A Fifth WAAS Satellite Coming

Articles about GPS, GLONASS, GALILEO, WAAS and other satellite navigation systems
jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

And a Fifth WAAS Satellite Coming

Postby jimh » Thu Dec 15, 2016 12:36 pm

Raytheon has selected the Luxemburg satellite operator SES to host the WAAS GEO6 payload aboard their SES-15 satellite. SES-15 is being built by Boeing Space and Intelligence Systems. It is planned for launch in mid-2017 and will be positioned in geostationary earth orbit (GEO) at longitude slot 129-West.

The SES-15/GEO6 Boeing satellite platform host will be another all-electric satellite, using the same platform as was used for GEO5/SatMex9/EUTELSAT 117 West B. Boeing calls this their all-electric 702SP (small platform) space vehicle. It is intended as a lighter weight and lower electrical power version of their larger 702 space vehicle.

SES has experience hosting GNSS space-based augmentation systems (SBAS); it is the host satellite operator for the European SBAS called EGNOS.

A mid-2017 launch suggests that the SES-15 satellite will not rise to GEO orbit until very late 2017 or early 2018.

In addition to the hosted payload for WAAS, SES-15 will also provide in-flight entertainment and WiFi service to aircraft in its coverage area using a number of high throughput satellite (HTS) spot beams which cover North America and the aircraft routes to Hawaii. I have not seen any mention of a PRN number reserved for GEO6/SES-15 for its WAAS payload.

UPDATE: The contract between Raytheon and SES calls for 11 years of operation of the SES-15 satellite in space. This suggests the fifth WAAS satellite is anticipated to be in service until 2028.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

A Fifth WAAS Satellite Coming

Postby jimh » Wed May 24, 2017 3:18 pm

Executive Summary: a fifth WAAS satellite is now in orbit, but won't be likely to be operational until 2018.

On May 17, 2017 the SES-15 satellite was successfully launched from the Centre Spatial Guyanais in French Guiana.

SES-15's owner-operator is SES, a private company founded in 1985 in Luxembourg as the first European private satellite operator. In 2001 SES acquired GE AMERICOM and its thirteen satellites over North American, becoming SES AMERICOM. In 2011 the single branding of SES was implemented. By 2013 SES had 55 spacecraft in orbit, including many government spacecraft, particularly for the United States.

SES-15 was launched by ArianeSpace, founded in 1980 as the world's first private satellite launching company. They operate the space launch facility in French Guiana, in the Amazon jungle, near the equator.

SES-15 was carried aloft by a Soyuz ST-A (Soyuz 2-1a) rocket manufactured by Progress State Research and Production Rocket Space Center in Samara, Russia. The first stage consists of four boosters around a core rocket, with each booster powered by the RD-107A engine. After about two minutes of flight, the four boosters are jettisoned, and the core stage continues to burn as the second stage.

After about five minutes of powered flight, the core second state exhausts its propellant, and separates from the upper part of the rocket and the remaining payload. The third core stage, powered by an RD-0110 engine, ignites and continues to propel the rocket into space. At about nine minutes into the powered flight, the third stage is jettisoned, leaving the upper stage and satellite payload.

The upper stage ignites its Fregat rocket engine and continues lifting the satellite into a preliminary elliptical transfer orbit. At about 23.5 minutes into the flight, the Fregat engine is shut down, and the rocket and satellite coast in orbit for about four-and-a-half hours. The satellite is then likely in a elliptical orbit. The coasting phase waits for the satellite's orbit to reach a particular location when further propulsion will be very useful in modifying the orbit.

At nearly five hours into the flight the Fregat rocket engine is re-ignited for a short duration burn of approximately 50-seconds, to push the satellite payload toward a final circular orbit deployment. At this point the rocket and satellite separate, leaving the SES-15 satellite on its own. SES-15 will now execute the final orbital maneuvers to reach its ultimate geo-stationary orbit position by using its on-board all-electric ion drive system. This will take several months for the satellite to raise its orbit into the proper parameters and to work its way to its final location.

