UPDATE: Agence France Presse (AFP) is reporting the problem with Ariane 5 involved more than just a loss of telemetry:
But a source told AFP the satellites did not detach from the rocket in the correct place after the craft followed an “imperfect trajectory”.
Arianespace said they were currently “repositioning the satellites in the right place using their propulsion systems” adding that the current status was “reassuring after strong concerns”.
I don’t see any further updates on the mission on the websites of Arianespace, SES or Yahsat. This leads me to believe the AFP report is accurate. If it had been a simple telemetry loss, Arianespace would have said so, and there would be press releases and social media messages declaring the flight to be a complete success.
Yahsat does have a link to a page with an update about the mission. It’s in Arabic so I ran it through Google Translate. The update doesn’t appear to go beyond Arianespace’s original statement about the spacecraft separating from the second stage and being in contact with control centers.
Controllers lost contact with the upper stage of an Ariane 5 booster carrying a pair of communications satellites on Thursday. The loss telemetry began a few seconds after ignition of the stage and continued through the rest of the powered flight, Arianespace said in a statement.
“Subsequently, both satellites were confirmed separated, acquired and they are on orbit,” the company said. “SES-14 and Al Yah 3 are communicating with their respective control centers. Both missions are continuing.”
The precise orbital parameters of the geosynchronous communications satellites are unknown. SES-14 will use electric propulsion to reach its intended orbit while the Al Yah 3 will use a liquid bi-propellant transfer system.
Earlier on Thursday, China launched the fourth group of three Yaogan Weixing-30 satellites. A Long March 2C booster flew from the Xichang Satellite Launch Center.
Officially, the Yaogan Weixing are remote sensing spacecraft. However, analysts believe they are military reconnaissance satellites.
The flight marked China’s fifth successful launch of 2018. The nation is aiming to achieve more than 40 orbital launches this year.