Space Station: Impact of the Grounding of the Shuttle Fleet
Published: 2003-09-12T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: In 1998, the National Aeronautics and Space Administration (NASA) and its international partners--Canada, Europe, Japan, and Russia--began on-orbit assembly of the International Space Station, envisioned as a permanently orbiting laboratory for conducting scientific research under nearly weightless conditions. Since its inception, the program has experienced numerous problems, resulting in significant cost growth and assembly schedule slippages. Following the loss of Columbia in February 2003, NASA grounded the U.S. shuttle fleet, putting the immediate future of the space station in doubt, as the fleet, with its payload capacity, has been key to the station's development. If recent discoveries about the cause of the Columbia's disintegration require that the remaining shuttles be redesigned or modified, delays in the fleet's return to flight could be lengthy. In light of these uncertainties, concerns about the space station's cost and progress have grown. This report highlights the current status of the program in terms of on-orbit assembly and research; the cost implications for the program with the grounding of the shuttle fleet; and identifying significant program management challenges, especially as they relate to reaching agreements with the international partners.
section_title: What GAO Found
paragraphs: Although the effects of the Columbia accident on the space station are still being explored, it is clear that the station will cost more, take longer to complete, and have further delay in the achievement of key research objectives. Due to the limited payload capacity of Russia's Soyuz and Progress vehicles--which the program must now rely on to rotate crew and provide logistics support--the station is currently in a survival mode. Onorbit assembly is at a standstill, and the on-board crew has been reduced from three to two members. NASA officials maintain that delays in on-orbit assembly will be at least a "month for month" slip from the previous schedule. However, these delays have presented a number of operational challenges. For example, several key components that were ready for launch when the Columbia accident occurred have been idle at Kennedy Space Center and now require additional maintenance or recertification before they can be launched. Moreover, certain safety concerns on-board the station cannot be addressed until the shuttle fleet's return to flight. The grounding of the shuttle fleet has also further impeded the advancement of the program's science investigations. Specifically, the limited availability of research facilities and new science materials has constrained on-board research. NASA has yet to estimate the potential costs and future budget impacts that will result from the grounding of the shuttle fleet. Throughout the life of the program, however, maintaining goals and objectives for the space station has been a challenge for NASA. NASA has analyzed anticipated costs that the program will incur to keep a limited crew on board the station until the U.S. shuttles resume flight, and officials have stated that there would not be significant changes to the execution of the current budget and that the fiscal year 2004 budget request would remain at current levels. NASA plans to continue to develop hardware and deliver station elements to Kennedy Space Center to be prepared for launch as previously scheduled. However, a number of factors will likely result in increased costs, including costs to maintain and store station components and costs for extending contracts. Important decisions regarding funding and partner agreements still need to be made. For example, agreements that cover the partners' responsibility for shared common operations costs may need to be adjusted, an adjustment that could result in NASA's paying a larger share of these costs. In addition, logistics flights using Russian vehicles may need to be accelerated to ensure continued operations on-board the station. Russia has stated that additional flights are possible, but it could need additional funding from the other partners. However, the United States may be prohibited from providing certain payments due to a statutory restriction. NASA and its partners must also develop a plan for assembling the partners' modules and reaching agreement on the final station configuration. The partners were on a path to agree on final configuration by December 2003, but this process has been delayed by the Columbia accident.

section_title: Letter
paragraphs: In 1998, the National Aeronautics and Space Administration (NASA) and  its international partners—Canada, Europe, Japan, and Russia—began on- orbit assembly of the International Space Station, envisioned as a  permanently orbiting laboratory for conducting materials and life-sciences  research as well as earth observations under nearly weightless conditions.  Since its inception, the space station program has experienced numerous  problems that have resulted in significant cost growth and assembly  schedule slippages. In February 2003, the immediate future of the space  station was placed in doubt when NASA grounded the shuttle fleet  following the loss of the shuttle Columbia. The U.S. shuttle fleet had been  key to the station’s development because of its greater payload capacity  for transporting essential hardware.