SES-15 was built by Boeing and is a Boeing 702SP (small platform) all-electric propulsion satellite that utilizes the xenon ion propulsion system (XIPS) for both orbit-raising and on-orbit maneuvering.

The Federal Aviation Administration have a hosted payload aboard SES-15 for a GPS space-based augmentation system (SBAS) payload for their Wide Area Augmentation System (WAAS) for aviation over North America. This hosted payload portion of SES-15 is referred to as GEO6 by the FAA.

The final geostationary orbital longitude for SES-15 is at 129-degrees-W longitude. This location will be four-degrees East of the present WAAS satellite carried on CRW or Galaxy 15 at position 133-degrees-W longitude. According to SPACEFLIGHTNOW.COM:

The ascent profile for Thursday’s launch placed the SES 15 satellite closer to its final perch in a circular geostationary orbit, where the spacecraft will loop around Earth’s equator at an altitude of nearly 22,300 miles (35,800 kilometers), the exact distance needed to move in concert with the planet’s rotation.

The unusual timing of the second Fregat firing will help shave several weeks off the time it will take to transition SES 15 into service, officials said.

The low-thrust xenon-ion jets on SES 15 will be activated in the coming weeks to nudge the satellite toward its final operating post. The orbit-raising maneuvers will take around 190 days to complete, according to Halliwell, and SES 15 should be operational by the end of December at 129 degrees west longitude.

The electric thrusters take longer to move between orbits than the conventional liquid-fueled engines carried by most communications spacecraft, but the tradeoff makes for a lighter satellite without giving up any capability. Without a heavy propellant tank, a satellite with the same broadcast capacity can launch on a smaller, less costly rocket.


With the SES-15 in orbit, the satellite's systems will have to be activated and verified. The GEO6 WAAS hosted payload will likely not be fully operational until 2018.

The actual WAAS transponder hosted payload was (apparently) built by Raytheon. In a press release a few days ago, Raytheon said, rather glibly, "Raytheon Company launched its GEO 6 satellite payload into orbit for its 12 year mission." That statement seems to ignore primary satellite owner and operator (SES), launch provided (ArianeSpace), rocket manufacturer ("Soyuz"), and host satellite manufacturer (Boeing). The WAAS transponder is bolted to the SES-15's nadir deck, and will depend on the SES-15 for its power and other subsystems. It seems a bit misleading to characterize Raytheon's role as it was described in their press release. Their payload more or less went along for the ride.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Thu May 25, 2017 11:05 am

The size of the SES-15 spacecraft can be appreciated in the image below.
SES15Assembly.jpg
SES15Assembly.jpg (27.37 KiB) Viewed 2601 times


The SES-15 weighs 2,302-kg (about 5,075-lbs). The design service life is 15-years in geostationary orbit. There is 8kW of electrical power available. For an enormous amount of information on the satellite, its launch, and its planned uses, see

https://www.ses.com/sites/default/files ... it-EN2.pdf

kfetter
Posts: 10
Joined: Fri Sep 15, 2017 5:57 pm

Re: A Fifth WAAS Satellite Coming

Postby kfetter » Thu Nov 02, 2017 6:06 pm

[Has] a PRN code been assigned for SES 15[?]

It's still undergoing orbit raising, but soon will reach geo-stationary orbit.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Sat Nov 04, 2017 12:00 am

Assignment of PRN codes for SBAS for GPS is made by the U.S. Air Force, the operator of GPS. For assignments of L1-C/A PRN codes for SBAS signals, see:

https://media.defense.gov/2017/May/10/2 ... N%2017.PDF

I do not see a PRN code allocated for SES-15. The link for this document appears on the Air Force webpage at

http://www.losangeles.af.mil/About-Us/F ... signments/

which was published in May 2017. If there is a newer version of the document, I haven't found it.

