by Douglas Messier
Boeing and SpaceX are continuing to work through a number of technical challenges on their commercial crew spacecraft as NASA struggles to process data needed to certify the vehicles, according to a new report from the Government Accountability Office (GAO).
There is sufficient schedule uncertainty, in fact, that GAO recommended the space agency continue planning for additional delays in providing crew transport to the International Space Station (ISS).
“GAO continues to believe that NASA should develop a contingency plan to ensure uninterrupted access to the ISS if delays persist beyond September 2020. NASA generally agreed with GAO’s findings,” the report stated.
Boeing’s Starliner and SpaceX’s Crew Dragon must each conduct automated and crewed flight tests of their spacecraft to the space station. NASA must also certify the spacecraft as meeting a complex set of standards.
Boeing must also complete a pad abort test using a Starliner capsule. SpaceX, which already performed a pad abort, will perform an in-flight test with the Falcon 9 booster.
A SpaceX Crew Dragon flew a successful demonstration flight to the station without astronauts in March. Boeing has yet to fly either Starliner demonstration mission.
SpaceX’s plan to launch a crewed demonstration mission this summer where derailed in April when the Crew Dragon capsule that flew to ISS exploded while engineers were testing the vehicle’s thrusters and emergency escape system.
SpaceX has not publicly identified either the cause of the accident or any modifications planned for the Crew Dragon. The GAO report does not shed any additional light on the explosion.
SpaceX has applied to the Federal Communications Commission (FCC) for radio frequency allocation for its crew demonstration flight from Nov. 1, 2019 to May 1, 2020. The Nov. 1 is probably a no earlier than (NET) date.
Meanwhile, NASA has set a Nov. 15 planning date for SpaceX’s seven-day crewed demonstration mission to ISS. This is also a NET date, not a firm time table for the mission.
NASA’s planning date for the Boeing Starliner’s automated flight to the space station is Sept. 17. If all goes well, a crewed Starliner mission would launch on Nov. 8, eight days after the return of the Dragon spacecraft.
Boeing’s second spacecraft would remain at the space station for six months until the end of May.
Program Risks — Boeing Starliner
The GAO report said Boeing is working through the following technical issues as it moves toward the first Starliner flight:
Parachute System Certification. Boeing is conducting five parachute system qualification tests to demonstrate that its system meets the Commercial Crew Program’s requirements, which will be validated on two spacecraft flight tests. However, in August 2018, Boeing identified a faulty release mechanism for its drogue parachute—which initially slows down the capsule—during its third parachute qualification test that successfully deployed all parachutes. Identifying and fixing the faulty mechanism delayed its fourth parachute qualification test. According to a NASA official, Boeing is conducting testing to qualify an alternative design, and Boeing must qualify this alternative design before the crewed test flight.
Launch Vehicle Engine Anomaly. Boeing is addressing a safety risk related to a launch vehicle component. Specifically, during a 2018 launch, the launch vehicle engine position during ascent deviated from commands but the launch vehicle provider stated that it achieved all mission objectives. Program officials told us that they have insight into the launch vehicle manufacturer’s ongoing investigation and have participated in a separate independent review team. Boeing will implement a set of corrective actions for the uncrewed test flight, and will continue testing the engines for the crewed test flight.
Spacecraft-Generated Debris. Boeing is addressing a risk that under normal operating procedures the initiators that trigger separation events, such as the separation of the crew and service module prior to re-entry, may generate debris and damage the spacecraft. These components function as expected, but Boeing plans to install hardware to contain debris generated when the initiators fire. Program officials told us that they believe Boeing has identified a solution that will be sufficient for the uncrewed and crewed test flights, but the program is continuing to explore a possible redesign for future operational missions.
Spacecraft Forward Heat Shield. We had previously found that Boeing was addressing a risk that during descent a portion of the spacecraft’s forward heat shield may re-contact the spacecraft after it is jettisoned and damage the parachute system. Since our last report, Boeing tested the performance of the forward heat shield in worst-case scenarios and found there was no damage to the parachute system or the spacecraft. After reviewing test data, the program determined that Boeing had completed the mitigation activities and, as of February 2019, no additional steps were needed.