Delays in the fleet’s return to flight could be lengthy if recent discoveries  about the cause of the Columbia accident require substantial redesign or  modifications to the remaining shuttles or if organizational changes are  recommended by the Columbia Accident Investigation Board. With the  grounding of the U.S. shuttle fleet and the uncertainty about its return to  flight, concerns about the space station’s cost and progress have grown. In  view of these concerns, you asked that we (1) describe the current status  of the program in terms of on-orbit assembly and research; (2) determine  the cost implications for the program with the grounding of the shuttle  fleet; and (3) identify significant program management challenges,  especially as they relate to reaching agreements with the international  partners.
subsections: section_title: Background
paragraphs: The International Space Station program has three key goals: (1) maintain  a permanent human presence in space, (2) conduct world-class research in  space, and (3) enhance international cooperation and U.S. leadership  through international development and operations of the space station.  Each of the partners is to provide hardware and crew, and each is  expected to share operating costs and use of the station.
On-orbit assembly of the space station began in November 1998 and, since  October 2000, two to three crew members, who maintain and operate the  station and conduct hands-on scientific research, have permanently  occupied the space station. The space station is composed of numerous  modules, including solar arrays for generating electricity, remote  manipulator systems, and research facilities. The station is being designed  as a laboratory in space for conducting experiments in near-zero gravity.  Life sciences research on how humans adapt to long durations in space,  biomedical research, and materials-processing research on new materials  or processes are under way or planned. In addition, the station will be  used for various earth observation activities. Figure 1 shows the  International Space Station on-orbit.
Since its inception, the station program has been plagued with cost and  schedule overruns. When the space station’s current design was approved  in 1993, NASA estimated that its cost would be $17.4 billion. By 1998, that  estimate had increased to $26.4 billion. In January 2001, NASA announced  that an additional $4 billion in funding over a 5-year period would be  required to complete the station’s assembly and sustain its operations. By  May 2001, that estimated cost growth increased to $4.8 billion. Since fiscal  year 1985, the Congress has appropriated about $32 billion for the  program. In an effort to control space station costs, the administration  announced in its February 2001 Budget Blueprint, that it would cancel or  defer some hardware and limit construction of the space station at a stage  the administration calls “core complete.” The administration said that  enhancements to the station might be possible if NASA demonstrates  improved cost-estimating and program management, but the  administration is only committed to the completion of the core complete  configuration.
In July 2001, the NASA Administrator appointed an independent  International Space Station Management and Cost Evaluation Task Force  to assess the financial management of the station program and make  recommendations to get costs under control. The task force published its  report in November 2001 and recommended that the program (1) extend  crew rotations from 4 to 6 months and reduce the number of shuttle flights  to 4 per year; (2) consolidate the number of contracts and reduce  government staff in station operations and sustaining engineering;  (3) establish an Associate Administrator for space station at NASA  Headquarters, with total responsibility for engineering and research; and  (4) prioritize research to maximize limited resources. NASA implemented  most of the recommendations, and the task force reported in December  2002 that significant progress had been made in nearly all aspects of the  program, including establishing a new management structure and strategy,  program planning and performance monitoring processes, and metrics.  NASA was postured to see results of this progress and to verify the  sufficiency of its fiscal year 2003 budget to provide for the core complete  version of the station when the Columbia accident occurred.
In response to the task force’s recommendations, the Office of  Management and Budget (OMB) imposed a 2-year “probation” period on  NASA to provide time to reestablish the space station program’s  credibility. Activities that are to take place during this period include  establishing a technical baseline and a life-cycle cost estimate for the  remainder of the program, prioritizing the core complete science program,  and reaching agreement with the international partners on the station’s  final configuration and capabilities. OMB, with input from NASA, is  developing criteria that are to be used for measuring progress toward  achieving a credible program. NASA provided its input to OMB in June  2003, but as of August 2003, OMB and NASA had not reached agreement  on the success criteria.
section_title: Grounding of Shuttle Fleet Has Further Delayed On-Orbit Assembly of Space Station and Research
paragraphs: The grounding of the U.S. shuttle fleet has presented a number of  operational challenges for the space station program. With the fleet  grounded, NASA is heavily dependent on its international partners—  especially Russia—for operations and logistics support for the space  station. However, due to the limited payload capacity of the Russian space  vehicles, on-orbit assembly has been halted. The program’s priority has  shifted from station construction to maintenance and safety, but these  areas have also presented significant challenges and could further delay  assembly of the core complete configuration. While some on-board  research is planned, it will be curtailed by the limited payload capacity of  the Russian vehicles.