Note that there is no such thing as a "NMEA number" in actual GPS satellite operation. The concept of NMEA renumbering PRN code number for SBAS is a workaround, probably for the NMEA original specification only providing two digits for the satellite "number" in the NMEA-0183 sentence GSV (Satellites in View). GPS satellites are identified by their PRN, and SBAS signals have three-digit PRN code numbers. To get three-digit PRN code numbers like 133 into a two-digit number, NMEA-0183 specifies that the NMEA number is the PRN code minus 87.

kfetter
Posts: 10
Joined: Fri Sep 15, 2017 5:57 pm

Re: A Fifth WAAS Satellite Coming

Postby kfetter » Sat Nov 18, 2017 6:26 am

SES 15 has reached geo-stationary orbit. Now for SES to fine tune the orbit and place it at its operational orbital slot.

I am waiting to see what PRN code it gets assigned.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Sat Nov 18, 2017 8:47 am

SES-15's geostationary orbit is located at longitude 129-West.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Mon Nov 27, 2017 6:25 pm

Several comments in this thread have been separated from their original posting, which was a thread about a different WAAS SBAS satellite.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Fri Dec 08, 2017 11:33 am

The GPSWORLD ALMANAC, a generally very good source of information about GNSS satellites, does not show a listing for a fifth WAAS satellite as of today.

You can get a PDF version of the ALMANAC from
http://gpsworld.com/wp-content/uploads/ ... ec2017.pdf

Regarding the WAAS satellite at 98-W, Inmarsat-4-F3, the ALMANAC notes:

As of July 18, 2015, Inmarsat-4-F3 indefinitely discontinued non-precision approach ranging service. The satellite transponder was retired in November 2017.


Perhaps the SES-15 satellite will be taking over that PRN (133). At the moment, there are only two unassigned PRN numbers in the SBAS PRN block of PRN 120 - 138, allocated to Space Based Augmentation System.

There is room for more PRN numbers is the block 139 - 158, allocated to Space Based Augmentation System Expansion/Testing.

Here is the list of current SBAS assignments, as of January 17, 2017:

PRN  GNSS     SATELLITE       LON.       STATUS
120 EGNOS (INMARSAT 3F2) 15.5 W Current
121 EGNOS (INMARSAT 3F5) 25 E Active until Apr 2024
122 Unallocated
123 EGNOS (ASTRA 5B) 31.5 E Active until Nov 2021
124 EGNOS (Reserved) Active until Apr 2024
125 SDCM (Luch-5A) 16 W Active until Dec 2021
126 EGNOS (INMARSAT 4F2) 25 E Active until Apr 2019
127 GAGAN (GSAT-8) 55 E Active until Sep 2020
128 GAGAN (GSAT-10) 83 E Active until Sep 2020
129 MSAS (MTSAT-2)iv 145 E Active until Jan 2020
130 ARTEMIS (ARTEMIS-1) 21.5 E Active until Sep 2017
131 WAAS (Satmex 9) 117 W Active until Mar 2025
132 GAGAN (GSAT-15) 93.5 E Active until Nov 2025
133 WAAS (INMARSAT 4F3) 98 W Active until Oct 2019
134 Unallocated
135 WAAS (Galaxy 15) 133 W Active until Sep 2017
136 EGNOS (ASTRA 4B) 5 E Active until Nov 2021
137 MSAS (MTSAT-2) 145 E Active until Jan 2020
138 WAAS (ANIK-F1R) 107.3 W Active until Sep 2017

Source: https://media.defense.gov/2017/May/10/2001745055/-1/-1/1/L1%20C-A%2026%20JAN%2017.PDF

kfetter
Posts: 10
Joined: Fri Sep 15, 2017 5:57 pm

Re: A Fifth WAAS Satellite Coming

Postby kfetter » Wed Jan 17, 2018 5:34 pm

[This article contained a link to a website reprinting portions of a press release regarding orbital status of SES-15; see press release text below. This article was originally posted to a different thread that was discussing a different WAAS satellite, Eutelsat-117W B; I moved it to this thread about SES-15--jimh]

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Thu Jan 18, 2018 9:09 am

KFETTER--thanks for the link to one of many other websites carrying the SES press release regarding SES-15, which will be the fifth WAAS satellite in orbit when it becomes operational.

