Boeing Starliner clock failure - Page 1
Forum section: electronics / general

author: bicycleguy
author_rank: Frequent Contributor
timestamp: December 23, 2019, 09:13:56 pm
content: Where is the timeNut discussion on the clock synchronization errorthat led to the Boeing Starliner failure to reach the International Space Station ?

author: Rerouter
author_rank: Super Contributor
timestamp: December 23, 2019, 09:41:37 pm
content: it was a 2 part failure, the mission clock being off meaning it still had the tighter tolerance on heading and orientation intended for the burn for quite a while, causing it to burn more maneuvering fuel then expected.they also failed to account for where the gap in the network they where using was, so right when they needed to issue a correction, it was unable to be contacted,From the scott manly video on it, they still had enough fuel to visit the ISS, but was called off, the exact reason was not given to my knowledge, probably fear of a repeat incident near the ISS

author: DaJMasta
author_rank: Super Contributor
timestamp: December 23, 2019, 11:14:04 pm
content: I don't know if it qualifies as time nut, though, since it sounds like the time on the clock was just set wrong, not so much that there was something wrong with the precision timekeeping.Strange kind of failure, I suspect the fix is quick to implement even if takes a while to directly track down. Maybe just want to add an extra immediately-before-launch clock reference check to prevent any future issues in any case.

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: December 24, 2019, 02:53:56 am
content: Seems like a novice engineer kind of a mistake, just set one line in code and not bother to check it. Kind of like they had with MAX, where the MCAS range limit was reset on each activation of the system. My guess is that all the old engineers have retired at Boeing, and the better new ones are going to SpaceX and other cooler companies. Firing their CEO won't really help, although it did make the stock price go up.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: December 24, 2019, 04:08:46 am
content: There is this "check yo staging"...

author: Rerouter
author_rank: Super Contributor
timestamp: December 24, 2019, 04:17:39 am
content: There has been another Scott manly video with an update. the spacecraft has a mission clock that is running while on the ground so it can abort while on the pad, there is a another clock from takeoff, they had the tolerances based on the wrong clock / timer.

author: texaspyro
author_rank: Super Contributor
timestamp: December 24, 2019, 05:10:11 am
content: The clock was only off by a paltry 11 hours...Who would expect that to cause any problems?

author: Jeroen3
author_rank: Super Contributor
timestamp: December 24, 2019, 07:46:50 am
content: Is this why they fired their CEO Dennis Muilenburg, or is that still the 737 MAX epic fail?

author: iMo
author_rank: Super Contributor
timestamp: December 24, 2019, 08:32:31 am
content: QuoteCNN Dec23rd

author: ian.ameline
author_rank: Regular Contributor
timestamp: December 25, 2019, 12:40:46 pm
content: Boeing has several problems here -- the first is that they apparently used the wrong clock. The second is that this did not happen in their simulations, and the third is the environment or culture that allowed both of these to happen. They need to find the root cause for all three before they are allowed anywhere near the ISS or manned spaceflight operations.

author: guenthert
author_rank: Frequent Contributor
timestamp: December 25, 2019, 06:37:10 pm
content: Quote from: texaspyro on December 24, 2019, 05:10:11 am12am comes right after 11:59am, right? Right?

author: BravoV
author_rank: Super Contributor
timestamp: December 25, 2019, 06:45:32 pm
content: Maybe this was caused by a fake 555 timer chip for the clock that was sourced from Aliexpress, as corners cutting knows no border.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 25, 2019, 07:14:13 pm
content: Supposedly is was a mistake in the communication between the Atlas rocket and the Starliner computer, asking for the wrong thing. 11 hours could be something like time since take off and time since starting the computer or GMT and local time.So this would be more like a software problem and a problem with quality control.It is not that unusual that such stupid software problems happen - quality control with software is a general problem, not just Boing. I remember an earlier European Ariane rocket to blow up because of an overflow (using old software tested for the smaller model) and the NASA probe lost due to mixing up lbs and kg. Other software bugs get updated on a monthly schedule. Quality control was better in times of core ropes.From the "video" shown there might be another problem with thruster control that cause so much fuel usage just to hold direction / position. Even for tighter control it looks like too active with the thrusters. So they may have to improve there control parameters.

author: iMo
author_rank: Super Contributor
timestamp: December 25, 2019, 07:22:52 pm
content: The 11 hours was the elapsed time the systems in Atlas+upper stage were switched on (before the launch T). They forgot to reset the system time in the Starliner stage to T+0, therefore Starliner capsule got T+11h upon lift off.The fuel was consumed because the Starliner assumed (at T+30min - when the Starliner separated from the second stage) it is T+11h+30min and the actual position did not fit - the system did erratic trajectory corrections burning fuel.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 26, 2019, 12:04:30 am
content: year 2k bug lolSerious lack to redo all check ups no ?

author: floobydust
author_rank: Super Contributor
timestamp: December 26, 2019, 04:27:50 am
content: Boeing VP admitted it's their software grabbing time from the Atlas V. Pretty much looking like they went to the wrong holding registerLegendary software errors occur between two pieces of equipment made by two different companies. Each piece of gear has correct software but the integration is where an error occurs. Just guessing the error was between United Launch Alliance (ULA) and Boeing.Atlas V User's Guideinteresting read to see the complexity of this gear, the planning, is amazing.I can't imagine the cost of this failed launch, all that rocket and fuel for a tiny capsule.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: December 26, 2019, 06:22:38 am
content: Quote from: floobydust on December 26, 2019, 04:27:50 amYep. And his fault for not putting in enough checks and balances. It'll be alright on the night doesn't cut it when the world is watching.