GALILEO Satellites

Articles about GPS, GLONASS, GALILEO, WAAS and other satellite navigation systems
jimh
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GALILEO Satellites

Postby jimh » Fri Dec 08, 2017 11:58 am

The European Union will be launching four more satellites into the GALILEO GNSS constellation next week, December 12, 2017. A heavy lift Ariane 5 ES launch vehicle will carry the four satellites into orbit from the Arianespace spaceport in French Guiana. To view the launch live, follow the link that appears at

https://ariane.cnes.fr/en/live-ariane-5 ... ember-2017

The launch is scheduled for 1:36:07 p.m. EST on December 12, 2017.

Each GALILEO satellite weighs 715-kg or about 1,576-lbs. The four Full-Operational-Capability (FOC) satellites, GALILEO 19, 20, 21, and 22, are mounted on a dispenser device, and then carried in a fairing. The total launch payload is 3,282-kg or 7,236-lbs. The GALILEO satellites are built by a partnership of OHB of Germany (spacecraft) and Surrey Satellite Technology Ltd of England (navigation payload).

FourGalileoAriane5.jpg
Four GALILEO GNSS satellites on dispenser
under fairing for Ariane 5 ES launch vehicle
FourGalileoAriane5.jpg (63.14 KiB) Viewed 1708 times


The target orbits are for an inclination of 56-degrees and a 22,922-km altitude, slightly lower than the final GALILEO orbit. The GALILEO constellation uses three orbital planes separated by 120-degrees of their ascending node (currently 317°, 77°, and 197° for the A/B/C planes, respectively). These satellites are heading for the Plane A orbit. The four satellites will separate from the dispenser in pairs 20-minutes apart, then will be lifted into their final orbits by individual maneuvers to reach 23,222-km altitude (14,430-miles). This plan leaves the spent rocket booster in a safe (lower) "graveyard" orbit. The position of the orbital plane is determined by the launch timing. All four satellite will enter the same orbital plane. In each orbital plane the constellation will have eight operational satellites, spaced at 45-degree intervals, and two in-orbit spare satellites. Thus the full GALILEO constellation will have 30 satellites in orbit. With this launch, if all works as planned, the constellation will have 19 operational satellites in orbit. This launch will be the second time that four GALILEO satellites have been carried to orbit by a single rocket booster. The previous four-satellite launch was in November 2016. The cost for these four satellite is estimated to be around $327-million. The four-satellite payload represents more than $1.35-billion in satellite costs.

A wonderfully illustrated and very informative packet of information about the launch and the satellites is available for download for readers who need more details.

GALILEO has been in status INITIAL SERVICES since December 2016, or about a year. The successful launch and operation of these four additional satellites will increase availability of GALILEO.

A number of newer smartphones are now capable of receiving and using the navigation signals from the GALILEO constellation. Here is a list:

    Apple: iPhone 8 Plus, iPhone 8, iPhone 10/X
    BQ: Aquaris V Plus, Aquaris V, Aquaris X5 Plus, Aquaris X, Aquaris X Pro
    Google: Pixel 2, Google Pixel 2 XL
    Huawei: P10 plus, Mate 9 pro, P10, Mate 10 Pro, Mate 9
    LG: V30
    Mediatek: Meizu Pro 7 Plus, Meizu Pro 7
    Motorola: Moto X4
    Nokia: Nokia 8
    Oneplus: Oneplus5
    Samsung: S8, S8+, Note 8
    Sony: Xperia XZ Premium
    Vernee: Apollo 2

Several marine GNSS receivers are also ready for GALILEO signals, including

    Furuno: GP 170
    Garmin: GPS 19x
    Lowrance: POINT-1
    Simrad: GS25

jimh
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Re: GALILEO To Launch Four More Satellites

Postby jimh » Tue Dec 12, 2017 5:35 pm

To check if your device can use GALILEO, visit

http://www.usegalileo.eu/EN/

jimh
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Re: GALILEO To Launch Four More Satellites

Postby jimh » Tue Dec 12, 2017 5:58 pm

All four GALILEO satellites have successfully reached their initial orbits and have separated from the dispenser and the upper stage of the Ariane 5 ES launch vehicle. All four have made contact with the GALILEO ground stations, and the satellites have deployed their solar panel arrays. This represent a complete success of the launch mission, so far.