There is still no sign of SES-15's WAAS signal on the FAA's real-time satellite map or an announcement that the WAAS signal is operational or even an announcement of a PRN for it. Actually, we are still waiting for the FAA to get the fourth satellite, EUTELSAT-117W B, into operation. See the other thread that has been watching that satellite for more information on Eutelsat-117W, soon to be operational as PRN-131 in the WAAS system.

Here is the full text of the press release from SES regarding their SES-15 satellite, which should be joining the WAAS system sometime this year:

SES-15 Enters Commercial Service to Serve the Americas

Luxembourg, 15 January 2018 – SES announced today that the new SES-15 spacecraft has been operational at the 129 degrees West orbital position since 1 January. As planned, the all-electric satellite took six months to reach its orbital position and to successfully complete its testing.

SES-15 carries a hybrid payload, comprising Ku-band wide beams and Ku-band High Throughput Satellite (HTS) capability, with connectivity to gateways in Ka-band. SES’s first hybrid satellite is equipped with 16 Ku-band transponders (36 MHz equivalent) as well as HTS capabilities to serve North America, Mexico, Central America and the Caribbean.

SES-15’s high throughput payload will deliver optimised and flexible coverage for major global inflight connectivity and entertainment (IFC/IFE) service providers, such as Global Eagle, Gogo and Panasonic Avionics. In addition, SES-15 has a dedicated wide beam that is designed to enable IFC/IFE providers to deliver live TV content on all flight routes across the US, including Hawaii and Alaska, as well as Canada, the Caribbean and Mexico. This unique combination of beams allows IFC/IFE providers to optimise HTS capacity use for internet traffic and wide beam coverage for broadcast content.

SES-15 also carries a Wide Area Augmentation System (WAAS) hosted payload, which will enable the US Federal Aviation Administration (FAA) to augment existing Global Positioning Systems (GPS) with the goal of improving accuracy, integrity and availability of the system for the aviation industry.

SES-15 was successfully launched onboard a Soyuz rocket from the Guiana Space Centre in Kourou, French Guiana on 18 May 2017.

Martin Halliwell, Chief Technology Officer at SES, said, “An operational SES-15 has been much anticipated by our customers. The hybrid satellite, which has both wide beams and high throughput capability, empowers our aeronautical customers to offer even faster connectivity speeds to airlines. In addition, the WAAS hosted payload will enable the US FAA to improve GPS. The Boeing, Arianespace and SES teams have done an excellent job in making this possible."

The beginning of contracted services on SES-15's HTS payload represents an important milestone in supporting SES's future growth trajectory and its strategy to develop innovative and high-power capabilities for specific and dynamic markets. SES-15 will be followed by the launches of two more hybrid geostationary (GEO) satellites with widebeam / HTS capabilities, SES-14 and SES-12, as well as another four O3b medium earth orbit (MEO) satellites in the near future. SES-14 will serve the Americas and the Atlantic region, and SES-12 will cover Asia-Pacific, and the Middle East. Together with SES-17, another HTS which will be launched in 2021, they will offer a global, multi-frequency system for aeronautical, maritime, government and enterprise customers.


