United Arab Emirates-based satellite operator Yahsat has launched its third commercial satellite, Al Yah 3, despite a rare anomaly and trajectory deviation leading to a loss of communication in the early stages of the launch.
The Al Yah 3 satellite is supposed to expand Yahsat's commercial Ka-band coverage to an additional 19 markets in Africa, reaching 60% of the continent's population, as well as providing coverage to 95% of Brazil.
The Ariane 5 rocket lifted off at 22:20 GMT on 25 January from the Guiana Space Centre in French Guiana carrying two satellites, the SES-14 and Al Yah 3 communications satellites, as well as a hosted payload for NASA.
However, the mission experienced some challenges early on and a trajectory deviation resulted in both satellites being inserted into an orbit that differed from the flight plan.
The SES-14 satellite was supposed to separate from the Ariane 5 rocket 27 minutes into the flight and Al Yah 3 was to separate eight minutes later. At first it seemed SES-14 had separated as planned but the separation of Al Yah 3 could not be confirmed. A tense 25 minutes followed.
Finally, Arianespace CEO Stephane Israel came to the podium to announce Ariane 5 had experienced an "anomaly". A loss of telemetry had occurred and the satellites' locations were unclear.
Later, Arianespace confirmed the telemetry issue actually happened nine minutes and 26 seconds into the flight when ground-tracking stations lost contact with the Ariane 5 launcher. Initial investigations show 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.
"Subsequently, both satellites were confirmed separated, acquired and they are in orbit. SES-14 and Al Yah 3 are communicating with their respective control centres. Both missions are continuing," the group added.
Yahsat later confirmed its satellite "is healthy and operating nominally".
"A revised flight plan will be executed in order to achieve the operational orbit and fulfil the original mission," Yahsat 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," said Yahsat CEO Masood M Sharif Mahmood.
Al Yah 3, an all Ka-band satellite, is the first hybrid electric propulsion GEOStar-3 satellite completed by American aerospace manufacturer, Orbital ATK.
"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," said Frank Culbertson, president of Orbital ATK's Space Systems Group.
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".
Post-launch it will be a few months before satellite services are commercially available. Yahsat said operations and testing may range from two to four months. In-orbit testing usually takes six weeks, but it could take an additional week because of the trajectory deviation. SES said that because of the anomaly, its satellite would need an additional four weeks to reach its allocated orbital slot.
The launch anomaly was highly unusual as the Ariane 5 had completed 82 consecutive launches 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 anomaly.
Despite this, Arianespace says the upcoming launch campaigns currently under way at the Guiana Space Centre will proceed as scheduled.
