You’re telling me they couldn’t find 19 more?!?

From NASA press release:



[quote]two major anomalies that led to the partial failure of the OFT mission. First, Starliner's onboard timer drew an incorrect time from the Atlas V rocket shortly after it launched, and consequently, the spacecraft didn't execute the orbit insertion burn needed to reach the space station. The second major problem was a valve-mapping error with the software that controls Starliner's thrusters, which could have led to an in-space collision.[quote]

[quote]NASA and Boeing announced this week that they have now also wrapped up a separate investigation into a third major anomaly, which led to a temporary drop in communications between Starliner and ground control crews during the mission's launch. That brief glitch left mission control unable to manually command Starliner to do the orbit insertion burn after the onboard timer issue prevented it from happening automatically.

"As we started to look at the data from the flight and why we didn't get a good forward communication link with a spacecraft, what we found was that the system perhaps allowed a little bit too big of a band of frequencies to come in to the transceiver itself," Stitch said.
"What Boeing has done to fix that and mitigate that problem is actually installing a filter, which essentially only allows the receiver to listen to a very narrow band of frequencies with the Tracking and Data Relay Satellite," he added. (NASA's Tracking and Data Relay Satellites, or TDRS, allow ground controllers to communicate with spacecraft.)[quote]

It's like they forgot 130 years of RF advancement.

More than 1 1/2 years later after failed to achieve proper orbit and 2 years behind SpaceX - another try to launch unmanned Starliner to actually achieve ISS orbit and docking.
https://www.space.com/news/live/boeing-starliner-oft-2-live-updates
What changed?..Boeing hired its first software engineering vice president at the company after all the software, communication and control related disasters in both space and commercial divisions.....
https://www.clickorlando.com/news/local/2021/07/27/whats-changed-since-boeings-last-attempt-to-send-starliner-to-the-space-station/#//

Boeing posted a surprise profit but Shareholders Equity (actually a huge deficit) is $-16.7 Billion on a book basis.

Leveraged! I wonder how many other large cap companies balance sheets show huge debit equity?

Launch delayed because an unscheduled thruster burn by a docked Russian capsule upset the Space Station attitude by 45 degrees (limited only because the other capsule fired its thrusters to counteract). I'm pretty sure the astronauts on board had to do an unscheduled underwear change after that one!!!!!!

Hopefully you don't have to reboot the starliner every XX days like the 787

They fixed that but the lesson is a good one.

The generator control units on the 787 check a host of parameters every 10 ms (100 times per second). This includes things like overcurrent trips which use time model so that nuisance trips don't happen for short current spikes.

The time being used is a 32 bit number which starts at zero when the GCUs are powered up. The 32 bit number is meant to be UNSIGNED, in which case it rolls over in 497 days. Basically, it counts from 0 to 497 days.

For some reason, the GCUs treated the number as SIGNED. That treated the number as counting from zero to 248 days, then rolls over to -248 days and counts back up to zero.

If a plane is kept powered for 248 consecutive days, which happened to an Al Nippon 787, then the GCU time variable will wrap so that it thinks time went backwards 497 days. This will cause the GCU to think there is a fault and it will shutdown the generator. The key here is that ALL the generators on the plane will shutdown AT THE SAME TIME since they all started at the same time.

The Al Nippon airplane just happened to be on the ground when this occurred. All 6 generators (2 for each engine, 2 on the APU) all failed at the same time. Yikes!

The AD was to completely depower the 787 every 120 days, including disconnection of the main battery. The good old power on reset. This reset the time counters back to zero. Later a software update fixed it properly.

Why 120 days? To give redundancy, you can miss one such event and still catch it 240 days in before day 248 occurs.

Aviation software is written with all this process that is supposed to catch things like this. In truth, all those software safety processes don't really work. That is why 787 GCUs can all fail simultaneously, why F22 navigation can go bonkers when crossing the dateline, and other things.

Mike C.

Boeing scrubs launch. Yet again they discover more technical issues related to propulsion systems.

https://www.space.com/boeing-starliner- ... ch-delayed

"unexpected valve position indications in the Starliner propulsion system." Yeah, that could ruin your whole day.

Boeing has had nothing but problems since MacDAC bought them with Boeing’s own money. This shows what happens when a company that designs highly engineered products is run by the business and bean counter types of the MacDAC mindset. They need to go back to being run by engineers that have the guts to design things right from the start.

That’s all my rant from today, coming from a former Boeing engineer who lived through the acquisition and beginning of the downfall of Bill Boeing’s namesake.

Boeing Starliner launch delayed indefinitely due to the unknown issues related to propulsion system control. Zero chance of launch today as was previously held out as a possibility.

Boeing's haplessness continues. NASA is probably happy they picked SpaceX for the next generation moon lander contract.

https://www.space.com/boeing-starliner-launch-delayed-indefinitely

If going into space was easy, young children and old women would be doing it.