Then how is the correct voice like?
Quote from: beidou on 10/25/2014 08:15 pmThen how is the correct voice like?all 6 are functional, IOV has 4, all operational, with 1 on less power, FOC has 2 functional but with part of the payload switched off until in better orbit.
An interesting article from GPS World - Galileo: A Constellation of One?http://gpsworld.com/galileo-a-constellation-of-one/
Galileo Satellite Recovered and Transmitting Navigation Signals3 December 2014 Europe’s fifth Galileo satellite, one of two delivered into a wrong orbit by VS09 Soyuz-Fregat launcher in August, has transmitted its first navigation signal in space on Saturday 29 November 2014. It has reached its new target orbit and its navigation payload has been successfully switched on. A detailed test campaign is under way now the satellite has reached a more suitable orbit for navigation purposes.RecoveryThe fifth and sixth Galileo satellites, launched together on 22 August, ended up in an elongated orbit travelling up to 25 900 km above Earth and back down to 13 713 km.A total of 11 manoeuvres were performed across 17 days, gradually nudging the fifth satellite upwards at the lowest point of its orbit.As a result, it has risen more than 3500 km and its elliptical orbit has become more circular.“The manoeuvres were all normal, with excellent performance both in terms of thrust and direction,” explained Daniel Navarro-Reyes, ESA Galileo mission analyst.“The final orbit is as we targeted and is a tribute to the great professionalism of all the teams involved.”The commands were issued from the Galileo Control Centre by Space Opal, the Galileo operator, at Oberpfaffenhofen in Germany, guided by calculations from a combined flight dynamics team of ESA’s Space Operations Centre, ESOC, in Darmstadt, Germany and France’s CNES space agency.The commands were uploaded to the satellite via an extended network of ground stations, made up of Galileo stations and additional sites coordinated by France’s CNES space agency.Satellite manufacturer OHB also provided expertise throughout the recovery, helping to adapt the flight procedures.Until the manoeuvres started, the combined ESA–CNES team maintained the satellites pointing at the Sun using their gyroscopes and solar sensors. This kept the satellites steady in space but their navigation payloads could not be used reliably.In the new orbit, the satellite’s radiation exposure has also been greatly reduced, ensuring reliable performance for the long term.A suitable orbitThe revised, more circular orbit means the fifth satellite’s Earth sensor can be used continuously, keeping its main antenna oriented towards Earth and allowing its navigation payload to be switched on.Significantly, the orbit means that it will now overfly the same location on the ground every 20 days. This compares to a normal Galileo repeat pattern of every 10 days, effectively synchronising its ground track with the rest of the Galileo constellation.The navigation test campaignThe satellite’s navigation payload was activated on 29 November, to begin the full ‘In-Orbit Test’ campaign. This is being performed from ESA’s Redu centre in Belgium, where a 20 m-diameter antenna can study the strength and shape of the navigation signals at high resolution.“First, the various payload elements, especially the Passive Hydrogen Maser atomic clock, were warmed up, then the payload’s first ‘signal in space’ was transmitted,” said David Sanchez-Cabezudo, managing the test campaign.“The satellite-broadcast L-band navigation signal is monitored using the large antenna at Redu, with experts from OHB and Surrey Satellite Technology Ltd – the payload manufacturer, based in Guildford, UK – also on hand to analyse how it performs over time.”The first Galileo FOC navigation signal-in-space transmitting in the three Galileo frequency bands (E5/E6/L1) was tracked by Galileo Test User Receivers deployed at various locations in Europe, namely at Redu (B), ESTEC (NL), Weilheim (D) and Rome (I). The quality of the signal is good and in line with expectations.The Search And Rescue (SAR) payload will be switched on in few days in order to complement the in-orbit test campaign.The way forwardThe same recovery manoeuvres are planned for the sixth satellite, taking it into the same orbital plane but on the opposite side of Earth.The decision whether to use the two satellites for Navigation and SAR purposes as part of the Galileo constellation will be taken by the European Commission based on the test results.About GalileoGalileo is Europe’s own global satellite navigation system. It will consist of 30 satellites and their ground infrastructure.The definition phase and the development and In-Orbit Validation phase of the Galileo programme were carried out by the European Space Agency (ESA) and co-funded by ESA and the European Union. This phase has created a mini-constellation of four satellites and a reduced ground segment dedicated to validating the overall concept.The four satellites launched during the IOV phase form the core of the constellation that is being extended to reach Full Operational Capability (FOC).The FOC phase is fully funded by the European Commission. The Commission and ESA have signed a delegation agreement by which ESA acts as design and procurement agent on behalf of the Commission.Learn more about Galileo