Author Topic: Galileo Deployment (Read 125323 times)

GWR64 · « **Reply #60 on:** 02/11/2019 08:11 pm »

USABINIT for four new Satellites today!!!

Quote

GSAT0219    E36    PHM    USABLE    2019002    USABINIT    USABLE AS FROM 2019-02-11
GSAT0220    E13    PHM    USABLE    2019004    USABINIT    USABLE AS FROM 2019-02-11
GSAT0221    E15    PHM    USABLE    2019005    USABINIT    USABLE AS FROM 2019-02-11
GSAT0222    E33    PHM    USABLE    2019003    USABINIT    USABLE AS FROM 2019-02-11

https://www.gsc-europa.eu/system-status/Constellation-Information

GWR64 · « **Reply #61 on:** 03/24/2019 02:51 pm »

22 Galileo-satellites are in operation. Next launch NET 2021 on Ariane 6!

https://forum.nasaspaceflight.com/index.php?topic=31484.msg1926676#msg1926676

GSAT0104 on Slot C05 is not usable since 2014. transmited SAR signals.
GSAT0204 on Slot B03 is not usable since Dec. 2017,in reserve, probably clock problems.
different orbit planes

GSAT0201 and GSAT0202 will never been full members of the constellation. The value range in the almanac for the eccentricity is too small. The launch was 2014.

The problems with the Passive Hydrogen Maser Clocks already occurred in the IOV phase.
GSAT0104 lost both until summer 2013. Clearly recognizable in the NAGU's.

If 4 satellites and 2 Soyuz had been reordered in 2014-2015, the constellation 2019 could be complete.
OHB would not have had to stop production.

So Galileo loses 2 years or more. 2 years operating costs without complete constellation.
And 2 years lifetime for the satellites already launched.

hektor · « **Reply #62 on:** 07/14/2019 02:21 pm »

Galileo is off since Thursday...

https://www.gpsworld.com/galileo-down-over-weekend/

https://insidegnss.com/update-galileo-service-degraded-on-all-satellites-precise-timing-facility-problems-cited/

GWR64 · « **Reply #63 on:** 07/14/2019 02:40 pm »

the NAGU:

Quote

NOTICE ADVISORY TO GALILEO USERS (NAGU) 2019026
DATE GENERATED (UTC): 2019-07-13 20:15

NAGU TYPE: GENERAL
NAGU NUMBER: 2019026
NAGU SUBJECT: SERVICE OUTAGE
NAGU REFERENCED TO: 2019025
START DATE EVENT (UTC): 2019-07-12 01:50
END DATE EVENT (UTC): N/A
SATELLITE AFFECTED: ALL

EVENT DESCRIPTION: UNTIL FURTHER NOTICE, USERS EXPERIENCE A SERVICE OUTAGE. THE SIGNALS ARE NOT TO BE USED.

https://www.gsc-europa.eu/system-status/Constellation-Information

hektor · « **Reply #64 on:** 07/14/2019 02:45 pm »

http://www.globaltimes.cn/content/1157850.shtml

gosnold · « **Reply #65 on:** 07/14/2019 07:23 pm »

It's poor design that a ground segment failure at a single location instantly brings down the whole system.

beidou · « **Reply #66 on:** 07/14/2019 07:50 pm »

Quote from: gosnold on 07/14/2019 07:23 pm

It's poor design that a ground segment failure at a single location instantly brings down the whole system.

The last time for a satellite navigation system completely taken down was for Glonass on April 1st in 2015, however it was recovered only after 12 hours with a reboot...

speedevil · « **Reply #67 on:** 07/14/2019 08:07 pm »

Quote from: gosnold on 07/14/2019 07:23 pm

It's poor design that a ground segment failure at a single location instantly brings down the whole system.

Do we know it is a ground segment failure, and not (for example) similar satellite firmware all dying at the same time?

Chasm · « **Reply #68 on:** 07/14/2019 11:18 pm »

Nobody knows, or at least they are not talking publicly.

There are (initial?) news reports that a wrong time sync got uploaded.
There are of course also reports that someone pushed the kill switch. (The one that the USA insisted on back in the day, for use in case of war. According to the same sources. So take that with a truck of salt.)

What I would like to know if the degradation warning worked correctly for users of the privileged service.

Looking a bit more there are reports that the problem started during a system upgrade. That apparently makes resolving the issue more complicated. (Unclear which system that is.)
SAR services are unaffected. And the Galileo is just classed as initial service at this time, so who cares anyway. Yeah, right...

hektor · « **Reply #69 on:** 07/15/2019 07:24 am »

Galileo sat-nav system experiences service outage (BBC News)

nzguy · « **Reply #70 on:** 07/15/2019 11:30 am »

From my sources (who have other sources) there was also something weird with the fifth "hidden" batch, which was around the time the first NAGU got released.

I analysed the data from the satellites, and normally they are updated every 10 minutes. However the updated stopped suddenly on Thursday before resuming for a few hours and stopping again.

After that the satellites continued to send the last 8 batches of predicted orbits, for 3 hours at a time. After the 8th batch expired then all GNSS receivers should have stopped using the satellites.

One of the GSA statements mentions that since Galileo is still in "initial operations" versus "full operations" (bit like beta vs final release) that not all ground segment items have redundant systems in place. So i suspect the timing facility that was impacted might not have redundant systems yet.

