Space Launch System. Credit: NASA

SAN JOSE, Calif.  In contrast to NASA and industry claims that work on the Space Launch System is on track, a report by the U.S. Government Accountability Office released July 23 warned that tight schedules and budgets could delay the first launch of that heavy-lift rocket.

The report, requested by Sen. Tom Coburn (R-Okla.), warned that the flat budget profile for development of SLS may be insufficient to keep the program on track for a first launch in December 2017. 

“The SLS program office calculated the risk associated with insufficient funding through 2017 as having a 90 percent likelihood of occurrence,” the report stated. “[F]urthermore, it indicated the insufficient budget could push the planned December 2017 launch date out 6 months and add some $400 million to the overall cost of SLS development.”

The development of the core stage, which is driving the overall SLS schedule, is compressed and much of its schedule reserve may already be spoken for, the GAO report found. 

“The SLS program is tracking threats to the core stage schedule that could take up as much as 70 percent of the 7 months of reserve,” it stated. “While these challenges are not overly complex from a technical viewpoint, resolving such threats to the schedule is critical because the element is in early development phases and still has several significant milestones and developmental activities ahead.”

That assessment contrasts with what NASA and industry have said about the status of SLS work, painting at times a rosy picture of progress on development of the rocket. In a discussion in May at the Space Symposium in Colorado Springs, Colorado, Ginger Barnes, vice president and program manager for SLS at Boeing, said the company was heading into the critical design review for the SLS core stage five months ahead of schedule.

The GAO report also addressed some other issues with the SLS, including the fact that its long-term missions, beyond the Exploration Mission-2 flight in 2021 that will be the first to carry a crew, remain unclear. That uncertainty affects plans to develop upgrades to the SLS to increase its 70-metric-ton payload capacity to 105 metric tons and eventually 130 metric tons. The GAO was also critical of plans not to compete a higher-performance upper stage for SLS, saying NASA’s rationale that Boeing won a competitive contract in 2007 under the since-canceled Constellation program did not reflect changes in the industry since then, including work by SpaceX and Orbital Sciences on launch vehicles NASA counts on for carrying cargo to the international space station.

The GAO report cautioned that if the SLS suffered cost and schedule overruns, other NASA programs could be at risk if NASA decided to pay for SLS by taking money from them. “Although cost and schedule growth can occur on any project, increases associated with NASA’s most costly and complex missions — such as SLS, which makes up about 9 percent of NASA’s annual budget — can have dramatic effects on the availability of funding for NASA’s portfolio of major projects,” the report said.

NASA, in a response, suggested it would not seek additional funding or delay SLS in order to meet the desired 70 percent confidence level in the program’s cost and schedule estimates. “[D]elaying the SLS development schedule or diverting funding from other priorities to satisfy a schedule confidence level could jeopardize these goals and result in an increase in costs to the taxpayer,” Bill Gerstenmaier, NASA associate administrator for human exploration and operations, wrote in a response to the GAO included in the report. “Plans are in place to adjust schedule and minimize costs within the agency commitment if either funding levels decrease or technical problems arise.”

 A version of this article originally appeared on Used with permission.

Jeff Foust has more than a decade of experience writing about space policy, entrepreneurial ventures and regulatory affairs. In 2001, he established to aggregate and summarize the day's space-related news stories. In 2003, he started The...