- Press Release
- Mar 29, 2023
Statement by Cristina Chaplain Hearing on NASA’s International Space Station
Challenges in Completing and Sustaining the International Space Station
Statement of Cristina T. Chaplain, Director Acquisition and Sourcing Management
GAO Testimony Before the Subcommittee on Space and Aeronautics, Committee on Science and Technology, House of Representatives
What GAO Found
NASA faces significant challenges in its plans to complete assembly of the International Space Station (ISS) prior to the scheduled retirement of the space shuttle in 2010. Since GAO testified on this issue in July 2007, the shuttle flight schedule has remained aggressive–slating the same number of launches in a shorter period. While NASA thinks the proposed schedule is still achievable, the schedule
- is only slightly less demanding than it was prior to the Columbia disaster when the agency launched a shuttle every other month with a larger shuttle fleet and
- leaves little room for the kinds of weather-related, technical, and logistical problems that have delayed flights in the past. Unanticipated delays could result in changes to the station’s configuration, that is, some components may not be delivered. We have previously testified that such changes could limit the extent of scientific research that can be conducted on board the ISS. After assembly is completed and the shuttle retires, NASA’s ability to rotate crew and supply the ISS will be impaired because of the absence of a vehicle capable of carrying the 114,199 pounds of additional supplies and spares needed to sustain the station until its planned retirement in 2016. For crew rotation and logistics, NASA plans to rely on:
- Russian, European and Japanese vehicles. These vehicles were designed to augment the capabilities of the shuttle, not replace them, and have far less capacity to haul cargo. Furthermore, aside from a single Russian vehicle that can bring back 132 pounds of cargo, no vehicle can return cargo from the ISS after the shuttle is retired.
- Commercially developed vehicles. NASA has pledged approximately $500 million for the development of commercial vehicles. NASA expects these vehicles will be ready for cargo use in 2010 and crew use in 2012, even though none of the vehicles currently under development has been launched into orbit yet and their aggressive development schedule leaves little room for the unexpected. If one of these vehicles cannot be delivered according to NASA’s current expectations, NASA will have to rely on Russian vehicles to maintain U.S. crew presence on the ISS until the new generation of U.S. spacecraft becomes available.
We are not making recommendations as a result of our review as NASA is well aware of the predicament it faces with the station and has weighed options and trade-offs for the remainder of the schedule manifest. However, it is important that flexibility continue to be maintained as events impacting schedule occur and that decisions be made with the goal of maximizing safety and results.
United States Government Accountability Office
Mr. Chairman and Members of the Committee:
I am pleased to be here to discuss challenges that the National Aeronautics and Space Administration (NASA) faces in completing and sustaining the International Space Station (ISS). After delays and redesigns, efforts are under way for a long-envisioned expansion of the station so it can support a larger crew and more scientific research. NASA officials estimate the entire cost to complete the station will total $31 billion, and another $11 billion will be needed to sustain it through its planned decommissioning in fiscal year 2016.
The space shuttle has been and is critical to completion of the space station and re-supplying the station. The shuttle remains the only vehicle capable of transporting large segments of the station into orbit for assembly. NASA plans to complete ISS assembly duties and retire the shuttle fleet in 2010 in order to pursue a new generation of space flight vehicles for exploration. To that end, NASA has begun the process of making key decisions on suppliers that will no longer be needed. NASA officials told us that in many cases, restarting suppliers after these decisions are made would be cost prohibitive and time consuming. However, a new NASA vehicle will not be available until 2015 at the earliest, when the Crew Launch Vehicle (Ares I) and Crew Exploration Vehicle (Orion) are expected to fly. To fill the gap following retirement of the shuttle and provide crew rotation and logistical support, NASA plans to rely on a variety of spacecraft developed by the commercial sector and other countries.
In July 2007, we testified on a number of challenges NASA was facing with regard to completing the ISS within the time constraints created by the shuttle’s retirement. Those challenges are still relevant. In light of these issues, we examined the risks and challenges NASA faces in (1) completing assembly of the ISS by 2010, and (2) providing logistics and maintenance support to the ISS after 2010.
