KENNEDY SPACE CENTER — While NASA and Boeing are determined to bring home two astronauts onboard the International Space Station in the troubled Starliner spacecraft, a NASA official confirmed to Spectrum News that the space agency is considering a "back-up option."

During a teleconference on Thursday, NASA and Boeing officials said they are not ready to give a return date for Boeing’s Starliner as they share new updates on the maiden crew flight.

The mission was supposed to be a minimum of eight days, but it has entered day 50 as of Thursday.

NASA’s Commercial Crew Program Manager Steve Stich started the teleconference by recapping the issues that have plagued the maiden crewed flight of Boeing’s Starliner.

The maiden voyage last month sent NASA astronauts Cmdr. Barry “Butch” Wilmore and pilot Sunita “Suni” Williams to the ISS, courtesy of United Launch Alliance’s Atlas V rocket.

Five small helium leaks, believed to be caused by a faulty seal, were discovered in a flange of the spacecraft’s service module’s thruster system.

The helium helps with the pressurization of the thrusters.

Five aft reaction control system thrusters on the service module failed as the spacecraft approached the space station on Thursday, June 6. The reaction control system thrusters are used to help maneuver Starliner, named Calypso, to and from the space station.

After conducting a hot-fire test, four of the five were re-selected and working. The fifth one is not functioning and has been deselected for the rest of the mission.

Despite the five leaks, officials have assured that Starliner has enough helium for the return trip home.

Stich said the Starliner team conducted a hot-fire test on a spare thruster at its White Sands Test Facility in New Mexico. He said this helped engineers understand how the four-working thrusters on Starliner can handle the re-entry to Earth.

The testing was done in two parts: The uphill phase copied the flight of the Starliner and its docking with the International Space Station. The downhill phase focused on the undocking and return to Earth.

A team of engineers replicated what happened to the thrusters during docking day with this spare thruster. What was revealed is that during the fifth downhill test, there was degradation of the thruster, the same kind that was seen while Calypso was in orbit, he said.

This spare thruster has been disassembled at the White Sands Facility and is being looked over, Stich said.

“And we are looking very carefully at the … fuel valve and the oxidizer valve. There are two valves that open and close as the thruster is commanded to allow propellant to enter into the combustion chamber, the injector and then the combustion,” he explained.

What was revealed during that test is that there is a bulge in the Teflon seal that is restricting the flow of fuel in the spare thruster, which reflects what was seen during the flight, he said. This seal is different than the ones that are believed to be causing the helium leak.

Mark Nappi explained the significance of this Teflon seal.

“The bigger finding was where the (nitrogen tetroxide/NTO) goes through a port to where it gets to the injector inside the thruster, and there's a poppet that opens and closes and allows that NTO to go through. At the end of that poppet, very small poppet, it's similar to the small inflation valve that you have on a car tire or a bike tire, that poppet has a Teflon seal at the end of it. Through the heating and the natural vacuum that occurs with the thruster firing, that poppet seal was deformed and actually bulged out a little bit, and again, was an indication that it’s restricting the NTO from going through the system. So again, a really good finding. It … when we looked at the information, we looked at the data, it really does replicate well what we're seeing in flight. So we think, we think these findings are very significant and are likely the root cause,” said Nappi, vice president and program manager at Boeing’s Commercial Crew Program.

Stich revealed that the weekend of July 27 and 28, officials will be conducting a hot-fire test of the operational thrusters on the Starliner as it is docked on the space station.

What will be done is that 27 of the thrusters on Starliner will be fired, but not the aft thruster that has been de-selected, Stich said.

Spare seals have also been tested back on Earth to figure out the cause of the helium leaks. However, it has been six weeks since they have been checked and officials want an update on them, he said. It was last checked on June 15.

Once officials complete a hot-fire test on the thrusters, they can determine what the leak rate is.

Once the tests are completed and data collected, NASA will be doing a readiness review to determine when the Starliner crew can return home, said Nappi.

‘A back-up option’

During the teleconference Thursday, Spectrum News asked the NASA-Boeing team that if Starliner isn't safe to return the pair of astronauts home, what other option do they have.

Stich admitted that there is a backup option and did mention Boeing rival SpaceX’s Dragon spacecraft.

“Yeah, I mean obviously, the luxury in our program today and we’ve never really had this option in other NASA programs, is we have two different systems that we’re flying. Obviously, the backup option is to use a different system. I would rather not go into all of those details until we get to that time, if we ever get to that time on what we plan to do. … The beauty of having Dragon and Starliner, two different, diverse space transportation systems is that we can, we can kind of use those as a backup. Someday Starliner can be back up to a Dragon mission. And we’ve looked at all different contingencies for that. You’ve seen the Russians send up an empty Soyuz, right, to return a crew when they had a coolant leak. So, I think the beauty of what we have in commercial crew is two different systems and we would employ those systems if we need to. But we really have our team focused on as we close in on our final flight rationale, returning Butch and Suni on Starliner,” he said.

A timeline of the Boeing Crew Flight Test mission

This maiden flight of Starliner has seen a series of issues, from launching to docking and trying to return home.

This timeline focuses on the issues of the troubled mission.