The GPS documentation mentions that GPS satellites are designed to operate autonomously for over 30 days without ground systems presumably driven by Cold War concerns of nuclear conflict when the system was built. However this has not been used as there has never been such a total failure.

speedevil · « **Reply #71 on:** 07/15/2019 11:36 am »

Quote from: nzguy on 07/15/2019 11:30 am

The GPS documentation mentions that GPS satellites are designed to operate autonomously for over 30 days without ground systems presumably driven by Cold War concerns of nuclear conflict when the system was built. However this has not been used as there has never been such a total failure.

Has there ever been a global GPS outage? I'm not recalling one, or finding anything on search.

nzguy · « **Reply #72 on:** 07/15/2019 11:57 am »

No the only other system to have total failure was GLONASS a few years ago and that only lasted less then a day (https://www.gpsworld.com/the-system-glonass-fumbles-forward/.

However there have been individual GPS satellite failures, or ground system bugs such as the UTC correction issue in 2016 (https://www.gps.gov/systems/gps/performance/2016-UTC-offset-anomaly-impact.pdf). As far as I am aware these incidents never affected the navigation service.

EDIT: Just noticed at the bottom of the GPS World article on the GLONASS failure, the section at the bottom "Lag in Recent GPS IIF’s Health Status" mentions that the GPS operators test the 30 day capabilities of the satellites every so often. If Galileo had a similar feature then the satellites could have ridden out this ground segment failure.

Targeteer · « **Reply #73 on:** 07/16/2019 05:58 am »

https://rocketrundown.com/europes-galileo-sat-nav-network-suffers-crippling-outage/?fbclid=IwAR0hu2Be_59hB0KqWVXG8UbjLZEs5kqjkbMpfrEfiiw9gkzxX3G-2eLRquQ

Europe’s Galileo Sat-Nav Network Suffers Crippling Outage
By
Andrew Parsonson -
July 15, 2019

Europe’s Galileo satellite navigation network has suffered a prolonged outage due to “a technical incident related to its ground infrastructure.” source The technical incident has crippled almost the entire network, with the exception of the Galileo Search and Rescue (SAR) service.

nzguy · « **Reply #74 on:** 07/17/2019 06:36 am »

New data has started to be uploaded to the satellite, but marked as unhealthy.

https://www.gsc-europa.eu/news/galileo-initial-service-recovery-actions-underway

speedevil · « **Reply #75 on:** 07/17/2019 11:29 am »

Quote from: nzguy on 07/17/2019 06:36 am

New data has started to be uploaded to the satellite, but marked as unhealthy.

https://www.gsc-europa.eu/news/galileo-initial-service-recovery-actions-underway

The 'New data' is not mentioned in the above, can you further explain?

Chasm · « **Reply #76 on:** 07/17/2019 06:31 pm »

Likely timing data required to make use of the constellation.
As of 24h ago there are user reports on twitter that position data is usable once again.

Updates to news articles say that the problem seems to be in the ground side component. It underwent an update/upgrade/change roughly at the time of the outage.

Question is why the redundant ground segment - supposed to be fully operational at ESOC Oberpfaffenhofen- did not or was not able to provide continued timing data to the satellites.

LouScheffer · « **Reply #77 on:** 07/17/2019 07:38 pm »

I was trying to think of what could have happened that takes so long to fix. Here's a purely hypothetical hypothesis:

Suppose there was some failure at the master clock facility - the power went out and the backup did not kick in, or the air conditioning failed and the clocks over-heated, or a fire sprinkler malfunctioned and watered all the clocks, or any similar failure that affected all the clocks. Then you've got to bring the whole clock ensemble up from a cold start, presumably not a quick operation (clock typically achieve the quoted stability after one year of continuous operation in an environment stable to 1/2 degree C). And you need to wait for the ground clocks to synchronize and measure offsets with each other and external standards (presumable GPS time, GLONASS time, etc)

In the meantime, the satellite clocks are drifting. In the article RUBIDIUM ATOMIC CLOCK FOR GALILEO it says "To keep a goal accuracy of 0.5 meter, an up-load every 9 hours would be required for the ESA-specified rubidium clock and every week in case of the ESA-specified maser". Since errors caused by clock drift tend to scale as the square of the elapsed time, this means after even a day or two with no updates, anything that relies on the rubidium clock would have large errors. This would account for why the first warnings said "degraded performance" but later were changed to "do not use".

Finally, and even more hypothetically, the complete lack of information could be consistent with some embarrassingly simple cause, which they would prefer not to admit until they have the situation under control.

LouScheffer · « **Reply #78 on:** 07/18/2019 01:19 pm »

Appears to be back up, according to their Constellation Information.

And here's the corresponding official navigation update.

Chasm · « **Reply #79 on:** 07/18/2019 05:13 pm »

From a slightly more in depth article:

"The technical incident originated by an equipment malfunction in the Galileo ground infrastructure, affecting the calculation of time and orbit predictions, and which are used to compute the navigation message. The malfunction affected different elements on the ground facilities.

[...] We will set an Independent Inquiry Board to identify the root causes of the major incident. "

via: https://www.gsa.europa.eu/newsroom/news/galileo-initial-services-have-now-been-restored