at: http://www.esa.int/Our_Activities/NavigationAbout the European Space AgencyThe European Space Agency (ESA) provides Europe’s gateway to space.ESA is an intergovernmental organisation, created in 1975, with the mission to shape the development of Europe’s space capability and ensure that investment in space delivers benefits to the citizens of Europe and the world.ESA has 20 Member States: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland and the United Kingdom, of whom 18 are Member States of the EU. Two other Member States of the EU, Hungary and Estonia, are likely soon to become new ESA Member States.ESA has Cooperation Agreements with six other Member States of the EU. Canada takes part in some ESA programmes under a Cooperation Agreement.ESA is also working with the EU on implementing the Galileo and Copernicus programmes.By coordinating the financial and intellectual resources of its members, ESA can undertake programmes and activities far beyond the scope of any single European country.ESA develops the launchers, spacecraft and ground facilities needed to keep Europe at the forefront of global space activities.Today, it develops and launches satellites for Earth observation, navigation, telecommunications and astronomy, sends probes to the far reaches of the Solar System and cooperates in the human exploration of space.Learn more about ESA at www.esa.intFor further information, please contact:ESA Media Relations OfficeEmail: [email protected]Tel: +33 1 53 69 72 99
ESA ops chief Reiter: 2 Galileo sats to launch ~ March 27 on Euro Soyuz, then 2 more on Sept Soyuz & final in Dec. No 2015 Ariane 5 Galileo.10:40am - 21 Jan 15https://mobile.twitter.com/pbdes/status/557835190660526080
The next Galileo launch after this evening's will be in December on a Soyuz launcher when another two satellites will be placed into orbit. In 2016, there will be one launch but using, for the first time, the Ariane 5 launcher, to place four satellites into orbit. In 2017, there will be two launches: a Soyuz launch orbiting two satellites, and an Ariane 5 launch, orbiting four satellites. A 30-satellite constellation will be in place by 2020, following ESA's slogan "30 satellites by 2020," with 10 satellites per plane with each plane having two spare satellites. This should be feasible as two satellites are now being manufactured every three months. Twenty-four satellites is the minimum for Galileo operational capability.
With Galileo-FOC M06, the 18 satellites necessary for IOC are now in orbit. For some reason, even though M06 has already put four new satllites on orbit, FM08 (Andriana) and FM09 (Liene) are still not commissioned into service. If they take more than six months to commission, IOC might end up in the second half of 2017.
Quote from: baldusi on 11/18/2016 11:39 amWith Galileo-FOC M06, the 18 satellites necessary for IOC are now in orbit. For some reason, even though M06 has already put four new satllites on orbit, FM08 (Andriana) and FM09 (Liene) are still not commissioned into service. If they take more than six months to commission, IOC might end up in the second half of 2017.The europeans can declare a Galileo IOC with only 14, not 18 satellites.
Across the 18 satellites now in orbit, nine clocks have stopped operating.Three are traditional rubidium devices; six are the more precise hydrogen maser instruments that were designed to give Galileo superior performance to the American GPS network.
All 18 spacecraft currently in space continue to operate, but one of them is now down to just two clocks.Most of the maser failures (5) have occurred on the satellites that were originally sent into orbit to validate the system, whereas all three rubidium stoppages are on the spacecraft that were subsequently launched to fill out the network.
It appears the rubidium failures "all seem to have a consistent signature, linked to probable short circuits, and possibly a particular test procedure performed on the ground".
The maser clock failures are said to be better understood, with two likely causes, the second of which has caused most grief.The Esa statement said this second scenario was "related to the fact that when some healthy [hydrogen maser] clocks are turned off for long periods, they do not restart due to a change in clock characteristics".
Esa staff at its technical centre, ESTEC, in the Netherlands are trying to isolate the cause the of failures - with the assistance of the clock (Spectratime of Switzerland) and satellite manufacturers (Airbus and Thales Alenia Space; OHB and SSTL). It is understood engineers have managed to restart another hydrogen clock that had stopped.
Galileo's atomic clocks by the numbers:- First four satellites launched were called In Orbit Validation (IOV) platforms- The next 14 were referred to as Full Operational Constellation (FOC) satellites- Three of the rubidium clock failures have occurred on Galileo's FOC satellites- Five of the hydrogen maser failures have occurred on the IOV spacecraft- One maser has stopped on an FOC satellite, giving nine failures in total- Three of the four IOVs are affected; two of the 14 FOC satellites are affected- Every satellite has two hydrogen maser clocks and two rubidium clocks- That means a total of 72 atomic clocks are currently in orbit- All Galileo satellites presently have at least two working clocks