2 Galileo Satellites Launched To Wrong Orbit

As reported by the BBC, two satellites meant to form part of the EU's Galileo global positioning network have been launched into a wrong, lower orbit, and it is unclear whether they can be salvaged. NASASpaceFlight.com has a more detailed account of the launch, which says [D]espite the Arianespace webcast noting no issue with the launch, it was later admitted the satellites were lofted into the wrong orbit. “Following the announcement made by Arianespace on the anomalies of the orbit injection of the Galileo satellites, the teams of industries and agencies involved in the early operations of the satellites are investigating the potential implications on the mission,” noted a short statement, many hours after the event. It is unlikely the satellites can be eased into their correct orbit, even with a large extension to their transit time. However, ESA are not classing the satellites as lost at this time. “Both satellites have been acquired and are safely controlled and operated from ESOC, ESA’s Operations Centre in Darmstadt, Germany,” the Agency added. Over the course of the next "year or so," an additional 24 satellites are slated to complete the Galileo constellation, to be launched by a mixed slate of Ariane and Soyuz rockets.

Re:Proves point

[JavaBear]

Says the Anonymous coward...

This is the 2012 report, and a summary of success rates. You'll find the first American rocket as #7...
http://www.spacelaunchreport.c... [spacelaunchreport.com]

In 2013 the Atlas moved up to #4, Still after the Russian and EU.
http://www.spacelaunchreport.c... [spacelaunchreport.com]

Re:Proves point

[nojayuk]

The final stage that was meant to put the two satellites into their proper orbit was a Fregat-MT upper stage built by the Russians and supplied as part of the complete Soyuz stack.

The satellites have their own motors used for station-keeping, trimming orbit etc. but I doubt they have enough fuel to move themselves to the planned orbit. Even in the wrong orbit the satellites will still work and provide position data to GPS receivers but they will not provide the sort of whole-sky coverage originally planned. They are high enough that they're not likely to deorbit within the next few years at least.

The complete Galileo constellation is intended to consist of twenty-four working satellites and six spares so ESA and the Galileo consortium have some leeway. They might revamp the deployment schedule to use fewer Soyuz launches and more Ariane V launches for the rest of the constellation though unless the Russians can explain what went wrong with the Fregat-TM and guarantee it won't happen again.

Re:Interesting difference between GPS and Galileo

[ChumpusRex2003]

The SAR component of galileo is a separate service to the positioning service. The intention is that it can operate as an EPIRB receiver. Conventional emergency beacons can be located by satellites, but the resolution is poor (tens of miles) and the time to fix is long (30-60 minutes). The beacon transmits a signal, and suitably equipped satellites detect the beacon, and relay it to ground stations, which then compute the location of the beacon by measuring the change in Doppler shift as the satellite flies by. The SAR component of galileo was designed with the intention that the overhead satellites would detect the time-of-arrival of the beacon signal and cross reference it with the satellites' atomic clocks, effectively performing a reverse GPS-fix. Such a system would be able to obtain a fix within minutes or seconds, and such a fix would likely have a resolution of 1-2 miles. The SAR component is not a mandatory service. You can use the passive location service without implementing SAR in a device. You would only use the SAR service, in an emergency locator beacon device. At the time the galileo SAR system was designed, feedback was a problem with locator beacons. The user had no idea if the signal had been received. Later revisions to the system mean that modern beacons and satellites now offer two big upgrades - the beacons can contain a passive GPS reciever, and can embed the location data in the beacon signal; and the satellite system can transmit feedback to a compatible receiver telling it that it's signal has been received and a position fix made. The Galileo SAR function is therefore rather redundant, but it's often helpful to have a 2nd independent and redundant safety system available, so I can see that it would still get used.