NASA working toward EM-1 test flight despite challenges
The Government Accountability Office (GAO) released two reports this month casting doubts on NASA’s ability to launch the Exploration Mission-1 (EM-1) – the first flight of the Space Launch System (SLS) with the Orion multipurpose crew vehicle – by Autumn 2018 and on budget. Additionally, a recent article in Space News reported while NASA is still pushing to launch EM-1 on schedule, program leaders were concerned about ground systems funding and the delayed delivery of the Orion Service Module.
The GAO weighs in
According to the GAO report on SLS, “[T]he first planned SLS flight, the ground systems for that effort, and the first two Orion flights are estimated to cost almost $23 billion. In July 2015, GAO found that SLS’s limited cost and schedule reserves were placing the program at increased risk of being unable to deliver the launch vehicle on time and within budget.”
The report noted SLS maintains very low-cost reserves – only $50 million for a program that costs $2 billion per year – and two months of overall program schedule margin. GAO questioned the SLS program’s ability to handle any unexpected problems within existing budget reserves, including potential future challenges, such as integrating SLS with the Orion spacecraft.
GAO identified the Vehicle Assembly Building, Mobile Launcher, and ground systems software as the top Exploration Ground Systems (EGS) program risks. Rigorous testing of the software will not occur until the flight qualification review, preventing programmers from being aware of potential defects early.
Meanwhile, “the Vehicle Assembly Building and Mobile Launcher have no schedule margin remaining to overcome any future technical challenges.” Other EGS schedule issues included modifying the Constellation Program-based Mobile Launcher for SLS and developing the software to monitor ground support equipment during a launch.
On the positive side, GAO did say that the SLS program has resolved several technical issues and the program demonstrated the vehicle’s design was stable enough to continue past its critical design review (CDR). NASA also released 92 percent of the vehicle’s design drawings at CDR (the goal was 90 percent). The GAO recommended NASA Administrator Charles Bolden “re-evaluate SLS and EGS cost and schedule reserves based on results of the integrated design review” to ensure that a November 2018 launch was still feasible.
The report on Orion shared similar commendations and concerns. While acknowledging progress in meeting previous technical challenges, the GAO questioned the program’s ability to handle unexpected problems in the future given the current budget and schedule.
Among the issues reported were a lack of best practices in controlling costs; the delayed delivery of the Service Module; and potential cost overruns of up to $707 million. The GAO recommended NASA perform an updated JCL (Joint Cost and Schedule Confidence Level) analysis, which would include updating cost and schedule estimates. They also recommended comparing the cost of deferred work to their existing management reserves, unallocated future expenses, and actual contractor performance.
Meanwhile, at the NASA Advisory Council…
Speaking before the NASA Advisory Council (NAC), Bill Gerstenmaier, NASA associate administrator for human exploration and operations, reported the Orion Service Module, originally scheduled to be delivered by the European Space Agency (ESA) and Airbus Defence and Space in January 2017, is now scheduled to arrive in April 2017. Space News quoted Gerstenmaier as saying, “We’re preparing for it to even be a little bit later than that.”
Nico Dettman, head of ESA’s space transportation department, said in another Space News story the delay was caused partly by not being able to assess several components during the full critical design review; Airbus needs more time to integrate them into the design.
Gerstenmaier indicated that NASA was investigating what sorts of testing could be done on SLS while waiting for Orion to arrive in April 2018, including a “wet” dress rehearsal of a launch, which would involve fueling up the rocket without Orion on top.
Space News reported Bill Hill, deputy associate administrator for exploration systems, was most concerned about a $20 million gap between NASA’s requested 2017 budget for ground systems and what it received in 2016. The funding is needed to upgrade ground systems that support the Exploration Upper Stage, a new upper stage NASA plans to use for the EM-2 crewed mission. “We’ve really got to get started in ’17 to make a launch in August of 2021,” Hill said.
Hardware and testing progress continues
Despite the concerns stirring in Washington, individual NASA centers continue to build hardware and make progress toward testing SLS and Orion.
Using a set of massive machine tools at the Michoud Assembly Facility in Louisiana, including a circumferential dome weld tool, gore weld tool, and enhanced robotic weld tool, NASA is in the process of completing the first full-size SLS core stage. The tank structures in fabrication will not fly but are being built to undergo structural load testing at a new test stand at Marshall Space Flight Center. The testing at Marshall will rock the test version of SLS back and forth on a series of hydraulic cylinders to simulate stresses encountered during liftoff and flight.
The 212-foot (64.6-meter) test stage will be shipped to Marshall via NASA’s Pegasus barge, a barge originally used to carry Space Shuttle External Tanks, which has since been extended 165 feet (51 meters) to support the SLS core stage.
Planning is also underway for “green run” testing of the core stage, which will be conducted at Stennis Space Center in Mississippi. A green run test occurs the first time the engines are assembled into a single configuration with the core stage and fired at nearly full power. The test will evaluate the functionality of the system to ensure the design is safe.
The primary messages coming out of NASA regarding SLS and Orion remain: progress is being made and “[w]hen completed, SLS will have the power and payload capacity needed to carry crew and cargo on exploration missions to deep space, including Mars.”
Bart Leahy is a freelance technical writer living in Orlando, Florida. Leahy's diverse career has included work for The Walt Disney Company, NASA, the Department of Defense, Nissan, a number of commercial space companies, small businesses, nonprofits, as well as the Science Cheerleaders.