Starliner at ISS: One thruster shut down, another helium leak found, and a new valve issue
According to an update from NASA yesterday, engineers are evaluating three different on-going technical issues with Boeing’s Starliner capsule, presently docked at ISS.
First, of the 28 attitude thrusters on the capsule’s service module, one remains what NASA calls “deselected”, which means it is presently shut down and not in the loop during operations.
Ground teams plan to fire all 28 RCS thrusters after undocking to collect additional data signatures on the service module thrusters before the hardware is expended.
Since the service module is ejected and burns up in the atmosphere, they want to test each thruster beforehand, probably one-by-one to gather as much data as possible. They have to do this after undocking because testing the thrusters while attached to ISS is too risky.
Second, it appears engineers have detected a fifth small helium leak.
Only seven hours of free-flight time is needed to perform a normal end of mission, and Starliner currently has enough helium left in its tanks to support 70 hours of free flight activity following undocking. While Starliner is docked, all the manifolds are closed per normal mission operations preventing helium loss from the tanks.
In other words, the issue is not critical, though understanding its cause is important for future flights.
Finally, engineers have discovered a new valve issue.
Engineers also are evaluating an RCS oxidizer isolation valve in the service module that is not properly closed. Ground teams performed a successful propulsion system valve checkout on Sunday. All other oxidizer and fuel valves within the service module were cycled normally. The suspect oxidizer isolation valve was not cycled in the recent checkout. It will remain commanded closed for the remainder of the mission while ground teams continue to evaluate its data signatures. The crew module propulsion valves, which are part of an independent system that steers the capsule in the last phase of flight before landing, also were successfully cycled, and all those valves are performing as designed.
As this valve is in the service module, it will not come back to Earth for inspection. It is likely not a serious issue, but as with the other problems, it is essential to know more about its cause.
Overall, it appears these technical problems do not pose a serious safety threat to the two astronauts who will come back to Earth on Starliner. That they exist however speaks poorly of the quality control culture at Boeing, especially after years of attempting to correct similar valve and thruster issues on the previous two unmanned demo missions.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
According to an update from NASA yesterday, engineers are evaluating three different on-going technical issues with Boeing’s Starliner capsule, presently docked at ISS.
First, of the 28 attitude thrusters on the capsule’s service module, one remains what NASA calls “deselected”, which means it is presently shut down and not in the loop during operations.
Ground teams plan to fire all 28 RCS thrusters after undocking to collect additional data signatures on the service module thrusters before the hardware is expended.
Since the service module is ejected and burns up in the atmosphere, they want to test each thruster beforehand, probably one-by-one to gather as much data as possible. They have to do this after undocking because testing the thrusters while attached to ISS is too risky.
Second, it appears engineers have detected a fifth small helium leak.
Only seven hours of free-flight time is needed to perform a normal end of mission, and Starliner currently has enough helium left in its tanks to support 70 hours of free flight activity following undocking. While Starliner is docked, all the manifolds are closed per normal mission operations preventing helium loss from the tanks.
In other words, the issue is not critical, though understanding its cause is important for future flights.
Finally, engineers have discovered a new valve issue.
Engineers also are evaluating an RCS oxidizer isolation valve in the service module that is not properly closed. Ground teams performed a successful propulsion system valve checkout on Sunday. All other oxidizer and fuel valves within the service module were cycled normally. The suspect oxidizer isolation valve was not cycled in the recent checkout. It will remain commanded closed for the remainder of the mission while ground teams continue to evaluate its data signatures. The crew module propulsion valves, which are part of an independent system that steers the capsule in the last phase of flight before landing, also were successfully cycled, and all those valves are performing as designed.
As this valve is in the service module, it will not come back to Earth for inspection. It is likely not a serious issue, but as with the other problems, it is essential to know more about its cause.
Overall, it appears these technical problems do not pose a serious safety threat to the two astronauts who will come back to Earth on Starliner. That they exist however speaks poorly of the quality control culture at Boeing, especially after years of attempting to correct similar valve and thruster issues on the previous two unmanned demo missions.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
There is no quality control problem at Boeing. The items in question. are performing as designed. The design is badly wrong.
”Overall, it appears these technical problems do not pose a serious safety threat to the two astronauts who will come back to Earth on Starliner. That they exist however speaks poorly of the quality control culture at Boeing, especially after years of attempting to correct similar valve and thruster issues on the previous two unmanned demo missions.”
I think that, unlike a great many other sites, you got this one right. It will be interesting what approach the engineers will take to solve this.
”There is no quality control problem at Boeing. The items in question. are performing as designed. The design is badly wrong.”
And you know this how?
My reading of the explanation when they assumed the risk of the helium leak was that it was minor, well-understood and only in the one place. They’ve got 70 hours hours of propulsion and only need 7, that’s great. When more leaks show up, and at this point is there any reason to think more leaks won’t occur; the margin of safety is reduced. If they have to go off nominal profile, like if there are more thruster problems, then there goes more of the safety margin.
Land this thing as expediently and safely as possible, fulfill the contract obligation, stop the bleeding and forget Starliner ever existed.
A key data point is how much of a reduction is 70 hours from the design amount? Based on earlier verbiage that some unlikely flight profiles could no longer be supported, I think it’s a non trivial amount.
From the article, “Mission managers are continuing to work through the return plan, which includes assessments of flight rationale, fault tolerance, and potential operational mitigations for the remainder of the flight.”
Contingencies would have been planned and documented pre-flight, given orginal helium. Re-doing that is the right thing to do, but shirley they see a pattern here.
It’s not too late, experiment all you want, leave the people on ISS.
Send it back empty and request a Dragon to bring them home.
Was the vehicle even TESTED in an unmanned flight? Would be interesting to see how this vehicle’s development and COSTS compare to the Super Heavy!
BLSinSC: Starliner was flown twice on unmanned demo flights to ISS.
As for costs, Boeing received a NASA contract for $4.2 billion for Starliner, plus what was later considered an illegal bonus payment of just under $400 million (which as far as I know was never returned).
SpaceX has raised around $12 billion in private investment capital to develop both Starship and Starlink, plus another $2 billion from the NASA manned lunar lander contract. Of the private capital, we do not know how much of that money has gone to either.
Robert Zimmerman wrote: “SpaceX has raised around $12 billion in private investment capital to develop both Starship and Starlink, plus another $2 billion from the NASA manned lunar lander contract. Of the private capital, we do not know how much of that money has gone to either.”
In April of 2023, SpaceX filed a response to a lawsuit against the FAA, in which SpaceX stated that they had invested over $3 billion into Starship and its facilities. They noted elsewhere that they intended to spend about $2 billion per year on Starship development and additional facilities. At that rate, SpaceX has invested more than $5 billion into Starship, leaving at least $7 billion of the raised capital for Starlink.
https://behindtheblack.com/behind-the-black/points-of-information/spacex-files-to-join-faa-as-defendant-in-lawsuit-trying-to-shut-down-boca-chica/
It is hard to say how much of the $2 billion from the NASA lunar lander contract has been paid due to milestones being met.