PARIS — Raytheon’s selection of a commercial telecommunications satellite owned by SES of Luxembourg to host a GPS-augmentation payload for the U.S. government means that two of the three satellites providing GPS corrections and GPS error notifications will be Boeing all-electric satellites.

The SES-15 satellite, now under construction by El Segundo, California-based Boeing Space and Intelligence Systems, is scheduled for launch in 2017 and to operate from 129 degrees west in geostationary orbit.

Tewksbury, Massachusetts-based Raytheon Integrated Defense Systems, the prime contractor for the GPS augmentation system, called Wide-Area Augmentation System, or WAAS, and SES agreed to a three-phase contract.

The first phase starts now, with the satellite’s construction by Boeing, and continues for three years to satellite integration, final testing and a mid-2017 launch plus the six to eight months it will take for the all-electric spacecraft to climb to its final geostationary position.

The contract’s second phase covers in-orbit testing, with the third phase, covering 10 years, following once the satellite is declared operational. The contract may be renewed in one-year increments. The satellite is designed to operate for at least 15 years.

Raytheon signed a similar contract with Satmex of Mexico, now called Eutelsat Americas and owned by fleet operator Eutelsat of Paris, to launch a WAAS terminal on the Satmex 9 satellite, which Eutelsat has renamed Eutelsat 117 West B. This satellite is scheduled for launch, together with a similar Boeing-built satellite owned by ABS of Bermuda, late this year. It will operate from 116.8 degrees west.

SES declined to disclose the WAAS payload’s mass and power requirements.

WAAS graphic
Credit: FAA

The WAAS payloads receive signals from ground stations that verify signal accuracy and then rebroadcasts that information to GPS users, including airline cockpits, the most demanding of civil GPS applications.

The U.S. Federal Aviation Administration wants three geostationary-orbiting WAAS payloads in operation at all times so that, if one failed, the system would not suffer service degradation.

The current satellites supporting WAAS are the Intelsat Galaxy 15 at 133 degrees west, launched in October 2005; the Telesat Anik F1R, launched in September 2005 and operating at 107.3 degrees west; and the Inmarsat 4F3, launched in August 2008 and stationed at 98.5 degrees west.

Under a September 2012 contract with the FAA valued at $249.7 million, Raytheon was given the role of developing new-generation WAAS terminals and selecting two more satellites to continue the WAAS coverage.

Raytheon subsequently contracted with Satmex but apparently had difficulty finding a suitable candidate for the second terminal. In February SES awarded the SES-15 contract to Boeing.

SES already operates satellites over Europe for the European WAAS, called EGNOS for European Geostationary Navigation Overlay System, with EGNOS payloads on two SES satellites. The contracting authority is the European Commission, which signed two separate contracts for 12 years of operations, each valued at around 75 million euros, or $82 million.

Raytheon announced April 21 that it had received a new contract from the FAA, valued at $103 million, relating to the provision of a payload in geostationary orbit and two related ground uplink stations.

Japan operates a similar system to verify GPS performance and notify aircraft of any GPS signal anomalies. Russia has an overlay system as well to warn of signal errors on Russia’s Glonass constellation of satellites, which like GPS operate in lower medium Earth orbit.

Peter B. de Selding was the Paris bureau chief for SpaceNews.