The report mentions a previously undisclosed anomaly last year with Starliner’s launch vehicle, United Launch Alliance’s (ULA) Atlas V. GAO did not identify which of the five Atlas V launches suffered the anomaly.
The GAO report also includes additional details on a failure Boeing experienced with in June 2018 resulted in a 12-month delay in its launch abort propulsion system testing.
“During a test firing, four of the eight total valves in the four launch abort engines failed to close after a shutdown command was sent,” the report stated. “In response to this event, Boeing initiated an investigation to identify the root cause.
“According to Boeing officials, Boeing plans to replace components on all of its service modules except for the uncrewed test flight service module. This is because the abort system will not be active for the uncrewed test flight,” the document added.
Boeing said it successfully completed tests of Starliner’s abort and thruster systems in May.
Program Risks — SpaceX Crew Dragon
GAO said that in addition to investigating the Crew Dragon explosion, SpaceX has been working through the following technical challenges:
Parachute System Certification. Like Boeing, SpaceX is conducting several parachute tests to demonstrate that its system meets the Commercial Crew Program’s requirements. However, SpaceX experienced two anomalies with its parachute system in August 2018. As a result, a SpaceX official told us they enhanced the parachute design to improve robustness. NASA officials told us SpaceX’s enhanced parachutes performed well on its uncrewed test flight. Prior to the crewed test flight, SpaceX must demonstrate the performance of its parachute system. SpaceX plans to continue to test its parachutes, and according to a SpaceX official, will take all steps necessary to ensure that the flight design meets or exceeds minimum performance levels.
Propellant Loading Procedures. SpaceX is continuing to address a safety risk related to its plans to conduct launch vehicle propellant loading procedures after the astronauts are on board the spacecraft. SpaceX officials told us that this loading process has been used in other configurations for multiple SpaceX flights. The Commercial Crew program has approved SpaceX’s proposed loading procedures, including the agreed upon demonstration of the loading procedure five times from the launch site in the final crew configuration before the crewed test flight. The five events include the uncrewed test flight and in-flight abort test. As of March 2019, SpaceX had completed the first two events.
Redesigned Composite Overwrap Pressure Vessel. SpaceX is continuing to address a risk that its launch vehicle’s redesigned composite overwrap pressure vessel, which is intended to contain helium under high pressure, may serve as an ignition source. The program and SpaceX conducted tests on the redesigned vessel and the program determined that all possible ignition sources, with one exception, have a low likelihood of creating ignition. The program continues to assess this ignition source. According to a NASA official, there were no indications of any issues during SpaceX’s uncrewed test flight. SpaceX officials also told us that the redesigned vessel has successfully flown on multiple flights. The program will need to determine whether to accept the risk associated with this technical issue prior to SpaceX’s crewed test flight.
Engine Turbine Cracking. NASA continues to assess a SpaceX risk related to the design of its launch vehicle engines, which has previously resulted in the turbine wheel cracking. To mitigate the turbine cracking risk, SpaceX conducted additional qualification testing and developed an operational strategy that resulted in no cracks. Consequently, the program accepted this risk for SpaceX’s uncrewed test flight but levied a constraint on the crewed test flight. Specifically, SpaceX has agreed to conduct a follow-on test campaign of the engines to demonstrate that it meets NASA’s standards in order to launch its crewed test flight. Program officials said SpaceX plans to build the launch vehicle engines for its crewed test flight concurrently with this follow-on testing series.
The report does not mention a parachute failure that occurred in April 2019 that resulted in the loss of a test item. During the test, one of the four parachutes was deliberately failed to demonstrate the ability of the others to bring the capsule down safety. However, the three remaining parachutes failed to open.
