accurate. The team did not process the raw data  collected by the sensor’s silicon detector array during Integrated Flight  Test 1A or develop their own reference data by running hundreds of  simulations. Instead, the team used target signature data extracted by  Boeing and TRW and developed reference data from a portion of the  simulations that TRW ran for its own post-flight analysis. Because it did  not process the raw data from Integrated Flight Test 1A or develop its own  reference data, the team cannot be said to have definitively proved or  disproved TRW’s claim that its software successfully discriminated the  mock warhead from decoys using data collected from Integrated Flight  Test 1A. A team member told us its use of Boeing- and TRW-provided data  was appropriate because the former TRW employee had not alleged that  the contractors tampered with the raw test data or used inappropriate  reference data.
section_title: Appendix V: Boeing Integrated Flight Test 1A Requirements and Actual Performance as Reported by Boeing and TRW
paragraphs: The table below includes selected requirements that Boeing established  before the flight test to evaluate sensor performance and the actual sensor  performance characteristics that Boeing and TRW discussed in the August  22 report.
section_title: Appendix VI: Scope and Methodology
paragraphs: We determined whether Boeing and TRW disclosed key results and  limitations of Integrated Flight Test 1A to the National Missile Defense  Joint Program Office by examining test reports submitted to the program  office on August 13, 1997, August 22, 1997, and April 1, 1998, and by  examining the December 11, 1997, briefing charts. We also held  discussions with and examined various reports and documents prepared  by Boeing North American, Anaheim, California; TRW Inc., Redondo  Beach, California; the Raytheon Company, Tucson, Arizona; Nichols  Research Corporation, Huntsville, Alabama; the Phase One Engineering  Team, Washington, D.C.; the Massachusetts Institute of  Technology/Lincoln Laboratory, Lexington, Massachusetts; the National  Missile Defense Joint Program Office, Arlington, Virginia, and Huntsville,  Alabama; the Office of the Director, Operational Test and Evaluation,  Washington D.C.; the U.S. Army Space and Missile Defense Command,  Huntsville, Alabama; the Defense Criminal Investigative Service, Mission  Viejo, California, and Arlington, Virginia; and the Institute for Defense  Analyses, Alexandria, Virginia.
We held discussions with and examined documents prepared by Dr.  Theodore Postol, Massachusetts Institute of Technology, Cambridge,  Massachusetts; Dr. Nira Schwartz, Torrance, California; Mr. Roy Danchick,  Santa Monica, California; and Dr. Michael Munn, Benson, Arizona.
In addition, we hired the Utah State University Space Dynamics  Laboratory, Logan, Utah, to examine the performance of the Boeing sensor  because we needed to determine the effect the higher operating  temperature had on the sensor’s performance. We did not replicate TRW’s  assessment of its software using target signals that the Boeing sensor  collected during the test. This would have required us to make engineers  and computers available to verify TRW’s software, format raw target  signals for input into the software, develop reference data, and run the  data through the software. We did not have these resources available, and  we, therefore, cannot attest to the accuracy of TRW’s discrimination  claims.
We also examined the methodologies, findings, and limitations of the  review conducted by the Phase One Engineering Team of TRW’s  discrimination software. To accomplish this task, we analyzed the Phase  One Engineering Team’s “Independent Review of TRW EKV  Discrimination Techniques” dated January 1999. In addition, we held  discussions with Phase One Engineering Team members, officials from the  National Missile Defense Joint Program Office, and contractor officials.
We did not replicate the evaluations conducted by the Phase One  Engineering Team and cannot attest to the accuracy of their reports.
We reviewed the decision by the National Missile Defense Joint Program  Office to reduce the complexity of later flight tests by comparing actual  flight test information with information in prior plans and by discussing  these differences with program and contractor officials. We held  discussions with and examined documents prepared by the National  Missile Defense Joint Program Office, the Institute for Defense Analyses,  Boeing North American, and the Raytheon Company.
Our work was conducted from August 2000 through February 2002  according to generally accepted government auditing standards. The  length of time the National Missile Defense Joint Program Office required  to release documents to us significantly slowed our review. For example,  the Program Office required approximately 4 months to release key  documents such as the Phase One Engineering Team’s response to the  professor’s allegations. We requested these and other documents on  September 14, 2000, and received them on January 9, 2001.
section_title: Appendix VIII: Major Contributors
subsections: section_title: General Counsel