Jason DavisJul 17, 2015

Report Finds SLS Cost and Schedule Estimates Tight, but on Track

The Government Accountability Office says NASA is generally doing a good job with cost and schedule estimates for its new heavy lift rocket, the Space Launch System. A report released Thursday said NASA’s SLS paperwork "substantially met" five out of six best practices, while a sixth criteria, credibility, had been partially met. But the 32-page audit also cautioned NASA was running short on schedule margin as it works to have SLS ready for flight by November 2018.

Crawlerway and launch pad 39B
Crawlerway and launch pad 39B NASA’s tank-like Crawler-Transporter will carry the Space Launch System and Mobile Launcher along this gravel road out to pad 39B, seen in the distance. The pad is surrounded by three lightning towers and a water tower used to supply the sound suppression system.Image: Jason Davis / The Planetary Society

The GAO report addresses a large swath of SLS topics, from lifecycle costs to contractor reporting systems. The project's price tag through the first flight, Exploration Mission 1, is listed at $9.7 billion. The total cost of SLS, Orion and ground systems development for that same time period—along with an additional Orion spacecraft for EM-2—is $23 billion. The GAO notes this does not include related work under the previous program, Constellation.

Beyond that, NASA has not provided lifecycle costs for SLS, which is expected to evolve from its initial, 70-ton variant into a 130-ton cargo carrier. Two intermediate versions with upgraded boosters and a supercharged upper stage are planned. But other than a vague mandate to send humans to Mars in the 2030s, SLS has no officially scheduled flights beyond EM-2 in 2021 or 2022.

"NASA has stated that cost estimates do not need to cover the program from 'cradle to grave,'" says the report. "Furthermore, NASA has yet to determine the number of launches, their missions, or the operating lifetime for the program, which according to agency officials makes it difficult to estimate the total costs of the program."

NASA, however, considers SLS more of a capability rather than an end-to-end program. SLS, Orion and ground systems are all managed separately through NASA’s Human Exploration and Operations Mission Directorate. The agency is intentionally putting the horse first, hoping Congress will let it pull a cart to Mars one day. Potential future SLS payloads include components of the Asteroid Redirect Mission, as well as a robotic mission to Europa.

Boeing SLS Europa mission promotional placard
Boeing SLS Europa mission promotional placard Image: Boeing

The report stops short of making a specific recommendation to cost out the entire SLS program. It does, however, suggest NASA annually update the rocket’s cost and schedule estimates in the run-up to EM-1, and implement an external contractor costing and reporting system. William Gerstenmaier, NASA’s associate administrator for human spaceflight, concurred with the recommendations.

The latest SLS cost and schedule estimates were completed in 2013. And while NASA received credit for having its Independent Program Assessment Office double-check the SLS math, the GAO said an outside evaluation was also necessary before those estimates could be deemed credible.

EM-1 is slated to fly no later than November 2018, but both SLS and ground systems have set more aggressive internal readiness goals. SLS managers are currently working toward December 2017, says the report, at a reduced cost of $8.4 billion. But that is now expected to slip to July 2018, following a construction glitch at NASA’s Michoud Assembly Facility near New Orleans, Louisiana, where a misalignment on a giant vertical welding machine caused a seven-month delay. The incident highlights how razor-thin NASA’s schedule margin is. 

Even if SLS is ready to fly in July 2018, it might have to wait on Orion and ground systems. Though Kennedy Space Center continues to project a readiness date at least two months prior to November 2018, Orion remains a question mark. The spacecraft, which completed its maiden voyage last December, faces two major milestones this year that will further solidify its budget and schedule. The first checkpoint, Key Decision Point C, marks the point where the program officially moves from formulation to development. NASA’s fiscal year 2016 budget request projected KDP-C would occur sometime in April through July.

Additionally, all three programs—Orion, SLS and ground systems—still face critical design reviews this year, where independent panels take one last look at each system’s major technical components before the construction phase begins.

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