Program Risks — NASA
The progress by Boeing and Starliner has created a lot of work for NASA Commercial Crew Program office that is overseeing the development of the two vehicles.
“The Commercial Crew Program’s ability to process certification data packages for its two contractors continues to create uncertainty about the timing of certification,” the report stated. “Specifically, the program is concurrently reviewing and approving both contractors’ phased safety reviews and verification closure notices.
“We previously reported that program officials, the contractors, and independent review organizations had concerns about a ‘bow wave’ of work for the program. For example, at that time, the program’s safety and mission assurance office identified the upcoming bow wave of work in a shrinking time period as a top risk to achieving certification,” the document added.
By buying additional seats aboard Russian Soyuz spacecraft and extending Boeing’s crewed flight test to six months, NASA will have a presence aboard the space station until September 2020. GAO recommended that in light of possible further commercial crew delays, NASA should develop a contingency plan for extending that date.
In a written response to the report, NASA Associate Administrator for Human Exploration and Operations William Gerstenmaier said the space agency considers the schedule margin to be adequate.
“Should that schedule margin change in the future, NASA will reassess our options to ensure we maintain a U.S. presence on the ISS,” he wrote.
The report’s summary is below.
NASA Commercial Crew Program:
Schedule Uncertainty Persists for Start of Operational Missions to the International Space Station
Government Accountability Office
Report to Congressional Committees
What GAO Found
Both of the Commercial Crew Program’s contractors, Boeing and SpaceX, have made progress on their crew transportation systems. However, neither is ready to begin carrying astronauts into space as both continue to experience delays to certification. Certification is a process that the National Aeronautics and Space Administration (NASA) will use to ensure that each contractor’s spacecraft, launch vehicle, and ground support systems meet its requirements for human spaceflight before any operational missions to the International Space Station (ISS) can occur. Factors contributing to schedule uncertainty include:
Fluctuating schedules. As the contractors continue to build and test hardware—including SpaceX’s March 2019 uncrewed test flight— their schedules for certification change frequently. As of May 2019, both contractors had delayed certification nine times, equating to more than 2 years from their original contracts (see figure). This includes several delays since GAO last reported in July 2018.
Program Workload. NASA’s ability to process certification data packages for its two contractors continues to create uncertainty about the timing of certification. The program has made progress conducting these reviews but much work remains. In addition, the program allowed both contractors to delay submitting evidence that they have met some requirements. This deferral has increased the amount of work remaining for the program prior to certification.
In February 2019, NASA acknowledged that delays to certification could continue, and announced plans to extend U.S. access to the ISS through September 2020 by purchasing seats on the Russian Soyuz vehicle. However, this arrangement does not fully address GAO’s July 2018 recommendation to develop a contingency plan for ensuring access to the ISS until a Commercial Crew Program contractor is certified. NASA concurred with the recommendation but has not yet implemented it. Continued NASA attention on this issue is needed given the uncertainty associated with the final certification dates.
Why GAO Did This Study
In 2014, NASA awarded two firm-fixed-price contracts to Boeing and SpaceX, worth a combined total of up to $6.8 billion, to develop crew transportation systems and conduct initial missions to the ISS. In July 2018, GAO found that both contractors continued to delay their certification dates and that further delays were likely. NASA must certify the contractors’ crew transportation systems before the contractors can begin operational missions to the ISS. The contractors were originally required to provide NASA all the evidence it needed to certify that their systems met its requirements in 2017.
The House Committee on Appropriations included a provision in its 2017 report for GAO to continue to review NASA’s human space exploration programs. This is the latest in a series of reports addressing the mandate. This report examines the extent to which the Commercial Crew Program and its contractors have made progress towards certification.
To do this work, GAO analyzed contracts, schedules, and other documentation and spoke with officials from the Commercial Crew Program, Boeing, and SpaceX.
What GAO Recommends
GAO continues to believe that NASA should develop a contingency plan to ensure uninterrupted access to the ISS if delays persist beyond September 2020. NASA generally agreed with GAO’s findings.