Lost in space

The Yahsat Al Yah 3 satellite is on target to reach its final orbital slot by June, despite the Ariane 5 rocket used to loft it into space experiencing a launch anomaly. Steve Nichols reports.
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Everything seemed normal at first when the Ariane 5 rocket launched from Kourou, French Guiana, in late January. It was carrying Al Yah 3, the SES-14 communications satellite, and a hosted payload for NASA.

Shortly after launch, however, Arianespace lost contact with the rocket.

Arianespace CEO, Stephane Israel, announced the Ariane 5 had experienced an “anomaly”. A loss of telemetry had occurred and the satellites’ locations were unclear.
Later, Arianespace confirmed the telemetry issue occurred nine minutes and 26 seconds into the flight, when ground-tracking stations lost contact with the Ariane 5 launcher. Initial investigations showed the situation resulted from a “trajectory deviation”.

“A few seconds after ignition of the upper stage, the second tracking station located in Natal, Brazil, did not acquire the launcher telemetry. This lack of telemetry lasted throughout the rest of powered flight,” Arianespace explained in a statement.

The result was that both satellites were inserted into orbits that differed from the flight plan.

Despite this, the Al Yah 3 satellite has been successfully acquired by Yahsat and the company reports it is healthy and responding to commands.
The company says a revised flight plan is being executed in order to “help Al Yah 3 achieve its operational orbit and fulfil the original mission”.

Yahsat CEO, Masood M Sharif Mahmood, said: “We are pleased to know the satellite is healthy, and that the necessary steps are being taken to ensure the original mission is fulfilled.”

Al Yah 3, an all Ka-band satellite, is the first hybrid electric propulsion GEOStar-3 satellite completed by American aerospace manufacturer, Orbital ATK.

Frank Culbertson, president of Orbital ATK’s space systems group confirmed: “Based on data from initial communications, I can report that Al Yah 3 is in orbit, healthy and responding to commands from our mission operations team."

It is still unclear why the rocket and satellites went off course but the Orbital ATK and Yahsat team say they are “working on a strategy to most efficiently get the satellite back into the original planned orbit”.

One report said the telemetry loss led to an off-nominal deployment of the satellites in an orbit with an inclination of 20.6° instead of 3°. It added the consequences on the lifetime of Al Yah 3 are currently not known.

The launch anomaly was unusual as the Ariane 5 had completed 82 consecutive blast-offs since 2003 without incident. Arianespace has set up an independent investigation commission, chaired by the European Space Agency’s general inspector, to establish what caused the problem.

Al Yah 3 joins Yahsat’s Al Yah 1 and Al Yah 2 satellites, which launched in 2011 and 2012 respectively. It will triple Yahsat’s commercial Ka-band coverage in Africa, and adds Brazil as a new market for the company.

Al Yah 3 will be able to provide broadband to 25 countries – 24 in Africa, plus Brazil. Five of the African countries (Angola, Lesotho, Nigeria, South Africa and Swaziland) are already covered by Yahsat’s previous satellites, while an additional 19 countries on the continent have been added. They include: Algeria, Botswana, Benin, Burundi, Cameroon, Congo, Cote D’Ivoire, Democratic Republic of the Congo, Gambia, Ghana, Libya, Morocco, Mozambique, Malawi, Senegal, Rwanda, Togo, Zambia and Zimbabwe.

Al Yah 3 was manufactured and tested at Orbital ATK’s satellite manufacturing facility in Dulles, Virginia. It carries 53 active Ka-band user beams and four gateway beams, and produces approximately 7.5 kilowatts of payload electrical power. The Ka-band spot beams provide two-way communications services to facilitate high-speed delivery of data to end-user applications, such as broadband internet and corporate networking, as well as IP back haul for telecommunications service providers.