subsections: section_title: Current On-Orbit Assembly, Maintenance Operations, and Safety Challenges
paragraphs: The space shuttle fleet has been the primary means to launch key  hardware to the station because of the shuttle’s greater payload capacity.  At about 36,000 pounds, the shuttle’s payload capacity is roughly 7 times  that of Russia’s Progress vehicle and almost 35 times the payload capacity  of its Soyuz vehicle. With the shuttle fleet grounded, current space station  operations are solely dependent on the Soyuz and Progress vehicles.Because the Soyuz and Progress vehicles’ payloads are significantly less  than that of the U.S. shuttle fleet, operations are generally limited to  transporting crew, food, potable water, and other items, as well as  providing propellant resupply and reboosting the station to higher orbits.  On-orbit assembly of the station has effectively ceased.
Maintaining the readiness of ready-to-launch space station components  has also presented a number of operational challenges, as in the following  examples:
A logistics module, which carries research facilities and life support items  to the station, that was scheduled and ready for launch in March 2003 had  to be opened and unpacked (see fig. 2). Several racks were removed to  provide the proper preventative maintenance of the contents until they  can be rescheduled on a future flight. In addition, crew-specific items had  to be removed in anticipation of crew changes for the next shuttle flight.
This module requires more than 2 months to be repacked and tested prior  to launch.
One of the solar array wings scheduled for launch in May 2003 was  approaching its 45-month prelaunch storage limit. Due to the launch delay,  the wing had to be removed from the truss section and replaced with a  new wing (see fig. 3). The removed wing was shipped to the contractor for  deployment testing, which NASA hoped would result in a lengthening of  the prelaunch storage limit to at least 60 months. However, according to  NASA officials, preliminary results were very positive, and the storage life  certification could be extended to as much as 8 years or more.
The performance of the batteries on the truss sections that were ready for  launch has also raised concerns. Prolonged storage at ambient  temperatures could shorten the overall life of the battery. According to  NASA officials, a process has been developed to charge the batteries  periodically without removing them from the trusses during storage, then  to provide a charge capability on the launch pad just prior to launch. This  process, however, will require a new device to be developed and  expending resources not previously planned for this function.
Station program managers are resolved to meet these challenges and have  station components ready for flight when the next shuttle is ready for  launch. In addition, NASA is using this longer storage time to determine  the feasibility of adding new testing procedures. For example, NASA is  developing tests to apply power to some elements and may also perform  additional leak tests.
The grounding of the shuttle fleet has also hampered NASA’s ability to  correct known safety concerns on-board the station. For example, NASA  has had to delay plans to fly additional shielding to the space station to  adequately protect the on-orbit Russian Service Module from space debris.  NASA’s analysis of the problem shows the probability of orbital space  debris penetrating the module increases by 1.6 percent each year the  shielding is not installed. NASA accepted this risk by issuing a waiver for  the noncompliance with a safety requirement, but planned to have the  shielding installed within 37 months of the module’s launch in July 2000.  Six of the required 23 panels have been installed on the module, and NASA  is negotiating with the Russian Aviation and Space Agency to manufacture  the 17 remaining panels. NASA officials told us that they are studying  alternatives for launching and installing the debris protection panels  earlier than originally planned. In addition, there will be delays in  analyzing the failure of an on-orbit gyro—one of four that maintain the  station’s orbital stability and control. According to NASA, a shuttle flight  planned for March of this year was to carry a replacement gyro to the  station and return the failed unit for detailed analysis. Because the shuttle  flight was canceled, the failed unit was not returned. Consequently, NASA  is unable at this time to provide a definitive analysis of the reasons for the  failure of the unit or to know if the problem applies to the remaining units.