It will take several months for the satellites to raise themselves with their own propulsion motors to their individual final orbital slots. During that time the satellites will undergo performance checks. The satellites probably won't be operational in the GALILEO constellation until Spring or Summer 2018.

jimh
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Re: GALILEO Four-at-once Launches

Postby jimh » Wed Dec 13, 2017 10:33 am

The opportunity to launch four satellites at once into the GALILEO constellation will be repeated next year. There is an economy of scale in launching four satellites on one rocket booster, but there is also the constraint: all four go into the same orbit plane. Because GALILEO is just beginning to fill its orbital slots with new satellites, it has this opportunity to launch four at once. The most recent launch put four satellites into GALILEO A-plane orbits. A previous four-satellite launch in November 2016 was aimed at the C-plane. Both A- and C-planes will now have eight satellites in orbit, leaving only the B-plane orbit open for the next four-at-once mission.

I suspect that once all the orbital planes are full, it will become more difficult to plan a launch with multiple satellites. The timing of the launch determines the fundamental characteristics of the orbit. In the case of this most recent launch, there was no "launch window" period; there was only a specific precise moment for the rocket to be fired so that the resultant orbit would be synchronized with the other satellites in the constellation.

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Re: GALILEO To Launch Four More Satellites

Postby jimh » Sat May 19, 2018 9:38 am

Another four-at-once GALILEO satellite launch is planned for July 25, 2018. There are three orbital planes, and each orbital plane can have a maximum of nine satellite in orbit. According to the European Space Agency, the next four-at-once launch "...will bring the 24‑satellite Galileo constellation to the point of completion, plus two orbital spares."

According to a Wikipedia article, the present Galileo constellation has in operation or in commissioning 18 satellites in these orbital positions:

A01 (FOC FM18), A02 (FOC FM10), A03 (FOC FM15), A04 (FOC FM17),
A05 (FOC FM6), A06 (FOC FM11), A07 (FOC FM16), A08 (FOC FM5)
TOTAL = 8

B05 (IOV PFM), B06 (IOV FM2), B08 (FOC FM3)
TOTAL = 3

C01 (FOC FM14), CO2 (FOC FM9), CO3 (FOC FM13), CO4 (IOV FM3),
CO6 (FOC FM7), CO7 (FOC FM8), CO8 (FOC FM12)
TOTAL = 7

GPS WORLD reported recently that two of the four satellites intended for the July launch are now at the French Guyana space port. The next launch will be into the B-plane, likely into planes B01, B02, B04, and B07.

Also in orbit but not available:
B03 (FOC FM4)--perhaps an in-orbit spare that could be reactivated
C05 (IOV FM4)--experienced power problems and loss of transmitter signals

Also in orbit but not in the intended orbital planes due to an error during launch and with status "testing":
FOC FM1 in orbit Ext01
FOC FM2 in orbit Ext02

That totals 22 satellites in orbit, with 18 in operation or commissioning; two in orbit and not available; two in non-standard orbit and under testing.

The four satellites to be launched in July will bring the total to 26, Assuming all proceed to operation status, there would then be 24 in operation and two "not available" satellites. Of those two, only FOC FM4 appears to be suitable for operation; IOV FM4 has limited transponder signals.

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Re: GALILEO To Launch Four More Satellites

Postby jimh » Tue Jul 31, 2018 2:53 pm

The July 25, 2018 launch of four more GALILEO satellites was successful. The GALILEO constellation will now have 26 satellites in orbit. It will be several months before these four latest satellites reach their final orbit and join the navigation system.

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Re: GALILEO Status October 2018

Postby jimh » Thu Nov 01, 2018 10:03 am

As of October 12, the four GALILEO satellites launched in December 2017 are now in operation. The four newly activated satellites are

FOC-FM15, E21, aka Nicole, slot A03

FOC-FM16: E25, Zofia, slot A07

FOC-FM17: E27, Alexandre, slot A04

FOC-FM18: E31, Irina, slot A01

All four are using a phased hydrogen maser (PHM) clock.

The four satellites (GSAT-219 Tara, GSAT-220 Samuel, GSAT-221 Anna, and GSAT-222 Ellen) launched on 25 July 2018 and inclined into the "B" orbit are still in the process of being commissioned for service.

There are several GALILEO satellites in orbit that are not in operational status. Two (GIOVE-A/B) were initial proof-of-concept satellites switched off c.2012. Two (FOC-FM1/2) are in non-standard orbits due to a launch rocket malfunction. and they are still in a testing phase. One (FM4) has ceased transmitting due to a payload power malfunction. One (FOC-FM4) is off for constellation management.

The total number of GALILEO operational satellites in their constellation at this moment is 18. The total in orbit is now 28 satellites: 18-operating, four in commissioning, two in testing, three switched off, and one no longer able to transmit.

Because the constellations orbital inclination rings are now near full capacity, future four-at-once launches may no longer be possible.