On Wednesday, Boeing's John Mulholland, who manages the company's commercial crew program, provided an update on Boeing's development of its Starliner spacecraft. And, as was widely expected, the company moved its schedule to the right.

Now, instead of August 2018, Boeing will target the end of this year (or early 2019) for an uncrewed orbital flight test of its Starliner vehicle. And the first flight of the spacecraft with astronauts aboard, which had been set for November 2018, will slip to mid-2019, Mulholland said. He added that NASA is working toward these dates as well and believes they are realistic.

Problems can always occur during the test phase of a spacecraft, of course. "There are certainly potential risks in front of us as we move through the remaining test program," Mulholland said. "There is always, by its nature, the risk of discovery." The biggest risk will come during the finalization of the test program and the discovery of new items that must be addressed before flight. "These development programs are hard," he said. "Especially for human spacecraft."

Service module anomaly

One of those challenges arose in June during a hot fire test of Starliner's abort motor. After a 1.5-second firing, four of eight valves remained "stuck" rather than closing when they should have. This led to a leak of hydrazine, which did not damage the test article. Mulholland says Boeing convened a team of investigators that included NASA after the incident, and it found the root cause. A fix is being put into place.

The anomaly has caused Boeing to shift its schedule. The company had planned to conduct a launchpad abort test this summer, in advance of its flight tests. But now Boeing will move the pad abort test—which ensures the ability of the spacecraft to pull rapidly away from its rocket in the event of an emergency during liftoff or ascent into space—to next spring. It is not necessary to conduct the pad abort test prior to the uncrewed orbital flight test.

Overall, Mulholland said the Starliner team has made "tremendous" progress toward getting the spacecraft ready for flight. Based upon NASA milestones and test events, Boeing has completed 80 percent of its overall test campaign. Several spacecraft are under various states of completion in Florida, and the two Atlas V rockets for the uncrewed and crewed flight tests are essentially ready to ship from the United Launch Alliance factory in Decatur, Alabama.

Looking ahead

Sources have told Ars to expect about six to nine months for detailed reviews between the uncrewed flight of Starliner (as well as SpaceX's Dragon, also in the commercial crew program) and the first flight with people on board. However, Mulholland said Wednesday that he expected this gap to only be five or six months.

Because the Atlas V rocket (the launch vehicle for Starliner's first flights) will be phased out at some point in the 2020s, the company is looking at other rockets for later missions. "One of the most important design criteria was to make sure Starliner was compatible with a number of launch vehicles," Mulholland said.

Given that Boeing owns half of United Launch Alliance, which manufactures the Atlas V rocket, it stands to reason that Boeing will use that rocket's successor, the under-development Vulcan, for future missions. Mulholland acknowledged that the launch control tower in Florida for Starliner was designed to accommodate Vulcan's larger size.

Finally, Mulholland would not be drawn out about Boeing's competitor in the commercial crew program. SpaceX, too, is nearing readiness for its test flights of the Dragon spacecraft. Asked if Boeing would beat SpaceX to the launchpad, Mulholland replied that he was focused on implementing Boeing's plan. "I really have no visibility into SpaceX's progress or the fidelity of the SpaceX schedule," he said.