NASA had planned to assemble the core complete configuration of the  station by February 2004. NASA officials have maintained that assembly  delays will be at least a “month for month” slip from the previous  schedule, depending on the frequency of flights when the shuttles resume  operations. At best, then, the core complete configuration would not be  assembled before sometime in fiscal year 2005.
section_title: Current Research Efforts Curtailed by Limited Payload Capability
paragraphs: While the space station crew’s current responsibility is primarily to  perform routine maintenance, the two-crew members will conduct some  research on-board the station. An interim space station research plan  developed by NASA details the amount and type of research that will be  conducted. Further, NASA states that although the crew has been reduced  from three to two members, more crew time will be available to carry out  research tasks because no assembly or space walks are planned.  Regardless, the limited payload capability of the Russian vehicles directly  affects the extent of research that can be conducted, as illustrated in the  following examples:
Outfitting of U.S. research facilities halted: Lacking the shuttle fleet’s  greater lift capability, the amount of research hardware transported to and  from the station has been significantly limited. With the fleet grounded,  three major research facilities—which, according to NASA, complete the  outfitting of the U.S. laboratory—could not be launched in March of this  year, as planned. As of August 2003, 7 of the 20 planned research facilities  are on orbit. NASA had planned to add 7 more facilities by January 2008.  At this time, it is unknown when the full configuration of the 20 research  facilities will be on-board the station.
Existing hardware failures: Because new and additional hardware  cannot be transported, NASA has to rely more heavily on existing on-orbit  science facilities—facilities that have already experienced some failures.  For example, in November 2002, the Microgravity Science Glovebox—  which provides an enclosed and sealed workspace for conducting  experiments—failed and did not become operational until late March 2003.  NASA officials state there also have been failures of the existing  refrigerator-freezers on-board the station, which serve as the main cold  storage units until a larger space station cold temperature facility becomes  available. The larger cold temperature facility was one of three facilities  that had been planned for launch in March 2003.
Limited science material: Currently, there are no allocations for science  materials to be transported to or from the space station by the Russian  Soyuz and Progress vehicles. Based on the payload planning for these  flights, however, there will be limited opportunities to launch small  research projects. NASA officials state that the next two Progress flights  could carry up to 40 kilograms and 100 kilograms, respectively, based on  continuous payload planning. This would be much greater than the April  2003 Soyuz flight, which was able to carry 2.5 kilograms (about  5.5 pounds) of science material to the station for experiments in the  current increment.
As a result, research experiments for the current flight increment have  been reduced. Specifically, only about two-thirds of new investigations  and about three-quarters of ongoing investigations from previous  increments will be accomplished on the current increment. Further,  returning samples from these investigations will be delayed until the U.S.  shuttle fleet returns to flight because of the Soyuz’s limited storage  capacity. The investigations on the next increment are also in jeopardy as  there is no planned up mass allocation for science material.
Delays in transporting needed hardware and materials for research to the  space station could be further constrained, depending on any safety  modifications to the shuttle fleet based on recommendations of the  Columbia Accident Investigation Board. If safety modifications to the  shuttle increase the vehicle’s weight, the payload carrying capability for  research could be adversely affected. For example, if NASA determines  that the shuttle’s robotic arm is needed on future flights to address safety  concerns, approximately 1,000 pounds of weight would be added, which  would reduce the shuttle’s payload capacity for research equipment and  other hardware.
section_title: Cost Implications Have Yet to Be Determined, but Increases Are Likely
paragraphs: Since the program’s inception, we have repeatedly reported on the  challenges NASA has faced in maintaining goals and objectives for the  space station program. And while NASA has conducted reassessments  and independent reviews of the program in efforts to institute corrective  actions that would ensure proper cost controls, difficulties in controlling  costs have persisted. NASA budgets and funds the space station program  at essentially a fixed annual average level of about $1.7 billion a year based  on full cost accounting. To date, NASA officials stated they have not  completely estimated the potential increased costs and future budget  impact incurred due to the grounding of the space shuttle fleet. However,  they have identified a number of factors that will likely result in increased  costs—including the continued maintenance and storage of ready-to- launch station components as well as the testing and recertification of  some components and the need to extend contracts to complete  development and assembly of the station.  NASA officials told us that the  agency is assessing these potential cost and schedule impacts and how to  mitigate the impacts within existing resources.