Source: https://www.ses.com/press-release/ses-1 ... e-americas

The press release announces the geostationary-orbit (GEO) satellite has raised its orbit and arrived on station. It may be several months before the WAAS transponder onboard is put into service.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Thu Apr 05, 2018 11:06 am

A recent listing of PRN assignments dated January 2017 is available:

https://media.defense.gov/2017/May/10/2 ... N%2017.PDF

This is linked from the page at

http://www.losangeles.af.mil/About-Us/F ... signments/

Here is a portion of the data showing just WAAS or unallocated resources for the L1 C/A signal:

PRN  ALLOCATION (SAT)         LON      STATUS   

122 Unallocated --- ---
131 WAAS (Satmex 9) 117 W Active until Mar 2025
133 WAAS (INMARSAT 4F3) 98 W Active until Oct 2019
134 Unallocated --- ---
135 WAAS (IntelsatGalaxy15) 133 W Active until Sep 2017
138 WAAS (ANIK-F1R) 107.3 W Active until Sep 2017


There is also a publication for the L5 signal dated January 2017, and it has some interesting allocations:

PRN  ALLOCATION (SAT)         LON      STATUS   
131 WAAS (Satmex 9) 117 W Active until Mar 2025
133 WAAS (INMARSAT 4F3) 98 W Active until Oct 2019
134 WAAS (GEO5) Reserved Current
135 WAAS (IntelsatGalaxy15) 133 W Active until Sep 2017
138 WAAS (ANIK-F1R) 107.3 W Active until Sep 2017


Based on the L5 signal SBAS allocation, it looks like PRN 134 may be used for the next (fifth) WAAS satellite, identified only as "GEO5", but the signal will be on the L5 carrier, not on the L1 C/A carrier. Most present-day recreational-grade marine GPS receivers do have the ability to utilize the L5 carrier.

Since SES-15 is already in orbit and is carrying a WAAS transponder as a hosted payload, it seems quite certain that "GEO5" will be SES-15.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Sun Oct 21, 2018 12:40 pm

A recent listing of PRN assignments dated 25 July 2018 is available:

https://media.defense.gov/2018/Aug/07/2 ... 202018.PDF

This is linked from the page at

https://www.losangeles.af.mil/About-Us/ ... signments/

The new listing show several minor changes. For L1 C/A carrier, PRN 134 has now been allocated to a Korean SBAS. For the L5 signal, PRN 134 is no longer reserved for WAAS GEO5.

Here is a portion of the data:

L1 C/A signal:
PRN  ALLOCATION (SAT)           LON  STATUS   

131 WAAS (Eutelsat 117WB) 117 W Active until Mar 2028
133 WAAS (INMARSAT 4F3) 98 W Active until Oct 2029
135 WAAS (IntelsatGalaxy15) 133 W Active until Sep 2017
138 WAAS (ANIK-F1R) 107.3 W Active until Sep 2017


PRN 134 (previously in category unallocated) has now been allocated to the KAAS SBAS service on INMARSAT 5F3 at 178 E Longitude, also known as the KASS (Korean Area Satellite System). KASS is in development and is planned for aviation use in 2022.

There is also a publication for the L5 signal dated 25 July 2018, and it has some interesting allocations:

L5 signal:
PRN  ALLOCATION (SAT)         LON      STATUS   
131 WAAS (Eutelsat 117WB) 117 W Active until Mar 2025
133 WAAS (INMARSAT 4F3) 98 W Active until Oct 2019
135 WAAS (IntelsatGalaxy15) 133 W Active until Sep 2017
138 WAAS (ANIK-F1R) 107.3 W Active until Sep 2017


Based on the L5 signal SBAS allocation, it looks like PRN 134 is no longer being reserved for the GEO5 satellite on SES-15.

jimh
Posts: 5416
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: A Fifth WAAS Satellite Coming

Postby jimh » Sun Oct 21, 2018 12:52 pm

According to THE ALMANAC at GPS World, the WAAS SBAS satellite SES-15 at 129 West using L1 C/A PRN 133 status is "Transmitting test signals" as of December 18, 2017.

Cf.: http://gpsworld.com/the-almanac/

With the SBAS signal (formerly sending PRN 133) from INMARSAT-4-F3 discontinued as of November 2017, it would appear that PRN 133 will be SES-15's identification once it goes into full service. The USAF listing still shows PRN 133 allocated to INMARSAT 4F3 at 98 West until October 2029.