In short, our work continued to find that NASA’s plans to complete assembly of the International Space Station prior to the scheduled retirement of the space shuttle at end of fiscal year 2010 require much to happen and very little to go wrong. While NASA believes the schedule is still achievable, the flight rate that NASA is projecting is only slightly less aggressive than it was prior to the Columbia disaster1 when, from 1992 to 2003, the agency launched a shuttle every other month. At that time, NASA used four vehicles to maintain its flight schedule. To complete the station by 2010, NASA will need to maintain a similar flight rate with fewer shuttles and with a shuttle fleet that is aging and continuing to face fuel sensor challenges. NASA remains confident that the current manifest can be accomplished within the given time, and in fact, it has several months of reserve time in its manifest. However, agency officials readily admit that the schedule is aggressive. If delays continue, NASA may need to reduce the number of flights to the station, which could prevent delivery of items currently scheduled for assembly and the pre-positioning of critical spares. Further, while NASA still expects to be able to increase crew capacity from three to six persons, changes it may need to make to the space station’s configuration could limit the extent of scientific research that can be conducted onboard the ISS or quality of life for the crew.
After assembly is completed and the shuttle is retired, NASA’s ability to rotate crew and supply the ISS will be impaired because of the absence of a vehicle capable of carrying the 114,199 pounds (or 51.8 metric tons) of additional supplies needed to sustain the station until its planned retirement in fiscal year 2016. NASA plans to rely on Russian, European and Japanese vehicles to service the station. Even with these vehicles, this shortfall remains. While the Russian vehicles are already in service, the European vehicle just completed its first operational test flight, and development efforts are still under way on the Japanese vehicle. In addition, these vehicles were designed to augment the capabilities of the shuttle, not replace them. Both the European and Japanese vehicles were designed to deliver supplies to the station but their capacities are not equal to the shuttle’s 37,864 pounds of capacity. Furthermore, aside from a single Russian vehicle that can bring back 132 pounds of cargo and rotate crew, no vehicle can return cargo from the International Space Station after the shuttle is retired. NASA plans to rely on commercially developed vehicles to address some of these shortfalls and has pledged approximately $500 million for their development. NASA expects one of these vehicles will be ready for cargo use in 2010 and crew use in 2012. However, no vehicle has successfully been launched into orbit and their development schedules may leave little room for the unexpected. If these vehicles cannot be delivered according to NASA’s current expectations, NASA will have to rely on Russian vehicles to maintain U.S. crew on the International Space Station until the new generation of U.S. spacecraft becomes available.
To conduct our work, we reviewed documents and testimonies by NASA officials relating to the challenges associated with ISS completion, the delivery schedule for ISS assembly and replacement units, and the space shuttle manifest. We reviewed key ISS budget and strategic maintenance plans, the ISS Independent Safety Task Force Report, and previous GAO reports relating to the ISS. We visited and interviewed officials responsible for ISS operations at NASA Headquarters, Washington, D.C., and the Johnson Space Center in Houston, Texas. At NASA Headquarters, we met with officials from the Exploration Systems Mission Directorate and the Space Operations Mission Directorate, including representatives from the International Space Station and space shuttle programs. We met with ISS and space shuttle officials at the Johnson Space Center. We also talked to a commercial developer of space vehicles and met with representatives of foreign space efforts. Complete details of our scope and methodology can be found in appendix I. We conducted this performance audit from July 2007 to April 2008, in accordance with generally accepted government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives. We believe that the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives.
The International Space Station program began in 1993 with several partner countries: Canada, the 11 member nations of the European Space Agency (ESA), Japan, and Russia. The ISS has served and is intended to expand its service as a laboratory for exploring basic questions in a variety of fields, including commercial, scientific, and engineering research. The first assembly flight of the station, in which the space shuttle Endeavor attached the U.S. laboratory module to the Russian laboratory module, occurred in early December of 1998. However, since the program’s inception, NASA has struggled with cost growth, schedule delays and redesigns of the station. As we reported in the past, these challenges were largely due to poorly defined requirements, changes in program content and inadequate program oversight. Due to these challenges, the configuration of the station has devolved over time. In the spring of 2001, NASA announced that it would make major changes in the final configuration of the ISS to address cost overruns. In 2003, the National Academies reported that this reconfiguration greatly affected the overall ability of the ISS to support science. NASA estimates that assembly and operating costs of the ISS will be between $2.1 billion to $2.4 billion annually for FY2009-FY2012. The ISS as of February 19, 2008, is approximately 65 percent complete.
The shuttle program and the ISS program are inherently intertwined. The shuttle has unique capabilities in that it can lift and return more cargo to and from orbit than any other current or planned space vehicle. Figure 1 shows the capabilities of the shuttle in various configurations. Most segments of ISS cannot be delivered by any other vehicle. For example, the Columbia disaster in 2003 put ISS assembly on hiatus as NASA ceased shuttle launches for 21/2 years while it investigated the safety of the fleet. During this period, the Russian Soyuz became the means of transportation for crewmembers traveling to and returning from the ISS.