In fiscal year 2003, NASA received $1.85 billion in appropriated funds for  the space station and has requested $1.71 billion for fiscal year 2004 (see  table 1). The funding reduction in fiscal year 2004 was based on near  completion of the hardware development for the U.S. core configuration  and the transition to on-orbit operations. NASA estimates that after the  last year of development, the annual cost to operate the station will  average $1.5 billion over a 10-year useful life. This estimate does not  include all funding requirements, such as costs associated with necessary  upgrades to preclude on-orbit hardware obsolescence, launch costs, and  other support costs that are captured in other portions of NASA’s budget.
NASA officials told us that soon after the Columbia accident, they  published ground rules and assumptions that stated there would be no  significant changes to the station’s budget execution and would maintain  budget requests at current levels until the shuttle returns to flight. At that  point, NASA program officials stated they will begin to evaluate the impact  that new developments, enhancements, inventories, and staffing needed to  sustain and operate the space station will have on future budget  submissions, including requests for supplemental appropriations, and the  execution of the station funding, including program reserves.
NASA’s strategy for the station program following the Columbia accident  has been to continue developing hardware as planned, to deliver these  components to Kennedy Space Center as scheduled, and to prepare them  for launch when the shuttle fleet returns to flight. Through contingency  planning efforts, NASA has identified additional costs to be incurred by  the space station program office as a result of these continuing  developmental operations. However, these additional costs are based on  an assumption that the shuttle will return to flight within 12 months of the  Columbia accident, an assumption that is subject to change based on more  definitive information concerning the status of the shuttle fleet’s  operations. NASA officials state they have not finalized plans or risk  assessments for continued assembly and operation of the space station if  the shuttle fleet is grounded for a longer period of time.
NASA has also implemented a management decision analysis that  anticipates additional costs to be incurred in keeping a crew on-board the  station while the shuttle fleet is grounded. The analysis is based primarily  on management decisions regarding crew rotation and payload issues that  involve shifting cargo and the use of consumables, such as potable water.  Other factors, according to NASA officials, that the station program office  identified could also result in cost increases, but it has not fully quantified  these costs: disassembly and reassembly of component parts; unpacking and repacking equipment from the logistics module that was storage of station components that are ready for launch; maintaining battery life; unfurling and testing solar array wings, which could be affected by additional travel to Russia to facilitate discussions on Soyuz and Progress  vehicles’ schedules and payloads and export controls issues; additional resupply flights; and retention of some critical skills necessary to complete development and  assembly of the station.
section_title: Uncertainty of the Shuttle’s Return-to- Flight Date Delays International Partner Agreements
paragraphs: In addition to the operational challenges facing NASA, funding and partner  agreements present significant challenges. While long-term plans are not  well defined at this time, alternative funding may be needed to sustain the  station, let alone achieve the station’s intended goals. At the same time,  NASA and its partners must develop a plan for assembling the partners’  modules and reaching agreement on the final station configuration. In  addition, since the final on-orbit configuration is likely to be different from  the configuration when the Intergovernmental Agreements were signed in  1998, NASA officials state the partners may have to adjust agreements that  cover the partners’ responsibility for shared common operations costs.
Depending on the duration of the shuttle fleet’s grounding, the space  station program may need to consider funding alternatives to sustain the  station. International agreements governing the space station partnership  specify that the United States, Canada, Europe, and Japan are responsible  for funding the operations and maintenance of the elements each  contributes, the research activities it conducts, and a share of common  operating costs. Under current planning, NASA will fund the entire cost of  common supplies and ground operations, then be reimbursed by the other  partners for their shares. Depending on contributions made by the  partners while the shuttle fleet is grounded, the share that each partner  contributes to the common operations costs may have to be adjusted and  could result in NASA’s paying a larger share of those costs. For example,  the European Automated Transfer Vehicle is scheduled to begin flying in  September 2004. If that vehicle takes on a larger role in supporting the  station than currently planned, the European’s share of common  operations costs could be reduced with the other partners paying more.
