Sept. 10 (UPI) -- Despite its test flight that docked with the International Space Station but left the Boeing Starliner capsule coming back to Earth empty, the spacecraft still could become a significant part of NASA's commercial payload program.
Two aerospace experts say Starliner flights likely will continue, despite its first crewed mission flight ending with a crewless return Saturday.
"I don't think this is a showstopper for future missions," Olivier de Weck, associate department head of the Massachusetts Institute of Technology's AeroAstro program, told UPI.
"It is officially a test flight, but NASA concluded the risk to the crew is higher than they wanted," de Weck said. "I do expect that the technical problem will be solved and I do expect that the Starliner program will continue."
Purdue University's Uhrig & Vournas Aeronautics and Astronautics head William Crossley told UPI Boeing officials were confident they could bring Starliner back safely, but NASA was "erring on the side of caution" to protect astronauts Sunita Williams and Barry Wilmore.
"The fact that a test flight of a vehicle having problems shouldn't be so surprising," Crossley said. "This incident is getting a huge amount of attention because it's a manned test flight. We always take manned space flights incredibly seriously, especially coming out of the two shuttle accidents."
The space suttle Challenger exploded shortly after lifting off Jan. 28, 1986, killing its crew of seven. The space shuttle Columbia disintegrated upon re-entry Feb. 1, 2003, killing its crew of seven.
"Space is actually still really hard," Crossley said. "We've gotten really good at it, but we're not perfect at it. We test as much as we can and try to get the risk as low as we can in this industry, but mathematically it's impossible to have zero risk."
Helium leaks, thruster problems
In Starliner's case, helium leaks and their effect on thrusters turned a 10-day crewed flight test a months-long ordeal.
"Having thrusters leak is not uncommon," Crossley said. "Helium is really tiny, so it's prone to having leaks in systems. "It's not as heavy as nitrogen, so they like to use helium to push all of the propellant out of the tanks."
De Weck said when helium leaks, it can weaken the thrusters and affect the ability to safely maneuver spacecraft like Starliner.
"Helium is used as a pressurization gas for both the oxidizer and fuel," de Weck said. "If you run out of helium prematurely, there's not enough pressure and the thruster fails."
He said the use of Teflon seals also has contributed to the thruster problems.
"Teflon is a material that the surface treatment to make smooth surfaces that reduce the friction," de Weck said. "When the thruster is fired, the Teflon tends to warm up and expand, and it's been more than expected, so it's impacted the flow, particularly of the oxidizer.
"Basically, what it's done is reduce the thrust of some of the thrusters more than expected, so it's more of a performance issue. It's an unexpected problem."
NASA administrators on Aug. 24 said they planned to take a safe approach to bringing Starliner astronauts Williams and Wilmore back to Earth in February aboard SpaceX Crew Dragon capsulet.
"NASA's decided to err on the side of incredibly safe operations" in bringing the astronauts back on SpaceX, Crossley said. "That's the good news that everybody's keeping safety at the top of the agenda."
NASA, Boeing need Starliner to succeed
NASA in 2014 authorized Boeing to design, build and test the Starliner with a fixed budget of $4.2 billion. NASA also authorized SpaceX to design and build the Crew Dragon capsule with a $2.6 billion budget.
Both are intended to shuttle astronauts from the Earth to and from the space station and its eventual replacement and support eventual missions to the moon and Mars.
De Weck said NASA needs more than one provider of reusable commercial spacecraft and program costs so far make it important for the Starliner's development to continue.
"NASA's already invested a lot of money into the Starliner, so there's a lot of sunken cost," he said.
"But the more important reason is, if Starliner were to be stopped as a program, then SpaceX and the Crew Dragon would become a monopolist," he said. "There would be the only way that U.S. astronauts can get to the space station. That would give SpaceX enormous leverage over NASA."
He said competition helps NASA's commercial program for financial and technical reasons.
"By having two viable human spacecraft providers in the United States, the financial and technical performance can be maintained and it's not a single-source contract," de Weck said. "This way we can avoid single-source procurement by having those two companies."
"The technical or logistical reason is it's always that there's a failure of the launchpad. We could have an accident at one of the launch sites that put it out of commission, so this gives us a lot more robustness."
Crossley also said the Starliner's continued development is important for NASA's commercial crew program.
"NASA wants to move people back and forth to the ISS while the ISS is still operating and have commercial entities take over operations in low-Earth orbit, and you need more than one vehicle," he said.
"If there's only one vehicle and an alternate's not available, then you have a situation almost like what we've got now when you are trying to get people back and forth to space on a regular basis," Crossley said.
Boeing can fix Starliner
Crossely said fixing the problems with the Starliner will help NASA and Boeing recover their investment costs in the project.
"If they get it fixed and start building many and getting more access to low-Earth orbit, you spread that big investment over a lot of flights and it's no longer so crazy-expensive," Crossley said.
"From an engineering and technical point of view, if we know the cause, we can fix it," he added.
"This is where going into space is expensive and the whole commercial endeavor is new, so it takes a lot of money to go into space," Crossley said. "Getting to space is really hard. It's hard for everybody."
Problems with Starliner are not expected to make a major dent in Boeing's balance sheet.
Boeing remains the nation's largest aircraft manufacturer and has a "solid growth opportunity in the commercial aviation services market," according to a Zacks equity research report published last week.
The generally positive outlook comes despite Boeing having problems with its popular 737-MAX commercial aircraft program, which Zacks said has hurt the firm's near-term growth trajectory.
Boeing also has a shortage of skilled labor and rising prices for jet fuel, both of which pose risks to the aerospace company's potential success.
Zacks indicated Boeing's defense, space and security segment produced $6.02 billion in revenues, which is down 2% from a year ago. It has operating income of $913 million.
Wells Fargo investment analyst Matthew Akers downgraded Boeing's stock last week from "equal weight" to "underweight" due to a reduction in the firms' free cash flow and $45 billion in debt.
Akers' report cites Boeing's debt and recent delays and problem with its commercial aircraft production as dragging down the company's cash flow and not issues with the Starliner.
Paying down the firm's $45 billion in debt "would consumer all of its cash through 2030," Akers said in his analysis.
Starliner's current technical issues aren't helping, but Akers said the Starliner is more of a risk for Boeing rather than a failure.
So far, members of the House Space and Aeronautics subcommittee haven't expressed concern regarding the Starliner or suggested NASA should end its projected participation in the commercial payload program.
Subcommittee chairman U.S. Rep. Brian Babin, R-Texas, and other committee members did not reply to requests for comment on the Starliner's future.
The subcommittee's communications director, Heather Vaughan, told UPI that members most likely won't have an opinion on the Starliner program's viability until members have a better idea of what happened.