Quote from: saliva_sweet on 03/18/2018 12:25 pmQuote from: woods170 on 03/18/2018 10:01 amWhat happened is that someone entered an incorrect parameter value (initial azimuth) into the guidance system parameter repository.Causing the guidance system to provide incorrect guidance i.e. malfunction.No. The guidance system flew the trajectory exactly as it had been programmed to do. Unfortunately, this deviated from what the trajectory was designed to be. Classic parameter input error.The guidance system in itself did not fail. It flew exactly what it was told to fly, to the best of its ability. What it had been told to do was incorrect. That is malfunction, but not of the guidance system. It is malfunction of the quality control system.
Quote from: woods170 on 03/18/2018 10:01 amWhat happened is that someone entered an incorrect parameter value (initial azimuth) into the guidance system parameter repository.Causing the guidance system to provide incorrect guidance i.e. malfunction.
What happened is that someone entered an incorrect parameter value (initial azimuth) into the guidance system parameter repository.
Any french speakers here that understands what the DDO said at 1:02? tendue [tense] is not good.
Quote from: woods170 on 03/20/2018 10:13 amNo. You don't understand. The CEO of Arianespace does not have a hotline with the CSG range safety office. Simply because there is no need to. The range safety office is not there to prevent the Arianespace CEO from looking like an idiot.You're suggesting some animosity between Arianespace and the CSG operations people?
No. You don't understand. The CEO of Arianespace does not have a hotline with the CSG range safety office. Simply because there is no need to. The range safety office is not there to prevent the Arianespace CEO from looking like an idiot.
Quote from: woods170 on 03/20/2018 10:20 amAll others, including the DDO, are fed secondary-source information. That is because there is no need for a primary source. If a vehicle strays off-course there is nothing that anyone in the Jupiter control room can do about it.So if they can't act on the information, it should not be presented? I understand this is how it is currently handled. Do you think it will change after VA241?
All others, including the DDO, are fed secondary-source information. That is because there is no need for a primary source. If a vehicle strays off-course there is nothing that anyone in the Jupiter control room can do about it.
Quote from: Jim on 03/20/2018 03:14 pmFact. They had telemetry data, we know this and the vehicle's state vector is part of it....Wouldn't telemetry be just as off course as the guidance? wouldn't both be taking info from the same incorrectly initialized IMU?Without radar data, it seems to me all the telemetry in the world would not tell them they were off course?
Fact. They had telemetry data, we know this and the vehicle's state vector is part of it....
Quote from: mn on 03/20/2018 08:11 pmQuote from: Jim on 03/20/2018 03:14 pmFact. They had telemetry data, we know this and the vehicle's state vector is part of it....Wouldn't telemetry be just as off course as the guidance? wouldn't both be taking info from the same incorrectly initialized IMU?Without radar data, it seems to me all the telemetry in the world would not tell them they were off course?Telemetry is basically the rocket telling to the ground what the rocket is doing. The ground compares this to what the rocket is supposed to do. And thus telemetry is usually very helpful in telling what went wrong (mostly after the mishap has taken place).
I understand the 'usually' but I'm trying to understand this specific case. if the IMU was incorrect initialized, am I correct in understanding that telemetry data would have been saying they are going right on course despite being 30 deg off course. Or am I missing something?
Just a quick point: the guidance system likely reports its residual errors as well. If the residual errors are small, the guidance system is "in control" and guidance is (in that sense) nominal... even if the rocket isn't going where you want it to. So it's meaningful to have a policy to delay a range safety destruct if residuals are remaining small.
if the IMU was incorrect initialized, am I correct in understanding that telemetry data would have been saying they are going right on course despite being 30 deg off course. Or am I missing something?
Quote from: woods170 on 03/21/2018 08:40 amQuote from: mn on 03/20/2018 08:11 pmQuote from: Jim on 03/20/2018 03:14 pmFact. They had telemetry data, we know this and the vehicle's state vector is part of it....Wouldn't telemetry be just as off course as the guidance? wouldn't both be taking info from the same incorrectly initialized IMU?Without radar data, it seems to me all the telemetry in the world would not tell them they were off course?Telemetry is basically the rocket telling to the ground what the rocket is doing. The ground compares this to what the rocket is supposed to do. And thus telemetry is usually very helpful in telling what went wrong (mostly after the mishap has taken place).I understand the 'usually' but I'm trying to understand this specific case. if the IMU was incorrect initialized, am I correct in understanding that telemetry data would have been saying they are going right on course despite being 30 deg off course. Or am I missing something?
It would neither say it was on the right course, nor would it say it was 30 degrees off course. It would say it was flying a 70 degree azimuth.
Telemetry reports facts, not conclusions.
Quote from: deruch on 05/31/2018 05:47 pmhttps://twitter.com/pbdes/status/1001818027153862656Quote30 May 2018Peter B. de Selding @pbdesUAE's @yahsatofficial: IOT done, Al Yah 3 sat ready for service at 20degW; Ka-band in Africa/Brazil. @Eutelsat a customer in Africa. ~43% loss of rev capacity w/ 5-month, fuel-using trip to GEO slot after off-target @Arianespace Ariane 5 in Jan; $108M insurance claim likely. <emphasis added> what he means:" w/ 5-month, fuel-using trip to GEO slot after off-target @Arianespace Ariane 5 in Jan; " ?the chemical fuel for the apogee-motor from Al-Yah 3 was about mid Februar over.after that they used the XR-5 electric engines. about on 04/25/2018 reached Al-Yah 3 a orbit slightly over GEO and drifted without force one week 1°/day to his slot 20.1W and stopped on 05/01 or 05/02
https://twitter.com/pbdes/status/1001818027153862656Quote30 May 2018Peter B. de Selding @pbdesUAE's @yahsatofficial: IOT done, Al Yah 3 sat ready for service at 20degW; Ka-band in Africa/Brazil. @Eutelsat a customer in Africa. ~43% loss of rev capacity w/ 5-month, fuel-using trip to GEO slot after off-target @Arianespace Ariane 5 in Jan; $108M insurance claim likely. <emphasis added>
30 May 2018Peter B. de Selding @pbdesUAE's @yahsatofficial: IOT done, Al Yah 3 sat ready for service at 20degW; Ka-band in Africa/Brazil. @Eutelsat a customer in Africa. ~43% loss of rev capacity w/ 5-month, fuel-using trip to GEO slot after off-target @Arianespace Ariane 5 in Jan; $108M insurance claim likely. <emphasis added>
LYON, France—French space agency CNES has tapped Zodiac Data Systems for the development of an autonomous range safety system at Arianespace’s Kourou, French Guiana launch site, thus making the destruction of an off-course launcher an automated process....