Station requirements dictate that some Progress launches be accelerated  and, depending on how long the shuttle fleet is grounded, could require  additional flights. Russia maintains that it can provide additional launches,  and the Russian Aviation and Space Agency is negotiating with its  government in an effort to obtain the necessary funding. If those  negotiations are unsuccessful, the other partners may have to provide the  needed funding. However, the U.S. may be prohibited from making certain  payments due to a statutory restriction. NASA is engaged in discussions  with the other partners on how to sustain operations if additional flights  are required.
Further, following the release of the Columbia Accident Investigation  Board’s report and recommendations, NASA and the partnership must  agree on a final configuration of the on-orbit station that will be  acceptable to all parties. Prior to the Columbia accident, options for the  final on-orbit configuration were being studied, and a decision was  planned for December 2003. NASA officials told us the process has been  delayed, and NASA now expects the partners to agree on a program action  plan in October 2003 that will lead to an agreement on the final on-orbit  configuration.
During a July 2003 meeting, international partner space agency leaders  from the U.S., Europe, Canada, Japan, and Russia expressed support of the  space station program. The leaders recognized the Russian Aviation and  Space Agency for its support of station operations, logistics, crew  transportation, and crew rescue while the shuttle fleet is grounded. The  partners also expressed their support of NASA’s return to flight strategy,  the resumption of station assembly, and the opportunity to enhance the  use of the station for conducting world-class research.
section_title: Conclusions
paragraphs: This is one of the most challenging periods in the history of the  international space station program. NASA officials acknowledge that the  loss of the space shuttle Columbia poses cost and schedule risks that have  direct implications on completing the development and assembly of the  station and the research that is to be conducted on-board as well as on  NASA’s budgets for fiscal year 2004 and beyond. However, NASA officials  told us that that it is too soon to determine the magnitude and costs of  delayed assembly and implications of any recommendations from of  Columbia Accident Investigation Board to the space station. Until the  shuttle return-to-flight date is known, it is difficult to determine how and  when potential cost and schedule increases will impact the station  program or the agency as a whole.
section_title: Agency Comments
paragraphs: In written comments on a draft of this report, NASA’s Deputy  Administrator said that the agency agrees with the content and  conclusions in the report. He said that the space station program is taking  the steps necessary to be ready to resume assembly immediately upon the  space shuttle’s return-to-flight and to eliminate or offset cost impacts. He  also pointed out that the international partners continue to collaborate on  how to best support near-term space station on-orbit operations until the  space shuttle returns to flight. NASA offered some technical comments on  the report, which have been incorporated as appropriate.
section_title: Scope and Methodology
paragraphs: To describe the current status of the space station program in terms of on- orbit assembly and research, we reviewed NASA’s plans for completing  station assembly prior to the Columbia accident and compared those plans  to the agency’s actions following the accident to continue on-board  operations while the shuttle fleet is grounded. To assess the planned  research program, we reviewed NASA’s efforts to prioritize research on- board the station as well as plans to continue research while the shuttle  fleet is grounded. We also interviewed NASA officials regarding the  agency’s efforts to maintain the station and continue research following  the Columbia accident.
To determine the cost implications for the program with the grounding of  the shuttle fleet, we reviewed NASA’s fiscal year 2003 budget amendment  and appropriations as well as the agency’s fiscal year 2004 budget request.  We also reviewed NASA’s assessments of potential cost impacts to the  program and plans for mitigating those potential impacts. In addition, we  reviewed NASA’s plans/interactions with its international partners to  secure support for the station while the shuttle fleet is grounded and to  reach agreement on a final station configuration that will be acceptable to  all partners. We interviewed NASA officials with responsibility for  estimating and controlling space station costs, managing space station  research, and dealing with the international partners.
To identify program challenges facing the space station program, we  reviewed actions being taken by NASA to ensure continued safe  operations of the station, toured the Space Station Processing Facility to  view flight-ready hardware in storage, and reviewed NASA’s actions in  response to the International Space Station Management and Cost  Evaluation task force report. We interviewed space station program  officials to obtain their views on the challenges facing the program.
To accomplish our work, we visited NASA headquarters, Washington,  D.C.; Johnson Space Center, Texas; and Kennedy Space Center, Florida.  We also attended two meetings of the NASA Advisory Council.
We conducted our work from November 2002 through August 2003 in  accordance with generally accepted government standards.
Unless you publicly announce the contents earlier, we plan no further  distribution of this report until 30 days from its issue date. At that time, we  will send copies to the NASA Administrator; the Director, Office of  Management and Budget; and other interested parties. We will also make  copies available to others on request. In addition, the report will be  available on the GAO Web site at http://www.gao.gov.
Please contact me at (202) 512-4841 if you or your staff have any questions  about this report. Major contributors to this report are listed in appendix III.
section_title: Appendix II: Prior GAO Reports and Testimonies Related to the International Space Station Program
paragraphs: NASA: Major Management Challenges and Program Risks. GAO-03-114.  Washington, D.C.: January 2003.
Space Station: Actions Under Way to Manage Cost, but Significant  Challenges Remain. GAO-02-735. Washington, D.C.: July 17, 2002.
NASA: Compliance With Cost Limits Cannot Be Verified. GAO-02-504R.  Washington, D.C.: April 10, 2002.
NASA: Leadership and Systems Needed to Effect Financial Management  Improvements. GAO-02-551T. Washington, D.C.: March 20, 2002.
NASA: International Space Station and Shuttle Support Cost Limits.  GAO-01-100R. Washington, D.C.: August 31, 2001.
Space Station: Inadequate Planning and Design Led to Propulsion  Module Project Failure. GAO-01-633. Washington, D.C.: June 20, 2001.
Space Station: Russian-Built Zarya and Service Module Compliance  With Safety Requirements. GAO/NSIAD-00-96R. Washington, D.C.: April  28, 2000.
Space Station: Russian Compliance with Safety Requirements.  GAO/TNSIAD-00-128. Washington, D.C.: March 16, 2000.
Space Station: Russian Commitment and Cost Control Problems.  GAO/NSIAD-99-175. Washington, D.C.: August 17, 1999.
Space Station: Cost to Operate After Assembly Is Uncertain.  GAO/NSIAD-99-177. Washington, D.C.: August 6, 1999.
Space Station: Status of Russian Involvement and Cost Control Efforts.  GAO/T-NSIAD-99-117. Washington, D.C.: April 29, 1999.
Space Station: U.S. Life-Cycle Funding Requirements.  GAO/T-NSIAD-98-212. Washington, D.C.: June 24, 1998.
International Space Station: U.S. Life-Cycle Funding Requirements.  GAO/NSIAD-98-147. Washington, D.C.: May 22, 1998.
Space Station: Cost Control Problems. GAO/T-NSIAD-98-54. Washington,  D.C.: November 5, 1997.
Space Station: Deteriorating Cost and Schedule Performance Under the  Prime Contract. GAO/T-NSIAD-97-262. Washington, D.C.: September 18,  1997.
Space Station: Cost Control Problems Are Worsening.  GAO/NSIAD-97-213.Washington, D.C.: September. 16, 1997.
NASA: Major Management Challenges. GAO/T-NSIAD-97-178. Washington,  D.C.: July 24, 1997.
Space Station: Cost Control Problems Continue to Worsen.  GAO/T-NSIAD-97-177. Washington, D.C.: June 18, 1997.
Space Station: Cost Control Difficulties Continue.  GAO/T-NSIAD-96-210.Washington, D.C.: July 24, 1996.
Space Station: Cost Control Difficulties Continue. GAO/NSIAD-96-135.  Washington, D.C.: July 17, 1996.
Space Station: Estimated Total U.S. Funding Requirements.  GAO/NSIAD-95-163. Washington, D.C.: June 12, 1995.
Space Station: Update on the Impact of the Expanded Russian Role.  GAO/NSIAD-94-248. Washington, D.C.: July 29, 1994.
Space Station: Impact of the Expanded Russian Role on Funding and  Research. GAO/NSIAD-94-220. Washington, D.C.: June 21, 1994.
section_title: Appendix III: Staff Acknowledgments
subsections: section_title: Acknowledgments
paragraphs: Individuals making key contributions to this report included Jerry Herley,  James Beard, Fred Felder, Lynn LaValle, Rick Cederholm, Josh Margraf,  and Karen Sloan.